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CHEMISTRY 
 
 FOUR SEASONS, 
 
 Spring, Summer, Autumn, antr Winter: 
 
 AN ESSAY, 
 
 PRINCIPALLY CONCERNING NATURAL PHENOMENA ADMITTING OF 
 
 INTERPRETATION BY CHEMICAL SCIENCE, AND 
 
 ILLUSTRATING PASSAGES OF SCRIPTURE. 
 
 BY THOMAS GRIFFITHS, 
 
 PROFESSOR OF CHEMISTRY IN THE MEDICAL COLLEGE OF ST. BARTHOLOMEW'S 
 
 HOSPITAL; AUTHOR OF "RECREATIONS IN CHEMISTRY," AND 
 
 " CHEMISTRY OF THE FOUR ELEMENTS." 
 
 LONDON; 
 JOHN CHURCHILL, PRINCES STREET, SOHO. 
 
 MDCCCXLVI. 
 
 \f\ n. ft 1 \\ A A 
 
LONDON J 
 PRINTED BY G. J PALMER, SAVOY STREET, STRAND. 
 
el 
 
 PREFACE. 
 
 " THE Chemistry of the Four Ancient Elements," 
 an Essay founded upon Lectures that I had the higli 
 and enviable honour of delivering before the Queen,, 
 and by Her most gracious special permission dedi- 
 cated to Her Majesty, had the good fortune to meet 
 with a favourable reception from the Public. 
 
 I am therefore induced to publish " The Che- 
 mistry of The Four Seasons," an Essay founded 
 upon Lectures that I have recently delivered at Scien- 
 tific Institutions in London and Liverpool, and I hope 
 that it will be found equally worthy of reception. 
 
 I have written this Essay, not for the proficient 
 but for the uninitiated in Chemistry; and I have 
 endeavoured to bear in mind that in tracing na- 
 tural phenomena, " there is not so much required 
 any strength of imagination, or exactness of method, 
 or depth of contemplation, as a sincere hand and 
 faithful eye to examine, and to record the things 
 themselves as they really appear." 
 
 It may be safely said, that there is no science more 
 admirably calculated to awaken feelings of interest 
 regarding the wonders of The Creation than that of 
 
 
VI PREFACE. 
 
 Experimental Chemistry ; the extraordinary disclosures 
 with which it abounds will immediately lead the stu- 
 dent to an acknowledgment of the power and goodness 
 of God. 
 
 The science of Chemistry will lead the student to 
 ' search the Scriptures,' and thus to imitate the exam- 
 ple of the best and greatest philosophers, for Newton 
 esteemed The Bible " the most authentic of all histo- 
 ries ;" Hale said, " none was like unto it for excellent 
 wisdom, learning, and use ;" Boyle considered it " u 
 matchless volume, impossible to be too much studied 
 or too highly esteemed ;" and Locke pronounced it as 
 " consisting of Truth without any mixture of Error 
 for its matter." 
 
 I have humbly endeavoured to select a few of the 
 beautiful passages of Holy Writ which refer to Natural 
 Phenomena, and to interpret these through the me- 
 dium of the science that it is my delight to follow, a 
 science to employ the words of Davy " which has 
 its moral and intellectual, as well as its common uses ; 
 its object is not only to apply the different substances 
 in nature for the advantages, comfort, and benefit of 
 man, but likewise to set forth that wonderful his- 
 tory of Wisdom and Intelligence which is written 
 in legible characters both in the heavens and on the 
 earth." 
 
 To those who have not studied the science of Che- 
 mistry, I may say, in the words of the same philoso- 
 pher, " its beginning is pleasure ;" and when they have 
 mastered its rudiments they will find, that " its pro- 
 
rrvPQfi ic; L-r 
 
 PREFACE. Vll 
 
 gress is knowledge ;" and lastly, when they have at- 
 tained its higher combinations and laws, and can ven- 
 ture upon the application of these to the interpretation 
 of natural phenomena, they will confess that " its ob- 
 jects are truth and utility," and eminently calculated 
 to inculcate feelings of thankfulness, gratitude, and re- 
 verence, towards The Great Creator, " He that is ex- 
 cellent in power and in judgment." 
 
 In this Essay it will be found, that in addition to 
 the interpretation of a few of the phenomena of The 
 Four Seasons, through the medium of Chemistry, I 
 have introduced a variety of other miscellaneous, and 
 I hope both interesting and useful information ; all 
 the experimental illustrations are of the simplest cha- 
 racter, and do not involve the necessity of costly appa- 
 ratus ; and I have given explicit directions for their 
 performance, so that the student may be certain of their 
 success. 
 
 Chemical experiments are often unsuccessful on 
 account of some apparently trifling matters having 
 been neglected ; I have endeavoured to point out all 
 these, and yet I find, that in the experiment at page 
 343, I have omitted to state, that in pouring the various 
 solutions through the long funnel, care should be taken 
 to pour them so gently, that no bullies of air le car- 
 ried down the pipe of the funnel, as these would dis- 
 turb the levels of the respective liquids ; and in re- 
 
Vlll PREFACE. 
 
 moving the funnel, care should -be also taken to lift its 
 pipe very slowly, to the level of each liquid, holding it 
 at each for two or three seconds. For the arrange- 
 ment of this experiment, I am indebted to my friend 
 Mr. T. S. Dick, who affords me his valuable assist- 
 ance in the Chemical Laboratory at St. Bartholomew's 
 Hospital. 
 
 At page 104, line 2 from the bottom, I must re- 
 quest the reader to insert the following paragraph, 
 which 1 find has been accidentally omitted. 
 
 " An equal portion of the clay containing moisture, 
 after being heated to 88 degrees, was exposed in a 
 temperature of 55 degrees ; in less than a quarter of 
 an hour it was found to have gained the temperature 
 of the room." 
 
CONTENTS. 
 
 INTRODUCTORY. 
 
 The subject proposed, 1 . Chief object of the science of 
 chemistry. Experiments of the laboratory may elucidate 
 natural phenomena. Prominent features of The Four Sea- 
 sons briefly enumerated, 2. Exalting tendency of the 
 study of chemistry. Object of the present work. Com- 
 pound and elementary matters, 3. Ponderable and impon- 
 derable elements enumerated, 4. Exact meaning of the 
 term element, the metal iron an element, 5. Common 
 salt a compound of chlorine and sodium, 6. These are 
 both elements in the modern acceptation of the term, 7. 
 Chalk a compound, ib. Its components also compounds 
 of the elements Carbon and Oxygen, and Calcium and 
 Oxygen ; these constitute carbonic acid and lime, and com- 
 bine to form chalk, 8. Primary and secondary combina- 
 tions. All chemical combinations and decompositions are 
 governed by definite weights, 9. Endeavour of the che- 
 mist to interpret Natural phenomena, and to discover 
 proofs of the power and goodness of God, 10. Chemistry 
 founded upon experiment, ib. Extraordinary facts disco- 
 
 a 5 
 
X CONTENTS. 
 
 vered by its practice. The elements Oxygen and Nitro- 
 gen, when combined, produce five poisons ; but when 
 mingled, they constitute the chief volume of the Atmo- 
 sphere throughout all the changes of the Seasons, 11. 
 Rigid examination or analysis of the atmosphere proves it 
 to contain small proportions of the compounds called water 
 and carbonic acid, 12. Total weight of the atmosphere, 
 and of its elementary and compound constituents. No 
 other medium fit for the support of life, 14. Lavish abun- 
 dance of water as presented throughout Nature. Water ne- 
 ver absolutely pure, or solely consistent of the two elements 
 Oxygen and Hydrogen, from whose union it may be 
 formed, 15. The Earths popularly so called, viz. Lime, 
 Clay, Sand, and Magnesia, are truly rusts of metals or 
 metallic oxides, 16. Earthy substances, viz. Limestone, 
 Marble, Gypsum, and Bone-earth, are compounds of the 
 foregoing with various acids, 17. General statement re- 
 garding the constituents of soils, as preparatory to more 
 particular examination, 18. Importance of chemistry to 
 agriculture, ib. Chemical analysis extends to organic bo- 
 dies, and discloses extraordinary facts. Elements of organic 
 bodies are few in number, viz. Oxygen, Nitrogen, Carbon, 
 and Hydrogen, 19. All organic bodies may be submitted 
 to analysis, but synthesis is impossible, 20. Tabular state- 
 ment regarding proximate organic compounds, and the 
 definite weights of their three or four ultimate elements, 
 21. Solar light necessary for the welfare of the animated 
 creation, 22. The rainbow displays the seven coloured 
 rays of solar light, 23. Colours of terrestrial surfaces, 24. 
 Beneficial agency of heat, 25. Habitudes of various forms 
 of matter with heat, more particularly Earth, Air, and 
 
CONTENTS. XI 
 
 Water, 26. Electricity constantly present throughout 
 Nature ; its occasional display as lightning, ib. The 
 examination of the principal chemical phenomena of The 
 Four Seasons, presents proofs of the power and goodness 
 of The Creator, 28. 
 
 CHAPTER I. 
 
 SPRING. 
 
 Reflections on the beauty of this season, 29. Outline of 
 the plan proposed for examining its principal chemical phe- 
 nomena, 30. The germination of seeds, 31. Changes of 
 their proximate principles induced by the joint agencies of 
 earth, water, air, and heat, 32. Conditions requisite for 
 germination to ensue. Dormant state of seeds, 33. Re- 
 ception and retention' of water, by soils for the excitement 
 of germination and the support of vegetation, ib. Illustra- 
 tions of capillary attraction, 35. Its effects in Nature and 
 Art, 39. The fertility of soils promoted by the absorption 
 of water, 40. Valuable information afforded by the che- 
 mist to the agriculturist, 41. Simple illustrations of the 
 art of analysis, 42. Statement regarding the composition 
 of various soils, and their general characters, 44. Nutri- 
 ment of plants, 46. Formation of springs of water in the 
 earth, 47. The accumulation of water in the form of 
 clouds referred to evaporation, ib. The return of water to 
 the earth in showers, 49. The absorption of watery va- 
 pour from the atmosphere by soils, is much connected with 
 their fertility, 50. Methods of ascertaining the quantity 
 of watery vapour absorbed by different soils, 5 1 . Results 
 
Xll CONTENTS. 
 
 of such experiments, 53. Amount of watery vapour pre- 
 sent in the atmosphere, 55. The effect of heat and cold 
 upon the atmosphere does not alter its nature, ib. Expe- 
 riments in proof of this wonderful and beneficial fact, 58. 
 Actual combustion, and animal respiration, both alter the 
 nature of the atmosphere, and render it mephitic, 59. Ex- 
 traordinary provision made for the escape of the products 
 of respiration, and their diffusion throughout the atmo- 
 sphere, 6 1 . Uniformity in the constitution of the atmo- 
 sphere, 64. Action of the germination of seeds and the 
 growth of plants upon the atmosphere, 65. Evaporation 
 of water from the earth, during the prevalence of March 
 winds, 66. Proverbs concerning the weather at this sea- 
 son, 67. The formation of rain-clouds cannot be satisfac- 
 torily explained, 68. Vesicular vapour of mists, ib. Ab- 
 sorption of heat by the surface of the earth, where it is 
 most needed for the welfare of the animated creation, 69. 
 The earth has no great power of conducting heat ; hence 
 springs of water are not materially affected during the Sea- 
 sons, 70. Earth, Air, and Water, are all imperfect con- 
 ductors of heat, ib. Experiments in illustration of the 
 conduction and non-conduction of heat, 71. Investigation 
 continued regarding the phenomena of germination and 
 growth, 75. Precautions in transplanting, 76. Plants 
 destroyed by various poisons. Natural constitution of soils 
 favourable for the growth of plants, 77. Circulation of the 
 sap, 78. Transpiration and absorption of water, by the 
 leaves of plants, 7880. 
 
CONTENTS. Xlll 
 
 CHAPTER II. 
 
 SUMMER. 
 
 Extraordinary increase in the growth of plants during 
 this season, 81. Remarkable experiment regarding the 
 growth of a willow tree, 82. Water is apparently the sole 
 aliment of plants, ib. Accurate examination proves that 
 plants derive the chief if not the whole amount of their 
 constituent carbon, from the Carbonic acid of the atmo- 
 sphere, 83. Enormous amount of Carbonic acid naturally 
 present in the atmosphere, and hourly exhaled into it by 
 animal respiration, 84. Carbonic acid, though a poison to 
 animals, is the food of plants, 85. Growing plants decom- 
 pose carbonic acid, secrete its carbon, and elicit its oxygen, 
 and thus renovate vitiated air, ib. Experiments concern- 
 ing this miraculous phenomenon, 87. Conclusions drawn 
 from them, 89. Vegetation will not proceed without the 
 presence of Carbonic acid, 90. The presence of light is 
 essential to the welfare of plants, 91. The absence of 
 light modifies their natural physical and chemical charac- 
 ters, ib. Solar light is absolutely essential to the health of 
 man, 94. The mountaineer and the miner contrasted, ib. 
 The importance of light is universally manifest, 95. Local 
 impurities in the atmosphere affect the growth of plants, 
 ib. Destruction of plants and modifications of the colours 
 of flowers by acid vapours, 97. Plants may be grown in a 
 confined portion of air, and thus protected from injury in 
 smoky cities, 98. Tremulous motion of objects when 
 
xiv CONTENTS. 
 
 viewed through the air incumbent upon a soil heated by the 
 solar rays, 102. Rate of the heating and cooling of soils 
 differing in their physical and chemical characters, 103. 
 Importance of the thermometer to the agriculturist, 105. 
 The thermometer merely denotes the degree of heat that a 
 medium can impart, and not the actual quantity of heat that 
 such medium contains, ib. Substances of the same tem- 
 perature contain different quantities of heat, ib. Experi- 
 mental illustrations regarding the capacity of bodies for 
 heat, 106 121. Diminution of the density of the atmo- 
 sphere in proportion to its altitude, 122. The " snow 
 line," or " line of perpetual congelation," 123. Miracu- 
 lous adjustment of the density and temperature of the air, 
 to the functions of human beings, 124. Summer heat 
 never gains sufficient intensity to cause the combustion of 
 terrestrial productions, 125. Reflections upon the beauty 
 and harmony of the foregoing phenomena, 126. Coolness 
 of the earth after a summer shower, chiefly referrible to 
 evaporation, 129. Rate of evaporation at different tem- 
 peratures and during different states of the atmosphere, 
 130. The evaporation of water employed as a means of 
 effecting reduction of temperature, 131. Water frozen in 
 summer by the cold produced during its own evaporation, 
 134. Hygroscopes for detecting the presence of watery 
 vapour in the atmosphere, 137. The sea and land breezes 
 of tropical islands and coasts, 140. Settled weather essen- 
 tial for the hay harvest, 142. Hay damaged by floods 
 Firing of damp hay, 143. Examination of the ashes of a 
 hay-stack and corn-rick, 144. Silica and potash are essen- 
 tial components of soils for the growth of grasses and corn, 
 145. Utility of straw for thatching, 147. 
 
CONTENTS. XV 
 
 CHAPTER III. 
 
 AUTUMN. 
 
 Radiation of heat from the earth, 150. Experiments 
 concerning radiation 151. Influence of mere alteration of 
 surfaces upon the reception and retention of heat, 152 
 157. Colour of surfaces affects their absorption of solar 
 radiant heat, 158. The black skin of the Ethiopian a de- 
 fence against the intensity of solar heat, 159. The " sun- 
 stroke," 161. Radiation of heat from different soils, 162. 
 Theory of the wonderful phenomenon of dew, 163. Depo- 
 sition of dew, upon terrestrial objects, does not take place 
 indiscriminately, 165. Experiments concerning dew, 166 
 
 170. Ice obtained by the cold induced during radiation, 
 
 171. Deposition of dew upon dead organic matters hastens 
 their putrefaction, 171. The phenomenon of a morning 
 mist, 173. Its disappearance, 175. Spherical figure of 
 dew and rain drops, 176 179. Honey dew, 181. Hy- 
 grometer for ascertaining the watery vapour present in the 
 atmosphere, 182 189. Deposition of water from the at- 
 mosphere in Eastern climates, 190. Investigations regard- 
 ing the phenomena of the universe a source of happiness, 
 191193. Blue colour of the sky, 194. Red appear- 
 ance of the evening and morning sky, 194 196. The 
 phenomenon of the rainbow, 1 97 200. Reliance placed 
 upon experiment, 202. Aeration of water for the respira- 
 tion of fishes, 203 208. Aquatic plants purify water from 
 the results of the respiration of fishes 209 218. Water is 
 incapable of being heated by the solar rays, 219. The solar 
 
XVI CONTENTS. 
 
 rays collected to a burning focus by a globular vessel filled 
 with water, 220. The gas of stagnant pools, 221. The 
 ignis fatuus or Will o' the wisp, ib. Phosphorescent light 
 of vegetable and animal matters, 222. Deleterious mat- 
 ters produced during the putrefaction of organic bodies, 
 223. The marsh-miasma, and malaria, ib. The nature of 
 contagious and infectious matters has not been discovered, 
 225. They may be destroyed by chemical means, viz., 
 Nitric acid and Chlorine, 227. Distinction between ancient 
 and modern Nitre, the term being now applied to Saltpetre 
 or Nitrate of Potash, 226. Its decomposition by sulphuric 
 acid for the evolution of Nitric acid vapour, 228. Com- 
 mon salt, by the action of sulphuric acid, produces Hydro- 
 chloric acid, 231. This deprived of Hydrogen evolves 
 Chlorine, the most powerful disinfectant, 232. Method of 
 fumigating an apartment, 233. Experiments regarding the 
 action of Chlorine upon organic and inorganic bodies, 236. 
 Contagious and infectious matters destroyed by a high arti- 
 ficial temperature, 238. Quick-lime an important adjunct 
 in cases of fumigation, 240. The phenomenon of the thun- 
 der-storm, 242. Various forms of lightning, 245. Pre- 
 cautions for personal safety during a thunder-storm, 250. 
 Identity of lightning and electricity, 254. Conductors at- 
 tached to buildings for averting the destructive effects of 
 lightning, 256. Nitric acid produced by the union of the 
 elements of the air during a thunder-storm, 259. Showers 
 of rain and hail during a thunder-storm, 260. The pheno- 
 menon of the water-spout, and its probable cause, 264. 
 "Wonderful phenomena that are constantly proceeding 
 throughout Nature during the changes of the seasons, 267. 
 The vital force displayed by vegetation, ib. The endeavour 
 
CONTENTS. XVli 
 
 of plants to remove obstacles opposed to their growth, 268. 
 The origin of the Corinthian capital, 266. Things of com- 
 mon occurrence present scientific information when properly 
 examined, 271. The corn harvest the grand feature of 
 Autumn, 272. A proper supply of food necessary for the 
 support of life, 273. Examination of the chief proximate 
 principles of wheaten flour, viz., Gluten and Starch, 280. 
 Utility of manuring wheat-lands with recent " bone-dust," 
 286. Utility of quick lime and stable manure, 288. Gum 
 and Sugar are proximate elements of many vegetables and 
 fruits, 289. Sugar essential in all cases of vinous fermenta- 
 tion, 292. The chief bulk of vegetables consists of Lignin 
 or woody fibre, 295. Various and important forms in 
 which it is presented, 297. Results of its decomposition 
 when absolutely pure or as commonly obtained, 302. The 
 non-conducting power of the bark of trees as regards the 
 heat of Summer or the cold of Winter, 304. Action of flowers 
 and fruits upon the atmosphere, 306. Seeds produced in 
 Autumn similar in all characters with those that were con- 
 signed to the earth in Spring, 308. The varied hues of 
 Autumn and fall of the leaf, 311. The phenomenon of 
 " fairy rings," ib. The frosts at the close of Autumn, 312. 
 
 CHAPTER IV. 
 
 WINTER. 
 
 Transition of water into ice, 315. Action of cold and 
 heat upon solids, liquids, and aeriform substances, 314. 
 Experimental illustrations, ib. Pure water undergoes no 
 decomposition by keeping, 321. The boiling fountains of 
 
XV111 CONTENTS. 
 
 Iceland, 322. Petrifying springs, ib. Contraction and 
 expansion of gases, liquids, and solids, 323. The anoma- 
 lous expansion of water by cold, 324. Slow progress of 
 the congelation of water during Winter, 325. Beneficial 
 effects of this phenomenon, 326. Very deep lakes resist 
 congelation, 327. Sea water does not freeze at the same 
 degree as fresh water, 328. Experiment regarding the 
 superficial formation of ice, 329. Ice lighter than water, 
 and though solid floats upon its surface, 334. Meaning of 
 the term specific gravity, ib. Methods of ascertaining the 
 specific gravity of pure and salt water, 335. The construc- 
 tion of the hydrometer, 338. Experimental illustrations 
 of the specific gravities of liquids, 34 1 . Methods of ascer- 
 taining the specific gravity of solids, 345. The freezing 
 point of water is immutable, 346. The graduation of the 
 Thermometer, 347. The principle upon which the Baro- 
 meter is constructed, 348. The examination of the freezing 
 of water continued, 350. Powerful expansion of water 
 during its transition into ice, ib. Experimental illustration 
 of this curious and important fact, 35 1 . Beneficial effects 
 that result throughout nature from the expansive force of 
 water in freezing, 352. Rupture of water-pipes and bottles 
 by frost, 354. Burning lens formed of a block of transpa- 
 rent ice, 356. The antiseptic power of ice, 357. The 
 preservation of provisions in ice, 358. The collection of 
 ice in the vicinity of London, 359. The construction of 
 an ice-house or ice-well, 362. The sheet of ice upon a 
 pond frequently causes the fishes to perish by preventing 
 the escape of the results of their respiration, 363. Won- 
 derful provision made in Nature for the preservation of the 
 life of fishes during Winter, 364. The " frost-smoke," ib. 
 
CONTENTS. XIX 
 
 The congelation of water contained in foot-prints, hoof- 
 marks, and wagon ruts, 367. The phenomenon of "ground 
 ice," or ice formed at the bottom of rivers, 369. The phe- 
 nomenon of snow, 3/2. Crystalline form of snow flakes, 373. 
 Snow is a great preservative against the effects of cold, 
 ib. Construction of snow-houses by the Esquimaux, 374. 
 Warmth of these dwellings, 377. Red snow of the Arctic 
 regions, 379. The collection of snow by the Neapolitans, 
 380. The preservation of snow on mount Etna, by the non- 
 conducting power of volcanic sand, 381. The reflection of 
 solar heat by white, and its absorption by black surfaces, 
 illustrated upon snow, ib. The phenomenon of hoar-frost, 
 383. Imitation of the appearance of hoar-frost upon 
 branches, 334. Beautiful forms of hoar-frost upon various 
 objects, 387. The formation of icicles, 389. Neither cold 
 nor heat alter the chemical constitution of water, 390. 
 Phenomena that ensue during the elevation of water to its 
 boiling-point, experimentally illustrated, 390. Atmospheric 
 pressure affects the temperature at which water enters into 
 ebullition, 397. The vapour of water the motive power of 
 the steam-engine, 404. Experiments concerning the de- 
 composition of water, 407- Enormous volume of Oxygen 
 and Hydrogen gases contained in a drop of water, 415. 
 Separation of Nitrogen from the atmosphere, 416. Exa- 
 amination of the chemical philosophy of an " English fire- 
 side," 419. The ascent of flame, 420. Accidents by 
 dresses catching fire, 421. Reason why flame is applied to 
 the lowest part of the fuel in a fire-grate, 422. Remarks 
 concerning the warming of an apartment by an open fire, 
 424. Production of gas from coal, for the purpose of ar- 
 tificial illumination, 432. The importance of coal, 437. 
 
XX CONTENTS. 
 
 The fire-damp of coal mines, ib. The miners' safety lamp, 
 439. Coke a valuable fuel for the reduction of metals, 442. 
 Utility of the metals for the construction of culinary im- 
 plements, 444. Destruction of matter does not ensue 
 during combustion, 445. Ordinary sources of artificial 
 light and heat, 447. Different sensations experienced upon 
 touching different substances having similar temperatures, 
 448. The terms heat and cold are merely relative, 452. 
 Aeriform substances extremely susceptible of change of 
 volume by change of temperature, 454. The specific gra- 
 vity of air and gases, 455. The winter clothing of animals, 
 456. The transition of ice into water upon the return of 
 Spring, 458. Experiments concerning latent heat, 461. 
 Latent heat of the vapour of water, 471. Miraculous ad- 
 justments of temperature during the thawing of ice, 474. 
 The magnitude of the earth as compared with the size of 
 man, 476. The study of chemistry and of all the high 
 sciences is well suited to keep down a spirit of arrogance 
 and intellectual pride, 478. Conclusion, 480. 
 
 APPENDIX, containing the names of the discoverers, 
 historians, and narrators of the principal facts which are 
 embodied in this work, 481. 
 
CHEMISTRY 
 
 OF 
 
 THE FOUR SEASONS. 
 
 INTRODUCTORY. 
 
 THE FOUR SEASONS present many phenomena 
 which admit of interpretation through the Science of 
 Chemistry. 
 
 Some persons imagine that the science of chemistry 
 consists entirely of experiments with furnaces, cru- 
 cibles, alkalies, acids, salts, and metals, which are all 
 more curious, than useful, and they will ask Can the 
 chemist emerge from the narrow precincts of his labo- 
 ratory, and venture upon the boundless realms of 
 Nature, with explanations concerning the verdure of 
 Spring, the heat of Summer, the harvest of Autumn, 
 and the cold of Winter ? 
 
 The reply of the chemist is in the affirmative ; he 
 can expound such phenomena to a certain extent, 
 
 B 
 
2 INTRODUCTORY. 
 
 for the chief object of chemistry, is to ascertain the 
 composition of things, and to determine the laws by 
 which they are governed. 
 
 By numerous experiments with furnaces, crucibles, 
 alkalies, acids, salts, and metals, the chemist has ob- 
 tained a key to the vast laboratory of Nature, and 
 although standing merely upon the threshold of its 
 newly-opened portal, if he temper his little knowledge 
 with humility, he may witness and understand many 
 of the gigantic and refined operations therein pro- 
 ceeding, under the guiding and protecting hand of 
 Almighty God, for maintaining the regularity and 
 order of the Four Seasons. 
 
 The most prominent features of Spring, Summer, 
 Autumn, and Winter, may be thus briefly enumerated: 
 In spring, the earth is covered with verdure, buds and 
 blossoms vary and adorn its surface ; soft showers 
 3escend, the air is clear, sunshine glads the heavens, 
 and steadily increases in power unto the fervent glow 
 of summer; then, generally speaking, vegetation has 
 attained its fulness, the earth is crowned with foliage 
 and flowers, the fields are becoming ripe for the scythe, 
 and sickle ; and soon the sultry noon- tide heat, the 
 refreshing night dew, and the lowering thunder-cloud, 
 herald the advent of autumn; it comes, laden with 
 purple fruit, and golden grain ; it yields its bounteous 
 store, it passes, and then, sunshine is pale and lan- 
 gdid, winds are bleak and cold, trees become leafless, 
 streams are fast bound with ice, hoar-frost and snow 
 form the winter mantle of the earth. 
 
INTRODUCTORY. 
 
 These Four Seasons, these miraculous changes in 
 the aspect of the globe, these definite periods of Ger- 
 mination, of Growth, of Maturity, and of Repose, 
 familiar to all men, yet unheeded by many, present 
 the votary of chemistry with magnificent illustrations 
 of facts regarding the powers and properties of matter, 
 which he has discovered upon a minor scale by expe- 
 riments in his laboratory. 
 
 To him, who comes with a mind duly prepared and 
 fitted to the business of the interpretation of Nature, in 
 accordance with the axioms of Inductive Philosophy, 
 the tendency of the science of chemistry is most exalt- 
 ing ; at each step, it implants a firm belief in the 
 Power, and a perfect reliance upon the Goodness of 
 God, who promised that, " While the earth remaineth, 
 seed-time and harvest, and cold and heat, and summer 
 and winter, and day and night, shall not cease." 
 
 The object of this essay is to adduce a few of the 
 principal phenomena of the four seasons, which admit 
 of explanation and illustration through the medium 
 of chemistry; and as it teaches the composition of 
 things, a general statement regarding natural objects 
 and the powers unto which they are subject, will form 
 the remainder of this introductory chapter. 
 y The chemist, by experimenting upon the various 
 solid, liquid, and aeriform matters, presented through- 
 out the creation, discovers that many of them can be 
 divided into two or more substances of distinct and 
 opposite characters, and that these cannot be again 
 divided into others. 
 
 B % 
 
4 INTRODUCTORY. 
 
 Substances that can be divided, analysed, or sim- 
 plified, are called Compounds ; and such as cannot be 
 so treated, are called Elements. 
 
 Fifty-five of these are known, all Ponderable, and 
 subject to the agencies of Light, Heat, and Electri- 
 city, which are Imponderable. The ponderable ele- 
 ments are distinguished by the following names; 
 those marked * are Combustible and non-metallic ; 
 those marked f are Incombustible and non-metallic ; 
 the others are Metallic. 
 
 1, Aluminum ; 2, Antimony; 3, Arsenicum; 4, Ba- 
 rium ; 5, Bismuth ; 6*, Boron ; 7f, Bromine ; 8, Cad- 
 mium ; 9, Calcium ; 10*, Carbon; 11, Cerium; 12f, 
 Chlorine; 13, Chromium; 14, Cobalt; 1 5, Columbium ; 
 16, Copper; 17f, Fluorine; 18, Glucinum; 19, Gold; 
 20*, Hydrogen; 21f, Iodine; 22, Indium; 23, Iron, 
 24, Lantanum ; 25, Lead ; 26, Lithium ; 27, Magne- 
 sium; 28, Manganesium; 29, Mercury; 30, Molybde- 
 num; 31, Nickel; 32f, Nitrogen ; 33, Osmium ; 34f, 
 Oxygen; 35, Palladium; 36*, Phosphorus; 37, Plati- 
 num ; 38, Potassium; 39, Rhodium ; 40*, Selenium; 
 41, Silicium ; 42, Silver ; 43, Sodium ; 44, Strontium ; 
 45*, Sulphur; 46, Tellurium ; 47, Thorium; 48, Tin ; 
 49, Titanium ; 50, Tungstenurn ; 51, Vanadium; 52, 
 Uranium ; 53, Yttrium ; 54, Zinc ; 55, Zirconium. 
 
 Of these elements, the following are the most abun- 
 dant, and will be most frequently mentioned throughout 
 this inquiry. 
 
 I. Combustible and non-metallic, Carbon, Hydro- 
 gen, Phosphorus, and Sulphur. 
 
INTRODUCTORY. 5 
 
 II. Incombustible and non-metallic, Chlorine, 
 
 Nitrogen, and Oxygen. 
 
 III. Metallic, Aluminum, Calcium, Iron, Magne- 
 sium, Potassium, Silicium, and Sodium. 
 
 The ponderable elements are capable of uniting in 
 various ways to form a great number of compounds ; 
 and these compounds in their turn are capable of 
 uniting with each other to form a greater number of 
 complex compounds ; and so far as the knowledge of 
 the chemist extends, it leads him to consider that all 
 natural and artificial objects consist of elements, and 
 their combinations and mixtures, arranged according 
 to definite laws of weight and measure. 
 
 The term Element will occur very frequently during 
 this examination of the principal chemical phenomena 
 of the Four Seasons, and therefore its exact meaning 
 demands explanation at this early stage. 
 
 The metal Iron, its tenacity, ductility, and nu- 
 merous uses, are familiar to all persons ; but the che- 
 mist is not satisfied with this mere knowledge of its 
 mechanical properties, he wishes to ascertain the com- 
 position of the metal, the things of which it consists ; 
 he endeavours to do this by making experiments ; he 
 submits iron to every process that -he can devise ; he 
 alters or disguises its ordinary properties in many 
 curious ways ; but at length the metal presents itself 
 in its original state, pure and unharmed by the ordeals 
 through which it has passed, and without yielding the 
 slightest clue regarding its composition. 
 
 The chemist depends entirely upon the results of 
 
INTRODUCTORY. 
 
 experiments for his knowledge, and in the ahove 
 instance, he has no alternative hut to make a candid 
 confession of his inability to prove of what things Iron 
 consists ; and, in accordance with the principles of 
 inductive philosophy, he is ohliged to call the metal a 
 Pure, Undecompounded, or Simple substance, a Eudi- 
 ment, or an Element. 
 
 In employing this term he wishes to he distinctly 
 understood, that he does not presume to say that Iron 
 must he absolutely simple or undecomposable, because 
 he is not sufficiently skilful to discover its composi- 
 tion ; he merely wishes to express, that he cannot ex- 
 perimentally prove it to contain two, or more sub- 
 stances, or in other words, that he cannot prove it to 
 be a Compound, and in this sense no objection can be 
 made to the term Element. 
 
 The substance called Common-salt, and its important 
 uses as a preservative of food, are universally known 
 and appreciated ; but the chemist wishes to know of 
 what things Common-salt consists. 
 
 " TRY," is the motto of the laboratory ; and ac- 
 cordingly, by trials or experiments, the chemist soon 
 discovers that he can divide Common-salt into two 
 new and distinct substances, one of them a Vapour of 
 a greenish yellow colour, and the other a Solid of a 
 silvery lustre ; he therefore terms Common-salt, a Com- 
 pound. 
 
 The Vapour, he terms Chlorine, in allusion to its pe- 
 culiar tint ; the Solid, Sodium, to denote its identity 
 with that obtained from a plant called the salsola soda ; 
 
INTRODUCTORY. 7 
 
 and as these are the only two substances obtained 
 by the analysis of Common-salt, he terms it Chloride 
 of Sodium, to express its constitution with precision. 
 
 But the chemist is now only half satisfied,, he has 
 another question ready : Of what does Chlorine con- 
 sist, and of what does Sodium consist ? 
 
 He again appeals to accurate experiment; but 
 finds that neither Chlorine nor Sodium can be ana- 
 lysed or simplified, they remain refractory as the 
 metal Iron, they demand to rank with it as Elements, 
 and this position the chemist is reluctantly com- 
 pelled to grant. 
 
 Chalk is another well-known substance ; Of what 
 does it consist, is the question of the chemist : is it an 
 Element like Iron, or is it a Compound like Salt ? 
 
 The chemist discovers that Chalk will immediately 
 relinquish two new substances, one of them an Invisible 
 Vapour, and the other a White Solid ; he therefore 
 terms Chalk, a Compound. But the chemist is not 
 contented with this result; he again puts the ques- 
 tion, Are these new substances elements or com- 
 pounds ? 
 
 Although one of the substances is an Invisible 
 Vapour, it can be confined, weighed, measured, and 
 experimented upon with the utmost facility ; and when 
 the chemist submits it to his most refined operations, 
 it yields two new substances, the one an Invisible Gas, 
 and the other a Black Solid ; whilst the analysis of 
 White Solid, yields the same Invisible Gas, and a Solid 
 of Silvery splendour. 
 
INTRODUCTORY. 
 
 These new substances now require to be denoted by 
 names ; the chemist finds that the Invisible Gas has 
 the power of producing many Acids, and therefore he 
 calls it Oxygen ; the Black Solid he discovers to be 
 the pure inflammable principle of Coal, and therefore 
 he calls it Carbon ; whilst the Solid of Silvery splendour 
 he discovers to be a constituent of Lime, and therefore 
 he calls it Calcium. 
 
 He generally draws upon the rich stores of the Greek 
 and Latin languages, for names to denote the various 
 substances that he obtains ; and this will be evident 
 upon reference to the list of elements, at page 4. 
 
 The Invisible Vapour obtained by the chemist during 
 his first experiments upon Chalk, proves to be an Acid 
 compound of Oxygen and Carbon, and to denote this 
 fact, he calls it Carbonic acid ; whilst the White Solid 
 substance proves to be an Alkaline compound of 
 Oxygen and Calcium, and therefore he calls it Oxide 
 of calcium, or more familiarly, Lime. 
 
 The composition of Chalk, in refined chemical no- 
 menclature, is accordingly expressed by the term Car- 
 bonate of oxide of calcium ; but the chemist, for bre- 
 vity, generally calls it Carbonate of lime. ^ it is a com- 
 pound of two compounds, and these lie -fimiiliarfy calls 
 its Proximate elements, because they^ immediately 
 come forth, upon the first, or proximate analysis, and 
 they will, under certain conditions, immediately unite 
 and reproduce chalk. 
 
 On the other hand, Oxygen, Carbon, and Calcium, 
 into which Carbonic acid and Lime are resolvable* do 
 
INTRODUCTORY. 9 
 
 not admit of further analysis or simplification ; they 
 are refractory like Iron, Chlorine, and Sodium, and 
 therefore the chemist calls them Ultimate elements, 
 meaning by the term, elements elicited when analysis 
 is carried to its utmost possible extent. 
 
 The union of two or more Ultimate elements, con- 
 stitutes a Primary combination ; and that of two or 
 more Proximate elements, a Secondary combination ; 
 and as the chemist, throughout all his researches, is 
 guided by a constant appeal to a just and delicate ba- 
 lance, he discovers that each kind of combination is 
 governed by a definite weight. 
 
 For example, if he experiment upon 1000 parts 
 by weight of Chloride of sodium, he will invariably 
 obtain 600 parts of Chlorine and 400 parts of Sodium ; 
 if upon 1000 parts of Carbonate of lime, he will first 
 obtain 440 parts of Carbonic acid, and 560 parts of 
 Lime ; if he pursue the ultimate analysis of these com 
 pounds, he will obtain from this quantity of Carbonic 
 acid 320 parts of Oxygen, and 120 parts of Carbon; 
 and from the Lime, 160 parts of Oxygen, and 400 parts 
 of calcium. 
 
 If the chemist, by well-known agents, excite the 
 above substances to combine as Primary, or Secondary 
 compounds, they will only do so in such weights, he 
 has no power of forcing them to combine according to 
 his caprice ; a grand and immutable law of Definite 
 weight presides over every analytical and synthetical 
 operation. 
 
 Chemistry, thus tending to the discovery of the 
 
 B 5 
 
10 INTRODUCTORY. 
 
 elements of things, and of the laws by which they are 
 controlled, presents its votary with powerful illustra- 
 tions of the Truth, that " a just weight and measure 
 are the Lord's ;" that " a just weight is His delight ;" 
 that " He comprehended the dust of the earth in a 
 measure, and weighed the mountains in scales, and 
 the hills in a balance." 
 
 The chemist endeavours to act as the humble and 
 faithful interpreter of the wonders of the Creation, and 
 everywhere discovers proofs of the power and goodness 
 of God : what a glorious contrast does this exalted 
 occupation present, to the sordid pursuits of the darker 
 ages, when the transmutation of metals, and the pro- 
 duction of an elixir of immortality, formed the vain 
 and presumptuous hopes of the experimenter ! 
 
 Throughout the Four Seasons, it must be obvious 
 that Air, Water, Earth, and Heat, are ever active and 
 important agents, and therefore a general account of 
 their chemical habitudes demands a place in these 
 introductory pages, to facilitate our future proceed- 
 ings. 
 
 The science of chemistry is founded upon the labo- 
 rious yet certain practice of EXPERIMENT, and by its 
 aid the Air, or Atmosphere, is proved to consist chiefly 
 of two elementary gases, named Oxygen and Nitrogen ; 
 they are strongly opposed in their chemical characters, 
 for the former will support life, and flame, for a time, 
 but the latter will destroy both, instantaneously. 
 
 The chemist can combine Oxygen and Nitrogen, in 
 
INTRODUCTORY. 1 1 
 
 definite proportions, by weight, and produce Five com- 
 pounds, as shown in the following statement : 
 
 I. Oxygen, 3640+Nitrogen, 6360=10000 Nitrous oxide. 
 II. Oxygen, 5333 -[-Nitrogen, 4667=10000 Nitric oxide. 
 
 III. Oxygen, 6320-f Nitrogen, 3680=10000 Hyponitrous acid. 
 
 IV. Oxygen, 6960+Nitrogen, 3040=10000 Nitrous acid. 
 V. Oxygen, 7410+Nitrogen, 2590=10000 Nitric acid. 
 
 I. Is an invisible vapour, called Nitrous oxide, to 
 
 denote that it is not acid. 
 
 II. Is an invisible gas, called Nitric oxide, to denote 
 that it is not acid; and by the termination ic, 
 that it contains more oxygen than the former. 
 
 III. Is an acid liquid, called Hyponitrous acid, to de- 
 
 note that it is intermediate with Nitric oxide and 
 Nitrous acid, and below the latter in its propor- 
 tion of oxygen. 
 
 IV. Is an acid vapour called Nitrous acid,- to denote 
 
 that it contains less oxygen than Nitric acid. 
 V. Is called Nitric acid, to denote its large amount 
 of oxygen ; the chemist has not determined if 
 nitric acid be solid, liquid, gas, or vapour, but 
 he is certain of its composition. 
 
 These five compounds are deadly poisons to ani- 
 mated beings, and yet they contain the elements of 
 Air, which is the pabulum of life, how can this be ? 
 The chemist replies, that to constitute Air, these 
 elements are not combined, they are only mixed, and 
 very nearly in the following weights : 
 
12 INTRODUCTORY. 
 
 Oxygen, 2300 + Nitrogen, 7700 = 10000 Air. 
 
 These elements are rendered incapable of combining 
 under all ordinary circumstances, they remain inti- 
 mately and uniformly mixed to constitute the first, 
 and the last food of life. 
 
 But when the lightning goes forth, as the terrible 
 display of natural electricity in the thunder-storm, the 
 chemist discovers that the elements of the air in the 
 immediate passage of the flash, are suddenly excited 
 to combine and produce the poison, called nitric acid ; 
 but this effect is miraculously restrained by the Hand 
 of Providence, and not permitted to ensue throughout 
 the entire volume of the air, or inevitable would be 
 the destruction of every living thing ; and the relatively 
 minute portion of poison thus formed during a long 
 protracted discharge of lightning, is soon infinitesi- 
 mally diffused throughout the untainted volume of air, 
 or absorbed by the waters, or neutralized by the earth, 
 and thus deprived of virulence. 
 
 The animated creation is thus miraculously pre- 
 served amidst the elements of destruction ; true indeed 
 is the solemn warning, that " in the midst of life we 
 are in death." 
 
 These extraordinary elements, Oxygen and Nitrogen, 
 form the chief volume of the Atmosphere during all 
 the vicissitudes of the Four Seasons; but a rigid 
 analysis likewise proves the simultaneous existence of 
 small quantities of two . compounds, named Carbonic 
 acid, and Water. Reference has been made to the com- 
 
INTRODUCTORY. 13 
 
 position of Carbonic acid, and when obtained from the 
 air or other sources, in a pure or insulated state, it is 
 fatal to animal and vegetable life, and is materially 
 heavier than either Oxygen or Nitrogen; but as mingled 
 with these elements, and the vapour of water, to con- 
 stitute Air, it has a beneficial influence, and never 
 subsides as a distinct mephitic stratum. 
 
 The chemist discovers that Water is a compound 
 of Oxygen and Hydrogen, an elementary gas thus 
 named in allusion to its producing that substance ; 
 the following are the weights in which these elements 
 combine : 
 
 Oxygen, 8890 + Hydrogen, 1110= 10000 Water. 
 
 It does not exist in the mixture of Oxygen, Ni- 
 trogen, and Carbonic acid, as Liquid water, but as 
 Vapour of water, produced by the all-prevailing agency 
 of solar heat ; thus it is wafted over the surface of the 
 globe, until local changes of temperature cause its 
 condensation, and fall, as rain or snow, and other well- 
 known forms, according to the season. 
 
 The result obtained by a minute analysis of Air, pre- 
 sents the following weights of its elementary and com- 
 pound constituents. 
 
 Nitrogen 7555 
 
 Oxygen 332 
 
 Carbonic acid .... 10 
 
 Aqueous vapour . . . . 103 
 
 10000 
 
14 INTRODUCTORY. 
 
 This wondrous medium, or atmosphere, containing 
 the elements of life and of destruction, enfolds the 
 earth, as a mantle ; and although the chemist cannot 
 experimentally determine its limit, he can determine 
 its total weight, and is perfectly astounded at its im- 
 mensity ; it is expressed by the sum of Five quatrillions, 
 two hundred and eighty- seven trillions, three hundred 
 and fifty billions of TONS ! 
 
 The accompanying statement will show the relative 
 proportions by weight, in which the elementary and 
 compound constituents of Air are blended, to produce 
 this gigantic sum total. 
 
 Nitrogen . . . 3.994.592.925.000.000 
 
 Oxygen .... 1.233.010.020.000.000 
 
 Carbonic acid . . 5.287.305.000.000 
 
 Aqueous vapour . 54.459.705.000.000 
 
 TONS 5.287.350.000.000.000 
 
 Both the chemist and the physiologist concur in 
 stating, from the results of numerous experiments, 
 that no elementary gas, no compound gas, no elemen- 
 tary vapour, no compound vapour, no other mixture 
 or combination of elementary or compound gases, or 
 of elementary or compound vapours, can support the 
 respiratory functions of the animated creation, like 
 Atmospheric air; and its ultimate analysis presents 
 Four elements, namely, Oxygen, Nitrogen, Carbon, and 
 Hydrogen. 
 
INTRODUCTORY. 1 5 
 
 Water is presented, throughout nature in lavish 
 abundance, it occupies more than three-fourths of the 
 superfices of the globe ; but philosophers cannot de- 
 termine the total weight of this enormous bulk of 
 water, as they can that of the atmosphere. 
 
 The chemist discovers that water, as it falls from the 
 clouds, invariably contains air, and sometimes a com- 
 pound of hydrogen and nitrogen, called ammonia, to 
 which much of its fertilizing power may be referred : 
 he further discovers that the water of springs, brooks, 
 and rivers, always contains portions of earthy and 
 saline compounds, particularly common-salt, although 
 not sufficient to destroy its freshness, and unfit it for 
 the beverage of man and animals. 
 
 The chemist discovers, that the water of springs in 
 certain localities, is so impregnated with gaseous, 
 earthy, and metallic compounds, as to be unfit for 
 constant use as a beverage, yet occasionally taken, it 
 exerts considerable influence in palliating or remov- 
 ing some forms of disease ; and pursuing his investi- 
 gations regarding the water of the ocean, which, when 
 drank, soon causes delirium and death, he discovers 
 it to derive its strong saline taste from a proportion of 
 common-salt, far exceeding that in ordinary spring 
 brook, or river water; and its bitter taste, from an 
 inferior proportion of compounds of lime and mag- 
 nesia. 
 
 But during all experiments and researches upon 
 water, the chemist cannot find a solitary instance 
 of its occurring, in nature absolutely pure, or solely 
 
16 INTRODUCTORY. 
 
 consistent of the elements, Oxygen and Hydrogen ; he 
 can render it so, artificially, and then he finds it is 
 perfectly unfit for the beverage of man and animals ; 
 he has, therefore, reason to admire the wonderful pro- 
 vision of the Creator, in ordaining water to contain 
 principles, in addition to its own elements, which are 
 indispensable to the support of vitality. 
 V The solid parts of the globe, which are popularly 
 called the Earths, as, for example, Lime, Sand, Clay, 
 and Magnesia, are, in fact, compounds of Oxygen, 
 with the metals, Calcium, Silicium, Aluminum, and 
 Magnesium ; they are rusts of these metals, or metallic 
 oxides, and as such they are styled in refined chemical 
 language, but they will be spoken of as Earths in this 
 inquiry, and the following statement will show their 
 composition. 
 
 I. Oxygen, 286 + Calcium, 714 = 1000 Lime. 
 II. Oxygen, 500 + Silicium, 500 = 1000 Sand or Silica, 
 
 III. Oxygen, 480 -J- Aluminum, 520 = 1000 Clay or Alumina. 
 
 IV. Oxygen, 400 + Magnesium, 600 = 1000 Magnesia. 
 
 These earths are sometimes found very pure, but 
 more frequently mingled together, or combined with 
 other metallic oxides, as, for example, those) of iron 
 and potassium: thus common clay contains^ a large 
 portion of alumina, to which its tenacity and plasticity 
 with water is entirely referrible ; but it also contains 
 portions of silica, and oxide of iron, which cause its 
 grittiness and colour ; and lastly, oxide of potassium 
 
 
INTRODUCTORY. 17 
 
 or potash, which renders it fertile for the growth of 
 corn. 
 
 The chemist discovers that the earths are likewise 
 presented by nature, in combination with Acids con- 
 taining the inflammable elements, Carbon, Sulphur, and 
 Phosphorus. These are respectively called Carbonic, 
 Sulphuric, and Phosphoric acids, and their combina- 
 tions with the earths are called Carbonates, Sulphates, 
 and Phosphates. 
 
 Thus, for example, Chalk, Limestone, and Marble, 
 are Carbonates of lime ; Gypsum and Alabaster are 
 Sulphates of lime; and Bone-earth contains Phosphate 
 of lime and phosphate of magnesia. 
 
 The earths, when absolutely pure, are solid, incom- 
 bustible, infusible, excepting in the most intense de- 
 gree of artificial heat that can be commanded ; they 
 are insoluble in water, with the exception of lime v 
 
 When the earths naturally occur in various states of 
 purity, they have the foregoing characters in a very 
 eminent degree ; their natural and artificial compounds 
 with each other, with several metallic oxides, and with 
 the above acids, in the generality of instances are simi- 
 larly characterized. ' ' 
 
 A general notion of the manner in which earths, 
 earthy and saline compounds, organic matters, and 
 water, are mingled together to constitute a soil, may 
 be gained from the following statement, which sup- 
 poses that 1000 parts by weight of a soil, have been 
 submitted to proximate analysis. 
 
18 INTRODUCTORY. 
 
 1000 Parts of Soil. 
 
 Parts. 
 
 Large loose stones and silicious gravel . 143 
 
 Fine silicious sand . . . . . . . 572 
 
 Aluminous earth 75 
 
 Carbonate of Lime 47.5 
 
 Carbonate of Magnesia 7.5 
 
 Sulphate of Lime 5 
 
 Oxide of iron 12.5 
 
 Salts of sodium and potassium .... 10 
 
 Phosphate of Lime 2.5 
 
 Vegetable and animal manure .... 72.5 
 
 Water 52.5 
 
 1000.0 
 
 The more particular examination of soils, as regards 
 their relative fertility, will be given hereafter ; and it is 
 by a correct knowledge of the nature of the pure 
 earths, and their compounds, and various mixtures 
 with organic and inorganic matters, that the chemist 
 is enabled to afford valuable information to the agri- 
 culturist, and thus assist him materially in augment- 
 ing the produce of the autumnal harvest. 
 
 It is true that every man can cause ground to bear 
 corn, yet it will only grow in abundance, and of the 
 best quality, where sown after rational principles, and 
 the labours of the agriculturist are profitable and 
 useful, in proportion as he is acquainted with the rudi- 
 ments of chemical science. 
 
 Air, water, and earths, are inorganic substances ; 
 
INTRODUCTORY. I 9 
 
 they neither grow nor are they reproduced ; they 
 have no period that may be called their perfection ; 
 but Seeds, upon which the hopes of the agriculturist 
 are founded, are Organic bodies, produced by the 
 powers of vitality ; they have periods of growth, ma- 
 turity, death, and decay. 
 
 Can the chemist extend his analytical researches to 
 seeds, and other organic bodies, and ascertain their 
 elements, as he can those of air, water, earths, and in- 
 organic matters ? He can : all organic bodies admit of 
 analysis, and with reason it might be imagined, that 
 hundreds of elements would be elicited by such an 
 extensive investigation of the diversified array of 
 animated nature. How different is the fact obtained 
 by experiment, for it teaches the chemist that only 
 Four elements enter into the essential constitution of 
 all organic productions ! 
 
 These Four elements are Oxygen, Nitrogen, Carbon, 
 and Hydrogen, or the ultimate elements of the atmo- 
 sphere. This statement may appear incredible, but it 
 is an experimental fact, and moreover, some vegetable 
 and animal structures do not even contain nitrogen. 
 
 This discovery presents a magnificent illustration of 
 the power and goodness of God, who created these 
 elements, and controls their arrangement by definite 
 and unerring laws, into countless forms of beauty and 
 utility, for the adornment and enrichment of the earth. 
 
 It must be remembered that such combinations are 
 under the influence of the incomprehensible agency of 
 vitality, and towards it man can make no approaches. 
 
20 INTRODUCTORY. 
 
 As a chemist, Le is permitted to analyse the air, the 
 water, the earths, and to recompose nearly all, in the 
 same weights of their constituents, as those in which 
 they were presented for his examination ; he is likewise 
 permitted to analyse all organic bodies, and to obtain 
 their three or four elements, in weights, the sum total 
 of which exactly equals the original weight of the body 
 subjected to experiment; but he is not permitted to 
 exercise synthesis. He may place these elements toge- 
 ther, in every possible manner that human skill can 
 suggest, employ upon them the most powerful exciting 
 agencies at his command, they will neither combine to 
 produce the original body, nor the slightest resem- 
 blance of an organized body. 
 
 The chemist thus meets with an impassable barrier 
 to synthetical operations, and upon all occasions when 
 he encounters recondite matters, which do not admit 
 of elucidation by his own limited and insignificant ac- 
 quirements, he does not perplex his mind with pre- 
 sumptuous efforts to tear the veil of mystery that he 
 cannot raise, but humbly yields submission to the 
 Truth "that the things which are impossible with 
 man, are possible with God." 
 
 " There is no part of chemistry which abounds in 
 more extraordinary disclosures than that connected 
 with the composition and properties of organic pro- 
 ducts. It teaches us that, infinitely diversified as they 
 apparently are, none of them seem essentially to con- 
 tain or include more than three or four elementary 
 substances." 
 
INTRODUCTORY. 
 
 " Fifty- five elements are presented to us by nature : 
 of these, only four are employed in the elaboration of 
 all the wonderful creations of living matter." 
 
 " Flowers and perfumes, leaves and wood, food and 
 poisons, flesh, fat, hair, feathers, when the chemist 
 comes to look at all these, he finds that such wonder- 
 ful diversity is the result, not of the employment of a 
 multiplicity of elements, but of the combination of a 
 very few, in varied proportions, and under the influ- 
 ence of vital agency." 
 
 To render this extraordinary fact still more impres- 
 sive, a tabular statement is here subjoined of the ana- 
 lysis of ten proximate principles, Gum, Sugar, Starch, 
 Lignin or woody fibre, Wax and Gluten are of vege- 
 table origin ; Gelatin, Albumen, Fibrin, and Fat, are 
 of animal origin. 
 
 Gum. 
 
 Carbon 414 
 
 Hydrogen 65 
 Oxygen 521 
 
 Sugar. Starch. Lignin. Wax. 
 
 421 428 500 806 
 
 64 63 56 114 
 
 515 509 444 80 
 
 1000 1000 1000 1000 1000 
 
 Gluten. Gelatin. Albumen. Fibrin. Fat. 
 
 Carbon 557 
 
 Hydrogen 78 
 
 Oxygen 220 
 
 Nitrogen 145 
 
 483 
 
 516 
 
 520 
 
 790 
 
 80 
 
 75 
 
 72 
 
 118 
 
 276 
 
 259 
 
 250 
 
 92 
 
 161 
 
 150 
 
 158 
 
 000 
 
 1000 1000 1000 1000 1000 
 
22 INTRODUCTORY. 
 
 From this statement, we discover that the proximate 
 principles of Vegetables, with the exception of Gluten, 
 contain but Three elements, and that those of Animals, 
 with the exception of Fat, contain Four ; and whilst its 
 composition is closely analogous to that of most vege- 
 table principles, that of gluten approximates to the 
 composition of most animal principles. The important 
 consequences of these discoveries will become apparent 
 at a future stage of our inquiry. 
 
 All ponderable elements, and the host of natural 
 and artificial compounds in which they exist, are sub- 
 ject to the imponderable agencies of Light, Heat, and 
 Electricity, which modify and control all chemical 
 changes, but more particularly those of organic pro- 
 ductions. 
 
 The chemist is totally ignorant of the ultimate na- 
 ture of these imponderable or ethereal matters; he, 
 cannot experiment with them as with solids, liquids, 
 gases, or vapours ; he is only acquainted with them 
 when acting upon such ponderable forms. 
 
 Solar light enters the confines of the atmosphere, 
 permeates its transparent volume with incredible velo- 
 city, and illuminates the solid opaque earth. 
 
 Such light is absolutely necessary for the welfare of 
 the animal and vegetable creation ; its presence stimu- 
 lates a healthy action of their vital functions, and causes 
 the elaboration of elements that enter into the consti- 
 tution of organized structures ; whilst, in the prolonged 
 absence of light, morbid and fatal changes will gene- 
 rally ensue. 
 
 7 ' 
 
INTRODUCTORY. 23 
 
 The power and goodness of God are magnificently 
 displayed in solar light, it being, not of one colour, 
 but of seven colours, a fact that we behold with ad- 
 miration and gratitude, in the stupendous arch of 
 varied light, which so frequently spans the heavens as 
 the rainbow. 
 
 "Look upon the rainbow, and praise Him that 
 made it, very beautiful it is in the brightness thereof ; 
 it compasseth the heavens about with a glorious circle, 
 and the hands of the Most High have bended it." 
 .. The very limited extent to which scientific inquirers 
 can reason and experiment upon an element so incon- 
 ceivably attenuated as solar light, leads them to con- 
 sider that the bow may be caused by the coloured re- 
 fraction of light by drops of rain, for it is found that 
 when the solar rays are caused to impinge upon watery 
 spray, similar colours to those of the rainbow appear, 
 although microscopic in comparison with its gigantic 
 span. 
 
 These colours likewise appear when the solar beam 
 is refracted by the denser solid medium of flint glass, 
 a triangular prism of this invaluable compound, pro- 
 bably elicits the phenomenon in the greatest perfection 
 and beauty attainable by human skill ; hence the term 
 Prismatic colours applied to the Eed, Orange, Yellow, 
 Green, Blue, Indigo, and Violet rays of light which 
 constitute the spectrum. 
 
 When these Seven coloured rays are collected to a 
 focus, by a glass lens, they coalesce into colourless 
 
24 INTRODUCTORY. 
 
 light, and are therefore presumed to constitute such 
 ethereal agent. 
 
 The chemist discovers that the coloured rays are 
 possessed of different chemical powers ; that the red 
 have the highest, and the violet the lowest temperature ; 
 that the former have hut little, and, in some instances, 
 no tendency to promote chemical changes, whilst the 
 latter are most powerful excitants of such phenomena. 
 
 If solar light were of one colour, or mono- chromatic, 
 all terrestrial objects would appear of such colour, or, 
 if incapable of reflecting it, they would appear black, 
 we should not be charmed with the varied and gorge- 
 ous hues of the creation ; but light being seven- 
 coloured, or chromatic, and the surfaces of objects 
 being differently constituted, both physically and che- 
 mically, they are capable of reflecting, in some cases, 
 all the rays, and thus of appearing white ; and, in other 
 cases, of absorbing them all, and thus of appearing 
 black ; but more generally of reflecting certain simple 
 rays, or mixtures of rays, in preference to others, and 
 of thus impressing the eye with numerous shades of 
 colour. 
 
 Light, is accompanied by heat during its swift pas- 
 sage from the sun to the earth, but heat is an impon- 
 derable element, and therefore the chemist is obliged 
 to rest content with examining its effects upon terres- 
 trial objects; and although he can artificially elicit 
 heat by various experiments, he is even then ignorant 
 of its nature. 
 
INTRODUCTOKY. 25 
 
 " In all our excursions over the surface of the globe, 
 innumerable objects excite our admiration, and contri- 
 bute to inspire delight; but whether our gratitude is 
 awakened by the verdure of the earth, the lustre of the 
 waters, or the freshness of the air, it is to the bene- 
 ficial agency of heat, under Providence, that we are 
 indebted for them all. 
 
 " Without the presence and effects of heat, the earth 
 would be an impenetrable rock, incapable of supporting 
 animal or vegetable life ; the waters would be for ever 
 deprived of their fluidity and motion ; and the air of its 
 elasticity and utility together. 
 
 " Heat animates, invigorates, and beautifies all na- 
 ture; its influence is absolutely necessary to enable 
 plants to grow, put forth their flowers, and perfect 
 their fruit ; it is closely connected with the powers of 
 life, since animated beings lose their vitality when heat 
 is withdrawn. 
 
 " Such is the universal influence of this powerful 
 agent in the kingdoms of nature ; nor is this influence 
 diminished in the provinces of art ; it is with the aid 
 of heat that rocks are rent, and the hidden treasures 
 of the earth obtained ; matter is modified in countless 
 ways by its agency, and rendered subservient to the 
 uses of man ; furnishing him with useful and appro- 
 priate implements, warm and ornamental clothing, 
 wholesome and delicious food, needful and effectual 
 shelter." 
 
 Solar heat, and artificial heat, are indeed pow- 
 erful agents; the 'former most particularly, as con- 
 
 c 
 
26 INTRODUCTORY. 
 
 nected with the varied phenomena of the Four Seasons, 
 and with one exception, to he reserved for minute con- 
 sideration hereafter; all substances enlarge in hulk 
 when heated, and contract when cooled. 
 
 These temporary expansions hy heat, and contrac- 
 tions by cold, are hut small in the generality of closely- 
 compacted solids, great in mobile liquids, and greatest 
 in attenuated gases and vapours. 
 
 Some substances, especially the metals and their 
 ores, have the power of conducting heat with great 
 facility throughout their entire mass, so that it matters 
 not where heat he applied, they will in due time be 
 equally elevated in temperature. 
 
 Other substances, especially the earths, and their 
 compounds, generally absorb heat rapidly upon their 
 surfaces, and only conduct it very slowly and imper- 
 fectly throughout their mass, therefore heat chiefly 
 remains upon the part to which it is originally ap- 
 plied. 
 
 Lastly, some substances, especially air and water, 
 will not admit of being heated by conduction. 
 
 The chemist accordingly classes the foregoing sub- 
 stances, as conductors, imperfect conductors, and non- 
 conductors of heat ; and he has reason to admire and 
 appreciate the beneficial results that ensue from their 
 several habitudes with this agent. The transparent 
 atmosphere is so wonderfully constituted, as to allow 
 the rays of the sun to pass through it, without absorb- 
 ing their heat ; but upon reaching the opaque surface 
 of the solid earth, it immediately absorbs heat, and 
 
INTRODUCTORY. 27 
 
 becomes elevated in temperature ; then the air incum- 
 bent upon it obtains heat by contact, and is thus ren- 
 dered lighter, volume for volume, than it was ; it rises, 
 and its place is immediately occupied by another and 
 colder stratum of air ; this becomes heated, and 
 lighter, and in its turn rises, whilst colder air falls, and 
 thus by ascending and descending, or convective cur- 
 rents, the atmosphere becomes heated from the earth, 
 and not by direct conduction from the sun. 
 
 Thus winds are produced by the continued motion 
 of cold air to supply the place of that which ascends 
 in a heated state. 
 
 Transparent water is heated by the warm air that 
 blows over its surface, and npt by direct conduction of 
 heat from the sun ; but these matters will be particu- 
 larly explained in their proper season : it may, how- 
 ever, be remarked, that if earth, air, and water, were 
 conductors of heat, the animated creation could not 
 exist ; the sun would immediately heat the earth 
 intensely, the water would wholly disappear ; the air, 
 instead of being a temperate mantle, would become a 
 scorching shroud, or, in the more emphatic language 
 of Scripture, " the heaven would be as iron, and the 
 earth as brass." 
 
 Electricity is the third imponderable element of 
 whose ultimate nature the chemist is entirely ignorant, 
 but he has every reason to suppose that it is univer- 
 sally present with light and heat ; it is not manifest to 
 the senses unless its equilibrium be disturbed either 
 naturally or artificially, and then in the former case its 
 
 02 
 
28 INTRODUCTORY. 
 
 mysterious power is displayed as flashing lightning, 
 and in the latter as snapping sparks. 
 
 The chemist can control electricity to a certi.in 
 extent, for he discovers, as in the case of heat, that 
 some substances have the power of conducting, others 
 of retarding it, or of arresting its passage. 
 
 Air is a non-conductor, water and earth are con- 
 ductors of electricity ; and when it has accumulated in 
 clouds to a certain degree of intensity, the flash of 
 lightning announces its escape by rending asunder the 
 non-conducting air to meet the conducting media of 
 the waters and the earth. 
 
 Such is a general introductory statement regarding 
 the elements of natural productions, and the agents 
 unto which they are subject; we may now proceed to 
 examine the Principal Chemical Phenomena of the 
 Four Seasons ; and throughout them all, we shall be 
 presented with proofs of the Power and Goodness of 
 God, " who hath created these things, that bringeth 
 out their host by number; He calleth them all by 
 names by the greatness of His might, for that He is 
 strong in Power ; not one faileth." 
 
CHAPTER I. 
 
 SPRING. 
 
 How beautiful is the Creation ! how full of harmony, 
 order, and proofs of the power and goodness of God ! 
 
 Abundantly as these are presented throughout the 
 Four Seasons, they are never more obvious than in 
 Spring, when verdure clothes the earth, as the snow 
 of Winter vanishes under the genial influence of solar 
 heat. A.11 things rise in praise of the Creator, and He 
 beneficently ordains them to be as salutary to our 
 bodies, as they are delightful to our senses : our fer- 
 vent emotions of gratitude are called forth by this 
 wondrous change of season; and if we cultivate an 
 acquaintance with its glad attributes, and humbly 
 endeavour to interpret the unerring laws by which they 
 are governed, we gain a valuable fund of knowledge, 
 which is calculated to make us not only wiser, but 
 better, as it leads us to the highest appreciation of the 
 miraculous workings of Providence. 
 
 The germination of seeds, and the growth of plants, 
 present " the servant and interpreter of nature " with 
 
30 SPRING. 
 
 several phenomena which admit of elucidation through 
 the science of Experimental Chemistry, and accord- 
 ingly these will first claim our attention ; it will next 
 be directed to an examination of the manner in which 
 the earth receives and retains water, for the welfare 
 and support of vegetation ; and having ascertained this 
 point, we shall proceed to examine the conditions 
 under which water accumulates in the atmosphere, ta 
 form the showers of Spring, and its fertilizing agency 
 even when it does not so descend upon the earth ; the 
 action of heat and cold upon the atmosphere will then 
 claim our notice, and the changes which it sustains by 
 respiration, germination, and combustion; we shall 
 then pass on to examine some of the habitudes of the 
 earth, in retaining heat, and the beneficial results 
 which ensue from these ; lastly, resuming the examina- 
 tion of vegetable growth, a few of the peculiar func- 
 tions of plants will occupy our attention, as prepara- 
 tory to others which will present themselves in the 
 ensuing season of Summer. 
 
 First, as regards the Chemical phenomena, attendant 
 upon the germination of seeds, and the growth of 
 plants. 
 
 If we examine a seed, and for our general purpose 
 no better can be selected than a garden bean, we find 
 that its external membrane, or covering, is easily 
 removed, and then it may be divided into two distinct 
 portions, which are called Cotyledons; these enclose 
 the germ, or embryo, whose largest part, or that most 
 embedded in the Cotyledons, is called the plumula, 
 
SPRING. 31 
 
 and its smallest part, or that almost escaping from 
 them, the radicle. 
 
 Fig. 1. 
 
 Upon tasting the cotyledons, we find them amy- 
 laceous, and insipid, for chemical analysis proves them 
 to consist chiefly of a proximate vegetable principle 
 called Starch, a compound of Carbon, Oxygen, and Hy- 
 drogen, wonderfully elaborated by Nature into the form 
 of the seed, and having no tendency to change under 
 ordinary circumstances during the lapse of ages. 
 
 If we cast a seed of this kind into the earth, no 
 matter in what position, and carefully examine it 
 from day to day, we find that it sustains changes 
 which are not presented by an equal bulk of inorganic 
 matter similarly situated. 
 
 The seed swells considerably ; its external membrane 
 bursts, an upward and a downward shoot protrude 
 
 Fig. 2. 
 
 from the cotyledons, the former being an enlarge 
 ment of the plumula, the latter that of the radicle. 
 
SPRING. 
 
 In a few days the plumula will emerge from the 
 soil, whilst the radicle penetrates much lower than 
 the original position of the seed; and then it will be 
 found, upon tasting the cotyledons, that they are no 
 longer amylaceous or insipid, but sweet and mucilagi- 
 nous, because the proximate element called Starch, 
 has arranged its elements, Carbon, Oxygen, and Hy- 
 drogen, to constitute two new proximate elements? 
 called Sugar, and Gum. 
 
 At the same time we shall observe, that numerous 
 vessels are disposed throughout the cotyledons, for the 
 purpose, as it is presumed, of conveying these princi- 
 ples as generous nutriment to the newly-born plant, 
 until it has acquired sufficient maturity to procure 
 other support for its welfare from the air and the 
 earth ; and when this happens, the saccharine and 
 mucilaginous principles entirely 
 disappear from the cotyledons ; 
 they decay, and allow the plant to 
 remain entirely dependent upon 
 the leaves which are developed in 
 the plumula, and the fibres of the 
 radicle, for its future sustenance. 
 
 This silent and miraculous phe- 
 nomenon of Germination, will only 
 ensue under certain conditions ; in 
 the first place darkness is required, 
 ^ejfflbg?- an d it is ensured by the opacity of 
 
 the soil in which the seed is cast ; 
 yet when the germ has acquired 
 
 p ig 3 
 
SPRING. 33 
 
 sufficient strength to burst, and rise as the plumula 
 from its terrestrial prison, and to meet the air, light 
 immediately becomes essential for its health and 
 growth towards maturity. In the second place, the 
 seed requires a due temperature, which must always 
 exceed 32 degrees, and never exceed 100 degrees of 
 Fahrenheit's thermometric scale; it also demands a 
 liberal supply of water, either in the liquid or the 
 vaporous state, and perfect access of air. 
 
 These agents, ponderable and imponderable, must 
 be admitted, not singly, but conjointly ; for example, 
 plant the seed in the earth, allow it the free access of 
 water and air, and it will not germinate if the tempera- 
 ture of the earth be reduced to 32 degrees; neither will 
 it germinate between such temperature and 100 de- 
 grees, though liberally supplied with water if the 
 access of the air be prevented. 
 
 Bury the seed deep in the earth, and so situate, it 
 will neither germinate nor decay, it will remain un- 
 changed or dormant ; but remove it near the surface, 
 so that the porosity of the soil may admit of the just 
 and naturally combined agencies of air, water, and 
 heat, it will quickly start into life, and its emerging 
 plumula become verdant under the influence of solar 
 light. 
 
 Knowledge of the above fact enables the Chemist to 
 explain why the surface of barren earth newly turned 
 or excavated, so frequently becomes covered with luxu- 
 riant vegetation ; seeds were buried deep in the earth, 
 probably by natural convulsions in past ages, and thus 
 
 c ft 
 
34 SPRING. 
 
 rendered incapable of undergoing the changes requisite 
 for their germination to ensue ; but these are imme- 
 diately excited when the combined influence of the 
 foregoing agents is admitted. 
 
 Common experience teaches us that seeds must be 
 sown at the depth of a few inches in the earth, or they 
 will never put forth shoots above its surface ; the 
 chemical reason of this practice is, that they may gain 
 a requisite supply of air, water, and heat through its 
 pores. 
 
 Thus loamy and calcareous soils, being porous and 
 light, admit air, water, and heat to seeds, and are 
 generally fertile ; whilst clay-land, being compact and 
 adhesive, opposes the admission of such agents, and 
 frequently is not so productive ; indeed it often retains 
 water in such excess that seeds become rotten and 
 worthless. 
 
 So far as the Chemist can ascertain by experiment, 
 it appears to be chiefly by the absorption of water in 
 properly tilled soils, that the cotyledons of a seed are 
 enabled to increase in bulk, to put forth a plumula 
 and a radicle, and to transmute their original consti- 
 tuent starch into the new principles of sugar and gum : 
 but of this matter hereafter. Let us now inquire how 
 the genial showers of spring are received by the earth, 
 to promote the germination of seeds and the growth of 
 plants, that clothe its surface with verdure. 
 
 Water is received by the earth in consequence of an 
 attractive force existing between liquids and porous 
 solids generally ; this force is denoted by the term 
 
SPRING. 35 
 
 Capillary Attraction ; it is a most important and ever 
 active agent throughout nature. 
 
 Capillary attraction admits of illustration by the 
 following simple experiments, and after performing 
 them they will be found explanatory of the manner in 
 which water is received and retained by the earth. 
 
 Take a piece of cane, about an inch and a half long, 
 having its ends cut perfectly flat and smooth, hold it per- 
 pendicularly and place a drop of water upon the upper end, 
 the drop will soon vanish, and so will another, 
 and another, until the lower end of the cane 
 becomes wetted ; the water will not suddenly 
 run through the pores of the cane, which are 
 nearly as fine as hairs ; they retain it in oppo- 
 
 x*7jv sition to the attraction of gravitation, and 
 
 ^Ss this retention is called capillary, attraction of 
 Fig. 4. the liquid, from the Latin word capilhis. 
 
 This capillary attraction of the fine pores of the 
 cane will also raise water in opposition to the attraction 
 of gravitation, which would otherwise cause its fall. 
 
 Take another piece of cane, similar in dimensions to 
 that employed in the last experiment, place one end 
 just below the surface of water, and, in the course of a 
 few seconds the upper end will become wetted. 
 
 In this instance capillary attraction is again superior 
 to the attraction of gravitation, or the water would not 
 rise above its ordinary level ; but still it is mere mecha- 
 nical attraction, unaccompanied by chemical change ; 
 the cane and the water are both of the same composi- 
 tion as they were at the outset of the experiment. 
 
36 
 
 SPRING. 
 
 Sponge is a very porous substance, and when thrown 
 into water it does not disappear or dissolve, because 
 the water has no chemical attraction for the particles 
 of which it is composed ; but it will mechanically 
 attract and retain a very large quantity of the liquid, 
 because sponge may be considered as consisting of 
 myriads of small tubes interwoven or interlaced in all 
 directions, and exerting capillary attraction for the 
 water, as energetically as did the perfectly straight 
 tubes or pores of the cane. 
 
 Take another example, bearing yet more strongly 
 upon the rationale of capillary attraction in nature ; 
 a heap of sand consists of countless solid atoms of 
 silica, not in absolute contact, as its examination by a 
 magnifier will immediately prove, but separated by 
 interstices ; or, in other words, a heap of sand is full of 
 capillary pores, and these will become filled upon the 
 addition of water. 
 
 To render this more intelligible, or to represent, upon 
 a magnified scale, the grains of sand and their inter- 
 
 Fig. 5. 
 
 stices, a large glass-may be filled with marbles ; whilst 
 to denote the water (whose liquid particles, philosophers 
 
SPRING. 37 
 
 have likewise every reason to believe are not in absolute 
 contact) a small glass may be filled with -tape-seed, 
 this, when poured among the marbles, will fill their 
 interstices, as the water did those of the sand. 
 
 Place a shell or a piece of tile over the aperture in 
 the lower part of a flower-pot, fill it with dry sand, 
 then pour water upon its surface, and remark the large 
 quantity that may be added before any portion flows 
 from the aperture ; when it does so, the capillary pores 
 of the sand are saturated, and the excess of water 
 passes through, in obedience to the attraction of gra- 
 vitation. 
 
 When the mould in a flower-pot becomes excessively 
 dry, we know that a great quantity of water may be 
 poured upon its surface before any escapes from the 
 aperture into the saucer beneath : this depends upon 
 the capillary attraction of the pores of the mould, as 
 just exemplified in the case of sand. 
 
 Suppose the saucer become filled with water, we 
 find it soon vanish if the plant in the flower-pot be in 
 full vigour. 
 
 Why does the water vanish ? Not by drying away., 
 in the common meaning of the term, but in consequence 
 of being attracted upwards as was the water by the 
 porous cane to supply the roots of the plant, in which 
 capillary vessels exist, and these transfer it to the stem, 
 leaves, and flowers, from whose surfaces it ultimately 
 dries away or evaporates ; therefore, in place of water- 
 ing the surface of the mould, we very frequently pour 
 
88 SPRING. 
 
 water into the saucer, and depend, as now shown, upon 
 capillary attraction for the rise of the liquid to main- 
 tain the life of the plant. 
 
 A porous substance has the power of raising water 
 to a very remarkable extent, as may he proved by the 
 following simple experiment. 
 
 Select a lump of common salt, cut it with a saw into 
 a regular shape, about six inches long, two inches 
 broad, and one inch thick, then set it to dry perfectly 
 before a fire. Fill a shallow plate with water, contain- 
 ing sufficient red ink to impart a deep tint, and when 
 the lump of salt is dry, place it upright in the plate, as 
 here shown. 
 
 Fig. 6. 
 
 The salt, though apparently solid, is in fact full of 
 capillary pores ; these will instantly attract the reddened 
 water, and the salt will become powerfully stained to a 
 very considerable height. The red ink is only added 
 to render the result more striking than it would be if 
 water alone were employed. 
 
 In the course of a few seconds the salt will fall, on 
 
SPRING. 39 
 
 account of the chemical solvent power of the water un- 
 dermining its lower part, or in other words, on account 
 of the solid particles of the salt heing now received 
 hy the interstices between the individual atoms of the 
 water, which action is regarded as solution ; but it does 
 not necessarily follow that a substance capable of 
 exerting capillary attraction, should thus be soluble. 
 A lump of porous sandstone, for example, similarly 
 placed, will attract water, but will not fall, even when 
 perfectly saturated, because it is an insoluble sub- 
 stance. 
 
 In nature, it frequently happens that capillary at- 
 traction and chemical solution act simultaneously, and 
 produce highly important results in conveying liquid 
 manure to the roots of plants, by which their growth 
 is wonderfully promoted. Vegetation on the margin 
 of a brook, or pond, is generally more luxuriant than 
 on the soil a few yards distant, because the porous 
 earth of the bank attracts water abundantly, and retains 
 it very forcibly even in time of drought. 
 
 Whilst upon this subject, it may be stated, that 
 much of the dampness in the walls of buildings depends 
 upon the porous brick or stone-work of the foundations 
 attracting water from the earth, and it frequently causes 
 great damage and inconvenience. 
 
 Oolite, or Bath-stone, as it is popularly called, is 
 much employed in the decorative architecture of inte- 
 riors, on account of the extreme facility with which it 
 may be sawn and wrought into the most delicate tracery, 
 and in such situations, if protected from damp, it will 
 
40 SPRING. 
 
 remain unimpaired for ages, as exemplified in many 
 abbeys and cathedrals. 
 
 Requiring little labour from the masons, and pro- 
 ducing a most beautiful effect, architects have been 
 occasionally tempted to employ oolite for external 
 work ; but it is not durable, because water is rapidly 
 absorbed by capillary attraction, and this extraordinary 
 liquid, by undergoing expansions and contractions 
 during the changes of atmospheric temperature, and 
 more particularly expansion upon freezing ; flakes of 
 the stones are violently detached, and the original sharp 
 outline of the work broken down. This action silently, 
 though certainly, continued for years, the sculptured 
 work becomes undistinguishable. 
 
 Turning from the works of Art to those of Nature, 
 as more particularly connected with this inquiry re- 
 garding the principal chemical phenomena of the Four 
 Seasons, we discover capillary attraction to be a most 
 active agent in retaining and administering a proper 
 supply of water to the vegetation upon certain soils 
 and rocks. 
 
 In sandstone and limestone districts, which particu- 
 larly abound in England, the absorption and retention 
 of water for the support of vegetation is very remarka- 
 able; we may see luxuriant plants, nay even forest 
 trees, flourishing upon both rocks, the sandstone being 
 porous, the limestone full of cracks or fissures, all 
 readily imbibing water from the heavens, retaining or 
 yielding it in proportion as it is demanded, for the 
 sustenance of vegetable life. 
 
SPRING. 4 1 
 
 It is no uncommon thing in such districts to see 
 plants and trees sending forth their roots into such 
 cracks and fissures in search of moisture, and occasion- 
 ally, when these cannot yield sufficient, the root will 
 travel completely down the external -surface of the 
 rocks to draw a supply from the more humid soil at 
 their hase. 
 
 Different is the case when compact, glassy granite is 
 the prevailing rock of the country ; it is incapable of 
 exerting capillary attraction for water, it cannot pro- 
 vide itself with vegetable clothing, and therefore stands 
 forth in bare and gaunt outline. 
 
 When the careful agriculturist observes a particular 
 district, in which vegetation naturally thrives, it be- 
 comes a matter of importance with him to ascertain the 
 cause of such fertility ; and upon application to the 
 chemist, the desired information can be obtained. 
 
 He can determine the average quantity of water ab- 
 sorbed and retained by the soil under ordinary vicissi- 
 tudes of the atmosphere ; he can determine the nature 
 of its components, the exact proportions of sand, clay, 
 calcareous compounds, organic, and other matters, that 
 it contains, and can frequently artificially compose a 
 soil equally fertile with that naturally found, or he can 
 render it still more productive by the judicious and 
 well-timed application of various organic and inorganic 
 matters as manures. 
 
 Chemistry thus becomes directly applicable to agri- 
 culture, and many agriculturists have embraced its 
 study, and by obtaining a sound knowledge of its 
 
42 SPRING. 
 
 rudiments, have been enabled to ameliorate the condi- 
 tion of soils upon rational principles. 
 
 " Plants, being possessed of no locomotive powers, 
 can grow only in places where they are supplied with 
 food ; and the soil is necessary to their existence, both 
 in affording them nourishment, and enabling them to 
 fix themselves in such a manner as to obey those 
 mechanical laws by which their radicles are kept below 
 the surface, and their leaves exposed to the free atmo- 
 sphere." 
 
 " As the systems of roots, branches, and leaves are 
 very different in different vegetables, so they flourish in 
 most different soils ; the plants that have bulbous roots 
 require a looser and a lighter soil than such as have 
 fibrous roots ; and the plants possessing only short 
 fibrous radicles, demand a firmer soil than such as 
 have tap-roots, or extensive lateral roots." 
 
 The manner in which the chemist proceeds to analyse 
 soils, cannot be particularly described in this examina- 
 tion of the Chemical Phenomena of the Four Seasons, 
 because it involves several agents whose action would 
 not be readily understood ; it mainly depends upon 
 presenting to the soil some element or compound that 
 will attract away one of its components in preference 
 to another. This may be tangibly illustrated, in the 
 first place, as follows. 
 
 Mix a heap of iron filings with an equal heap of 
 sand ; let these represent two distinct components of 
 a soil, and suppose that their ready separation is re- 
 quired . 
 
SPRING. 43 
 
 If a strong magnet be thrust into the mixture, it 
 will only attract the iron filings, and effectually sepa- 
 rate them from the grains of sand; the mixture is 
 thus immediately analysed. 
 
 Mix common salt and sand ; it would be very diffi- 
 cult, almost impossible, to separate, or to pick out, 
 their individual grains, even if the eye were aided by a 
 magnifier; and, as mechanical means fail, chemical 
 means must be tried. 
 
 Experience teaches us that salt will dissolve in water, 
 and that sand will not : therefore if water be added to 
 this mixture, and agitated, and poured off", and more 
 water added and agitated, and again poured off, until it 
 has no saline taste, the sand will remain, and by placing 
 the solution of the salt in a warm oven, the water, or 
 the chemical solvent, will dry away, and leave the 
 salt. This is a simple example of analysis. 
 
 Mix common salt, sand, and sawdust, how are these 
 to be separated ? Add water to dissolve the salt ; the 
 sand will subside, but the sawdust will float, or remain 
 suspended in the solution ; and if this be poured upon 
 a fine sieve, the sawdust will remain, whilst the solution 
 passes through, and the salt can be obtained from it as 
 before. This is another example of analysis. 
 
 The chemist, therefore, by extensive knowledge of 
 the habitudes of substances with water, and more 
 powerful solvents, is enabled to separate the components 
 of soils ; he adapts the process of analysis and the 
 agents which he employs according to circumstances ; 
 but invariably takes the utmost care to educe, or draw 
 
44 SPRING. 
 
 forth, the several components as they naturally exist in 
 the matter upon which he operates, and not to disturb 
 or modify the arrangements of their elements to produce 
 new compounds. 
 
 In illustration of the varied composition of soils 
 fitted for the support of the different kinds of vegeta- 
 tion ahove described, their chemical analysis is here 
 subjoined. " A good turnip soil afforded eight parts 
 out of nine of Silicious sand, and the finely divided 
 matter (that remained suspended, like the sawdust 
 upon the water,) yielded 63 parts of Carbonate of lime, 
 15 Silica, 11 Alumina, 3 Oxide of iron, 5 Vegetable 
 and Saline matter, and 3 of Moisture. 
 
 " A soil remarkable for producing flourishing oaks 
 afforded 3 parts of Carbonate of lime, 54 Silica, 28 
 Alumina, 5 Oxide of iron, 4 Decomposing vegetable 
 matter, and 3 of Moisture. 
 
 " An excellent wheat soil gave three parts in five of 
 Silicious sand, and the finely divided matter consisted 
 of 28 parts of Carbonate of lime, 32 Silica, 29 Alumina, 
 1 1 Organic matter and Moisture. 
 
 " Of these soils the last was by far the most, and the 
 first the least, coherent in texture ; in all cases the 
 constituent parts of the soil which give tenacity and 
 coherence, are the finely divided matters, and they 
 possess the power of giving those qualities in the 
 highest degree when they contain much alumina." 
 
 " A small quantity of finely divided matter is suffi- 
 cient to fit a soil for the production of turnips and 
 barley ; and a crop of turnips has been grown on 
 
SPRING. 45 
 
 a soil containing eleven parts out of twelve sand ; a 
 much greater proportion of sand, however, causes 
 sterility." 
 
 " Vegetable or animal matters, when finely divided, 
 not only give coherence, but likewise softness and 
 penetrability ; but neither they, nor any other part of 
 the soil, must be in too great proportion ; and a soil is 
 unproductive if it consist entirely of impalpable matters. 
 No soil is fertile that contains as much as nineteen 
 parts out of twenty of any of the constituents that have 
 been mentioned." 
 
 The power that different soils possess of becoming 
 heated by the solar rays, and of retaining heat, will 
 demand future attention ; at the same time it must be 
 evident that the general heat of the soil, particularly 
 in spring, is of the highest importance to the rising 
 plant. f( The moisture in the soil influences its tem- 
 perature, and the manner in which it is distributed 
 through, or combined with, the earthy materials, is of 
 great importance in relation to the nutriment of the 
 plant." 
 
 " If water be too strongly attracted by the earths and 
 their compounds, it will not be absorbed by the roots 
 of the plants ; if it be in too great quantity, or too 
 loosely held amidst them, it tends to injure or destroy 
 the fibrous parts of the roots." 
 
 The power of the soil to absorb water by capillary 
 attraction depends in a great measure upon the state of 
 division of its particles the more divided they are, the 
 greater is their capillary power ; thus fine sand will 
 
46 SPRING. 
 
 absorb and retain more water than coarse sand, but 
 each component of the soil has its particular capillary 
 attraction ; thus vegetable matters seem to be more 
 absorbent than animal matters when employed as ma- 
 nures, and animal substances are more so, than com- 
 pounds of alumina and silica, and these again are more 
 absorbent than carbonate of lime and magnesia ; but the 
 chemist states that these differences may depend to 
 some extent upon their mechanical division, and upon 
 the surface exposed. 
 
 " Water, and the decomposing animal and vegetable 
 matter existing in the soil, constitute the true nourish- 
 ment of plants ; and as the earthy parts of the soil are 
 useful in retaining water, so as to supply it in the proper 
 proportions to the roots of the vegetables, so they are 
 likewise efficacious in producing the proper distribution 
 of the animal and vegetable matter of manure ; when 
 equally mixed with it they prevent it from decomposing 
 too rapidly, and by their capillary attraction the soluble 
 parts are supplied in due proportions." 
 
 The foregoing are a few of the facts relating to the 
 philosophy of soils which have been discovered by the 
 chemist ; many others will be presented as we proceed 
 throughout the Four Seasons. 
 
 Water appears to be the chief agent upon which 
 plants depend for sustenance; and although seeds may 
 be sown in a heap of insoluble sand, or of small lead 
 shot, and will both germinate and flourish for a time, 
 if such materials be kept moistened with water, expe- 
 rience teaches us that they will do so more perfectly, 
 
 6 
 
SPRING. 47 
 
 if some form of organic matter, in a decomposing state, 
 be applied at the same time. Chemical analysis points 
 out the reason of this ; and when we come to the con- 
 sideration of a plant in its advanced stage of growth, 
 the theory of organic and inorganic manures will be 
 investigated. 
 
 It is chiefly to the capillary attraction of the pores 
 and fissures of the earth, that we are indebted for our 
 supplies of spring-water ; when rain falls, a great portion 
 is absorbed and retained by the surface for the main- 
 tenance of vegetation ; whilst the excess not so em- 
 ployed percolates or filters through the soil, abstracts 
 various saline and earthy compounds, until it meets 
 with an impermeable stratum of rock ; it then accu- 
 mulates, and ultimately gushes forth at a lower level 
 as a refreshing fountain. 
 
 A question now presents itself to the chemist, how 
 does water accumulate in the air to form the showers 
 whose influence in promoting germination and growth 
 in the Spring season, has passed into the proverb 
 that " April showers bring forth May flowers ?" 
 
 Experiment proves that such accumulation of water 
 in the air is dependent upon a natural phenomenon 
 called Evaporation, to denote a property possessed by 
 the air, of causing the gradual wasting away, or the 
 disappearance of the surface of water in the state of 
 vapour ; and such evaporation is proportionate to the 
 temperature of the air, and the rapidity of its move- 
 ment over the surface of the water. 
 
 Fill a broad shallow vessel with rain-water, collected 
 
48 SPRING. 
 
 before it has touched the earth, leave it uncovered and 
 exposed to the air, in a situation sheltered from rain, 
 and in the course of a few days of warm weather, the 
 whole of the water will vanish, and leave the vessel 
 perfectly dry. 
 
 The rationale of this simple experiment may be thus 
 stated ; air contains heat, and this incites the liquid 
 water to change into vapour or steam ; this is lighter 
 than air, but immediately blends with its volume, and 
 is wafted away ; fresh portions of air blow over the 
 surface of the water and convert it into vapour as 
 before, until at length the whole of the liquid is thus 
 consumed. 
 
 Evaporation is constantly proceeding throughout 
 nature, and the parent source of the fresh water that 
 diversifies and enriches the surface of the earth, is the 
 vast ocean, although this may not be directly evident, 
 as its waters are well known to be saline, bitter, and 
 poisonous. 
 
 An experiment will elucidate this point ; collect a 
 pint of rain-water, as already described; select two 
 finger-glasses of equal size ; measure half a pint of the 
 water into each of these, and in one of these portions 
 dissolve half an ounce of common salt. 
 
 Place both glasses in a situation sheltered from 
 rain, but freely exposed to the air, and it will be 
 found in the course of a few days, that the water 
 has evaporated from both, and has left in the one glass 
 no solid deposit, but in the other the original half- 
 ounce of common salt. 
 
SPRING. 49 
 
 Pure water, solely consistent of Oxygen and Hydro- 
 gen, and rain-water is very nearly pure is totally 
 volatile by natural or artificial heat ; but common salt, 
 and other saline and earthy compounds capable of being 
 held in solution by such water, are not similarly volatile, 
 they are fixed, and accordingly remain when pure 
 water has evaporated. 
 
 The waters of the ocean are saline and bitter from 
 containing common salt, or chloride of sodium, and 
 chloride of magnesium ; these compounds are fixed at 
 all natural ranges of atmospheric temperature ; and 
 accordingly when currents of air, or winds, blow over 
 the wide expanse of the ocean, its absolutely pure water 
 is incited to change from the liquid state to that of 
 vapour, and thus to mingle with the air, to travel on 
 the wings of the wind far inland, where, meeting with 
 depression of temperature, the vapour chills or con- 
 denses into drops, which the air cannot support, and 
 therefore they fall through it as showers of rain, in 
 obedience to the attraction of gravitation. 
 
 These showers partly sustain the vegetable produc- 
 tions of the earth, and partly accumulate to form 
 springs ; these gush forth as fountains, as already 
 stated, and soon meander as streams upon its surface, 
 and gradually spread and flow onward as rivers, which 
 ultimately reach the ocean ; from whence, by evapo- 
 ration, the water again travels inland, again condenses 
 as rain, accumulates as springs, rivers, and is again 
 received by the ocean ; thus performing an incessant 
 round of utility, and displaying the power and goodness 
 of God. D 
 
50 SPRING. 
 
 A similar process of evaporation is constantly pro- 
 ceeding from the surface of streams, rivers, lakes, and 
 from the humid earth itself; the beneficial effects of 
 this grand natural phenomenon are powerfully set forth 
 in the Sacred Writings. 
 
 " God maketh small the drops of water, they pour 
 down rain according to the vapour thereof, which the 
 clouds do drop and distil upon man abundantly, and the 
 tree of the field shall yield her fruit, and the earth shall 
 yield her increase." Again, " Thou visitest the earth 
 and waterest it, thou greatly enrichest it with the river 
 of God which is full of water, thou preparest them corn 
 when thou hast so provided for it ; thou waterest the 
 ridges thereof abundantly, thou makest it soft with 
 showers ; thou blessest the springing thereof."" 
 
 How eloquent, how beautiful, are these passages, 
 how calculated to enlighten, adorn, exalt, and purify 
 the mind of the philosopher, and lead him to extol 
 with reverence and gratitude the Giver of every good 
 and perfect gift ! 
 
 The watery vapour thus present in the air is imbibed 
 or attracted by soils with various degrees of energy, 
 and is as much connected with their fertility as the 
 direct absorption of the waters of the Spring showers. 
 When this power of attracting aerial moisture is great, 
 the plant is supplied with water, even in the absence 
 of rain ; and the effect of the evaporation in the day is 
 counteracted by the absorption of aqueous vapour from 
 the air by the interior parts of the soil during the day, 
 and by both the exterior and interior during night. 
 
 The compact, tenacious varieties of clay soils which 
 
SPRING. 5 1 
 
 absorb a great quantity of the water of the shower, do 
 not attract a great quantity of moisture from the air 
 during the absence of rain, they become hard and the 
 vegetation upon them is liable to wither away. 
 
 Chemical analysis of soils distinguished for their 
 power of attracting aerial moisture, points out that 
 they contain sand, finely-divided clay, carbonate of 
 lime, and organic manure, all so lightly bound together 
 as to admit of the perfect access of air to a considerable 
 depth ; and the great utility of carbonate of lime, or 
 chalk, and manure, consists in their conferring attrac- 
 tive powers upon the soil without rendering it adhesive 
 and compact ; sand likewise will destroy tenacity, but 
 it appears also to impair this attractive power. 
 
 Soils which attract aerial moisture with the greatest 
 avidity are always the most fertile ; and very simple 
 experiments upon this subject will afford means of 
 judging of the value or productiveness of land. 
 
 One thousand grains of the soil collected during dry 
 weather, may be placed on a metallic " hot- water plate/' 
 filled with boiling water; then let the soil be stirred 
 with a piece of thick wire, until no dew or steam is 
 deposited upon a cold glass plate or tumbler held about 
 an inch above its surface. 
 
 This is a test that the soil is dried, and upon carefully 
 removing it from the plate to the scale pan, the number 
 of grain weights required to restore the original balance 
 will indicate the quantity of water that was retained in 
 the soil by capillary attraction, although it might have 
 felt perfectly dry. 
 
 D 2 
 
52 SPRING. 
 
 If this dried soil be left in the scale pan exposed to 
 the air, it will gradually increase in weight by attracting 
 aqueous vapour. The temperature of boiling water is 
 directed to be used for the desiccation, because it is a 
 good standard of comparison, viz. 212 degrees; and 
 moreover such temperature will not alter the chemical 
 nature of the soil by decomposing its organic consti- 
 tuents, like the greater heat of an open fire or lamp. 
 
 If it be required to ascertain the utmost quantity of 
 moisture that the artificially dried soil is capable of 
 attracting from the air, the following arrangement may 
 be made. 
 
 Place the soil in an earthenware saucer, supported 
 on an egg-cup, in the centre of a large dinner-plate 
 full of water ; place a bell-glass, or a large earthenware 
 jar, over this arrangement, that the rim of the glass or 
 jar may stand in the water contained in the plate. 
 
 No liquid water can rise to the soil in the saucer, 
 but the vessel with which it is covered contains air ; this 
 will excite the water to rise in vapour, and become 
 
SPRING. 53 
 
 saturated ; a portion of this 'vapour will be attracted 
 and condensed by the soil ; examine its weight after a 
 few hours, then replace it as before ; and upon future 
 examination, when it has ceased to gain weight, it 
 may be considered to have attracted the greatest 
 amount of water of which it is capable ; again place it 
 upon the plate to dry as before, and the water will 
 evaporate. 
 
 Accurate experiments of this nature presented the 
 first chemist who devoted his talents to agriculture 
 with the following results. 
 
 I. One thousand parts of a celebrated soil from 
 Ormiston, in East Lothian, which contained more 
 than half its weight of finely- divided matter, of which 
 1 1 parts were carbonate of lime, and 9 parts vegetable 
 matter, when dried at 212 degrees, gained by exposure 
 for an hour to air saturated with moisture, at a tem- 
 perature of 62 degrees 18 grains. 
 
 II. One thousand parts of a very fertile soil from 
 the banks of the river Parret, in Somersetshire, under 
 the same circumstances gained 1 6 grains. 
 
 III. One thousand parts of a soil from Mersea, in 
 Essex, worth 45 shillings an acre, gained 13 grains. 
 
 IV. One thousand parts of a fine sand from Essex, 
 worth 28 shillings an acre, gained 1 1 grains. 
 
 V. One thousand parts of a coarse sand, worth 1 5 
 shillings an acre, gained only 8 grains. 
 
 VI. One thousand parts of the soil of Bagshot 
 Heath, gained only 3 grains. 
 
 A very considerable degree of chemical attraction is 
 
54 SPRING. 
 
 discovered to exist between the aluminous portion of 
 soils, and the organic matter of manure; thus it is 
 preserved from too rapid decomposition, and from 
 being carried away by water ; or, in other words, the 
 soil remains rich, and capable of yielding nutriment to 
 vegetation, whilst very silicious soils have little or no 
 such chemical attraction, and therefore often remain 
 poor, and incapable of yielding generous support to 
 their produce. 
 
 When soils are immediately situated upon a stratum 
 of rock or stone, they become dry much sooner than 
 when the sub-stratum is of marie or clay, which are 
 strongly absorbent of water, and accordingly in some 
 cases this is of great advantage to light sandy soils, as 
 a reservoir of moisture upon which they can draw in 
 time of drought for the support of their vegetation ; in 
 other cases, where the external soils are too absorbent, 
 this property is corrected by the sub -stratum being of 
 sand or gravel ; this admits of the percolation of the 
 excess of water. 
 
 In limestone districts, the actual soil is a kind of 
 marie, generally only a few inches deep, but highly ab- 
 sorbent, and capable of supporting vegetation, because 
 the limestone rock upon which it rests does not allow 
 the water to escape by rapid capillary attraction ; 
 whilst on the other hand, in sandstone districts, where 
 the sandy soil, although absorbent, rests on absorbent 
 sandstone rock, vegetation frequently suffers from the 
 capillary attraction of the latter, withdrawing the water 
 too rapidly ; indeed during the height of summer it is 
 
SPRING. 55 
 
 no uncommon thing to see the grass on sandstone dis- 
 tricts parched and browned, whilst that on limestone 
 districts is luxuriant and green. 
 
 The student of Nature must bear in mind, that the 
 enormous amount of fifty-four trillions, four hundred 
 and fifty-nine billions, seven hundred and five millions 
 of tons of watery vapour, is sustained by the atmo- 
 sphere, which is a mechanical mixture of the elements 
 Oxygen and Nitrogen, and the compound Carbonic 
 Acid; and that during all the wonderful vicissitudes 
 of the Four Seasons, the atmosphere is never sensibly 
 altered in the due proportion of its constituents. 
 
 Even when replete with solar heat, gained indirectly 
 by convection from the warm surface of the earth, the 
 air is simply expanded in volume, not altered in actual 
 constitution ; and when from local causes it has parted 
 with a certain degree of heat, or become cold, it is 
 simply contracted in volume ; the pure abstract effect 
 of artificial heat and cold upon air, is likewise attended 
 by similar phenomena ; this can be experimentally 
 proved by the following arrangement. 
 
 Fig. 8. 
 
 A Florence flask is placed with its neck dipping 
 beneath the water contained in a glass ; the flask, 
 
56 SPRING. 
 
 although empty, in the ordinary acceptation of the term, 
 is actually full of air ; this has no tendency to escape, 
 because it is nearly of the same density and elasticity 
 as the external atmosphere ; neither has the water a 
 tendency to enter but a very little way into the neck 
 of the flask, because it is opposed by the included air. 
 
 Fig. 9. 
 
 Apply the flame of a spirit-lamp very gently to the 
 bulb of the flask, its thin glass immediately conducts 
 the heat to the air, which expands in volume, or be- 
 comes too large for the flask to contain, and accord- 
 ingly a portion escapes from the neck, and bubbles 
 through the water. 
 
 Allow twelve or fourteen bubbles to escape, then 
 remove the lamp, and as the flask cools, water from 
 
 Fig. 10. 
 
 the glass will gradually rise into the neck of the flask, 
 and. at last become stationary. 
 
SPRING. 57 
 
 The explanation of this experiment is as follows : 
 the air was expanded by heat, and a portion escaped, 
 the remainder- then contracted by cooling ; and if the 
 neck of the flask had not been under water, the exter- 
 nal air would have entered to restore the original vo- 
 lume ; but being thus placed, the pressure of the exter- 
 nal air forces water upward, to supply the place of the 
 air that escaped. 
 
 Again apply the flame of the lamp to the bulb of the 
 flask, until the expansion of the portion of air that it 
 now contains, forces down the water nearly to the 
 neck ; then remove the lamp, and upon cooling the 
 water rises as before; again heat and again cool, to 
 the same degree ; the air will invariably expand in the 
 one case and contract in the other, and cause the water 
 to fall and rise as many times as may be thought pro- 
 per ; the same results will ensue upon alternate expo- 
 sure of the flask to sunshine and shade. 
 
 When the air has contracted for the last time, lift 
 the flask with one hand, that its mouth may be only 
 half an inch beneath the water, and take a cork be- 
 tween the fingers of the other hand, and dip it beneath 
 the water, to close the mouth of the flask; then it 
 may be placed to stand upon a wooden or pasteboard 
 ring, as shown in the next engraving ; the water that 
 was in the neck of the flask, will now occupy part of 
 its bulb, the air will occupy the remainder. 
 
 Provide a small wax taper, about one inch and a 
 half long, attach it to the end of a bent wire, rather 
 exceeding the height of the flask ; kindle the taper, 
 
 D 5 
 
58 
 
 SPRING. 
 
 remove the cork, and gently let the taper down the 
 neck into the bulh of the flask, the flame will be found 
 to continue for a time, with the same brilliancy as in 
 the open air ; at last it is extinguished. 
 
 Fig. 11. 
 
 Fig. 12. 
 
 These experiments are to prove that the pure and 
 abstract effect of heat from the flame of the spirit- 
 lamp conducted through the glass, is merely to cause 
 expansion of the volume of the air, and that of cold, its 
 contraction ; and that no chemical change in the pro- 
 portion or nature of its constituents is effected, or the 
 flame of the taper could not exist for a moment when 
 plunged into air subjected to these ordeals. 
 
 Whether the air be hot or jcold, it invariably con- 
 tains the relative proportions of nitrogen and oxygen, 
 which have been so frequently named; the latter 
 element supports the flame of the taper for a time, but 
 why does it not continue as it would do in the sur- 
 rounding air ? Because actual combustion in air 
 effects its decomposition, chemical changes are in- 
 stantly summoned into activity, the chief elements of 
 
SPRING. 59 
 
 the wax taper are Hydrogen and Carbon ; at an 
 elevated temperature both combine with Oxygen, to 
 form in the one case Water, and in the other Carbonic 
 acid ; and the flame or chemical change ceases when 
 the given volume of oxygen is thus abstracted, be- 
 cause these results of combustion, water and carbonic 
 acid, and the liberated nitrogen, can yield it no 
 support. 
 
 The flame of the spirit-lamp employed for heating 
 the flask, decomposed the free air for its support ; and 
 in every case of the combustion of ordinary fuel, the 
 air is similarly decomposed, the elements of the fuel 
 combining with the oxygen, and producing water and 
 carbonic acid, and liberating nitrogen, for which they 
 have no attraction. 
 
 Animal respiration effects changes upon atmospheric 
 air, closely analogous to those of combustion ; air that 
 has passed from the lungs is rendered perfectly unfit 
 for the further support of life or flame; the fact as 
 regards flame may be experimentally proved, by a very 
 simple arrangement of apparatus, of which a sketch is 
 given in the following page. 
 
 Provide a glass vessel, in the form of a quart bottle, 
 having the lower part removed ; withdraw the ground- 
 glass stopper, and then place the glass, to stand in a 
 shallow pan of glass or earthenware, containing about 
 two pints and a half of water; introduce a lighted 
 taper through the neck of the glass, and ascertain that 
 the included air supports flame; then remove the 
 taper, lift the glass perfectly out of the water, and 
 
00 SPRING. 
 
 move it backwards and forwards in the open air, to 
 allow the products of the flame of the taper to escape ; 
 the glass will thus become filled with fresh air, and is 
 to be placed in the water as first directed. 
 
 Fig. 13. Fig. 14. 
 
 Make a deep expiration, or sigh, of air from the lungs, 
 apply the lips closely around the neck of the glass, and 
 draw air from it into the lungs ; as this is done, water 
 will rise from the pan into the glass, and when it 
 nearly reaches the lips, expel air from the lungs, until 
 the water falls to its original level ; again inhale, and 
 again exhale, then remove the lips from the neck of 
 the glass, and immediately insert the stopper. 
 
 Kindle the taper, remove the stopper, and introduce 
 the flame; it will be extinguished as effectually as 
 though plunged into water, not even a glowing spark 
 will remain; therefore the air must have sustained some 
 most extraordinary change during its brief contact 
 with the lungs ; it is as follows. 
 
 The chemist has discovered that Carbon is an 
 
SPRING. 61 
 
 element of the blood, and in that wonderful fluid, it 
 has a powerful affinity for oxygen; therefore, when 
 the blood is exposed to the action of air inhaled by 
 the lungs, carbonic acid is instantaneously produced, 
 whilst nitrogen is liberated, and both compound and 
 element are to be found in the exhaled air, which is 
 perfectly unfit for the further maintenance of life, or 
 the support of flame. 
 
 The manner in which these mephitic results of re- 
 spiration are prevented from injuring vitality, presents 
 another wonderful example of the Power and Goodness 
 of the Creator. 
 
 From experiments conducted upon Aqueous vapour. 
 Nitrogen and Carbonic acid, the chemist discovers that 
 the two first are lighter, and the latter heavier, than a 
 similar volume of air of the same temperature ; there- 
 fore, reasoning a priori upon this fact, the most ob- 
 vious inference would be, that when they are con- 
 jointly exhaled from the lungs, the aqueous vapour 
 and nitrogen would ascend, the carbonic acid descend, 
 and thus leave a mid-path for the inhalation of 
 fresh air. 
 
 How different is the action, induced by the refined 
 and miraculous power of vitality ! The temperature 
 of the living body exceeds that of the surrounding air ; 
 the aqueous vapour ; nitrogen and carbonic acid are 
 all exhaled from the lungs in a heated state ; the action 
 of vital heat is not merely to expand the exhaled mat- 
 ters to more than their original volume, but to render 
 aqueous vapour and nitrogen still lighter than they 
 
62 SPRING. 
 
 are inherently, and to render inherently heavy car- 
 bonic acid, equally light with them ; accordingly, all 
 conjointly ascend swiftly from the respiratory organs, 
 without vitiating the fresh air that immediately enters 
 the lungs to discharge its functions, and in its turn to 
 undergo similar change and disposal ! 
 
 This fact admits of experimental illustration, by a 
 very simple arrangement ; provide a cylindrical glass, 
 about eighteen inches long and four inches in diameter, 
 closed at one end, and its rim ground smooth ; also a 
 piece of flat plate-glass, to cover this, and about a 
 pint of lime-water ; this is prepared by adding an ounce 
 of quicklime to a quart of water, contained in a glass 
 bottle, corking it closely, shaking it several times, then 
 allowing it to settle, and carefully decanting a part of 
 the transparent find colorless liquid into a clean bottle, 
 that must be provided with a glass-stopper. 
 
 These preparations being completed, place the glass 
 jar, with its rim, just below the lower lip, and breathe 
 across it twice or thrice ; then cover the rim with the 
 glass plate, and set the glass jar upon the table. 
 
 Remove the stopper of the bottle containing the lime- 
 water, then slide the glass plate a little on one side; 
 that sufficient room may be made for pouring about 
 half the lime-water into the glass cylinder ; it is then 
 to be closed with the glass plate, and shaken two or 
 three times, for the lime-water to come into contact 
 with the air that it contains ; no change will be percep- 
 tible in the clearness of the lime-water ; pour it away ; 
 then hold the glass cylinder in an inverted position, 
 
SPRING. 63 
 
 with its rim just above the upper lip, and breathe be- 
 neath it twice or thrice; close the jar with the glass 
 plate, and place it to stand on the table ; then proceed 
 as before, to pour in the rest of the lime-water ; and 
 upon agitation it will lose transparency, and become 
 milk-white. 
 
 The chemist presents the following explanation or 
 rationale of these experiments : lime is slightly so- 
 luble in water, and in that state has a strong attrac- 
 tion for carbonic acid, or, in technical terms, it is 
 a test of carbonic acid, forming white carbonate of 
 lime; this it will do slowly, even from the atmo- 
 sphere. 
 
 The aeriform matters were exhaled from the lungs 
 in a heated state, therefore they did not fall through 
 the air contained in the glass cylinder held with its 
 rim upwards, as in the first experiment, but as- 
 cended, and were lost in the surrounding air; had 
 they fallen, the lime-water would have detected the 
 carbonic acid, by the immediate formation of carbonate 
 of lime or chalk. 
 
 On the other hand, when the glass cylinder was 
 held with its rim downwards, the heated exhalation 
 from the lungs ascended, and displaced the air that it 
 originally contained, and the lime-water immediately 
 detected the newly-formed Carbonic acid, by combining 
 with it to produce Carbonate of Lime or Chalk. 
 
 Thus do the results of respiration and of combustion 
 ascend and diffuse themselves throughout the atmo- 
 sphere ; but they are destined to perform a ceaseless 
 
64 SPRING. 
 
 round of changes, the consideration of which will 
 claim our attention at a future season ; for in the vast 
 and perfect laboratory of Nature, nothing is lost, 
 nothing is destroyed, or rendered worthless. 
 
 The germination of seeds effects a chemical change 
 upon the air, analogous to that now described ; this 
 may be experimentally proved : place a handful of 
 peas in a quart bottle, moisten them with water ; intro- 
 duce a lighted taper for a moment, to prove that the 
 air is unvitiated, then close the mouth of the bottle 
 with a ground stopper, place it in a warm situation, 
 and in a few days germination will ensue ; the produc- 
 tion of carbonic acid, and the liberation of nitrogen, 
 may then be proved by the extinction of the flame of 
 the taper when introduced into the bottle. 
 
 From experiments similar in principle to the fore- 
 going, but conducted with the utmost skill and preci- 
 sion, the chemist concludes, that combustion, respira- 
 tion, and germination, are active in producing changes 
 upon the nature of the air, and yet he fails in detect- 
 ing any accumulation of mephitic matters; this is 
 partly on account of the utterly insignificant volume 
 of air only a few gallons upon which he can operate 
 with analytical agents, and partly on account of a dis- 
 covery that he makes regarding plants when in full 
 vigour, and especially when under the direct influence 
 of solar light, having the miraculous property of de- 
 composing carbonic acid, and thus restoring the just 
 balance of the atmosphere : this will demand future 
 consideration. 
 
SPUING. 65 
 
 It must now be remarked, that the presence of un- 
 combined oxygen is requisite for the phenomenon of 
 germination to proceed ; and the chemist discovers 
 that such condition is wonderfully provided for in the 
 vast atmosphere, in which oxygen is only mingled 
 with, and not combined with, nitrogen. 
 
 The presence of uncombined oxygen is indispen- 
 sable, that it may exert chemical affinity for a portion 
 of the Carbon of seeds, and convert it into Carbonic 
 acid ; and unless seeds thus lose carbon, they will not 
 germinate. 
 
 Place seeds in elementary nitrogen, or in compound 
 carbonic acid, supply them with a due temperature 
 and water, but instead of germinating, they will rot, 
 because nitrogen has no affinity for carbon under these 
 circumstances, neither has carbonic acid, as it already 
 contains that element. A vigorous and healthy plant 
 will soon wither and die, if placed in nitrogen or car- 
 bonic acid, a phenomenon analogous to the cessation 
 of animal life, when imprisoned in the same media. 
 
 On the other hand, place seeds in pure elementary 
 Oxygen, supply them with a due temperature and 
 water, they will germinate with extreme rapidity ; but 
 the action is morbid, for carbonic acid is formed at 
 the expense of their carbon, in great excess, and they 
 soon decay ; so when an animal is imprisoned in the 
 same medium, respiration becomes hurried by the 
 unnatural escape of carbon from the blood, and death 
 quickly ensues, from the intense excitement into which 
 the system is thrown. 
 
66 SPRING. 
 
 We have therefore reason to admire the power and 
 goodness of God, in preserving the wonderful uni- 
 formity in the constitution of the air in every terres- 
 trial locality, and rendering it alike congenial to the 
 welfare of animal and vegetable life. 
 
 The negative properties of the large volume of 
 nitrogen, restrain the positive properties of the small 
 volume of oxygen ; this element is therefore slowly 
 received by animals and vegetables, and without mor- 
 bid excitement, because their secretory organs are 
 compelled to perform the preliminary office of seeking 
 and of separating it from a state of admixture with 
 nitrogen. 
 
 In connexion with this subject it may be remarked, 
 that unless the large volume of negative nitrogen were 
 existent in the atmosphere, all the materials which are 
 now advantageously employed as sources of fire and 
 artificial light, would consume with a degree of rapidity 
 entirely disproportionate to their abundance upon the 
 earth, or to the limited power of mankind to extract 
 them from its strata. 
 
 Another phenomenon of Spring, upon which the 
 germination of seeds and the growth of plants depend, 
 now demands attention. 
 
 The thaws and floods of February leave the earth 
 saturated with water, and unfit for the reception of 
 seeds ; but the aerial currents, familiarly called " March 
 winds," which reach the shores of England, cold and 
 almost anhydrous from sweeping over the frozen con- 
 tinent of Europe, are ordained to evaporate the surplus 
 
SPRING. 67 
 
 of such moisture, and to dry the soil sufficiently for 
 the husbandman to commence his active labours. 
 
 In the ensuing month, the evaporated water hovers 
 above on the wings of the clouds, and ultimately con- 
 denses into drops, and descends as the showers of 
 April, to fertilize the earth from whence it ascended. 
 
 Hence the origin of the proverb March comes in 
 like a lion, and goes out like a lamb meaning that 
 the weather at the beginning of the month is generally 
 rough and boisterous, but in the end softened and 
 subdued. 
 
 Again, a peck of March dust is worth a king's 
 ransom Why ? Because it indicates to the husband- 
 man the probable continuance of dry weather, and 
 upon the proper dryness of the soil, for the reception 
 of the seed, at this season, that it may not rot and 
 decay, depends the produce of the autumnal harvest. 
 A dry and cold March never begs its bread, be- 
 cause it prepares the earth for seed-time ; but a wet 
 March makes a sad August because, urged by ne- 
 cessity, the husbandman is obliged to cast seed into 
 the ground saturated with the waters of February, 
 and much is spoiled, and yields no crop in August. 
 
 " The late Spring makes the fruitful year ;" for if 
 very mild weather happen in March, nature assumes 
 the aspect which properly belongs to April; buds 
 and blossoms are pinched by the night frosts, and 
 are either killed, or so injured that they produce 
 neither flowers nor fruits in due season ; and hence 
 the expression, ' March flowers make no summer 
 bowers.' 
 
68 SPRING. 
 
 These proverbs must not be despised for their home- 
 liness; they convey philosophical truths, and prove 
 how accurately our ancestors studied the changes of 
 the Four Seasons, though undirected by refined sci- 
 entific knowledge. 
 
 The chemist can offer no satisfactory explanation of 
 the formation of clouds or rain ; but so far as his 
 researches have been carried, they tend to the conclu- 
 sion, that clouds and mists consist not of actual drops 
 of water, but of myriads of excessively thin vesicles of 
 water, similar to soap bubbles ; if clouds, mists, and 
 fogs, consisted of drops, their fall would be rapid, - for 
 mathematicians calculate, that a drop whose diameter 
 amounted to a thousandth part of an inch, in obeying 
 attraction of gravitation would acquire a velocity of 
 nine or ten feet per second ; whereas we see clouds 
 hover at a small elevation for hours ; and they are 
 transported from the sea, lake, river, or marsh, from 
 which they are raised, far into the country, or to the 
 tops of mountains, where the requisite supply of mois- 
 ture cannot be had in any other way. 
 
 A scientific traveller in the Alps was enveloped in a 
 mist which was almost stagnant ; he was greatly sur- 
 prised at the size of the drops as he imagined them 
 to be float slowly along instead of falling ; some of 
 these were larger than the largest peas, and upon close 
 examination proved to be vesicles of water of extreme 
 tenuity. Clouds are probably formed when two vo- 
 lumes of air of different temperatures, and both satu- 
 rated with aqueous vapour, meet, and mix together ; 
 
SPRING. 69 
 
 but the cause of the production of vesicular vapour, 
 and the fall of rain, remains a mystery. 
 
 " He causeth the vapours to ascend from the ends 
 of the earth : He hindeth up the waters in the thick 
 clouds, and the cloud is not rent under them. 
 
 He weigheth out the waters by measure. 
 
 Canst thou tell the balancings of the clouds, the 
 wondrous works of Him which is perfect in know- 
 ledge ? " 
 
 Leaving, therefore, these recondite yet beneficial 
 phenomena, let us proceed with such as admit of 
 interpretation through the medium of experiment. 
 
 The porous surface of the earth has been shown to 
 be peculiarly fitted for the reception of water, and its 
 accumulation as springs; but this beneficial result 
 could not ensue if the earth were a good conductor of 
 heat, because such imponderable agent would then 
 travel beneath the surface, and vaporize or dry up the 
 whole of the water. 
 
 The Creator, in His power and goodness, has consti- 
 tuted the earth of materials that are incapable of con- 
 ducting heat to any great extent, and therefore it 
 chiefly remains at or near the surface, where it is 
 needed for the welfare of animal and vegetable life. 
 
 In the height of summer, when the surface of the 
 earth is parching hot, if we excavate only a few feet 
 beneath, it feeJs many degrees colder : and in the 
 depth of winter, when frost is on the surface, if we 
 proceed similarly, it feels several degrees warmer, and 
 
70 SPRING. 
 
 is always above 32 degrees, or the clods of earth 
 thrown out by the spade would not be soft and moist, 
 they would be hard and dry as ice. 
 
 Thus, the imperfect, or bad conducting power of the 
 earth as regards heat and cold, the terms being merely 
 relative, is the reason that springs of water do not 
 wholly escape as vapour in summer, and that they do 
 not wholly become solid ice in winter. 
 
 The coolness of a draught of water, drawn from a 
 deep spring in summer, and its comparative warmth 
 from the same source in winter, is a familiar example 
 of the point in question ; indeed during the intense 
 cold of winter, as the water of a deep spring gushes to 
 the surface of the frosted earth, it actually steams, or 
 in more chemical language, its warm vapour under- 
 goes condensation by the cold air into which it 
 escapes. At the depth of 100 feet from the surface, 
 the temperature of the earth is the average temperature 
 of the climate, and differs with the latitude; thus at 
 Wadso, in Lapland, it is 36, at St. Petersburgh, 40, 
 in England, 52, at Paris, 54, at Kome, 61, and at 
 Cairo, 70. 
 
 Air and water are non-conductors, and the earth is 
 an extremely imperfect conductor of heat ; good con- 
 ductors of this extraordinary imponderable agent do 
 not, generally speaking, occur abundantly upon the 
 surface of the earth, which they would render sterile, 
 but as metallic treasures deeply hidden in its bosom, 
 where there is no life, and from whence they are arti- 
 
SPRING. 71 
 
 ficially extracted, and rendered subservient, amongst 
 thousands of other uses, to the formation of the 
 ploughshare, and the sickle, for tilling the ground, 
 and reaping its produce. A few experiments regard- 
 ing the difference between good and bad conductors of 
 heat, can be easily performed. 
 
 Provide a metallic " hot-water plate," as commonly 
 used at the dinner- table, then spread evenly fine iron 
 filings over one half of its surface, and fine dry sand 
 over tl^e other half, to the depth of three quarters of 
 an inch, and place a lump of tallow about the size of 
 a pea upon each ; lastly, pour boiling water through 
 the hole in the rim of the plate, until it is filled. 
 The iron and the sand are thus exposed to the same 
 degree of heat, but they will not conduct it with 
 the same facility, as will be proved by the tallow 
 melting on the iron in the course of a few seconds, 
 whilst it remains unmelted on the sand for many mi- 
 nutes afterwards. 
 
 The difference between the conducting power of a 
 metal, an earth, and an earthy compound, may be 
 further illustrated by the following simple and instruc- 
 tive experiment : Provide solid cylinders, of these 
 three materials, viz. iron, sandstone, and chalk ; let 
 them be one inch in diameter, and six inches long, 
 and perfectly flat at each of their ends. 
 
 Place a cup, containing an ounce of tallow, upon 
 the warm hob of the grate ; and when the tallow is 
 perfectly melted, dip into it for about half an inch one 
 end of the iron cylinder, and then lift it out ; a por- 
 
72 SPRING. 
 
 tion of tallow will adhere, and quickly become solid, 
 because the iron, by good conducting power, deprives 
 it of the heat of fluidity. Dip one end of each of the 
 other cylinders in the same way ; they will attract, or 
 absorb, a considerable portion of the melted tallow, 
 and some time will be required before it will become 
 equally solid with that on the iron cylinder, because 
 sandstone and chalk have not sufficient conducting 
 power" to deprive it of heat in a similar degree. 
 
 Dip the end of all three cylinders again, and lift 
 them out, and when the tallow becomes solid, dip 
 them again, and lift them out, until they have all 
 obtained an equal coating of tallow, then allow them 
 to cool. 
 
 Pour boiling water into a " hot-water plate," and 
 place the three cylinders to stand upon it, at equal dis- 
 tances, with their coated ends uppermost, as shown in 
 the annexed sketch. 
 
 Fig. 15. 
 
 In the course of a few minutes, the iron will again 
 prove its good conducting power, by melting the tallow ; 
 but the sandstone and chalk will prove their bad con- 
 
SPRING. 73 
 
 ducting power by the tallow remaining solid during 
 the whole time that the water is cooling down to com- 
 mon temperatures. 
 
 When heat is applied to the surface of good con- 
 ductors, their entire mass will eventually become 
 equally elevated in temperature ; whilst, on the other 
 hand, with bad conductors, the heat will chiefly remain 
 upon the point to which it is first applied, and the great 
 part of their mass gains no increase of temperature. 
 
 If, for example, the iron cylinder be felt when the 
 whole of the tallow has fairly melted from its upper 
 end, this will be found as hot as the lower end ; if the 
 cylinders of sandstone and chalk be felt, their lower 
 ends alone will be found hot, and by moving the finger 
 slowly upwards, the limited extent to which they have 
 conducted heat will become sensible. 
 
 By reversing the arrangement of the last experi- 
 ment, namely, by applying heat above, instead of 
 beneath the cylinders, it can be proved that neither 
 the conducting power of the iron, nor the non-con- 
 ducting power of the sandstone and chalk, are in the 
 least degree affected or modified. 
 
 Let the iron cylinder be again coated with tallow, 
 but pare away all from its circular extremity, that it 
 may now stand firmly upon this, and have only a ring 
 of tallow about half an inch wide around its circum- 
 ference ; do the same with the cylinders of sandstone 
 and chalk; then set the three, at equal distances, 
 within a circle, similar in diameter to the bottom of 
 the " hot-water plate," that they may form a tripod 
 
 E 
 
74 SPRING. 
 
 for its support ; this arrangement must be made upon 
 a steady table; then remove the plate, without dis- 
 turbing the cylinders ; fill it with boiling water, and 
 carefully replace it to stand upon them, as represented 
 in the annexed sketch. 
 
 Fig. 16. 
 
 The three cylinders will now be subjected to heat, 
 applied from above, instead of from below, as in the 
 last experiment ; but this arrangement will cause no 
 difference in their conducting or non-conducting power, 
 as will be proved in the course of a few minutes, by 
 the ring of tallow melting from the iron cylinder, 
 whilst that upon each of the other cylinders remains 
 solid as before. 
 
 Thus in Nature, solar heat impinges on the surface 
 of the earth, and there chiefly remains, as it cannot 
 escape downwards on account of the bad conducting 
 materials of which the earth is constituted. 
 
 During a hot day, a sandy district is perfectly dry 
 and dusty; but upon removing the surface for the 
 depth of a few inches, damp sand appears, proving 
 that heat has not been conducted downwards to any 
 great extent. 
 
SPRING. 75 
 
 The reason that heat does not accumulate to a 
 destructive extent upon the earth, will appear when 
 we are considering the chemical phenomena of another 
 Season. 
 
 In some countries, Spring and Winter are hardly 
 known, vegetation being constantly luxuriant, but 
 sudden showers, or rather torrents of water, periodi- 
 cally fall, and are absorbed by the capillary structure 
 of the non-conducting soil, and there treasured up 
 for due transmission to vegetation in future seasons 
 of drought. 
 
 Other countries, from their low level, are subject to 
 periodical inundations, by the rise of large rivers; 
 these saturate the earth with water, and then subside, 
 leaving a sediment or mud, consisting of finely-divided 
 earthy and organic matter, which acts as a powerful 
 stimulus to the germination and growth of seeds 
 This phenomenon is alluded to in the following beau- 
 tiful metaphor " Cast thy bread upon the waters, and 
 thou shalt find it after many days." 
 
 In oriental countries, bread is synonymous with rice, 
 which is cast upon the soil, saturated by the inunda- 
 tion, and apparently lost, but appears in due season, 
 as a plenteous harvest. 
 
 We may now resume our investigation concerning 
 the phenomena of germination and growth, which we 
 quitted at the time that the seed had put forth its 
 radicle and plumula. 
 
 The radicle sends out its fibres amidst the soil, in 
 
 E 2 
 
76 SPRING. 
 
 search of moisture and soluble matters, and by an 
 incomprehensible vital power, transfers them into the 
 body of the plant, where they undergo mysterious 
 elaboration to form the fluid called sap. 
 
 The terminal fibres of the radicle are so minute as 
 almost to defy detection by the aid of a microscope, 
 and if injured, they will not fully exert their proper 
 functions ; therefore, in transplanting, we always en- 
 deavour to avoid wounding them with the spade, by 
 digging some distance around the stem, and thus car- 
 rying away with the plant a large ball of earth, through 
 which the terminal fibres have not penetrated. 
 
 This precaution protects the radicle, and also the 
 plant, from sustaining the derangement of its functions 
 that would ensue, if it were rudely torn up, and sud- 
 denly transplanted to a soil physically and chemically 
 different to that in which it originally germinated and 
 grew ; the plant continues to draw for food upon its 
 parent clod of earth, until its organs are enabled to 
 pierce beyond such limit, and to become inured to 
 the change of nutriment presented by the neighbouring 
 soil. 
 
 The chemist is acquainted with numerous substances 
 which act as poisons upon the animal frame ; of these, 
 white-arsenic, corrosive- sublimate, blue-vitriol, prussic 
 acid, and opium, may be cited as examples ; and he 
 discovers that any of these, if dissolved in water, and 
 applied to the roots of a plant, will soon cause it to 
 languish, droop, and die. 
 
SPRING. 77 
 
 Many experiments have been made upon this 
 destruction of the vitality of plants by poisonous sub- 
 stances ; the following are a few of the most re- 
 markable. 
 
 Beans were watered with a solution of white-arsenic ; 
 they faded in the course of a few hours, then became 
 yellow, and in three days were dead, 
 
 A lilac was killed by the introduction of a portion 
 of solid white- arsenic into a cut made in one of its 
 branches ; and a similar effect was produced by corro- 
 sive-sublimate. 
 
 Beans were killed by prussic acid in the course of a 
 single day, and deadly nightshade in four days ; while 
 spirit of wine killed the plant to which it was applied 
 in a few hours. 
 
 An experiment can be easily made regarding the 
 poisonous action of a metallic solution upon a plant 
 
 For example, water a succulent plant with a solution of 
 blue vitriol (sulphate of copper) until it die ; then cut its 
 stem across with a perfectly clean steel knife ; and that 
 the poisonous compound has been transferred to the 
 plant, and caused its death, will be evident by bright 
 metallic copper appearing on the knife-blade. 
 
 All things are so miraculously adjusted throughout 
 Nature, that the earth seldom or ever presents the 
 roots of plants with poisonous matters, but in their 
 stead, soluble compounds of potash and lime, which, 
 under the influence of vitality, promote the elaboration 
 of healthy sap or vegetable blood. The chemist can 
 throw but very little light upon the composition of 
 
78 SPRING. 
 
 sap, and no analysis unto which it has been subjected, 
 can be regarded as correct, on account of the difficulty 
 of obtaining it in a normal state, or free from other 
 juices of the plant ; the cause of its motion or circula- 
 tion is also a mystery ; it is observed to travel through 
 the stem' and the branches, and chiefly towards the 
 leaves, it enters their peculiar structure as a compara- 
 tively thin fluid, containing a large amount of water ; 
 and by the combined agencies of heat, air, and light, 
 much of this is evaporated in a pure state, or in other 
 words, the sap becomes thickened, .or concentrated, 
 and excited to form new proximate principles, which 
 increase the growth of the entire plant. 
 
 Upon close examination, the chemist discovers this 
 evaporation to be enormous ; for example, a large sun- 
 flower was proved to lose one pound four ounces, and 
 a cabbage one pound three ounces, of water during 
 twenty-four hours ; and many plants were proved to 
 lose one hundred times their weight of water during 
 three months. 
 
 This evaporation of water from plants may be proved 
 very readily, by covering them with a cold, dry, bell- 
 glass, for in the course of a few minutes its interior 
 will become lined with small drops of water resulting 
 from the condensation of the vapour; and that it 
 ensues chiefly from the lower surfaces of the leaves, 
 may be shown by placing them between two cold, 
 dry plates of glass, as represented in the opposite 
 sketch. 
 
 Drops of water will thus condense most abundantly 
 
SPRING. 79 
 
 upon the glass plate, which is opposed to the lower 
 surfaces of the leaves ; ({ their organization is such, as 
 to render these surfaces the most apt for the escape of 
 watery vapour ; but in some plants the upper surfaces 
 are said to be most active." 
 
 Fig. 17. 
 
 As evaporation thus proceeds from the leaves, they 
 incessantly demand a fresh supply of moisture from the 
 roots ; and if the soil be too dry, or water not abun- 
 dantly furnished to meet the demand, the plant will 
 inevitably sustain derangement of its functions. 
 
 Plants are frequently "blighted" during early Spring, 
 by dry winds, for when branches and leaves are first 
 put forth, they are extremely succulent, and part with 
 water so readily, that during a dry easterly wind this 
 loss by evaporation cannot be rapidly compensated for, 
 by the capillary attraction of the roots. 
 
 The drooping of a plant during a hot day, mainly de- 
 pends upon the extreme evaporation of water that has 
 been excited from the leaves, and the inadequacy of the 
 terminal fibres of the roots to collect more with suffi- 
 cient rapidity from the arid earth ; if then water be 
 artificially added to it, the plant revives, sometimes 
 with extraordinary quickness. 
 
80 SPRING. 
 
 Leaves have not only the power of transpiring the 
 vapour of water, but likewise of absorbing it under 
 certain conditions ; thus a plant, drooping beneath the 
 heat of Summer, will soon revive if placed in a damp 
 cellar ; the leaves absorb the damp, or vapour of water, 
 and through its genial influence the plant speedily 
 regains its wonted strength and beauty. 
 
 The leaves in their exercise of these functions of 
 evaporation and of absorption are of vital importance 
 to plants ; and upon stripping them away, the plants 
 suffer in health, or suddenly die. 
 
 The further consideration of the vital functions of 
 plants upon surrounding media, will be presented in 
 the next Chapter ; and in proportion as we extend these 
 researches, so shall we have cause to appreciate, with 
 admiration and gratitude, the power and goodness of 
 the Creator. " He causeth the grass to grow for the 
 cattle, and herb for the service of man : that he may 
 bring forth food out of the earth." 
 
81 
 
 CHAPTER II. 
 
 SUMMER. 
 
 SUMMER arrives, the sun attains its zenith of splen- 
 dour and heat, and under its influence the buds and 
 blossoms of Spring have transmuted into foliage and 
 flowers ; they adorn and diversify the scenery of the 
 earth; they captivate our senses, by their exquisite 
 structure, and their delicious fragrance ; they all exert 
 specific functions upon surrounding media, for main- 
 taining the harmony and order of the Creation ; let us 
 therefore resume our investigation regarding vegetable 
 growth. 
 
 The seed weighed only a few grains, when cast into 
 the earth in Spring; it has now produced a plant, 
 weighing many ounces, and the general increase of 
 bulk which has ensued throughout the vegetable king- 
 dom, cannot fail to elicit a remark from the most list- 
 less observer : let us endeavour, if possible, to account 
 for this growth upon chemical principles. 
 
82 SUMMER. 
 
 If the chemist undertake the ultimate analysis of a 
 vegetable, or the generality of vegetable products, for 
 example, Lignin or woody-fibre, Sugar, and Starch, 
 he finds them to yield nearly half their weight of 
 Oxygen and Hydrogen in the proportions requisite for 
 the constitution of Water ; and nearly half their weight 
 of Carbon ; this will be evident, upon reference to the 
 tabular statement at pages 21 and 22 of the Introduc- 
 tory Chapter. 
 
 Now the dry timber, or lignin, or woody fibre, of 
 an average sized oak, weighs about Sixty tons, and 
 therefore it contains about Thirty tons of Carbon. 
 
 Again, Europe alone, annually consumes about Five 
 hundred thousand tons of Sugar, containing about 
 Two hundred and fifty thousand tons of Carbon. 
 It therefore becomes a curious question, as to the 
 source of the enormous quantity of this solid element 
 Carbon ; for the chemist discovers, upon close exami- 
 nation of the earth in which vegetables grow and 
 flourish, that it loses no considerable weight, as the 
 following account of an experiment will prove. 
 
 Two hundred pounds of earth were dried in an oven, 
 and afterwards put into a large earthenware vessel ; the 
 earth was then moistened with rain-water, and a willow 
 tree, weighing five pounds, was planted therein. 
 
 During the space of five years, the earth was care- 
 fully watered with rain water, or pure water ; the willow 
 grew and flourished; and to prevent the earth from 
 being mixed with fresh earth, or dust blown upon it 
 by the winds, it was covered with a metal plate, per- 
 
SUMMER. 83 
 
 forated with a great number of small holes, suitable 
 for the free admission of air only. 
 
 After growing in the earth for five years, the willow 
 tree was removed, and found to weigh One hundred 
 and sixty-nine pounds, and about three ounces; the 
 leaves which fell from the tree every autumn were not 
 included in this weight. 
 
 The earth was then removed from the vessel, again 
 dried in the oven, and afterwards weighed ; it was disco- 
 vered to have lost only about two ounces of its original 
 weight ; thus, One hundred and sixty-four pounds of 
 lignin or woody fibre, bark, roots, &c., were certainly 
 produced, but from what source ? 
 
 Why, the chemist who made this remarkable expe- 
 riment, in very early days of scientific investigation, 
 reasonably concluded the tree to have derived the 
 increase of its structure from water alone, as no other 
 source was obvious ; and the opinion that water was 
 the sole aliment of vegetables, was entertained by 
 many of the greatest philosophers ; but as knowledge 
 regarding the powers and properties of matter through- 
 out the Creation, became gradually extended by expe- 
 riment, the Air was discovered to be the source of the 
 solid element at least, which enters into the structure 
 of the vegetable kingdom. 
 
 This statement may at first appear incredible, but 
 upon slight reflection, its truth is proved, because the 
 Air, or atmosphere, contains Carbonic acid, and it is a 
 Compound of 714 parts by weight of Oxygen, and 
 286 parts by weight of Carbon. 
 
84: SUMMER. 
 
 By means of several inorganic agents, having an 
 intense affinity for Oxygen, the chemist can decompose 
 Carbonic acid, and obtain its solid elementary Carbon ; 
 but he discovers, that the leaves of vegetables under 
 the influence of vitality, effect the decomposition, with 
 a degree of refinement and precision perfectly inimitable, 
 by his utmost skill ; in fact, that they withdraw, and 
 secrete into their structures, Carbon from Carbonic 
 acid, and liberate pure Oxygen. 
 
 Still the young student may ask, Although this 
 curious compound called Carbonic acid, does exist in 
 the air, is it in sufficient quantity for the supply of 
 Carbon to constitute half the weight of trees, shrubs, 
 plants, herbage, and the endless variety of vegetable 
 clothing that now adorns the earth, and likewise the 
 important proximate principles obtainable from these ? 
 
 The experienced chemist, in reply, states, that there 
 is abundance of Carbonic acid for this purpose, natu- 
 rally existing in the air, its weight being expressed by 
 the enormous sum of Five trillions, two hundred 
 and eighty- seven billions, three hundred and five 
 millions of TONS. 
 
 In other words, the number for expressing this 
 quantity of Carbonic acid, vastly exceeds that for ex- 
 pressing the number of SECONDS which have elapsed 
 since the Creation, namely, One hundred and eighty- 
 four billions, four hundred and fifty-four millions, 
 one hundred and fifty thousand, and four hundred ! 
 
 in addition to the enormous weight of Carbonic 
 acid, just stated, it must be remembered, that the 
 
SUMMER. 85 
 
 respiration of man and animals, the processes of com- 
 bustion, the phenomena of the germination of seeds, 
 the ripening and the decay of fruits, the putrefaction 
 of organic matters, are hourly sending forth incal- 
 culable quantities of the same compound into the 
 atmosphere. 
 
 In fact, the chemist can only determine with tolerable 
 accuracy the weight of the quantity of carbonic acid 
 exhaled by human beings ; and when this is done, it 
 strikes the mind with wonder and amazement, at the 
 stupendous scale upon which natural phenomena pro- 
 ceed, under the guidance of Omnipotence. 
 
 The volume or bulk of Carbonic acid produced by a 
 healthy adult individual in twenty-four hours, amounts 
 to about Fifteen thousand cubic inches, containing 
 about Two thousand six hundred grains of Carbon, or 
 about Six ounces, or to between Thirty-seven and 
 thirty-eight pounds, from every Hundred persons ; so 
 that, assuming thirty- seven pounds as the average, One 
 million of human beings would thus exhale into the 
 surrounding air, a compound containing no less than 
 Three hundred and seventy thousand pounds, or up- 
 wards of One hundred and sixty-five TONS of Carbon! 
 
 The total population of the globe is estimated at 
 Seven hundred and sixty millions; and accordingly, 
 on the above data, they would exhale Carbonic acid, 
 containing One hundred and twenty-five billions, and 
 four hundred millions of TONS of Carbon ! 
 
 " If there were not excellent, and adequate adjust- 
 ments, which compensate for, and virtually remove, 
 
86 SUMMER. 
 
 this poisonous effluvium of Carbonic acid, for poison- 
 ous it must be called in reference to its abstract effect 
 upon the animal system, as mentioned at page 13, 
 it would soon overwhelm us;" and we have indeed 
 occasion to extol the power and goodness of God, 
 when we discover the miraculous workings which He 
 has ordained, for the disposal and uses of the agent 
 we are considering. 
 
 In the first place, Carbonic acid is a vapour, and 
 escaping from the lungs in a heated state, by which it 
 gains wings, as it were, and is instantly wafted away ; 
 in the next place, it has what is termed " diffusive pro- 
 perty," meaning the power of uniformly blending with 
 the enormous volume of the atmosphere, so as to elude 
 detection in hurtful quantity ; and lastly, as most par- 
 ticularly applicable to the present inquiry, " this car- 
 bonic acid, which is poison to us, is the food of plants, 
 and of the whole vegetable world ; they absorb it into 
 their systems, and whilst they retain the Carbon, they 
 emit the Oxygen, and so feeding themselves, they 
 purify our Atmosphere." 
 
 " Here, then, the chemist reveals the mutual de- 
 pendence of the animal and vegetable kingdoms," and 
 presents for our admiration and gratitude a magnificent 
 example of the power and goodness of God, " Who 
 hath created nothing in vain ; and Whose tender mer- 
 cies are over all His works." 
 
 This miraculous process of the analysis, or decom- 
 position of Carbonic acid by the vegetable kingdom, 
 appears to be constantly active, though certainly in the 
 
SUMMER. 
 
 87 
 
 greatest degree, under the direct influence of solar- 
 light ; and it admits of most satisfactory illustration 
 by simple experiments. 
 
 Provide a quart wide-mouthed stoppered bottle, of 
 flint-glass; remove the stopper, and apply a slight 
 touch of pomade to its ground part, and likewise to 
 that of the neck of the bottle ; replace the stopper, 
 turn it gently round twice or thrice, to distribute the 
 pomade thinly and evenly between the ground sur- 
 faces, to make an air-tight joint; then again remove 
 the stopper, and pour in a few spoonfuls of water. 
 
 Kindle a wax-taper, attached to the end of a bent 
 wire, as in the experiment described in page 57 ; 
 introduce this into the bottle, and keep it there until 
 the flame ceases ; then withdraw the extinguished 
 taper, and quickly introduce a sprig or two of growing 
 mint ; lastly, insert the stopper, tie it over with string, 
 that it may not be forced out by expansion, and then 
 place the bottle in the sunshine : the arrangement is 
 here represented. 
 
 Fig. 18. 
 
 The combustion of the taper in the confined portion 
 of the air, has withdrawn the greater portion of its 
 
88 SUMMER. 
 
 oxygen, and formed carbonic acid, and liberated nitro- 
 gen ; the rays of the sun will excite the leaves of the 
 mint to decompose the Carbonic acid, to secrete its 
 Carbon and to liberate Oxygen, which blending with 
 the unaltered Nitrogen, will restore the contents of the 
 bottle to their original condition ; this fact is proved 
 by removing the stopper after a few days, and again 
 introducing the lighted taper ; it will then burn, as it 
 did at the outset of the experiment. 
 
 If a portion of air be vitiated by respiration, as in 
 the experiment described at page 60, upon intro- 
 ducing a few sprigs of mint into the glass, and then 
 exposing the arrangement to sunshine, a similar result 
 will be obtained. 
 
 Sprigs of mint, are directed to be used in these 
 experiments, as they were the simple means by which 
 this important discovery was originally made, as fol- 
 lows : A chemist found that air was not vitiated by 
 the growth of a sprig of mint, kept in it for some 
 months ; he therefore thought it possible that the pro- 
 cess of vegetation might restore the air injured by 
 burning candles ; accordingly he put a sprig of mint 
 into air in which a wax candle had burned out ; and 
 ten days afterwards he found that another candle 
 burned perfectly well in it; and then to verify the con- 
 clusion, he divided the injured air into two separate 
 portions, putting the plant into one of them, and 
 merely leaving the other; he always found that a 
 candle would burn in the former, but not in the 
 latter. 
 
SUMMER. 89 
 
 This restoration of the air, the chemist found to 
 depend upon the health and vegetating state of the 
 plant ; for though he kept many fresh leaves of 
 mint, in a small quantity of air, vitiated by combus- 
 tion, and changed them repeatedly for many days, 
 they did not ameliorate the state of the air. 
 
 This remarkable effect was not dependent upon 
 anything peculiar to mint, because several portions of 
 vitiated air were perfectly restored by sprigs of balm, 
 and then groundsel, spinach, and other plants were 
 used with like effect, to prove that it did not depend 
 upon aromatic principles. 
 
 The conclusions drawn by the chemist from these 
 experiments he thus stated ; These proofs of a resto- 
 ration of air by plants in a state of vegetation, though 
 in a confined and unnatural situation, cannot but 
 render it highly probable, that the injury which is 
 continually done to the atmosphere by the respiration 
 of such a number of animals, and the putrefaction of 
 such masses of both animal and vegetable matter, is, 
 in part at least, repaired by the vegetable creation ; and 
 notwithstanding the prodigious mass of air that is 
 corrupted daily by the above-mentioned causes, yet, 
 if we consider the immense profusion of vegetables 
 upon the face of the earth, growing in places suited 
 to their nature, and, consequently, at full liberty to 
 exert all their powers, both inhaling and exhaling, it 
 can hardly be thought but that it may be a sufficient 
 counterbalance to it, and that the remedy is adequate 
 to the evil." 
 
90 SUMMER. 
 
 The experiments now detailed, were made upwards 
 of seventy years since, when refined methods of ope- 
 rating were unknown, but they have received full cor- 
 roboration, from recent researches, conducted with 
 accurate apparatus. 
 
 Vegetation will not proceed, in a mixture of Oxygen 
 and Nitrogen, in whatever proportions they may be 
 blended together, because there is no compound of 
 Carbon present to yield solid matter, and when the 
 above elements are mingled in the proportions in 
 which analysis proves them to constitute the chief 
 constituents of the air, the addition of eight or ten per 
 cent, of carbonic acid forms a medium, fatal to plants, 
 when in the shade, but not when exposed to solar 
 light. 
 
 The proportion of carbonic acid naturally present 
 in the air, is certainly essential for the welfare of 
 animal life, although the chemist is unable to ascer- 
 tain the manner in which its influence is exerted. 
 
 Experiments similar in principle to the foregoing, 
 but conducted with the utmost refinement, and un- 
 wearied patience, lead to the conclusion that the 
 vegetable kingdom, though a silent, is an ever active 
 agent in sustaining the uniform balance of the con- 
 stituents of the atmosphere, and in contributing its 
 share to the maintenance of the harmony and order of 
 the works of God. 
 
 The phenomena that we have been considering are 
 eloquently set forth in the following words : 
 
 " From these discoveries we are assured that no 
 
SUMMER. 91 
 
 vegetable grows in vain ; but that, from the oak of 
 the forest to the grass of the field, every individual 
 plant is serviceable to mankind, if not always dis- 
 tinguished by some private virtue, yet making a part 
 of the whole which cleanses and purifies the atmo- 
 sphere. In this the fragrant rose and deadly night- 
 shade co-operate ; nor is the herbage nor the woods 
 that flourish in the most remote and unpeopled re- 
 gions unprofitable to us, nor we to them, considering 
 how constantly the winds convey to them our vitiated 
 air, for our relief and their nourishment. And if ever 
 these salutary gales rise to storms and hurricanes, let 
 us still trace and revere the ways of a beneficent 
 Being, who not fortuitously, but with design, not in 
 wrath, but in mercy, thus shakes the water and the 
 air together, to bury in the deep those putrid and 
 pestilential effluvise which the vegetables on the face 
 of the earth had been insufficient to consume." 
 
 The imponderable agency of solar light, though not 
 required in the early stages of germination, becomes, 
 at a more advanced season, of the utmost importance 
 to the welfare of the growing plant. 
 
 For example ; take a flourishing plant, with leaves 
 full verdant, supply it with a due share of heat, air, 
 and water, but shut it in darkness for a few days ; 
 then withdraw it from such imprisonment and remark 
 its appearance ; the leaves are no longer vigorous 
 and green, they are languid and pale; why this 
 change ? 
 
 Because the stimulus of light was denied them, and 
 
92 SUMMER. 
 
 the vessels of the plant could not elaborate those prin- 
 ciples, from the earth, water, and air, which are essen- 
 tial to its welfare j the physical structure of the leaves 
 has also suffered derangement, and they are incapable 
 of reflecting a proper amount of the green rays of 
 light. 
 
 Now expose the languid and pale plant to the 
 sunlight for a few hours, its functions will be excited 
 to proper action, it will regain health and verdancy. 
 
 The generality of plants have a predilection for solar 
 light, and if they be either accidentally or inten- 
 tionally placed in gloom, through which penetrates 
 but one ray, their leaves and branches turn and bend 
 towards the spot upon which its effulgence falls, as if 
 eager to exchange their pallor and languor for colour 
 and health. 
 
 Solar light excites strange chemical affinities in 
 growing plants, the reason of which is not understood ; 
 thus some leaves are acid in the morning, tasteless at 
 noon, and bitter at night ; some flowers are white or 
 blue, according to the intensity of the light; many 
 fruits are more acid in the morning than in the even- 
 ing ; some flowers expand their petals to meet the 
 sunshine, others close them against its power. 
 
 The influence of light in promoting the colour and 
 ripening of fruits is also remarkable ; select a peach 
 for example ; the portion of it which is fully exposed 
 to light, has a brilliant crimson hue, whilst that in 
 shadow, or merely covered by a leaf, is pale green 
 and yellow ; the taste of the one part is more luscious 
 
SUMMER. 93 
 
 than that of the other, because, light has there sti- 
 mulated the elaboration of the most sugar ; hence, 
 also, the sweetest fruits are generally found in southern 
 climates. 
 
 On the other hand, some plants, when grown in 
 the full glow of light, become unfit for food ; this is 
 the case with celery, it grows rank, green, and bitter ; 
 but by banking earth around the stem to exclude the 
 light, it becomes blanched, and pleasantly aromatic 
 to the taste, with the exception of the tuft just above 
 the ground, which remains dark green and hurtful. 
 
 During the growth of lettuces, they are tied round, 
 that the exterior leaves may exclude light from the 
 interior, or heart ; this becomes white, and eatable, 
 and does not contain a poisonous principle, which is 
 discoverable in the green leaves ; plants of endive and 
 secale are grown under earthen covers, and thus be- 
 come blanched, and fit for food. 
 
 The shoots of a potato produced in a dark cellar 
 are white, straggling, and differently formed from 
 those which the plant exhibits under its usual circum- 
 stances of growth ; the seeds of mustard and cress, 
 germinating in darkness, put forth a crop of a 
 dingy yellow colour, instead of a brilliant green; 
 a plot of green grass, perfectly excluded from 
 the light, by a board or stone, becomes of a pale 
 yellow colour, and is soon killed ; and even when par- 
 tially excluded from light, by the dense summer foliage 
 of surrounding trees and shrubs, it suffers a similar 
 change of colour, and ultimately dies away. 
 
94 SUMMER. 
 
 The term etoile, or " star-grown/' is applied to vege- 
 tables, when their colours have been thus modified or 
 prevented by the exclusion of light. 
 
 The effect of light upon the animal creation is no 
 less remarkable ; beasts and birds of tropical climates 
 have generally brighter skins^ and more vivid- coloured 
 plumage, than those of climates farther distant from 
 the equator, and a difference is even observable in the 
 same climates between such as bask in sunshine, and 
 such as prowl in darkness. 
 
 Solar light is absolutely essential to the health 
 of man, a strong contrast is presented between the 
 athletic stature and the ruddy cheeks of him who roves 
 on the mountain, and the stunted figure and the pallid 
 features of him who crawls in the mine ; in the one 
 case, by light, conjoined with air, food, and exercise, 
 chemical attractions are promoted between the elements 
 of the secretions, to form principles conducive to 
 health ; whilst in the other, the absence of such stimu- 
 lants in due proportions deranges the vital functions, 
 and disease results. 
 
 The vigorous mountaineer, if immured in a dark 
 dungeon, even with a proper supply of food, will soon 
 become more pallid, and yet more unhealthy, than the 
 miner, who, between the intervals of his subterranean 
 toil, may have the benefit of ascending for a few 
 hours to enjoy the light of day. 
 
 The poor inhabitants of gloomy and crowded dis- 
 tricjis are invariably found with blanched and haggard 
 features, partly on account of the absence of sunlight 
 
SUMMER, 95 
 
 and pure air ; but chiefly, with sorrow be it spoken, 
 on account of their inability, through poverty, to ob- 
 tain a moderate share of wholesome food. 
 
 If we turn from these natural examples of the in- 
 fluence of solar light, to those artificially presented 
 in the chemical laboratory, it is found to affect the 
 brilliancy of dyes, the deposition of crystals, the de- 
 composition of substances, to an extent unheeded in 
 early days of scientific inquiry, and hence the former 
 uncertainty of many operations that are now conducted 
 with precision. 
 
 Independently of stimulating the exquisite struc- 
 ture of the eye to the sense of vision, the importance 
 of light is universally manifest, and it displays the 
 wisdom and power of the Creator, who in the be- 
 ginning said : 
 
 (( Let there be light : and there was light." 
 " And God saw the light that it was good." 
 " Vegetables, in general, are extremely susceptible 
 of impurities in the air that surrounds them, and very 
 slight modifications in the proportions of its consti- 
 tuents are more or less prejudicial to their growth, 
 especially when they are prevented from the access of 
 light." 
 
 In the free and open air of the country, excepting 
 in a very few instances, no matters hurtful to vegeta- 
 tion can be discovered ; but the air of large cities and 
 towns is subject to many local contaminations, from 
 several causes, such as the combustion of coal, the 
 
96 SUMMER. 
 
 smoke of furnaces, the gases and vapours that are 
 produced, or elicited, during metallurgical operations 
 and other processes of chemical arts and manufac- 
 tures : " and instead of our heing surprised at the 
 injury which plants sustain in the atmosphere of a 
 city like London, we should rather wonder that they 
 are not more generally affected by it." 
 
 " There is no doubt, however, that plants, like ani- 
 mals, vary in regard to the delicacy of their constitu- 
 tions, and that some are infinitely more susceptible, 
 not only of changes in the temperature and humidity 
 of the air, than others, but are fatally influenced by 
 the presence of foreign matters which the more hardy 
 tribes resist." 
 
 In the immediate vicinity of chemical works, where 
 large quantities of poisonous exhalations are hourly 
 sent forth into the atmosphere, the vital functions of 
 vegetables are strangely deranged or altogether de- 
 stroyed ; the grass, for example, is stunted and brown, 
 the trees are leafless and withered, and we need not 
 wonder at delicate organic structures being thus af- 
 fected, when we find even the stone and iron-work 
 of adjacent buildings sustain decay and corrosion 
 from the action of the same agents. 
 
 An acid vapour called Hydrochloric acid, to denote 
 its consisting of Hydrogen and Chlorine, is probably 
 the most fatal to the life of plants; this is abundantly 
 produced in some chemical manufactories, and causes 
 sterility in the immediate neighbourhood ; a very 
 
SUMMER. 
 
 79 
 
 simple experiment will prove its baneful effects, as 
 follows. 
 
 Select a small geranium or myrtle, growing in a 
 pot, and tie the stem to an upright iron wire, made 
 perfectly bright ; set the pot to stand in a tea-saucer, 
 and place this in the middle of a large dinner- pi ate, 
 containing about half a fluid ounce of liquid hydro- 
 chloric acid, then cover this arrangement with a bell- 
 glass, the rim of which will rest upon that of the 
 plate. 
 
 Fig. 19. 
 
 Liquid hydrochloric acid contains the vapour of the 
 acid dissolved in water, and when exposed to air, it 
 will readily escape, thus in the act of pouring the 
 acid into the plate a dense white fume will be ob- 
 served ; and this will continue to rise and contaminate 
 the air contained in the bell-glass ; its poisonous effect 
 upon the plant is manifested in the course of a very 
 short time by the leaves drooping and shrivelling ; 
 
98 
 
 SUMMER. 
 
 and its corrosive effect upon the iron is shown by the 
 metal losing its polish and becoming tarnished. 
 
 Upon removing the plant from this noxious atmo- 
 sphere, all attempts at its restoration will be in vain ; 
 it is killed, and so would an animal be if subjected to 
 similar treatment. 
 
 The colours of flowers are curiously affected by 
 acid vapours, as may be proved in the following man- 
 ner : place a red rose in the centre of a bunch of 
 dark purple pansies, sufficiently large for the stems 
 to fit the neck of the glass employed at page (60) 
 when introduced in an inverted position, so that the 
 flowers may hang in the glass with their petals down- 
 wards. 
 
 Fig. 20. 
 
 Place a fragment of sulphur, about the size of a 
 hazel-nut, upon an egg-cup turned bottom upwards, 
 and standing in the middle of a dinner-plate ; kindle 
 the sulphur by touching it with a glowing coal, and 
 then place the glass containing the flowers over this 
 arrangement, as directed in the last experiment. 
 
 The sulphur will continue to burn for a considerable 
 
SUMMER. 99 
 
 time, and during this combustion, the oxygen of the 
 confined air combines with it, to produce Sulphurous 
 acid vapour, fumes of which will be observed to 
 ascend, and upon coming into contact with the 
 flowers, the red rose will bleach, and the purple pansies 
 will be more or less deprived of colour. 
 
 If a similar experiment be made with autumnal 
 dahlias of varied colours, they will present a still 
 more striking example of the destruction or modifica- 
 tion of their colours by the acid vapours. 
 
 In consequence of the existence of the above acid, 
 and other vapours in the atmosphere of large cities, 
 many plants cannot be grown exposed to its influence, 
 and therefore the following arrangement has been 
 successfully adopted for preventing them from sus- 
 taining injury in such localities. 
 
 Fig. 21. 
 
 The engraving represents a circular wooden box, 
 about fifteen inches in diameter, and six inches deep, 
 lined with sheet-lead, or sheet-zinc, so as to be water- 
 tight; a stratum, about two inches thick, of clean 
 
 F 2 
 
JOO SUMMER. 
 
 gravel stones, is placed upon the bottom of the lining ; 
 then a stratum, about two inches thick, of turfy loam 
 upon the gravel, and the remaining space filled with 
 well-moistened loam ; in this various small plants and 
 flower-roots are set in the usual manner ; and then 
 covered with a large bell-glass, that rests upon the 
 rim of the box. 
 
 The arrangement of the earthy materials in the box 
 closely resembles that of a naturally fertile soil, be- 
 cause the water filtrates by capillary attraction, and 
 remains among the gravel, until the wants of the 
 plants above, require it for their support ; the water 
 cannot escape by evaporation into the external air, 
 but it saturates that contained in the bell-glass, con- 
 denses as drops, and trickles down again to the soil, 
 again to rise as vapour, and again to condense, and 
 thus incessantly circulating, the plants are never sub- 
 jected to irregular watering, at the same time they are 
 preserved from cold, dust, soot, smoke, and noxious 
 vapours, and continue to flourish in perfection and 
 beauty. 
 
 The glass shade merely stands on the rim of the 
 box, and is not perfectly air-tight, so that during 
 changes of temperature the included air undergoes 
 expansions and contractions, by which it becomes re- 
 newed from the external atmosphere ; but experiments 
 have been made with glass shades fitting perfectly 
 close, and even then the plants flourished for a time. 
 
 A very curious fact was likewise discovered, namely, 
 that the portion of air thus effectually confined and 
 
SUMMER. 101 
 
 prevented from renewal, in the course of a short time 
 after exposure to sunlight, contained a considerably 
 greater proportion of oxygen than at first ; this some- 
 times amounted to an excess of one and a half, two 
 and a half, and even four per-cent., and apparently 
 depended upon the vital functions of the included 
 plants being excited to decompose the carbonic acid 
 exhaled from the soil. 
 
 When air is either partially or wholly confined, or 
 rendered stagnant, it forms an exceedingly bad con- 
 ducting medium of heat and cold, therefore the plants 
 growing in it will bear local variations in temperature 
 which would otherwise prove fatal to them. 
 
 The following is a good illustration of this fact : 
 In New Holland, in the month of February, when the 
 temperature was 94 degrees in the shade, a case of 
 plants was prepared for a voyage to this country ; in 
 rounding Cape Horn, two months subsequently, the 
 temperature was only 20 degrees; a month later, in 
 the harbour of Rio, it rose to 100 degrees ; and upon 
 crossing the line, it even rose to 120 degrees, and fell 
 to 40 degrees upon arrival in the British Channel, 
 in November, eight months after the plants were en- 
 closed; they were in most healthy condition, on ac- 
 count of the confined air having protected them from 
 experiencing these extreme changes of temperature 
 with suddenness or irregularity. 
 
 The apparatus upon the above principle may be 
 constructed of any size, and if very large, glazed 
 frames are employed for the covering ; costly plants 
 
102 SUMMER. 
 
 need not be collected, for common ivy, honeysuckle, 
 primroses, anemones, ferns, and mosses, by the luxu- 
 riance and beauty of their growth, will amply reward 
 the little trouble required for this arrangement. 
 
 During a hot and brilliant summer day, if we look 
 across a tract of dark- coloured land, we frequently 
 observe that all objects upon it, or surrounding it. 
 appear to have a dancing or tremulous motion ; this 
 singular phenomenon admits of the following explana- 
 tion. 
 
 The land becomes exceedingly hot, by absorbing 
 the solar rays, and imparts heat to the air incumbent 
 on its surface ; the air so heated becomes lighter and 
 ascends, whilst a colder and heavier portion descends, 
 so that the solar light, in traversing a medium of such 
 unequal density, does not pass through with steadi- 
 ness, but is distorted or broken, or refracted, and the 
 rays, coming to the eye of the observer with irregu- 
 larity, the objects consequently appear distorted. 
 
 This phenomenon may be artificially imitated by 
 heating a bar of iron red-hot, then holding it hori- 
 zontally in the air, at arm's length from the face, and 
 looking at surrounding objects, through the air above 
 the heated surface, they will all appear distorted, be- 
 cause the natural equilibrium of the air is disturbed, 
 convective currents take place, and the light is un- 
 equally refracted. 
 
 Again ; the same phenomenon is observed when 
 we look at objects beyond the top of a chimney, from 
 which the heated products of a clear burning fire are 
 
SUMMER. 103 
 
 rising without smoke ; and if the chimney belong to a 
 cottage built in a small hollow, with rocks or trees im- 
 mediately above it, the distortion of their positions is 
 very remarkable. 
 
 The examination of this refraction of light belongs 
 to the science of Optics, and not to that of Chemistry ; 
 but the reception of heat by the land, which is the 
 cause of the phenomenon, is a legitimate branch of the 
 latter science, and therefore demands our attention. 
 
 By the aid of the thermometer, the chemist has dis- 
 covered that some soils are more easily heated than 
 others, when equally exposed to the rays of the sun ; 
 and when they eventually acquire the same degree 
 of temperature, some cool faster than others. 
 
 Soils principally consisting of white, and strongly ad- 
 hesive clay, are not, generally speaking, easily heated, 
 and containing a very considerable amount of water, the 
 heat soon escapes, because it is immediately concerned 
 in producing evaporation ; chalky soils agree with 
 these, as regards heating with difficulty, but as they 
 do not contain a large quantity of water, they do not 
 lose much heat by evaporation. 
 
 The chemist has farther ascertained, that an exceed- 
 ingly dark, or black soil, containing a large quantity 
 of vegetable matter, becomes the most heated, both by 
 the direct rays of the sun, and by warm air, that 
 wafts over its surface from other localities ; and that 
 soils containing either much carbonaceous or ferru- 
 ginous matter, exposed, under equal circumstances, to 
 
104 SUMMER. 
 
 natural heat, acquire a much higher temperature than 
 pale-coloured soils. 
 
 " When soils are perfectly dry, those that most 
 readily become heated by the solar rays, likewise cool 
 most rapidly ;" but it has been determined by accurate 
 experiment, " that the darkest coloured dry soil, (that 
 which contains abundance of animal or vegetable mat- 
 ter, substances which most facilitate the diminution of 
 temperature,) when heated to the same degree, pro- 
 vided it be within the common limits of the effects of 
 solar heat, will cool more slowly than a wet pale soil 
 composed entirely of earthy matter. 
 
 A specimen of rich black mould, which presented 
 upon analysis nearly one-fourth its weight of vegetable 
 matter, was exposed for an hour to sunshine, during 
 which time its temperature increased from 65 to 88 de- 
 grees : whilst a chalk soil, under the same circum- 
 stances, had its temperature increased only to (39 de- 
 grees; however, upon removing the mould into the 
 shade, where the temperature was 62 degrees, in half 
 an hour it lost 1 5 degrees, whereas the chalk similarly 
 situated lost only 4 degrees. Portions of brown fertile 
 soil, and barren clay, were accurately dried, and then 
 artificially heated to 88 degrees ; they were afterwards 
 placed in a room at 57 degrees; in the course of half 
 an hour the brown soil lost 9 degrees, but the clay lost 
 only 6 degrees of heat. 
 
 Throughout all these experiments, the temperatures 
 were ascertained by a delicate thermometer, and the 
 
SUMMER. 105 
 
 soils were placed upon equal-sized shallow trays, made 
 of tin plate. 
 
 Upon considering the results of these experiments, 
 " nothing can be more evident than that the general 
 heat of the soil, particularly in Spring, must he of the 
 highest importance to the rising plant. And when 
 the leaves are fully developed, the ground is shaded ; 
 and any injurious influence which in Summer might 
 be expected from too great a heat, entirely prevented ; 
 so that the temperature of the surface, when bare, and 
 exposed to the rays of the sun, affords at least one 
 indication of the degrees of its fertility; and the 
 thermometer may be sometimes a useful instrument to 
 the purchaser or improver of lands." 
 
 The thermometer, although so frequently consulted 
 throughout the Four Seasons, merely denotes the 
 degree of heat that air, water, earth, and other media 
 are capable of imparting, and not the actual quantity 
 of heat therein contained ; several experiments can be 
 made concerning this fact, and they will lead to the 
 elucidation of some curious natural phenomena. 
 
 Introduce the bulb of a thermometer into one pint 
 of water, and then into four pints of water, drawn at 
 the same time, from the same spring ; the temperature 
 of both portions of water will be found alike, although 
 it is evident, upon the slightest reflection, that four 
 times as much heat must be present in the one case 
 than in the other ; this the thermometer does not 
 indicate. 
 
 To proceed further in this inquiry ; Provide two 
 
 F 5 
 
106 
 
 SUMMER. 
 
 glass bottles, of equal size and thickness, and resem- 
 bling each other in every respect as nearly as possible ; 
 pour into one of these a pound of Olive oil, and into 
 the other a pound of Water, of the same tempe- 
 rature, which, for the sake of illustration, may be 
 40 degrees. 
 
 Provide two similar mercurial thermometers, one of 
 which place in the water, the other in the olive oil, as 
 shown in the engraving. 
 
 Fig. 22. 
 
 Carry the bottles, thus prepared, into a room heated 
 to 70 degrees ; place them side by side upon a table ; 
 allow the air of the room to remain undisturbed by 
 draughts ; and in time the oil and the water will gain 
 its temperature ; this does not appear remarkable, it 
 is what might be expected ; if, however, the thermo- 
 meters be inspected from time to time during this pro- 
 ceeding, we find something to excite our attention ; 
 we find that the temperature of the room is acquired 
 by the Oil, in exactly half the time that it is acquired 
 by the Water. 
 
 Keverse the conditions of the experiment, by re- 
 
SUMMER. 107 
 
 moving the bottles to a cold room, at 40 degrees, for 
 example, and it will be found that the Oil will acquire 
 such temperature, or cool, in exactly half the time that 
 the Water will require to cool. 
 
 What inference is to be drawn from these experi- 
 ments ? Why, in the first place, that the oil requires 
 less heat than the water to raise it to the thermometric 
 temperature of 70 degrees; and in the second place, 
 that it parts with such heat more easily than the 
 water. 
 
 The chemist denotes these results by a technical 
 term that conveys a direct and concise meaning ; and 
 technical terms facilitate inquiry when they are under- 
 stood, but impede it if employed without explanation ; 
 the Oil required less heat than the Water, and parted 
 from it with the greatest readiness, therefore the che- 
 mist says, that the Capacity of Oil for heat is less 
 than that of Water, exactly as we should say that the 
 capacity of one mind for the reception and retention 
 of knowledge, was less than that of another. 
 
 In fact, the Oil acquired and lost heat with twice 
 the facility of the Water ; and if, for the sake of ex- 
 ample, the Capacity of the Oil be called Fifty, that of 
 the Water is One Hundred ; or yet more simply, 
 the Capacity of oil is Half that of water. 
 
 A very simple and decisive experiment will prove, 
 that equal weights of Oil and of Water, although at 
 the same thermometric temperature, do not contain 
 the same amount of heat ; and for the performance of 
 this, the following preparations are required. 
 
108 SUMMER. 
 
 Two cylindrical canisters, of tin-plate, each of these 
 being six inches in height, two inches and a half in 
 diameter, and having a cover with a knob in its centre, 
 and a perforation near that, about three quarters of an 
 inch in diameter ; these covers must fit very tight, or 
 have small catches, so that upon holding them by 
 their knobs, the canisters will not fall away, but will 
 require considerable force to effect a separation. 
 
 Two cylinders of tin-plate, in height equal to that 
 of the canisters, but in diameter about an eighth of 
 an inch greater, and open at each of their ends, so 
 that the canisters may easily slide through them. 
 
 Two earthenware flower-pots, alike in shape and 
 size; in depth equal to the height of the cylinders, but 
 in diameter at bottom about three quarters of an inch 
 greater than them ; two large hyacinth glasses, resem- 
 bling each other in shape and size as nearly as pos- 
 sible ; and lastly, two small mercurial thermometers, 
 similarly graduated, and with bulbs small enough to 
 enter the apertures in the covers of the canisters. 
 
 Suspend a pair of common scales from any conve- 
 nient and steady support, and in each of its pans place 
 a canister without its cover ; they will probably not 
 balance each other, therefore small shot and sand 
 must be added to the scale-pan containing the lightest 
 of the two, until an equilibrium is effected. 
 
 Pour olive oil into one canister, until it is filled 
 within half an inch of its rim ; then pour water into 
 the other, until it is sufficient to balance the oil ; thus 
 equal weights of the two liquids are obtained; the 
 
SUMMER. 109 
 
 canisters are then to be removed from the scale-pans, 
 and firmly closed with their respective covers, and the 
 thermometers introduced through their respective 
 apertures. 
 
 Place the canisters to stand upright in a saucepan, 
 sufficiently deep and narrow to prevent them falling 
 upon one side or the other ; then pour water into this, 
 until the canisters are rather more than half immersed ; 
 lastly, place the saucepan over a clear glowing fire, 
 that the water may boil. 
 
 This it will probably do, at or near 212 degrees; 
 but whatever temperature a thermometer may indicate, 
 as the boiling point, of course it will be imparted to 
 the canisters, their contents will become equally 
 heated, and the thermometers will be equally affected : 
 this is the condition to be fulfilled. 
 
 Whilst it is in progress, a few more arrangements 
 can be made : select two pieces of wood, each of these 
 being two inches in length, and sufficiently square to 
 remain firm, when thrust half way into each of the 
 small circular apertures of the flower-pots ; then place 
 each of these to stand upon a deep cup, or jar. 
 
 Fold about two pounds of clean ice in a flannel, and 
 beat it with a mallet, until the ice is broken into pieces 
 about the size of ordinary hail-stones, and, if neces- 
 sary, let it drain in a sieve. 
 
 Thrust a crumpled sheet of thin paper into one end 
 of each cylinder, to form a temporary stopper ; then 
 place each with this end uppermost, to stand in the 
 centre of each flower-pot ; and carefully fill the space 
 
110 SUMMER. 
 
 between the exterior of each cylinder and the interior 
 of each flower-pot, with the powdered ice ; this is most 
 easily done, by dropping in a small portion at a time 
 from a wooden spoon. 
 
 The ice is prevented from entering the interiors of 
 the cylinders by the paper stoppers ; these are now to 
 be removed, and each flower-pot lifted, to stand upon 
 the top of each hyacinth glass. 
 
 If the water boil in the saucepan, remove it from the 
 fire ; protect the hands with thick woollen gloves, and 
 lift out each heated canister at the same time, holding 
 one in the right hand and the other in the left ; then 
 drop each at the same moment into each cylinder, and 
 immediately lift up each cylinder completely away, that 
 the ice may simultaneously come in contact with each 
 canister. 
 
 In this arrangement, the canisters are supported one 
 inch above the apertures in the flower-pots, by the 
 plugs of wood, and these being square, they prevent 
 the ice from falling through, whilst they readily allow 
 the water resulting from its thawing to pass, and direct 
 it into the respective hyacinth glasses. 
 
 When removed from the boiling water in the sauce- 
 pan, the Water and the Oil were of the same thermo- 
 metric temperature; and if they contain the same 
 amount of heat, if they have the same Capacity for 
 heat, then, in cooling down to the same degree, they 
 should most certainly thaw equal quantities of ice, and 
 equal quantities of water should flow into the glasses. 
 
 But the Capacity of Water for heat is Double that 
 
SUMMER. Ill 
 
 of the Oil, as already stated, and as now strikingly 
 proved ; for upon the thermometers indicating the same 
 temperature in both liquids, it will be found that the 
 Water has thawed Twice as much ice as the Oil, and 
 accordingly the hyacinth glass that supports the 
 flower-pot holding the Water- canister, will receive 
 twice as much water as that which supports the flower- 
 pot holding the Oil -canister. 
 
 The annexed engraving shows this result, and may 
 aid the whole description that has been given of the 
 method of performing this remarkable experiment. 
 
 Fig. 23. 
 
 By a similar proceeding with other liquids con- 
 ducted with extreme precision, and accurate apparatus, 
 the chemist arrives at the conclusion that Water pos- 
 sesses the greatest capacity for heat, and the least sen- 
 sibility to heat of any substance with which he is 
 acquainted ; the extraordinary, the important conse- 
 quences of this fact throughout nature, will be appa- 
 rent at a future Season. 
 
112 SUMMER. 
 
 Solids, liquids, and aeriform substances, though of 
 the same thermometric temperature, have different 
 capacities for heat; and these are most singularly 
 affected by changing their physical state of density. 
 
 Thus, at common temperatures, if a given bulk of 
 Water weigh 1000 parts, the same bulk of Lead will 
 weigh 11,350 parts ; if this be violently compressed by 
 machinery, the individual particles of the metal are 
 thrust, or packed into less bulk, than they originally 
 occupied, the lead becomes more compact or dense ; 
 and now, if its weight be compared with that of an 
 equal bulk of water, it may be found perhaps 
 increased to 11,360 parts, or, in other words, the lead 
 has increased in density. 
 
 Lead, in common with other substances, contains a 
 certain amount of heat, or has a certain capacity for 
 heat ; and if a strip of the metal, placed on an anvil, 
 be suddenly and forcibly beaten with a hammer, its 
 density is increased, but its capacity for heat is dimi- 
 nished, the particles of the metal being compacted into 
 a smaller space, have not room for all the original 
 heat ; some, therefore, escapes, and warms the lead, to 
 a degree painful to the hands ; indeed it will imme- 
 diately kindle a small piece of phosphorus. 
 
 A dextrous blacksmith will place the point of a 
 soft iron horse- shoe nail upon an anvil, and strike it 
 only two violent blows with a hammer, and the point 
 will instantly become red-hot, and inflame a sulphur 
 match ; thus he generally obtained fire, before the 
 introduction of Lucifer matches. 
 
SUMMER. 113 
 
 In further elucidation of these curious matters, 
 which at first sight may appear to have no connexion 
 with the chemical phenomena of the Four Seasons ; 
 a piece of sponge may represent the metal ; the sponge 
 has a certain capacity for holding water, the same as 
 the metal has a certain capacity for holding heat ; 
 when the sponge is squeezed, its particles are brought 
 closer together, it has less capacity for holding water, 
 and accordingly some will run out ; so the metal, when 
 struck, has its particles more closely compacted, and 
 therefore less capacity for holding heat, and some must 
 escape. 
 
 Change of density in liquids is also attended with 
 change in their capacities for heat, and the chemist 
 can furnish experimental illustrations of this pheno- 
 menon ; provide an apparatus resembling the annexed 
 engraving. 
 
 Fig. 24. 
 
 It is a glass tube, twelve or fourteen inches long, 
 half an inch diameter, closed at one end, and enlarged 
 at the other into two bulbs, about three inches diameter, 
 connected by a neck the same size as the tube ; the 
 bulb farthest from it has a mouth, provided with 
 an accurately-fitted stopper, slightly touched on its 
 ground part with pomatum, for a reason already 
 described. 
 
 Remove the stopper, and holding the apparatus 
 
114 SUMMER. 
 
 upright by the bulb to which the stopper belongs, pour 
 in water until the tube and lower bulb are filled ; then 
 pour in alcohol, until the upper bulb and its mouth 
 are filled ; carefully insert the stopper, and wipe away 
 the little quantity of alcohol that will flow over. 
 
 In this arrangement, the water, being the heaviest 
 liquid, will remain below, and distinct from the lighter 
 alcohol ; the two liquids are prevented from mixing 
 rapidly, by the narrow neck between the bulbs, and 
 they are both of the same thermometric temperature. 
 
 Place the palm of the hand over the stopper, grasp 
 it and the bulb, and invert the apparatus, that the 
 tube may now stand perpendicularly ; and in this posi- 
 tion the heavy water will fall through the light spirit, 
 or vice versa; the tube will not appear full as it was 
 originally, and the bulbs will become sensibly warm. 
 
 Why is the tube deficient of its contents, for the 
 ground stopper has prevented any portion of liquid 
 from escaping, and why do the bulbs feel warm ? 
 
 Because the light alcohol, by combining with the 
 water, has its density increased, it occupies a smaller 
 space than at first, and like the solid lead, has its ca- 
 pacity for heat diminished ; a portion therefore escapes, 
 and affects the hand. 
 
 These experiments are preliminary to others upon 
 the atmosphere, which most concerns our present 
 inquiry ; and we shall find that changes in its density, 
 by condensation and rarefaction, produce changes in 
 its temperature, elevation in one case, depression in 
 the other. 
 
SUMMER. 1 1 f> 
 
 All aeriform substances admit of more sudden con- 
 densation and rarefaction than either solids or liquids, 
 and therefore experiments, upon such highly atte- 
 nuated, and often invisible forms of matter, are not 
 only extraordinary, but instructive. 
 
 The annexed sketch represents an apparatus for 
 proving that the condensation of air compels it to part 
 with heat. 
 
 Fig. 25. 
 
 It consists of a well-annealed, and perfectly cylin- 
 drical glass-tube, fourteen inches long, a quarter of an 
 inch thick, . and rather more than a quarter of an inch 
 internal diameter, containing air ; one end of this tube 
 is closed with resinous cement, which likewise secures 
 a brass cap, terminating in a ball, about one inch and 
 a half in diameter, whilst the other end of the tube is 
 open, but its circumference bound with a brass band, 
 about two inches broad, to prevent it from being acci- 
 dentally chipped. 
 
 The other part of the sketch represents a rod of 
 well-tempered steel, about one inch longer than the 
 glass-tube, but rather smaller than the bore, for about 
 twelve inches ; one end of this rod is firmly screwed 
 into a flat brass knob, about one inch in diameter, 
 whilst the other end is enlarged and closely packed 
 with oiled leather, to form a piston, which accurately 
 fits the tube ; the end of the piston has a small hook, 
 
116 SUMMER. 
 
 or it is slightly cupped, to hold a fragment of perfectly 
 dry German tinder, ahout the size of half a pea. 
 
 Insert the piston with the tinder into the glass tube, 
 place the brass knob upon a solid table, that the brass 
 ball may be uppermost ; grasp this with the right hand, 
 steady the tube with the left, then with one sudden 
 and powerful jerk, thrust the tube down as far as prac- 
 ticable ; a vivid flash of light will instantaneously ap- 
 pear; and upon quickly withdrawing the piston, the 
 tinder will be found burning as perfectly 'as though it 
 had been kindled at a common flame. 
 
 Why is this ? Because the sudden compression, 
 condensation, or increase of the density of the air in 
 the tube, diminished its capacity for heat, or in other 
 words, the sudden thrust, beat the heat from the air, 
 as the sudden blow, beat the heat from the lead in the 
 first experiment ; the heat is caught by the tinder with 
 sufficient intensity to cause its combustion. 
 
 If the experiment do not succeed, the piston must 
 be withdrawn, the tinder examined, and if oily, it 
 must be thrown away, and replaced by a fresh dry 
 piece ; the air in the tube must be renewed by intro- 
 ducing a long straw, applying the lips to its projecting 
 end, and gently drawing, not blowing, fresh air through 
 for three or four seconds ; then the experiment may 
 be tried again, and after a few trials, the proper method 
 of sudden condensation will be discovered, so that 
 success will be certain at any future time. 
 
 If so much heat be elicited from so small a portion 
 
SUMMER. 
 
 117 
 
 of air as that contained in the glass tube, what an incon- 
 ceivably enormous store must be emitted from the vast 
 atmosphere by natural changes in its density through- 
 out the Four Seasons. 
 
 Diminution of the density of the air, or, in other 
 words, its sudden rarefaction or expansion, produces 
 the opposite effect of cold ; an experiment in proof of 
 this fact may be performed by the aid of an air-pump, 
 and most persons are now familiar with the construc- 
 tion of this important apparatus. 
 
 Fig. 26. 
 
 For simplicity of description, the engraving repre- 
 sents a section of an air-pump, with merely a single 
 barrel ; at the bottom of tin's is a small chamber, con- 
 taining a hemispherical valve, and upon the top of the 
 piston is a similar valve ; these are both arranged to 
 open upwards ; the barrel is unclosed at its mouth, 
 and the two featherless darts indicate the air, that it 
 
J 18 SUMMER. 
 
 of course includes as far as the valve upon the 
 piston. 
 
 The horizontal tube is connected, on the one hand, 
 with the valve chamher, and on the other, with the 
 central aperture of a flat, smooth, and circular plate 
 of brass, technically called " the pump -plate ;" upon 
 this, and near its edge, is placed a delicate thermo- 
 meter, attached to a standard having a firm base ; 
 then the smooth ground rim of a large bell-glass, 
 technically called " a receiver," is slightly touched 
 with pomatum, and placed over this arrangement, to 
 rest evenly upon the pump-plate. 
 
 The air contained in the horizontal tube, and that 
 contained in the receiver, now coalesce and form one 
 volume of equal density and temperature ; the degree 
 of this must be noted. 
 
 Grasp the cross handle of the piston-rod, and thus 
 raise the piston to the mouth of the barrel, both the 
 density and the temperature of the air will be instantly 
 affected as follows. 
 
 The air contained in the barrel of the pump, as 
 indicated by the featherless darts, is lifted up and 
 expelled from its mouth as the piston is raised ; the 
 space in the barrel, between the bottom of the piston 
 and the valve of the chamber, would therefore be void 
 of air; but this valve being made to open upwards, 
 the air in the receiver, in consequence of its extraor- 
 dinary property of elasticity, or property of self-ad- 
 justment to the circumstances under which it is placed 
 immediately expands, passes in the direction of the 
 
SUMMER. 119 
 
 perpendicular and horizontal feathered darts, lifts the 
 valve and fills the barrel, as indicated by the two 
 double-barbed darbed darts in the annexed figure. 
 
 By thus expanding, rarefying, or 
 diminishing, in density, the heat ori- 
 ginally contained in the air is, of course, 
 more weakly diffused throughout such 
 enlarged volume; it is not so concen- 
 trated around the thermometer, and this 
 instrument will indicate a slight depres- 
 sion of temperature. 
 
 By thrusting down the piston, its 
 Fig. 27. valve will open and permit the air, indi- 
 cated by the two doublebarbed darts, to escape, and 
 fill the barrel as formerly indicated by the two feather- 
 less darts ; whilst the valve in the chamber firmly closes, 
 and prevents its return into the receiver. 
 
 By raising the piston a second time, a second call 
 is made upon the air in the receiver; it again ex- 
 pands, lifts the valve, and fills the barrel ; its density 
 is now less than before, its heat is more diffused over 
 an equal space, and the thermometer will again de- 
 note cold ; and by thus proceeding, repeated calls are 
 made upon the air in the receiver to supply the re- 
 peated losses of that from the barrel, until at length 
 it is exhausted, and the thermometer will fall several 
 degrees. 
 
 It will now be impossible to lift the receiver from 
 the plate, because it is firmly held on by the pressure 
 of the external atmosphere, which amounts to about 
 
120 SUMMER. 
 
 fifteen pounds upon each square inch of surface ; this 
 pressure manifests the endeavour of the external at- 
 mosphere to enter and to restore the equilibrium that 
 has been disturbed. 
 
 By removing the small screw that is placed under 
 the valve chamber, the external air will immediately 
 enter, the equilibrium will be restored, the density of 
 the air in the receiver will be the same as it was, and 
 the thermometer will slowly rise to its original de- 
 gree. 
 
 During the ascents and descents of the piston in 
 this experiment, another phenomenon will be observed 
 namely, the interior of the receiver appears as though 
 it were filled with mist ; this is really the case, and for 
 the following reason. 
 
 Air invariably contains the vapour of water, and 
 to raise such vapour, and to retain it, a certain amount 
 of heat is necessary. The air included by the receiver 
 contained the vapour of water, invisibly maintained 
 throughout its volume by heat, but upon being sud- 
 denly compelled to expand, the heat is as suddenly 
 diffused throughout such expanded volume, the va- 
 pour thus chilled or robbed of heat, is converted into 
 minute drops of water, and forms an artificial 
 mist. 
 
 This experiment accordingly furnishes the chemist 
 with an explanation of the formation of a natural 
 mist, the invisible heated watery vapour present in 
 the air becoming visible, minute drops of water, when 
 its temperature falls, either by sudden local rarefaction 
 
SUMMER. 121 
 
 of the air, or by coming in contact with cold surfaces 
 of the earth and waters. 
 
 To impress these curious and important matters 
 upon the mind of the young student of Nature, take 
 the following example ; suppose a cubic foot of air 
 contain a certain amount of heat, equally diffused 
 throughout its elementary and compound constituents, 
 and capable of affecting the thermometer to a given 
 degree ; if this volume of air be compressed to one-tenth 
 of a cubic foot, of course there will be ten times as much 
 heat concentrated into that tenth as there was, and the 
 thermometer would indicate a rise of temperature. 
 
 On the other hand, suppose the cubic foot of air 
 to be expanded to ten cubic feet, the heat would be so 
 diffused throughout such volume, that the thermo- 
 meter would indicate depression of temperature, or, in 
 other words, the air would feel cold. 
 
 These experiments of the laboratory furnish the 
 chemist with a key to the explanation of natural phe- 
 nomena ; an enormous store of heat is contained in 
 the atmosphere, but this medium is not of uniform 
 density from the earth to its own confines, those por- 
 tions that are directly incumbent upon the earth are 
 most dense, because they bear the weight of super- 
 incumbent portions; as, to use a very humble simile, 
 the hay at the lower part of a rick bears the weight 
 of that above, and is therefore more compact and 
 dense ; or it may be conveyed by the accompanying en- 
 graving, the gradual shading of which denotes the 
 
 
 
1 22 SUMMER. 
 
 gradual diminution in the density of the atmosphere 
 in proportion to its altitude. 
 
 Fig. 28. 
 
 The compression of the lower, by the upper portion 
 of the atmosphere, alters its capacity for heat, as it 
 was altered by the compression of the piston in the ex- 
 periment so recently described, and accordingly heat 
 escapes from the atmosphere in quantity suited to time 
 and season for the welfare of the animated creation. 
 
 If we ascend a lofty mountain, and thus approach 
 many hundred feet nearer to the sun than we were in 
 a valley, we might expect to find the temperature con- 
 siderably warmer ; but the contrary is the case, 
 when we left the valley, it was glowing under the heat 
 of the summer sun, we can see it still glowing, and 
 though we are nearer the sun on the mountain sum- 
 mit, the air is intensely cold ; what reason can be 
 assigned for this ? The chemist submits the follow- 
 ing : It has been already stated that the sun does 
 not heat the transparent air ; and at the elevation just 
 mentioned, it is greatly rarefied or comparatively free 
 from pressure ; the heaflbfthat it has derived from con- 
 tact with the warm earth is widely diffused, and in a 
 given volume of air on the mountain summit, there 
 
SUMMER. 123 
 
 is not the actual heat that exists in a similar volume 
 in the valley. 
 
 Again ; warm air in ascending from the valley 
 expands, and reinotion of heat, or, in other words, 
 cold is produced, and frequently to such an extent 
 that the watery vapour of the air condenses in clouds, 
 which, when surcharged, deliver rain, or it congeals as 
 snow, and clothes the mountain summit. 
 
 Air, in rising from the level of the sea, becomes 
 nearly one degree colder for the first two hundred feet 
 of ascent, and altogether about fifty degrees colder in 
 rising fifteen thousand feet, thus, water would freeze 
 at this elevation even near the equator, where the tem- 
 perature of the low plains is at least eighty degrees ; 
 this is the reason why the summits of lofty mountains 
 are covered with perpetual snow, and the height at 
 which it occurs is called the " snow line," or " line of 
 perpetual congelation." 
 
 The Andes present a magnificent illustration of 
 these phenomena attendant upon the varying capacity 
 of air for heat ; placed nearly under the equator, they 
 tower from parching sands ; about their middle height 
 the climate is temperate ; their summits are crowned 
 with unchanging snow, and these ranges of tempera- 
 ture are always distinct ; the hot winds from below, 
 if they ascend, become gradually cooled by expansion, 
 and if by any force of the blast the cold air be driven 
 downwards, it is condensed, and rendered warmer in 
 its fall. 
 
 How grand, how beautiful, how harmonious ; are 
 
 G 2 
 
124 SUMMER. 
 
 these adjustments and balancings of The Almighty 
 Hand, who " made the weight for the winds, and 
 weighed out the waters by measure !" how eminently 
 calculated they are to inspire us with emotions of 
 admiration and gratitude towards the Author of our 
 being ! 
 
 He has ordained the level earth to be chief dwell- 
 ing-place of mankind, and commanded the air directly 
 incumbent upon it to be of the just weight or density, 
 and to contain the due amount of heat which vitality 
 requires for the proper maintenance of its manifold 
 recondite functions; whilst on greater elevations, 
 which are but thinly peopled, or on mountain sum- 
 mits, which are but rarely visited, these wondrous 
 agents, air and heat, are rare and feeble, because they 
 are not required in abundance and power for the sup- 
 port of life ! 
 
 Exploring and investigating throughout the trea- 
 sures of the Creation, we become more and more 
 impressed that it is founded upon the most miraculous 
 scale of beneficence; that bounteous gifts are not in- 
 discriminately scattered where they would be useless 
 to organic beings, but are abundantly presented where 
 required for their manifold wants. 
 
 Great, inexpressibly great, is the delight in thus 
 b'-jmg permitted to follow the marvellous works of The 
 Creator, to trace the unbounded power and trans- 
 cendent goodness which are displayed alike in the 
 mightiest and the lowliest parts of the terrestrial 
 world. 
 
SUMMER. 125 
 
 " In the heavens hath He set a tabernacle for the 
 sun, which is as a bridegroom coming out of his 
 chamber, and rejoiceth as a strong man to run a race ; 
 his going forth is from the end of heaven, and his 
 circuit unto the ends of it, and there is nothing hid 
 from the heat thereof." 
 
 In the splendid poetical images of the above pas- 
 sage, are set forth the beauty, power, glory, and genial 
 effects of solar light and heat during an unclouded 
 day ; let us trace The Hand by which these are all 
 directed to work together for our good. 
 
 .During the brilliant zenith of summer, even in 
 torrid climes, although the heat of the sun impinges 
 upon the earth, with vast and continued power, its 
 degree is so miraculously adjusted and restrained by 
 Providence, that it never attains sufficient intensity 
 to cause the destruction of organic bodies by combus- 
 tion. Nay more, the chemist, after all his extensive 
 researches throughout the varied objects of the Crea- 
 tion, can find neither a single element nor a single 
 compound in a native state which is capable of in- 
 flaming by solar heat. 
 
 If the heat of the sun were not thus miraculously 
 adjusted, by the power and goodness of God, to the 
 earth and its productions ; if the earth were capable 
 of receiving and retaining all the heat that is constantly 
 sent forth from the sun ; if the air were capable of 
 being heated by conduction, the increase of the tem- 
 perature of the globe instead of being, as now, pro- 
 
126 SUMMER. 
 
 bably only one degree in one thousand years, would 
 be upwards of three hundred degrees in a single year ; 
 and, above all, if the whole atmosphere were to sus- 
 tain sudden condensation of its volume, the tem- 
 perature would instantly exceed that of red-hot iron. 
 
 Thus all living things would perish, the waters 
 would be dried up, and the earth, by the accumulated 
 heat, would ultimately " pass away." 
 
 Considering the elements and constituent parts of 
 which this terraqueous globe is composed, how slight 
 a disturbance in the present harmony and order of its 
 adjustments would cause its instantaneous destruction! 
 
 These are facts which become apparent during the 
 pursuit of science, and like all others so discovered 
 by man, they emanate from " The Fountain of All 
 Truth." 
 
 Pure science, therefore, corroborates the testimony 
 of Scripture, which recounts the first revolutions of 
 The Creation, and which equally foretells the last. 
 
 Scripture recounts, " That by the word of God, 
 the heavens were of old, and the earth, standing out 
 of the water, and in the water : 
 
 " Whereby the world that then was, being overflowed 
 with water, perished." 
 
 Scripture foretells, " But the heavens and the 
 earth, which are now, by the same word are kept in 
 store, reserved unto fire against the day of judgment 
 and perdition of ungodly men. 
 
 " In the which the heavens shall pass away with a 
 
SUMMER. 127 
 
 great noise, and the elements shall melt with fervent 
 heat, the earth also, and the works that are therein, 
 shall be burned up.'"' 
 
 " Wisdom is the breath of the power of God, and a 
 pure influence flowing from the glory of the Almighty," 
 and concerning His manifold, wondrous, and perfect 
 works, it is gradually permitted to man, through the 
 proper and chastened exercise of his noblest faculties, 
 during the short period of his sojourn here upon earth, 
 that he may be led to a sincere and grateful apprecia- 
 tion of the power and goodness of God; and this will 
 blend in perfect harmony with the humble and devout 
 confession of an implicit faith, and constant obedience, 
 as commanded in His Eevealed Will. 
 
 Unless a firm belief of another and far higher stage 
 of existence be deeply fixed in the mind of man, to 
 uphold him during his present state of progress and 
 trial, his science is vain, his philosophy is false. 
 
 As intricate derangements of the elements of nutri- 
 tious food, cause its transition into deadly compounds 
 by the refined experiments of the chemist, so do subtle 
 perversions of the elementary truths of pure science 
 yield moral poisons by the cunning of the sophist ; but 
 the first shrinks back with fear and dread, lest his dis- 
 covery should be wilfully or accidentally misapplied, 
 whilst the second stands forth with presumption and 
 arrogance, and prides himself upon the exhibition of his 
 morbid skill in turning good gifts to bad purposes. 
 
 It is accordingly the duty of the teacher of science, 
 to " put on the whole armour of God ; to stand girt 
 
128 SUMMER. 
 
 about with Truth ;'' and thus, not only instruct, but 
 guard the mind of the young disciple entrusted to his 
 care, by the Divine admonitions which irradiate the 
 invincible " shield of Faith, wherewith he shall be able 
 to quench all the fiery darts of the wicked." 
 
 " Prove all things ; hold fast that which is good." 
 
 " Let no man spoil you through philosophy." 
 
 " Be not carried about with divers and strange doc- 
 trines." 
 
 " Perverse disputings of men of corrupt minds, and 
 destitute of the truth, supposing that gain is godliness, 
 from such withdraw thyself." 
 
 " And this I say, lest any man should beguile you 
 with enticing words." 
 
 The foregoing remarks were called forth during an 
 early stage of our investigation of the beautiful pheno- 
 mena consequent upon the miraculous adjustment of 
 the temperature of the solar rays to the earth and 
 its productions ; let us now resume this interesting 
 subject. 
 
 During the most intense heat of Summer, the at- 
 mosphere is never anhydrous, or devoid of watery 
 vapour, though frequently so desiccated, that the 
 animal and vegetable creation droop beneath its parch- 
 ing influence ; then, mark the power and goodness of 
 the Almighty Hand, that is beneficently extended for 
 their relief. 
 
 The invisible watery vapour is commanded from its 
 wide aerial expanse in other localities, and gathered 
 into opaque clouds ; these float between the sun and 
 
SUMMER. 129 
 
 the earth, and act as veils in preventing the direct 
 transmission of solar heat. 
 
 The clouds thus permit the earth to lower in tem- 
 perature, and in so doing, they either gain sufficient 
 heat for their own dispersion as invisible vapour, again 
 to collect, and to perform the same genial .office in 
 other suffering districts, or they fully complete the 
 wondrous work of present relief, by relinquishing 
 their waters in showers. 
 
 These are eagerly imbibed by the arid earth, and its 
 productions, whose leaves and flowers immediately 
 send forth their delicious fragrance and perfume in 
 grateful return for such miraculous and salutary aid. 
 
 This phenomenon, upon close examination, appears 
 to depend upon the functions of plants being suddenly 
 excited by water, to the elaboration of aromatic prin- 
 ciples, although its exact theory is still unknown ; but 
 the peculiar odour which is emitted even by barren 
 earth, after a summer shower, is fully proved to depend 
 upon the combination of water with the aluminous and 
 ferruginous matters which are present in the soil. 
 
 Neither pure alumina, nor oxide of iron, emit odour 
 when separately watered, but it immediately becomes 
 perceptible when they are mingled together, and in 
 such condition they are naturally found in soils. 
 
 The water of the shower, having yielded refreshment 
 to the earth, is again destined to ascend as vapour into 
 the atmosphere, under the agency of heat derived from 
 the earth. 
 
 The delightful coolness of the earth, after a summer 
 
 G 5 
 
130 SUMMER. 
 
 shower, induces man and animals to venture forth 
 from the dense non-conducting foliage, "beneath which 
 they gladly sought refuge from the scorching sun ; and 
 this coolness depends upon the evaporation which en- 
 sues, and carries away the superfluous heat ; it is very 
 much facilitated if the air be in gentle motion at the 
 same time, and a considerable reduction of temperature 
 is thus effected. 
 
 It has been already stated, at page 47, that evapo- 
 ration is dependent upon the temperature of the air, 
 and the velocity of its movement over the surface of 
 water; the rate at which it ensues may be judged of 
 by reference to the annexed table, showing the number 
 of grains of water which evaporate per minute from a 
 circular surface six inches in diameter, during different 
 temperatures and states of the atmosphere. 
 
 Temperature. Calm. Breeze. High Wind. 
 
 Fahrenheit. Grains. Grains. Grains. 
 
 35 
 
 0.95 
 
 1.22 
 
 1.49 
 
 45 
 
 1.36 
 
 1.75 
 
 2,13 
 
 55 
 
 1.90 
 
 2.43 
 
 2.98 
 
 65 
 
 2.62 
 
 3.37 
 
 4.12 
 
 75 
 
 3.65 - 
 
 4.68 
 
 5.72 
 
 85 
 
 4.92 
 
 6.49 
 
 8.04 
 
 The amounts of the evaporation of water in this 
 table are rather above those of the natural phenome- 
 non, since they refer to air Artificially dried, and it is 
 never perfectly dry throughout the Four Seasons. 
 
SUMMER. 131 
 
 For the conversion of water into vapour, heat is in 
 all cases required, and the surfaces which impart it 
 become cold ; advantage is taken of this fact, for ob- 
 taining artificial reduction of temperature, even during 
 the summer of tropical climates ; thus in India, apart- 
 ments are often separated from the courts, by curtains 
 instead of walls, and these being continually sprinkled 
 with water, its rapid evaporation occasions a reduction 
 of temperature from ten to fifteen degrees below that 
 of the atmosphere ; this is also done in Sicily and 
 Malta during the prevalence of hot winds, and is faci- 
 litated by putting the air into motion by fans. 
 
 The door-ways of apartments or tents in India are 
 often fitted with light frames of bamboo, enclosing 
 the dried roots of a fragrant grass sparingly distributed 
 in vertical lines all over them ; on these water is occa- 
 sionally thrown, which, gently trickling down and eva- 
 porating, reduces the temperature of the air which 
 passes through the frame-work from the external 
 atmosphere to the interior of the apartments or tents. 
 
 Even in England, during the height of summer, we 
 very frequently sprinkle water upon the ground or pave- 
 ment in front of our houses, and experience relief by 
 the reduction of temperature that ensues. 
 
 The Egyptians availed themselves of this produc- 
 tion of cold by evaporation for the purpose of cooling- 
 water : pitchers were filled with the coldest water that 
 could be obtained, and servants were employed through- 
 out the night, to keep the outsides of these constantly 
 
132 SUMMER. 
 
 wetted with water ; as it evaporated, it abstracted heat 
 from the pitchers and their contents, and when the 
 utmost depression of temperature was gained, the 
 pitchers were hound round with bands of straw, which, 
 being a very imperfect conductor, prevented the water 
 from immediately gaining the heat of the surrounding 
 atmosphere. 
 
 The porous vessels of earthenware which are used 
 for wine-coolers act upon the same principle; being 
 dipped into water, they imbibe a large portion by ca- 
 pillary attraction ; this gradually evaporates upon their 
 removal into the air ; and as part of the heat requisite 
 for the production of vapour will be taken from a bottle 
 of wine placed in the vessel, a considerable diminution 
 of temperature is obtained. 
 
 To remain in wet clothes, is proverbially dangerous, 
 especially when exposed to a draught of air, for evapo- 
 ration immediately takes place with such rapidity, that 
 the animal heat of the body is lowered below its natural 
 standard, and rendered injurious to vitality ; if, how- 
 ever, exercise be taken, there is less danger, because 
 the action of the muscles incites the evolution of 
 animal heat, in proportion as it is demanded by 
 evaporation. 
 
 The natural temperature of the human body is be- 
 tween 96 and 98 degrees; but when we take very 
 active exercise, or when we are exposed to a great 
 degree of heat, there is a tendency to a rise of tem- 
 perature, which is conducive to health ; and the most 
 
SUMMER. 133 
 
 injurious effects would ensue, if it were not for perspi- 
 ration, which withdraws heat from the body, and cools 
 it down to the healthy standard ; if this perspiration 
 be checked in its escape, by air-tight, or water-proof 
 clothing, the most serious and occasionally fatal con- 
 sequences may ensue. 
 
 By merely placing the hand on a cold, dry plate 
 of glass, or in a bell-glass, the watery vapour which 
 escapes as perspiration will condense, and immediately 
 become perceptible, as it was found to do from the 
 surfaces of leaves in the experiment at page 79. 
 
 Upon applying a cambric handkerchief to the per- 
 spiring brow, great relief and coolness are immediately 
 experienced, because the fine fibres of the cambric 
 have an extremely strong capillary attraction for mois- 
 ture, and a good conducting power as regards heat; 
 thus by rapidly abstracting both moisture and heat 
 from the skin, the refreshing sensation of coldness is 
 produced. 
 
 The case is different with a cotton handkerchief, be- 
 cause its coarse fibres have neither strong capillary 
 attraction nor good conducting power ; and its appli- 
 cation to the skin produces a sensation of heat. 
 
 The cold produced by evaporation can be imme- 
 diately detected by several simple experiments; for 
 example, let the bulb of a thermometer be smoothly 
 covered with a piece of fine cambric ; and by keeping 
 this constantly wetted during the time that the ther- 
 mometer is suspended in a draught of air, or by blow- 
 ing upon it from a pair of bellows, the thermometric 
 
134 SUMMER- 
 
 liquid, be it either mercury or spirit, will descend, and 
 indicate cold. 
 
 Fig. 29. 
 
 The above engraving represents a glass tube, about 
 one quarter of an inch internal diameter, and ten inches 
 long, having at one extremity a bulb one inch and a 
 half diameter, and at the other, which is bent like a 
 shepherd's crook, another similar bulb, with a small 
 short neck; pure water is introduced through this, 
 until the plain bulb is about half filled ; and then, by 
 cautiously holding it over the flame of a spirit-lamp, 
 the water will soon boil ; its steam will expel all the 
 air originally contained in the instrument ; and when 
 this happens, the orifice of the neck is suddenly melted 
 by the flame of another lamp. 
 
 The instrument is thus finished, and by shaking it, 
 the water will fall through the tube from one bulb to 
 the other, not with a gurgling sound, but with a sharp 
 clicking noise, because there is no air to resist its rapid 
 fall, or to act as a spring against its immediate contact 
 with the glass ; or in other terms, the water is in vacuo, 
 as regards the absence of air, and only subject to the 
 pressure of its own vapour. 
 
 If the instrument be now held slightly inclined, as 
 shown in the engraving, with the hand grasping the 
 
SUMMER. 135 
 
 plain bulb, the expansion of tbe vapour will force 
 nearly all tbe water into the other ; the moment after 
 this has ensued, it will be succeeded by a rapid bub- 
 bling, and the hand will then experience a sensation 
 of cold, because heat is suddenly withdrawn from it to 
 enable the small portion of water adhering to the bulb 
 to assume the state of vapour. 
 
 The empty bulb of the instrument may be now placed 
 in a mixture of equal parts of finely-powdered ice and 
 salt, contained in a pint finger-glass, and covered with 
 a glass shade, for the performance of another expe- 
 riment, the rationale of which is as follows. 
 
 Fig. 30. 
 
 The mixture of ice and salt produces a very low 
 temperature, (for a reason to be explained hereafter,) 
 it immediately condenses* the vapour in the bulb into 
 water, and afterwards solidifies it into ice ; but the 
 water contained in the upper bulb immediately emits a 
 portion of vapour to supply the loss below ; this in 
 turn is condensed and solidified, fresh vapour is again 
 
136 SUMMER. 
 
 emitted from above, and so on, until the water by 
 these successive calls has lost so much heat that it can 
 no longer remain liquid, but is forced to become solid 
 or to freeze, although at so great a distance from the 
 source of cold. 
 
 Hence the instrument is known to the chemist by 
 the name of " Cryophorus, or Ice-bearer ;" and when 
 the phenomenon has ensued, the bell-glass should be 
 lifted off, and the instrument immediately removed, 
 (for a reason to be given hereafter,) that the ice may 
 slowly thaw; and it will present the same pheno- 
 menon, upon immersion in a freezing mixture at any 
 future time, even in the height of summer, if covered 
 with the bell-glass to prevent the direct access of warm 
 air to the upper bulb. 
 
 It illustrates the curious fact, that water may be 
 frozen by the cold produced during its own evapora- 
 tion; but the more particular consideration of the 
 wonderful natural law which presides over the tran- 
 sition of water into ice, will demand our attention, 
 during our examination of the chemical phenomena of 
 Winter. 
 
 From this experiment, and from the Table at page 
 1 30, it is evident that water is capable of evaporating 
 at very low temperatures ; and on account of the im- 
 mense quantity which is spread over the globe, many 
 extraordinary and important changes in the atmo- 
 sphere are doubtless caused by this phenomenon. 
 
 Accurate experiments appear to justify the conclu- 
 sion, that the annual evaporation of water averages 
 
SUMMER. 137 
 
 thirty inches, meaning, that the vapour, if re- con- 
 verted into water, would cover the surface from which 
 it ascended, to a depth of thirty inches ; then the sur- 
 face of all the waters of the globe being assumed at 
 One hundred and twenty-eight millions of geographical 
 miles, nearly Sixty thousand cubic miles of water 
 would be annually changed into vapour. 
 
 The presence of watery vapour in the air is indicated 
 by its condensation upon a cold surface; as for ex- 
 ample, on that of a decanter, containing water drawn 
 from a deep spring ; and yet more satisfactorily, by the 
 action of certain substances which have a powerful che- 
 mical attraction for water, Pearl-ash, or Carbonate of 
 potash, is one of these ; if an ounce of it be carefully 
 weighed, and left in the scale for a few hours, even 
 during the driest weather, it will be observed to pre- 
 ponderate, on account of attracting water, and in the 
 course of some days, although thoroughly protected 
 from rain, the solid pearl-ash will change into a thick 
 oily liquid ; this is only an extremely strong solution 
 of the substance in water attracted from the atmo- 
 sphere ; Pearl-ash is accordingly called a Hygrometric, 
 and Deliquescent compound. 
 
 It is popularly known, that clothes wetted with sea- 
 water will seldom become perfectly dry ; this is be- 
 cause sea-water contains chloride of sodium and chlo- 
 ride of magnesium, the former being hygrometric, and 
 the latter deliquescent, so that in place of the clothes 
 drying perfectly, they absorb water from the air, with 
 greater or less avidity according to the temperature. 
 
138 
 
 SUMMER. 
 
 In very hot and dry weather, a white crust appears 
 on clothes that have been wetted with sea-water ; this 
 is the saline matter, deposited by the evaporation, but 
 it will soon disappear or dissolve upon the approach of 
 damp weather. 
 
 Hence a sea- weed forms a natural hygroscope, the 
 alternate appearance and disappearance of its saline 
 matter, its crispness, and softness, indicating changes 
 in the dryness and dampness of the weather. 
 
 If a large sponge be dipped in sea-water, and then 
 squeezed almost dry, upon being accurately balanced 
 in a pair of scales suspended from a steady support, it 
 will be found to preponderate, or to ascend, according 
 to the relative dampness or dryness of the weather. 
 
 f 
 
 Fig. 31, 
 
 It by no means follows that hygrometric substances 
 should contain deliquescent salts, for many do not, yet 
 their physical, fibrous, or capillary structure is such as 
 to enable them to absorb water mechanically, and 
 thus become affected in form ; this is the case with the 
 beard of the wild oat, it is commonly placed in a small 
 
SUMMER. 139 
 
 circular frame at the top of the household u weather- 
 glass," and by twisting and untwisting, during atmo- 
 spherical changes in the local quantity of watery 
 vapour, carries round a piece of straw as an index to 
 " Dry " and " Moist." 
 
 " The weather-house" is a very ingenious and accu- 
 rate hygroscope, well known to most husbandmen; it 
 consists of a small model of a building, having two 
 archways, separated by an intervening pier, or column, 
 which does not quite touch the floor ; one end of a 
 piece of harp, or violin string, is secured to the roof; 
 and passing down the pier, carries at the other end a 
 cross-wire, an extremity of which proceeds into the 
 centre of each of the archways, supporting on the one 
 hand a male, and on the other a female figure. 
 
 The harp, or violin string, is then gently turned, 
 that the figures may be parallel with the archways ; 
 and as it is a hygrornetric substance like the beard of 
 the wild oat, it will twist or untwist according to the 
 dryness or dampness of the air, and cause in the former 
 case the cross wire to turn, that the female figure may 
 come beyond its arch, whilst in the latter case, the 
 male figure will advance. 
 
 This " weather-house," and another similar con- 
 trivance equally well known, as " the .monk and cowl," 
 to indicate changes in the humidity and dryness of the 
 air, should be kept in a hall or passage, where the 
 natural temperature is unaffected by the artificial heat 
 of a fire ; if they be placed in a warm dry room, the 
 female figure will be always beyond its arch, and the 
 
140 SUMMER. 
 
 cowl always thrown back from the head of the figure 
 of the monk. 
 
 Although the foregoing, and many other, sub- 
 stances are commonly called " Hygrometric," they are 
 more correctly denoted by the term " Hygroscopic," 
 since they do not measure, they only show, the pre- 
 sence of watery vapour in the air, the true " Hygro- 
 meter " will engage our attention when considering the 
 chemical phenomena of Autumn. 
 
 The atmosphere being continually in motion from 
 the disturbance of its equilibrium by heat, performs a 
 most important part in the economy of Nature, the 
 tropical regions are refreshed, and their temperature 
 prevented from attaining a degree insupportable to the 
 human frame by the cool currents that arrive from the 
 polar regions ; and, on the other hand, these have the 
 severity of their cold modified by the arrival of warmer 
 gales. 
 
 Tropical islands and coasts are subject to the re- 
 freshing agency of sea and land breezes ; these result 
 from the motion of the atmosphere in seeking to re- 
 store the disturbance of equilibrium that it has sus- 
 tained by heat. 
 
 The chemist offers the following explanation of these 
 phenomena : the solar beams are incapable of eleva- 
 ting the temperature of the transparent water of the 
 ocean, or the transparent volume of the atmosphere, 
 but they heat the surface of the opaque earth, as 
 already stated, with great facility ; therefore an island 
 exposed to the tropical sun, has its soil greatly 
 
SUMMER. 141 
 
 elevated in temperature, and communicating heat to 
 the air, a strong ascending current is produced, whilst 
 other portions of air from the cooler surface of the 
 ocean, immediately glide inland to restore the equili- 
 brium, and this constitutes the sea-breeze. 
 
 During the night, the surface of the island, no longer 
 subject to the direct influence of the sun, becomes 
 much cooler than the super-incumbent air, and causes 
 it to contract in volume, to become heavier, therefore 
 it sinks down, and spreads on all sides, producing the 
 land breeze; this is frequently loaded with unhealthy 
 exhalations from decomposing vegetation, whilst the 
 sea breeze is salubrious and fresh. 
 
 Although water is so essential to the growth of ve- 
 getables, if it remain in them after they are removed 
 from the soil, or deprived of vitality, it is the most 
 active agent in causing their decay and corruption ; 
 and in order to preserve them, they must be dried to a 
 very great extent, but always short of that which 
 would cause a new arrangement of their elements or 
 decomposition. 
 
 The atmosphere, on account of its strong attraction 
 for water, and its miraculous adjustment of tempera- 
 ture, is a grand natural agent for effecting this de- 
 siccation generally, and of the hay and corn harvest 
 particularly. 
 
 The long green grass, as it falls beneath the scythe 
 of the mower, is extremely succulent or abundant in 
 water, and if collected into heaps, it would soon pu- 
 trify and become worthless. 
 
142 SUMMER. 
 
 The careful and provident husbandman, knowing 
 this fact from experience, not only chooses the most 
 settled weather for the commencement of the hay- 
 harvest, but engages a troop of active work-people, to 
 follow directly in the track of the mowers, and to shake 
 and turn the green swathes about, that all may be 
 quickly and effectually dried in the warm air; and 
 when this is properly done, the hay may be stacked 
 without danger, it is no longer prone to rot, but re- 
 mains a fragrant nutritious store of provender against 
 the " time of need." 
 
 The very best sun-dried hay generally contains upon 
 the average from fourteen to fifteen per cent, of water ; 
 but this quantity does not interfere with its preser- 
 vation. 
 
 In this country, the weather is not always propi- 
 tious during the hay-harvest ; heavy showers are very 
 frequent, these saturate the newly-mown grass, and 
 dissolve out a considerable portion of nutritious mat- 
 ter, and load the air with so much vapour, that no 
 drying can ensue until the return of fine days. 
 
 It is an old saying, that " hills draw the wet," or 
 " hills draw the clouds," but they have no inherent or 
 particular attraction in this respect, they are only 
 surfaces of the earth, projecting above its common 
 level, and thus being nearest to the clouds, they 
 soonest receive the rain, and often in such abundance, 
 that it swells into floods, which descending on the re- 
 cently-mown low lands, suddenly inundate them, and 
 carry off the hay. 
 
SUMMER. 143 
 
 This disaster is not only confined to the immediate 
 districts in which it first occurred, hut is very fre- 
 quently extended to others many miles remote, as the 
 flood rolls onward, to seek its level; every possible 
 means are therefore taken by the husbandman, for 
 preventing the total loss of the valued crops, upon 
 which his hopes of future prosperity were anxiously 
 founded ; hurdles and tall stakes are thickly set upright 
 in the course of the flood, ropes and chains drawn 
 across it wherever practicable; all hands are active 
 with rakes, and these contrivances, aided by fences, 
 hedgerows, and plantations, are sometimes effectual in 
 arresting or collecting a portion of the hay ; it then 
 requires fair weather for drying, but is found to be 
 greatly damaged, not only by the solvent power of the 
 water, but by the sandy and earthy matters deposited 
 from the mud. 
 
 During the anxiety and hurry consequent upon un- 
 propitious weather, the husbandman is often compelled 
 to stack the hay whilst it is damp ; but he generally 
 takes the precaution of leaving one or more vacant 
 spaces, reaching from the bottom to the top of the 
 stack, to admit air, and to allow of moisture evapo- 
 rating from the hay ; and thus the chance of its heat- 
 ing or firing is greatly if not effectually prevented. 
 
 When a stack consisting of many tons of hay is 
 burned, either by natural causes, or by the accidental 
 contact of household fire, or by the wilful application 
 of the torch of an incendiary, the only remaining traces 
 of the originally valuable property, are a few pounds of 
 
144 SUMMER. 
 
 apparently worthless vitrified ashes, How are we to 
 account for this ? 
 
 On chemical principles: the chemist, during his 
 manifold researches, examines the elements and com- 
 pounds which are required for the growth of " the 
 grass of the field ; " and he proves, that unless the 
 earth Silica, and the alkali Potash, be duly present in 
 the soil, it will not yield a full crop ; he discovers that 
 the minute terminal fibres of the roots of every kind of 
 grass, during vitality, have the extraordinary power of 
 withdrawing these two inorganic compounds from the 
 soil, and of elaborating them as clothing for their own 
 organic structures ; and that when the vitality of the 
 grass is destroyed by the scythe of the mower, the 
 silica and the potash still remain in the dead and 
 withered hay. 
 
 The chemist prepares a mixture, containing certain 
 weights of Silica and Potash ; he heats this in a fierce 
 fire, he finds these two substances combine, and 
 melt into a liquid, which upon cooling becomes solid 
 Glass. 
 
 This curious experimental fact enables the chemist 
 to explain, that during the combustion of the hay- 
 stack, the elements, Oxygen, Hydrogen, and Carbon, 
 constituting its actual organic matter, escaped as flame 
 and smoke, whilst the compounds Silica and Potash, 
 being inorganic and fixed, were incited by the intense 
 heat to combine and produce Glass, similar to that 
 obtained in the operations of the laboratory. 
 
 The destruction of the valuable stack by fire, may at 
 
SUMMER. 
 
 145 
 
 first sight be regarded as a loss, for which no compen- 
 sation is made by the curious discovery concerning its 
 vitrified ashes ; but after the grief of the moment has 
 passed, and the husbandman can reason calmly, he 
 finds that the catastrophe teaches him an important 
 lesson. 
 
 In plain terms, it places before him, directly and 
 palpably, the inorganic substances which every kind 
 of grass requires for its clothing ; it leads him to rea- 
 son upon this, and to mingle silica and potash with 
 soils in which they are not naturally abundant ; and 
 thus, under Providence, the next consignment of seed 
 to the earth, may germinate and flourish in greater 
 perfection and luxuriance, and yield at the season of 
 maturity a greater and more valuable harvest than even 
 that of which a portion was destroyed. 
 
 The chemist proves the same facts to be even more 
 importantly applicable, as regards the growth of corn, 
 for he discovers the beautifully smooth and polished 
 clothing of its straw, consists of silica naturally with- 
 drawn from the soil, in company with potash, and 
 elaborated by the wonderful vital functions of the 
 plant. 
 
 This silica, by its flinty hardness, and its insolubility 
 in water, shields the soft organic tissue of the straw 
 from the depredations of insects, and protects it from 
 the solvent action of rain ; it likewise confers strength 
 and elasticity upon the tissue which alone would form 
 a weak and fragile stem, enables it to support the 
 weight of the full ear, permits it to bend beneath the 
 
 H 
 
146 SUMMER. 
 
 passing blast, and causes"! t to recover an erect position 
 in the tranquil air, that its maturity may be promoted 
 by the rays of the glowing sun. 
 
 Silica is nearly absent from the ear of corn, but 
 the earthy compounds already mentioned as phosphate 
 of lime and phosphate of magnesia, are invariably pre- 
 sent in considerable proportion ; and if these sub- 
 stances, together with potash, do not naturally occur 
 in soils intended for the growth of corn, they must be 
 artificially added by the agriculturist, or a full harvest 
 can never be obtained. 
 
 " Sandy and calcareous soils are generally deficient 
 in potash, and are unfruitful in grasses and corn ; but 
 turnips, and other plants which require but little of 
 such compound, will thrive exceedingly well ; on the 
 other hand, clayey, or argillaceous soils, are very abun- 
 dant in potash, and accordingly are fruitful in grasses 
 and corn." 
 
 The agriculturist is aware that successive crops of 
 wheat cannot be advantageously grown upon the same 
 soil ; the chemist points out the reason of this, namely, 
 that the potash of the soil becomes exhausted ; and he 
 proves that wheat crops, of all others, are the most ex- 
 hausting ; for example, one hundred pounds of wheat- 
 straw, when burned, will generally yield fifteen pounds 
 of ash or cinder; whilst the same weight of barley 
 straw will yield but nine pounds, and of oat straw only 
 four pounds. The growth of beans and of beet de- 
 mands none of the earthy compounds which are so 
 imperatively requisite for that of wheat and other grain. 
 
SUMMEK. 147 
 
 The insolubility and permanence of the silicious 
 clothing of straw, point it out to the husbandman as 
 the best natural material for covering hay- stacks and 
 corn-ricks in the form of thatch. 
 
 Long unbroken straw is selected for this purpose, as 
 it is water-proof, and allows the rain to trickle freely 
 from its surface ; but broken straw will not answer, 
 because its silicious clothing is full of fissures or ca- 
 pillary channels, which would receive and retain a con- 
 siderable portion of the rains of Autumn, or the snow 
 waters of early Spring, and soon become rotten and 
 useless as a protection against further inclemency of 
 weather. 
 
 A thick layer of good thatch is a covering not only 
 water-proof, but of exceedingly imperfect conducting 
 power, equally preventing the sudden penetration of 
 heat and cold ; thus in Summer, ice may be prevented 
 from thawing by overing it thickly with straw ; and 
 in Winter, fruits may be preserved from frost by 
 similar means. 
 
 The " bungalows " of India are built with baked or 
 unbaked bricks, and they are generally thickly thatched, 
 to prevent the transmission of heat ; so are tents like- 
 wise protected from sun and rain by a straw thatch 
 laid on frames of bamboo. 
 
 The limit prescribed for this general investigation 
 concerning the phenomena of the Four Seasons, which 
 admit of elucidation through the science of Chemistry, 
 now demands the conclusion of this Chapter relating 
 to a few only, of those which are presented during the 
 
 H 2 
 
148 SUMMER. 
 
 beautiful season of Summer, and throughout it, whilst 
 humbly considering, and endeavouring to explain the 
 manifold and " wondrous works " by which we are 
 surrounded, we have been inevitably led to extol the 
 power and goodness of " The Great Workmaster." 
 
 " He that created the heavens and stretched them 
 out; He that spread forth the earth, and that which 
 cometh out of it ; He that giveth breath unto the 
 people upon it, and spirit to them that walk therein." 
 
 Numberless phenomena remain veiled in impene- 
 trable mystery to all men, and regarding such the lowly- 
 minded and true " lovers of wisdom" make a full con- 
 fession of their ignorance ; but, unhappily, examples 
 are numerous, of men proudly assuming the title of 
 " philosophers," and so greatly estimating their own 
 abilities, as to be ready, not only to explain everything, 
 but dogmatically to state what MUST be the physical 
 cause of everything, in the vast and perfect laboratory 
 of Nature, as if they were explaining the machinery, 
 and demonstrating the motive power, of a work made 
 with hands. 
 
 These are not " philosophers ; " nor have they the 
 remotest claim to the title, as they are deficient in its 
 leading attribute of humility, for " Hardly do we guess 
 aright at things that are upon earth ; and with labour 
 do we find the things that are before us." 
 
CHAPTER III. 
 
 AUTUMN. 
 
 *' HE changeth the times and the seasons ;" He now 
 ordains the reign of Autumn to commence, accompa- 
 nied by the glorious sun, still shedding brilliancy and 
 heat, for the advancement of the productions of the 
 earth to the mature and bounteous harvest, the hope 
 of which has so long cheered the husbandman through- 
 out his anxious toils. 
 
 Many extraordinary and beneficial natural pheno- 
 mena, several of which may be elucidated through the 
 science of chemistry, are frequently presented in an 
 equal degree during the end of Summer and the be- 
 ginning of Autumn; these will accordingly now demand 
 our attention ; and in the first place, let us direct it in 
 continuance of the investigation concerning the mira- 
 
150 
 
 AUTUMN. 
 
 culous provision that is made to prevent the earth from 
 the accumulation of a withering and destructive inten- 
 sity of heat. 
 
 We have already found that the earth is capable of 
 absorbing heat, though incapable of conducting it to 
 any considerable extent ; we shall now discover that 
 the earth has likewise the power of parting with an 
 excess of heat by radiation towards the unclouded 
 Summer and Autumnal skies. 
 
 The meaning of the term " radiation " may be thus 
 explained : suppose the circle in the centre of the 
 annexed engraving to represent a heated body, the 
 star-like lines emanating from it may denote that heat 
 is escaping, or radiating from it in all directions, quite 
 independent of conduction or of convection. 
 
 Fig. 32. 
 
 A few simple experiments of the chemical laboratory 
 will serve as an introduction to the grand natural phe- 
 nomenon of radiation. 
 
 A plate of metal, either dull or bright, is an excel- 
 
ACJTUMN. 151 
 
 lent conductor of heat ; if, for example, a lighted coal 
 be placed upon any part of its surface, this will soon 
 become equally warm throughout its whole extent. 
 
 At the distance of four or five feet in front of a clear 
 glowing fire, hold a large bright tin-plate, in any posi- 
 tion, and it will not become warm ; turn it about, pre- 
 sent its surface at different angles to the fire, and at 
 last a certain angle will be found, at which, although 
 the plate remain cold, heat will instantly dart from 
 its surface, and may be sensibly felt upon the face or 
 hands. 
 
 Thus, in chemical language, heat is said to radiate 
 from the glowing fire, through the intervening non- 
 conducting air, to impinge upon the metal plate, and 
 although it is an excellent conductor, of mere heat of 
 contact, as that of the lighted coal in the first experi- 
 ment it is not a conductor of this radiant heat which 
 reaches it from the distant fire, it is not even a re- 
 tainer of this radiant heat, but it is an admirable 
 reflector of this imponderable element, and accordingly 
 it instantly darts upon surrounding objects, whilst 
 the metal plate or reflecting surface remains perfectly 
 cold. 
 
 Place the bright tin-plate flat upon a table, fold 
 half a sheet of fine emery-paper smoothly around a 
 small book, or a flat piece of cork, and with this rub 
 the surface of the tin-plate all over, in the direction of 
 its length ; then do the same in that of its breadth ; 
 and thus effectually destroy all brightness or polish, 
 
 Now hold the tin-plate in front of the fire, as at first ; 
 
152 AUTUMN. 
 
 it will soon become hot, and it will reflect but little 
 heat; thus, by mere mechanical alteration of its surface, 
 the metal is instantly rendered a retainer of radiant 
 heat, and depnved of its power of reflecting such 
 agent. 
 
 Select another tin-plate, brush one of its bright sur- 
 faces over with weak glue ; then sift fine sand over 
 this, and allow it to dry ; thus the bright polish is 
 covered, and not destroyed; and upon holding this 
 sanded side in front of the fire, as already directed, 
 the tin-plate will become hot, but no heat will be 
 reflected. 
 
 Similar will be the result, if the tin-plate be painted 
 with a mixture of weak glue and lamp-black, whiting, 
 yellow ochre, Venetian red, Brunswick green, or any 
 pigment that may be chosen. 
 
 In like manner, if a large flat surface of paving- 
 stone, or an unglazed earthen paving-tile, be held in 
 front of the fire, no heat will be reflected from them ; 
 but they will absorb heat, and soon become warm. 
 
 The following striking experiments will afford far- 
 ther illustrations concerning the extraordinary manner 
 in which the mere alteration of the lustre of a metallic 
 surface affects its habitudes with radiant heat. 
 
 Select a large tin-plate, equally bright and polished 
 on both sides, and with a strong pair of scissors, or 
 small shears, cut it across to form two pieces similar 
 in size, leave one of these without any farther prepara- 
 tion, but blacken one side of the other with lamp- 
 black, mixed with thin glue, and allow it to dry. 
 
AUTUMN. 
 
 J53 
 
 Provide a strip of wood, one foot long, one inch thick, 
 and four inches wide, and with a saw, make two cuts 
 or grooves across this, each of these being an inch 
 from each of the ends of the wood, and each suffi- 
 ciently deep to hold a tin-plate firm and upright when 
 inserted on its shortest edge. 
 
 Place each plate in its groove, the black surface of 
 the one being opposed to the bright surface of the 
 other ; attach a marble to the centre of the exterior 
 surface of each with a lump of pomatum, then hold a 
 red-hot heater of an " Italian iron" exactly between 
 the plates, as shown in the annexed engraving. 
 
 Fig. 33. 
 
 The plates are thus exposed to the same degree of 
 heat that is radiating from the red-hot iron ; but they 
 have different habitudes with it, the bright surface will 
 reflect nearly all, and will not become sufficiently hot 
 to melt the pomatum, and so cause the marble to 
 drop ; whilst the black surface will absorb nearly all, 
 
 H 5 
 
154 AUTUMN. 
 
 and will soon become sufficiently hot for such pur- 
 pose. 
 
 By experimenting with great accuracy, the chemist 
 has discovered, that as the unmetallic surface will absorb 
 heat with the most facility, so will it part with such 
 heat, or cool, or radiate such heat with the most faci- 
 lity ; the following experiment will prove this fact 
 sufficiently well for our present purpose. 
 
 Fig. 34. 
 
 Take the tin canisters that were used in the expe- 
 riment at page 111, cleanse the adhering oil from the 
 one by washing it thoroughly with a strong solution 
 of pearlash, then rinse it with water, and polish its 
 exterior as bright as possible ; paint the exterior of 
 the other with the black mixture already described, 
 and allow it to dry. 
 
 Pour an equal quantity of cold water into each, 
 place on their respective covers, and insert the ther- 
 mometers, that the bulbs may dip beneath the water, 
 the bulb of the oily thermometer having been cleansed 
 as above directed. 
 
 Lay a soft brick flat upon the table, and in its 
 
AUTUMN. 155 
 
 centre, with a knife or chisel make a hole about three- 
 quarters of an inch deep, and sufficiently large to 
 admit the end of the iron-heater of a tea-urn ; make 
 the heater red-hot, and then drop it into the hole, and 
 place a canister to stand at each end of the brick. 
 
 They will be equally distant from the radiant heat 
 of the iron indeed , more accurately so than the tin- 
 plates were in the last experiment but still the black 
 surface will heat the water the fastest, as an inspection 
 of the thermometers will prove. 
 
 Let it heat to 100 degrees; using a fresh heater, 
 if necessary ; then remove the canister from the 
 brick, and place it upon the table ; remove the bright 
 canister also, throw away its almost cold water, and 
 fill it with water heated to the same degree as that 
 contained in the black canister, and place it likewise 
 upon the table; watch the thermometers, and they 
 will indicate that the water in the black canister is 
 cooling, or radiating heat, more rapidly than that 
 in the bright canister, which will remain sensibly warm 
 when the other is cold. 
 
 These results are directly contrary to those which 
 might be anticipated to ensue, we might think that by 
 coating a metal-plate with black paint, a bad con- 
 ductor, that it would prevent the heat from coming 
 into contact with the metal beneath, and so keep it 
 cold ; and, on the other hand, the bad conductor 
 would keep in the heat of the water ; but the chemist 
 proves that unmetallic, or earthy substances, though 
 
156 AUTUMN. 
 
 extremely bad conductors, are most excellent absorbers 
 and radiators of heat. 
 
 Another curious and instructive experiment con- 
 cerning this power of surfaces in radiating heat may 
 be made by covering one of the sides of a cubical tin- 
 plate canister with lamp-black, another with thin jelly, 
 a third with writing-paper, and leaving the fourth 
 bright and polished : then upon filling the canister 
 with boiling water, and approaching the sides in suc- 
 cession with the hands, or a thermometer with a 
 blackened bulb, the different radiating powers of the 
 various coatings will be immediately detected. 
 
 The greatest heat will be found radiating from the 
 lamp-black, the least from the polished surface, and 
 if for the sake of illustration, the heat from the lamp- 
 black be supposed equal to one hundred, that from the 
 writing-paper is ninety-eight, from the jelly eighty, 
 and from the polished surface only twelve. 
 
 " During all these experiments, it will be remarked 
 how singularly these effects of radiation are opposed 
 to the conducting powers of the respective surfaces, 
 if we touch the clean part of the canister it burns us ; 
 but we may place the finger with impunity upon the 
 lamp-black, the paper, or the jelly, which, though 
 good radiators, are bad conductors of heat." 
 
 Kadiation not only proceeds from the immediate 
 particles which form the surface of a body, but like- 
 wise from those at some distance beneath, and this 
 curious fact may be easily determined ; for example. 
 
AUTUMN. 157 
 
 take a cylindrical tin canister, and cover one half of 
 its surface with a coating of extremely thin jelly, and 
 the other half with four or five coatings of the same, 
 letting one coat dry before another is applied ; when 
 all are dry, fill the canister with boiling water. 
 
 In this arrangement, although the nature of the 
 two surfaces is precisely the same as regards material 
 and smoothness, they will radiate very differently ; the 
 hand held at some little distance from the thin coat- 
 ing will not feel so hot as when held at the same 
 distance from the thick coating, and if a thermometer, 
 with a blackened bulb, be similarly held, it will indicate 
 a small elevation of temperature in the one case, but 
 great in the other. 
 
 " In this experiment the increase of radiating power 
 must be attributed to the increased quantity of radiat- 
 ing material, and it is discovered to continue until the 
 coating amounts to the thickness of about one hun- 
 dredth part of an inch ; after which no further in- 
 crease takes place ; it is inferred, therefore, that the 
 particles constituting the jelly have the power of 
 radiating, from a thickness below the actual surface, 
 equal to the above amount." 
 
 As regards terrestrial radiant heat, meaning by the 
 term that of a fire, or any other artificial source, the 
 chemist discovers that surfaces, if similar in me- 
 chanical texture, may differ in colour, without having 
 their receptive or radiating power either increased or 
 diminished ; whilst, on the other hand, with solar radi- 
 ant heat, he discovers that the colours of such surfaces 
 
158 AUTUMN. 
 
 do certainly affect both these powers most strangely ; 
 for dark-coloured, or black, surfaces absorb and ra- 
 diate more rapidly than such as are light- coloured, or 
 white. 
 
 Paint the bulb of one thermometer with the black 
 mixture already mentioned, and the bulb of another, 
 similar in size and graduation, with a mixture of 
 whitening and glue, of equal thickness with the black ; 
 let these bulbs dry, and then expose the thermometers 
 simultaneously to bright sunshine, it will be imme- 
 diately found that the black bulb absorbs heat quicker 
 than the white bulb, by the greater rise of the mercury 
 in its tube ; and upon removing the two thermometers 
 into the shade, probably the black bulb will indicate that 
 it radiates heat quicker than the white bulb, by the 
 more rapid descent of the mercury in its tube. 
 
 Again, nine pieces of equally fine kerseymere cloth, 
 seven of them having the prismatic colours, and of 
 the others, one black, and the other white, upon expo- 
 sure to sunshine for the same time, will heat very 
 differently, and of the colours, probably in the follow- 
 ing order, the first being the hottest ; violet, indigo, 
 blue, green, red, orange, and yellow; but the black 
 cloth will surpass even the violet in temperature, 
 whilst the white cloth will not even attain that of the 
 yellow, as the application of the bulb of a thermometer 
 will immediately prove. 
 
 From an experiment of this kind, we discover that 
 " the warmth or coolness of clothing depends as well 
 on its colour as its quality ; a ' white dress, or one 
 
AUTUMN. 159 
 
 of a light colour, will always be cooler than one of 
 the same quality, hlaok, or of a dark colour,, and espe- 
 cially so in clear weather, where there is much sun- 
 shine; white, or presence of colour, and very light 
 hues, reflect heat copiously ; hut black, or absence of 
 colour, and very dark hues, reflect little." 
 
 " Experience has long supplied the place of science 
 in directing the choice of clothing ; the use of light 
 colours always prevails in summer, and that of dark 
 colours in winter/' 
 
 Eeasoning upon this property of black and dark 
 surfaces in absorbing heat, a natural conclusion is 
 drawn that the black skin or " rete mucosum" of the 
 Ethiopian, would cause him to undergo severe suffer- 
 ing under the intensity of the tropical solar rays ; but 
 our experiments, be it remembered, have been made 
 either upon inorganic matters, or matters deprived of 
 vitality, and they do not hold good with bodies under 
 the influence of the recondite agencies of life, an extra- 
 ordinary fact or anomaly, so called by the finite wis- 
 dom of man, is then presented. 
 
 The Creator, in His power and goodness, has mer- 
 cifully ordained, that the skin of the Ethiopian shall 
 absorb heat powerfully, but, at the same time, that it 
 shall not sustain the slightest injury. 
 
 This extraordinary fact was originally investigated 
 by a physiologist in a series of extremely simple 
 yet decisive experiments, of which the following are 
 selected. 
 
160 AUTUMN. 
 
 During an intensely hot day, he exposed the back 
 of each hand to the sunshine for ten minutes, one 
 hand being bare, and having a thermometer attached 
 to it, the other being covered with black cloth, and 
 having the bulb of a thermometer beneath this. 
 
 At the expiration of the above time, the exposed 
 thermometer indicated eighty-five degrees, whilst the 
 covered thermometer indicated ninety-one degrees ; in 
 a second trial, the former indicated ninety-one degrees, 
 the latter ninety-four degrees ; and in a third trial, 
 the first thermometer indicated ninety-eight degrees, 
 whilst the second indicated one hundred and six. de-; 
 grees. 
 
 In these three trials, the bare skin was powerfully 
 scorched and raised in blisters, but the covered skin, 
 though so much hotter, was not in the slightest degree 
 injured. 
 
 Upon covering one hand with white cloth, and the 
 other with black cloth, and exposing them for a simi- 
 lar time to sunshine, the former was invariably 
 scorched, but the latter never afiected. 
 
 The power of the solar rays to scorch the skin of man 
 and animals is destroyed when these surfaces are 
 black, although the absolute heat in consequence of 
 the absorption of the rays is greater. 
 
 " The same wise Providence which has given so 
 extraordinary a provision to the Negro for the defence 
 of his skin, while living within the tropics, has extended 
 it to the bottom of the eye, which otherwise would 
 
AUTUMN. 16 f 
 
 suffer in a greater or less degree when exposed to 
 strong light ; the retina from its transparency allowing 
 it to pass through without injury." 
 
 The black or dark matter of the " retina" is techni- 
 cally called the " nigrum pigmentum," and is probably 
 not absolutely necessary for vision, but only provided 
 as a defence against strong light, since it is found to be 
 much darker in the Ethiopian than in the European, 
 and is of a lighter colour in fair people than in dark, 
 and therefore lightest in those countries farthest re- 
 moved from the effects of the sun. 
 
 The scorching power of the solar rays being de- 
 stroyed when received by black surfaces is an incon- 
 trovertible fact, and the only explanation that the 
 chemist can offer regarding it is that the mixture of 
 heat and light in the solar rays is absorbed by black 
 surfaces, and converted into sensible heat. 
 
 The sudden and fatal infliction called " the sun- 
 stroke" that frequently seizes reapers and labourers, 
 in the intense heat of harvest time, is referred to the 
 scorching effect of the solar rays, upon the scalp of 
 the head, producing inflammation of the brain, and 
 probably the first record of this is in th& following 
 Scripture passage. 
 
 " And when the child was grown, it fell on a day that 
 he went out to his father to the reapers. And he said 
 unto his father, My head, my head ! And he said to 
 a lad, Carry him to his mother. And when he had 
 taken him, and brought him to his mother, he sat on 
 her knees till noon, and then died." 
 
162 AUTUMN. 
 
 In extremely Lot climates the traveller is often 
 " sun-stricken," and dies ; and in allusion to the 
 watchful care of Providence over His chosen people, 
 it is said, " They shall not hunger nor thirst ; neither 
 shall the heat, nor sun smite them : for He that hath 
 mercy on them, shall lead them, even by the springs 
 of water shall he guide them." 
 
 The difference between the heating of dark and 
 light-coloured soils, when equally exposed to solar 
 heat, and their difference in cooling when equally 
 placed in the shade, as mentioned at page 104, may 
 be now stated in technical terms, viz., that dark soils 
 absorb heat more powerfully, and radiate heat more 
 energetically than light- coloured soils, which reflect 
 a great portion of heat; we have now to examine 
 how these facts, and others concerning the mere alter- 
 ation of surfaces in affecting both absorption and ra- 
 diation of heat, are applicable to the explanation of 
 a beautiful phenomenon of Summer and Autumn. 
 
 The night has been serene, the moon and stars have 
 shed their brilliant light, no clouds have obscured the 
 heavens, no rain has fallen, and yet when we step 
 forth at daybreak, we find the grass and the flowers 
 of the field loaded with myriads of drops of water, 
 sparkling like gems in the golden rays of the rising 
 sun. 
 
 We recognize this beautiful phenomenon as Dew ; 
 but from whence has it silently journeyed and ar- 
 rived during the hours of night? can the chemist- 
 reply ? 
 
AUTUMN. J63 
 
 He can ; and the reply will furnish another example 
 of the power and goodness of God, for " His favour is 
 as dew upon the grass ;" another proof of the ever- 
 watchful care of Him with Whom " the darkness and 
 the light are both alike/' Whose Hand is equally 
 extended for the protection of the animated creation 
 during its noontide activity and its midnight repose. 
 
 Throughout the fervent glow of a Summer or Au- 
 tumnal day, the solid opaque earth absorbs heat ; this 
 abides upon its mere surface, and is not conducted 
 beneath ; but at sunset, if the sky be cloudless and 
 calm, the earth immediately radiates part of the heat 
 upward, and soon becomes many degrees colder than 
 the air directly incumbent upon its surface ; accord- 
 ingly the watery vapour that is present in the yet 
 warm air, is chilled or condensed into drops of water, 
 and these " distil as the dew" upon the earth, for the 
 refreshment of its productions. 
 
 This phenomenon cannot fail of appearing remark- 
 able, even to the most careless observer, and it be- 
 comes yet more so, when accurately investigated by 
 the chemist. Examine a garden immediately after 
 sunrise at this season ; probably the grass-plat is 
 saturated with dew ; the gravel walk is nearly dry ; 
 the leaves of the hollyhock are dripping with water ; 
 the leaves of the laurel are free from moisture ; but 
 all these objects were similarly exposed to the night 
 air, and if dew were a fine rain, as some persons ima- 
 gine it to be, all should be equally covered with- its 
 drops ; why is this difference observed ? 
 
164 AUTUMN. 
 
 Because the surfaces of the various objects differ in 
 their radiating power ; the grass-plat and the leaves 
 of the hollyhock are excellent radiators; they throw 
 off heat with great energy, and so becoming cold, they 
 induce a more copious deposition of water from the 
 air than the gravel -walk and the laurel leaves, which, 
 being bad radiators, retain heat, and remain so warm 
 that the watery vapour in the air wafts over their 
 surfaces without being chilled or condensed, and 
 therefore they are free from dew. 
 
 Hough or woolly leaves, like the painted or sanded 
 surface of the tin-plate, radiate heat most rapidly, 
 whilst smooth or varnished leaves, like the polished 
 or bright surface of the tin-plate, do not radiate with 
 such energy, and as a consequence of this, the former 
 leaves, ensure a more plentiful deposition of dew than 
 the latter. 
 
 From the limits of the garden, let us carry forth 
 these observations and facts into the boundless fields 
 of Nature, and discover the miraculous workings of 
 Providence. 
 
 Barren rocks and soils, by reason of their peculiar 
 hard and compact structure, have neither the power 
 of absorbing nor of radiating heat with great energy, 
 they do not speedily acquire a low temperature during 
 the clear nights of Summer and Autumn, and as a 
 consequence, dew is scarcely, certainly not abundantly, 
 deposited upon them ; it is not required for their sup- 
 port, and they have no vegetable life, or but little of 
 the lowest grade to maintain. 
 
AUTUMN. 165 
 
 Like every treasure from the bountiful Hand of 
 God, the precious (f dew of Heaven" is not lavished 
 and scattered upon objects that are unfitted for its 
 reception, and therefore can derive no benefit from its 
 genial influence, but only abundantly upon such as are 
 properly prepared, and accordingly these obtain whole- 
 some nurture, and bring forth good fruit, whilst the 
 former remain as barren stones. 
 
 Naturally fertile soils, and such as are artificially ren- 
 dered productive, are generally of a loose porous struc- 
 ture ; this physical peculiarity enables them to absorb heat 
 abundantly during the day, and to radiate it so power- 
 fully at night, or, in other words, to become so many 
 degrees colder than the -ambient air, that its watery 
 vapour condenses upon them and their productions 
 as dew in abundance. 
 
 It is indeed a subject well calculated to arrest our 
 attention, and excite our admiration and gratitude, 
 when we thus find every soil, plant, shrub, and tree, 
 has, by its own physical peculiarity of structure, in- 
 duced the deposition of dew in proportion to its 
 wants ; and when we reflect that not a single dew- 
 drop is created in vain, but each is measured by The 
 Hand of Infinite Wisdom, and appointed to fulfil some 
 useful end. 
 
 Some tracts of land, when clothed with vegetation, 
 radiate heat with such vast energy that their low tem- 
 perature not only causes the plentiful deposition of 
 dew, but subsequently changes it into frost ; but this 
 extreme of cold, if continued, would be equally fatal 
 
166 AUTUMN. 
 
 to vegetable life as an extreme of beat, and as upon a 
 former occasion, we discovered The Hand of Provi- 
 dence extending clouds for protecting the earth 
 from the heat of noon, so upon this, do we discover 
 the same Hand, extending them for preventing the 
 undue escape of heat from the earth during the cold 
 of night ; "for His mercy is great above the heavens, 
 and His truth reacheth unto the clouds." 
 
 These recondite accumulations of vapour, or clouds, 
 intervening between the earth and the confines of the 
 air, act as screens in arresting radiation from the 
 earth to the sky, and also being warmer than the 
 earth, they now radiate part of their own heat to it, 
 and thus restore a due temperature to its chilled pro- 
 ductions. 
 
 Moderate tranquillity of the air, and a serene sky, 
 are essential requisites for the perfect deposition of 
 dew, for very little takes place during the prevalence 
 of winds, and none during that of clouds, unless they 
 are exceedingly high in the air, because the former 
 disturb, and the latter arrest, the radiation of heat 
 from the earth. 
 
 During a fine Summer or Autumnal night, the 
 following curious and instructive experiments can be 
 made regarding this beautiful phenomenon of dew. 
 
 Weigh some dry wool into two portions of twenty 
 grains each, for example ; then bend a large sheet of 
 pasteboard in half, to form a kind of pent-house, place 
 this with its ridge uppermost on a closely mown 
 grass-plat, and lay one of the portions of wool on the 
 
AUTUMN. 167 
 
 middle of the grass beneath the pent-house ; and the 
 other portion on the adjacent grass fully exposed to 
 the sky. 
 
 Fig. 35. 
 
 Examine this arrangement at sunrise, and the 
 sheltered wool will he found to have increased only 
 about four grains in weight, whilst the exposed por- 
 tion will probably have increased about thirty-two 
 grains ; the slight pent-house, although open at both 
 ends, and admitting the free access of air, yet pre- 
 venting, in a remarkable degree, the direct radiation 
 of heat from the wool, and accordingly opposing any 
 great deposition of dew; in fact, throughout the 
 night it has been warmer beneath the pent-house than 
 in the open air. 
 
 The foregoing experiment admits of variation to 
 prove that even more partial shelter from direct radia- 
 tion causes the deposition of dew in smaller quantity 
 to that which appears upon objects fully exposed, and 
 it will entirely remove the notion that dew is a kind 
 of fine rain, falling from the atmosphere. 
 
 Place a few bricks upon a grass-plat, to form a 
 small wall, about three feet in height ; at the foot 
 of this, spread twenty grains of dry wool, and some 
 feet distant place a similar weight of the same sub- 
 
108 AUTUMN. 
 
 stance ; let this arrangement remain during the night, 
 and upon examining it at sunrise next morning, 
 (always providing no rain have fallen,) the partially 
 sheltered wool will be found to have increased only a 
 few grains in weight, whilst the exposed portion eight 
 or ten times as many grains in weight. 
 
 Fig. 36. 
 
 Gravel walks, and stone pavements, radiate heat and 
 acquire dew, less readily than grass-plats, hence, wool 
 placed on the former has its temperature less de- 
 pressed than on the latter, and therefore obtains less 
 dew ; and this effect is by no means referrible to the 
 capillary attraction of the fibres of the wool, for it 
 ensues equally well if the wool be placed in a clean 
 saucer ; nor is it referrible to hygrometric attraction 
 of water from the air, because wool, placed upon a 
 board, elevated at some feet from the earth, during a 
 cloudy night, will acquire only a very minute increase 
 of weight ; the effect is entirely dependent upon ra- 
 diating power. 
 
 Before the cause of dew was discovered, scientific 
 inquirers were at a loss to account for the principle 
 
AUTUMN. 169 
 
 upon which a thin mat, employed by gardeners, pro- 
 tected tender plants from cold ; it appeared scarcely 
 possible, that such a slight covering could have any 
 effect in preventing them from attaining the tempera- 
 ture of the external air, and yet common experience 
 proved its utility. 
 
 When the discovery was made, that bodies on the 
 surface of the earth become much colder than the 
 atmosphere, by radiating heat during -a still and serene 
 night, the true reason of the gardener's homely prac- 
 tice of covering plants with matting, was fully evident ; 
 it prevented radiation from taking place. 
 
 Fig. 37. 
 
 In order to acquire precise information upon this 
 subject, the following simple arrangement was made : 
 the experimenter " fixed perpendicularly in the earth 
 of a grass-plat, four small sticks, and over their upper 
 extremities, which were six inches above the grass, 
 and formed the corners of a square, whose sides were 
 two feet long, a very thin cambric handkerchief was 
 tightly drawn. 
 
170 AUTUMN. 
 
 " Therefore nothing existed to prevent the free pas- 
 sage of air from the exposed grass, to that which was 
 sheltered, except the four small sticks, and there was 
 no suhstance to radiate downwards to the latter grass, 
 except the cambric handkerchief." 
 
 ' The sheltered grass, however, was found nearly of 
 the same temperature as the air, while the unsheltered 
 was 5 degrees or more colder; one night the fully ex- 
 posed grass was 1 1 degrees colder than the air, hut the 
 sheltered grass was only 3 degrees colder." 
 
 Hence we see the power of an awning, infinitely 
 more slight in texture than that of matting, in averting 
 or lessening the coldness of the ground that would 
 otherwise occur, and be injurious to plants. 
 
 It is for this reason that a tent, or marquee, although 
 merely constructed of thin canvass, and by no meaas 
 air-tight, becomes a comparatively warm shelter during 
 a cold night ; no dew will be found upon the plot of 
 grass shielded by the tent, but abundance upon that 
 exposed to the open air around. 
 
 A piece of matting, that has covered a plant during 
 an autumnal night, will be found copiously bedewed, 
 whilst the plant remains dry ; the matting having pre- 
 sented its radiating surface, and parted with heat, 
 which otherwise the plant would have done ; nay, even 
 the matting occasionally performs this office with such 
 energy, that its surface becomes covered with hoar- 
 frost, from which it suffers no injury, as it has no 
 vitality, whilst it shields the living plant, that other- 
 
AUTUMN. 171 
 
 wise would be compelled to radiate, and perish, by the 
 degree of cold induced by its own power. 
 
 In some countries, the temperature never falls to 
 the freezing point of water, and yet ice may be pro- 
 cured by taking advantage of the radiation of heat 
 from surfaces, in the following manner. 
 
 A layer of dry straw, or stubble, is spread in an 
 open situation during a calm and cloudless night, and 
 upon this surface are placed shallow earthen pans, filled 
 with water; radiation immediately commences from 
 the straw and the water ; both lose heat so rapidly and 
 so effectually, that the water can no longer remain 
 liquid, and therefore becomes covered with a thin 
 crust of ice. 
 
 It has been already stated, that water hastens the 
 putrefaction of dead vegetable substances ; the same 
 remark is applicable to those of animal origin ; in 
 warm climates, more especially, the deposition of water, 
 in the form of dew upon these, induces putrefaction 
 with great rapidity; and as this generally happens 
 only during clear bright nights, it was anciently sup- 
 posed that moonlight favoured animal corruption. 
 
 The moon, when at full, reflects upon the earth only 
 about one three hundred thousandth part of the light 
 of the sun ; and the lunar rays, even when concen- 
 trated by a powerful lens, and the focus directed upon 
 the bulb of a delicate thermometer, do not affect it in 
 the slightest degree ; hence the phrase, " the pale, 
 cold moon," is not only poetically beautiful, but phi- 
 losophically correct ; and as the light alone will not 
 
 I 2 
 
172 AUTUMN. 
 
 induce putrefaction, and as there is no heat, the phe- 
 nomenon appears to be solely referrible to the radiating 
 power of animal substances inducing a copious deposi- 
 tion of dew upon their surfaces, for water is essentially 
 requisite in all cases of putrefactive changes. 
 
 If a thermometer be placed upon a grass-plat, it will 
 very frequently indicate a temperature of fifteen or 
 twenty degrees colder than one suspended over the 
 grass, at the height of three or four feet, thus prov- 
 ing that radiation is proceeding with extreme rapi- 
 dity in the one case, from the comparatively solid 
 vegetable matter and the soil, but not from the am- 
 bient air. 
 
 Accordingly, the portions of air in immediate con- 
 tact with the grass, become much colder than those far 
 above, and are compelled to deposit dew ; and if the 
 air over a given locality remain tranquil for some 
 hours, this phenomenon will solely ensue from the 
 lower and colder portions. 
 
 Small valleys, and hollow-ways, permit the air to 
 repose undisturbed ; and although they are apparently 
 situations sheltered from cold, yet they are frequently 
 more subject to reduction of temperature than higher 
 situations ; and accordingly, much to our surprise, we 
 find delicate plants chilled, or even frost-bitten, in 
 hollows, whilst others suffer no injury upon the adja- 
 cent slopes. 
 
 ' In the close and sheltered streets of cities, the 
 deposition of dew is very rarely observed, because there 
 the objects are necessarily exposed to each other's 
 
AUTUMN. 173 
 
 radiation, and an interchange of heat takes place, 
 which maintains them at a temperature uniform with 
 that of the air ; a deposition of dew in this case can 
 only take place when the natural temperature of the 
 air falls below its point of saturation." 
 
 At sunrise during Summer or Autumn, we may fre- 
 quently see a dense white mist, only a few feet in 
 height, directly incumbent upon a grass or corn-field, 
 whilst the air above is clear and bright with the rays 
 of the sun ; and we may even walk along the foot- 
 path across the field, with the lower part of our body 
 enveloped in this mist, whilst the upper, is perfectly 
 free from its humidity. 
 
 This phenomenon of mist, is consequent upon the 
 calm of the previous night having admitted rapid ra- 
 diation to ensue from the earth, which then became so 
 much colder than the great volume of the atmosphere 
 above, that the portion in immediate contact with the 
 earth was suddenly deprived of a large amount of its 
 aqueous vapour, and then the mist, or " earth-cloud," 
 thus formed, prevented any farther radiation from en- 
 suing towards the clear sky, and therefore remained 
 until dawn. 
 
 Let us now remark another beautiful phenomenon 
 in connexion with our present subject of inquiry : 
 although at sunrise the dense mist reposes upon the 
 surface of such tracts of land, and although innu- 
 merable dew-drops bespangle the trees, plants, herbs, 
 and flowers of others, yet as the sun mounts higher in 
 
174 AUTUMN. 
 
 the heavens to run its appointed course, both mist and 
 dew vanish, and the earth and its productions become 
 dry ; how is this ? 
 
 Because the water of the mist and dew gains suffi- 
 cient heat, to change from the state of visible liquid, to 
 that of invisible vapour; this the air immediately re- 
 ceives, and treasures in its capacious volume, through- 
 out the glowing day ; and then at its close, if the sky 
 be calm and cloudless, the earth and its productions 
 again radiate the stores of heat which they had with- 
 drawn from the noontide intensity ; they again be- 
 come cooled, and the air commences its wonderful 
 work of relinquishing its aqueous store as mist and 
 dew, in just proportion for the relief of all. 
 
 Thus, in the sublime and all-powerful language of 
 Scripture, " Dew after heat refresheth : to every thing 
 there is a season : -and shall not the dew assuage the 
 heat ? " 
 
 Or, in the imperfect and limited terms of science, 
 thus the earth, by its peculiar habitudes as regards the 
 reception and retention of solar heat, resists an exces- 
 sive or destructive accumulation of this powerful, im- 
 ponderable agent, and maintains a temperature condu- 
 cive to the well-being of the animated creation. 
 
 These are the pleasures and advantages of the pro- 
 per pursuit of science, to examine, and if possible, 
 interpret the varied phenomena around us, which pre- 
 serve the order and harmony of the Creation ; they all 
 unfold volumes of wonders, and prove, as in the case 
 
AUTUMN. 175 
 
 that we have been considering, " who seeketh Wisdom 
 early, shall have no great travail, for he shall find her 
 sitting at his doors." 
 
 It is only of late years that man has been permitted 
 to interpret and understand the cause of dew, but from 
 the earliest ages he has experienced and acknowledged 
 its wonderful and beneficial effects, and more particu- 
 larly in those countries where rain seldom or ever 
 falls ; hence the Sacred Writings so abound in eloquent 
 passages, and splendid metaphors, concerning the 
 blessings which emanated from the presence of dew, 
 and the miseries entailed by its absence, of which the 
 following have been selected: 
 
 " For the seed shall be prosperous ; the vine shall 
 give her fruit, and the ground shall give her increase, 
 and the heavens shall give their dew." 
 
 " God give thee of the dew of heaven, the fatness of 
 the earth, and plenty of corn and wine." 
 
 " The heaven over you is stayed from dew, and the 
 earth is stayed from her fruit." 
 
 " I will make your heaven as iron, and your earth 
 as brass." 
 
 The metaphor of the last passage is thus humbly 
 interpreted : that the intense power of the sun should 
 directly heat the air, and render it so arid, that neither 
 dew nor rain should descend, and that the earth should 
 consequently be so parched and hardened, as to be 
 rendered incapable of being ploughed into furrows for 
 the reception of seed. 
 
 Knowledge concerning the phenomena and laws of 
 
176 AUTUMN. 
 
 the Creation, is not revealed to man, and he must 
 attain it by the proper use of his noblest faculties ; 
 and the subjects which he now classes into the form 
 of a science, when mentioned in Scripture, are always 
 couched in language accommodated to sensible ap- 
 pearances, and popular notions, as in the foregoing, 
 and many other passages that have been, and yet 
 remain to be adduced. 
 
 In Egypt, the wind that traverses extensive tracts of 
 sandy deserts, is so dried as to deposit no dew ; whilst 
 that which crosses the Mediterranean, is so saturated 
 as to deposit it in abundance. 
 
 In this country, the deposition of dew from the 
 atmosphere is generally less during the continuance of 
 easterly, than of westerly winds, a phenomenon attri- 
 butable to the different nature of the surfaces over 
 which these winds travel, the former crossing the con- 
 tinent of Europe, and thus becoming comparatively 
 dry or arid, the latter sweeping across the vast expanse 
 of the Atlantic ocean, and therefore becoming moist or 
 hydrated, requiring but little reduction of their tem- 
 perature for the copious deposition of dew to ensue 
 upon terrestrial objects. 
 
 The mere form of a drop of rain or of dew, presents 
 matter of inquiry to the philosophic mind ; why is it 
 either a perfect sphere, or some modification of a 
 sphere, and not cubical, or octohedral, or other an- 
 gular figure; and why does it equally adhere to the 
 upper and under surfaces of the blades of grass ? 
 
AUTUMN. 177 
 
 Because the impress of perfection is set upon every 
 work of the Creator, and He permits man to discover 
 that a sphere is a perfect and simple figure, the consti- 
 tuent particles of which are equally distant from one 
 common centre of attraction, and thus being equally 
 and simultaneously attracted, no other figure can pos- 
 sibly result, unless some superior external attractive 
 force be presented. 
 
 Fig. 38. 
 
 A sphere, is the figure assumed by liquid water, when 
 a portion of it is either perfectly unsupported, or sup- 
 ported upon a surface having little attraction for it ; 
 but it becomes more or less spheroidal, or ultimately 
 disappears, in proportion to the extraneous attraction 
 of the surfaces upon which it is received. 
 
 Thus a drop of rain or of dew, in descending from 
 the air is a sphere, and will so continue when received 
 only at a minute point of contact by the upper surface 
 of a dry blade of grass, and even gently roll unto its 
 extremity, and pass to the under surface, and there 
 remain pendent in opposition to the attraction of gra- 
 vitation which is soliciting its return to the earth, the 
 attractive force of the minute point of contact with 
 
 i 5 
 
178 AUTUMN. 
 
 the blade of grass, being superior for a time to that of 
 gravitation. 
 
 If several drops coalesce into one large drop, the point 
 of solid contact likewise increases, and then becomes 
 far superior to the attractive force between the mobile 
 liquid particles, and thus drawing them away from 
 each other, produces a spheroid ; but this will remain 
 well defined upon the upper surface of the blade of 
 grass, or even continue pendent from the lower. 
 
 By successive additions, its size becomes so great, 
 that the surfaces can no longer oppose the attraction of 
 gravitation, and therefore the spheroidal drop becomes 
 more and more oblate, until it rolls or falls away, and 
 immediately loses its form amidst the capillary chan- 
 nels of the earth, from whence it is destined to ascend 
 as vapour, to mingle with the air, and again to descend 
 as rain or dew, or other forms suited alike to time and 
 season, for not even a drop of water is lost or anni- 
 hilated in the laboratory of Nature. 
 
 When drops of water fall heavily upon the generality 
 of vegetable productions, the abrupt shock forces them 
 into such extensive contact with these surfaces, and 
 also with each other, that in place of remaining as 
 beautifully defined spheres and spheroids, they rapidly 
 coalesce as a slender stream of water, and thus flow 
 away into the soil, with the exception of a compara- 
 tively few drops, which sometimes escaping this sud- 
 den attraction, remain yet clinging to that of the ter- 
 minal points of the leaves. 
 
 The surfaces of many leaves are covered with an 
 
AUTUMN. 179 
 
 extremely fine powder, which, like fine dust upon the 
 floor of an apartment, is repulsive of gently-sprinkled 
 water ; thus, upon the leaves of the cabbage and the 
 garden poppy, brilliant globules repose, and if shaken 
 by the wind, or by the hand, they rapidly glide about 
 without wetting the surface ; and although they may 
 divide into many more globules, the most minute, 
 always having the most perfect spherical form, they 
 immediately exert attraction for each other when 
 allowed to come into mutual contact, and coalesce into 
 one or two large spheroidal forms of silvery radiance. 
 
 The chemist proves that the petals of many beautiful 
 and delicate flowers contain a minute portion of essen- 
 tial oil, yet amply sufficient to render them incapable 
 of the rapid absorption of either drops of rain or dew, 
 by which their structures might be injured. 
 
 Fig. 39. 
 
 A drop of pellucid water, thus reposing within the 
 crimson petals of a rose, and sparkling like a diamond 
 in the morning light, must certainly present more 
 
180 AUTUMN. 
 
 attraction to the experimenter or investigator of its cause, 
 than to the mere admirer or delineator of its beauty. 
 
 In connexion with this inquiry relative to the sphe 
 rical figures of drops of water when supported upon 
 surfaces for which they have little or no attraction, it 
 may be remarked, that the feathers of aquatic birds 
 are imbued with an oily secretion, which renders them 
 eminently repulsive of water ; thus the majestic swan, 
 after diving its graceful neck beneath the stream, 
 proudly raises it in the air, perfectly free from humi- 
 dity ; or if the spray of a light wave dash over its plu- 
 mage, the sparkling drops coalesce into one large and 
 brilliant globule, which reposes on the snow-white 
 feathers of its back, without wetting or disturbing their 
 beautifully soft and regular arrangement. 
 
 Water-fowl swim about boldly, dive deeply, remain 
 for a considerable time beneath the water, and then 
 rise buoyantly to its rippling surface with unwetted 
 and unruffled plumage. 
 
 Even the loose feathers that escape when birds are 
 pluming on the banks of the water, are wafted by the 
 wind upon its surface, and as they gently sail along, 
 they afford matter of reflection to a philosophic mind ; 
 for the slightest occurrence in Nature surely cannot be 
 unworthy the attention of man. 
 
 Again, during a summer or autumnal evening, it is 
 both interesting and instructive to stand on the bank 
 of a calm sheet of water, and watch the swarms of ex- 
 quisitely-formed insects, with delicate and slender limbs 
 so perfectly repellent of water, that are running, or 
 
AUTUMN. 181 
 
 rather darting, upon its actual surface, and scarcely 
 depressing or disturbing its smooth and glassy tran- 
 quillity. 
 
 The foregoing, and many similar phenomena, must 
 have been remarked by the most indifferent observer ; 
 they are popularly called instances of the " repulsions 
 of water, by pulverulent or oily substances ;" but the 
 correct philosophical expression is, that such surfaces 
 have not so great an attraction for the drops of water 
 as their constituent particles have for each other, and 
 therefore they preserve as much as possible the sphe- 
 rical form which they had when entirely deprived of 
 support. 
 
 The dew that we have been considering, consists of 
 water very nearly pure, and is therefore perfectly dif- 
 ferent to a thick sweet liquid that is frequently ob- 
 served to collect on the leaves of trees during Autumn, 
 and is popularly called " honey-dew." 
 
 This liquid is shed by a species of insect, known to 
 the Entomologist under the name of the " Aphis ; " it 
 dwells upon the under side of the leaves, and when 
 this " honey- dew" escapes from its body, it is received 
 upon the upper surface of the leaves below ; this liquid 
 is very deleterious to vegetation, it fills the pores of 
 the leaves, and disturbs their proper functions of 
 transpiration and absorption ; they soon become dis- 
 eased, and from being originally of a brilliant green, 
 they turn of a dingy yellow colour. 
 
 But this " honey-dew" is a favourite food witli 
 ants, and they may very frequently be observed crawl- 
 
182 
 
 AUTUMN. 
 
 ing up exceedingly lofty trees, in order to gain a sup- 
 ply of it from the leaves. 
 
 Several contrivances for denoting the existence of 
 watery vapour in the atmosphere, or in other words, 
 its relative dampness and dryness, have been already 
 noticed at page 140, under the name of " Hygro- 
 scopes," the principle of an instrument for denoting, 
 or actually measuring, the quantity of aqueous vapour 
 in the atmosphere, now demands our attention, and it 
 properly bears the name of a " Hygrometer ; " its form 
 is shown in the annexed engraving. 
 
 Fig. 40. 
 
 It consists of a small and delicately -constructed 
 " Cryophorus," (page 134,) but containing the liquid 
 called Ether, instead of Water; the two thin glass 
 bulbs are about one inch and a quarter in diameter, 
 and are connected by a glass tube, the horizontal part 
 of which is about the eighth of an inch, and the per- 
 
AUTUMN. 183 
 
 pendicular, about a quarter of an inch internal diameter; 
 the horizontal part is only thus made of thicker glass, 
 that it may be stronger, and not so liable to break 
 when inserted into the small spring clip, on the top of 
 the brass standard or column, to the shaft of which is 
 attached a small and delicate mercurial thermometer. 
 
 The horizontal part of the tube is about four inches, 
 and the perpendicular part, six inches in length ; this 
 latter includes another and equally delicate thermo- 
 meter, but having an elongated, or pear-shaped bulb, 
 merely to facilitate its introduction into a tube so 
 small ; and this bulb dips fairly into the ether, with 
 which one of the glass bulbs already described is three- 
 quarters filled. 
 
 The other bulb, attached to the upper and shorter 
 part of the tube, is smoothly covered with a piece of 
 fine cambric, secured around the tube by thread ; a 
 small capillary neck, closed by melting the glass, pro- 
 jects about a quarter of an inch beyond this covering. 
 This is the appearance of the instrument, but its con- 
 struction is as follows: the perpendicular tube, with 
 its bulb, is first made, and the small thermometer in- 
 troduced ; then the horizontal tube and its bulb, with 
 the capillary neck open, are made ; the left hand 
 extremity of this tube is then melted, or welded, to the 
 perpendicular tube ; after this is done, ether is intro- 
 duced through the capillary neck, until the bulb unto 
 which it belongs is nearly filled ; and then, by invert- 
 ing the instrument thus far constructed, the ether is 
 
184 AUTUMN. 
 
 caused to flow into the bulb attached to the tube con- 
 taining the thermometer. 
 
 The gentle heat of a lamp is then applied to this 
 bulb, that the ether may boil ; this it will do at 96 de- 
 grees ; its vapour perfectly expels all the air from the 
 interior of the instrument, through the capillary neck ; 
 and when the vapour itself, fully and fairly issues forth, 
 the opening of the neck is suddenly closed by melting 
 it in the flame of a lamp. 
 
 Thus the greater portion of the ether still remains 
 in a vacuum, as far as the absence of air is concerned, 
 and only subject to the pressure of its own vapour, 
 as was the water in the " Cryophorus ;" the bulb is 
 then enveloped in cambric, and the instrument is com- 
 pleted. 
 
 Now as regards the method of using it, or of causing 
 it to act as a Hygrometer : should any ether enter the 
 covered bulb, this must be grasped in the hand, and 
 by holding it as directed for the " Cryophorus/' the 
 heat of the hand will expand the vapour, and force the 
 liquid ether into the other bulb ; at the same time a 
 sensation of cold will be felt, because ether, although 
 more volatile than water, still requires heat for its eva- 
 poration; and this it takes from the hand, which, 
 losing heat, feels cold. 
 
 When all the ether has entered its proper bulb, the 
 instrument is placed upon the standard, and then set 
 at an open window, or still better, in the free atmo- 
 sphere on some steady support, level with the eye, 
 
AUTUMN. 1 85 
 
 taking care, if possible, that a dark tree or wall, or a 
 black hat, at some few feet distant, will throw it out 
 into strong relief. 
 
 An examination of the thermometer attached to the 
 brass standard, and of that enclosed in the glass tube, 
 with its pear-shaped bulb dipping into the ether, will 
 prove that they both indicate the same temperature : 
 tbis must be noted; and then from a small bottle, 
 provided with a conical tube stopper, as shown in the 
 next engraving, a few drops of ether are let fall upon 
 the cambric envelope. 
 
 Fig. 41. 
 
 Ether being exceedingly volatile, infinitely more 
 so than water, will immediately gain heat from the 
 bulb, for its conversion into vapour, or its evaporation ; 
 the bulb will be reduced in temperature, and the va- 
 pour of ether that it contains will be condensed therein 
 into liquid ether, as was the vapour of the water, 
 first condensed into liquid water in the experiment 
 with the " Cryophorus." 
 
 As in that case, a call or demand is now imme- 
 diately made upon the bulb containing the thermo- 
 meter and the liquid ether, for a portion of vapour to 
 
186 AUTUMN. 
 
 supply the place of that which has heen condensed; 
 and there "being no air in the instrument to oppose this 
 demand, it is instantly supplied by gaining heat from 
 the bulb in which the ether is contained. 
 
 This vapour in its turn is instantly condensed ; but 
 as the ether evaporates from the capillary attraction of 
 the cambric, another, and another, and many calls, are 
 so quickly made, that the bulb containing the ether, 
 by yielding heat, becomes extremely cold, as its in- 
 cluded thermometer will indicate, and at length be- 
 comes so cold, that the watery vapour contained in the 
 atmosphere coming into contact with it, is condensed, 
 as a fine ring of dew upon its surface at the level of the 
 remaining ether. 
 
 This is instantly detected, by the strong relief into 
 which the transparent bulb is thrown by the dark 
 object, and the included thermometer shows the degree 
 of temperature at which this phenomenon ensues ; it 
 must be immediately noted, and it is technically called 
 " The dew-point." 
 
 Suppose the external thermometer indicate 60 de- 
 grees, and the internal thermometer indicate 48 de- 
 grees, the difference between the two is 12 degrees, 
 and therefore the atmosphere does not contain a very 
 large amount of watery vapour, since a reduction of 
 temperature so considerable, is required for the depo- 
 sition of dew ; but suppose the one thermometer indi- 
 cate 66 degrees, and the other 64 degrees, the dif- 
 ference between the two is only 2 degrees, and there- 
 fore the atmosphere does contain a very considerable 
 
AUTUMN. 187 
 
 amount of watery vapour, since it is immediately prone 
 to deposit dew by such a slight reduction of tempera- 
 ture ; therefore, in the first example, the degree of its 
 dryness may be denoted by 12, and in the second by 
 2 degrees. 
 
 Or, the fact may be stated in the following terms, 
 namely ; the more widely that the thermometers differ 
 in their indications, the smaller is the quantity of the 
 vapour in the atmosphere ; and the more closely that 
 they agree, the greater is the quantity of the vapour 
 contained in the atmosphere. 
 
 For example ; in exceedingly dry weather, the cam- 
 bric will require to be well saturated with ether more 
 than once, before it can produce sufficient cold to sum- 
 mon the small quantity of atmospheric vapour to chill 
 and deposit as dew ; whilst on the other hand, in ex- 
 ceedingly damp weather, the addition of a very few 
 drops of ether to the cambric, will quickly summon 
 the large quantity of vapour with which the atmosphere 
 is almost saturated, and can hardly retain, to con- 
 dense and deposit as dew upon the plain bulb. 
 
 Experimental proof of these facts may be gained, by 
 first employing the " hygrometer " in a hot dry room, 
 when great difference will be observed between the 
 thermometers at the moment of the " dew point ;" and 
 next in a cold damp cellar, when little difference will 
 be found between them at th^ moment of the " dew 
 point ; " indeed, if the air of the cellar be already na- 
 turally saturated with vapour, or the air of a small 
 
188 AUTUMN. 
 
 apartment be artificially saturated with vapour, by a 
 large wet cloth or blanket hung within it, the two ther- 
 mometers will almost coincide at the moment of the 
 deposition of the ring of dew, or the " dew-point." 
 
 In England, the degree of atmospheric dryness, or 
 freedom from watery vapour, as measured by the ther- 
 mometers of the " hygrometer," seldom amounts to 
 30 degrees; that is to say, the " dew-point" is seldom 
 30 degrees below the temperature of the air ; but in 
 the Deccan Shabarpore, an island which is situated 
 near the eastern mouth of the river Ganges, at a 
 temperature of 90 degrees, the " dew point " has been 
 seen as low as 29 degrees, thus marking the dryness 
 or aridness of that unwholesome atmosphere at 61 
 degrees. 
 
 In deeply scientific investigations, accurate experi- 
 ments have been made with the "hygrometer," and 
 elaborate tables have been constructed, to show the 
 actual weight of aqueous vapour locally contained in 
 the atmosphere, at the time that the " dew point" is 
 ascertained ; but these tables or calculations, although 
 highly interesting and important to professed meteoro- 
 logists and chemists, would scarcely be intelligible to 
 general readers and juvenile students, therefore no 
 reference is made to them during this slight inquiry 
 regarding the phenomena of the Four Seasons. 
 
 What has been stated concerning the construction 
 and method of employing the " hygrometer/' the man- 
 ner in which it may be caused to act as " a weather- 
 
AUTUMN. 189 
 
 glass," in the popular acceptation of the term, to 
 indicate the dryness and dampness of the atmosphere, 
 and therefore the lesser or greater probability of rain, 
 may be sufficiently intelligible. 
 
 Watery vapour, although invariably present in the 
 whole atmosphere, and its mean quantity expressed by 
 the enormous sum at page 14, is liable to local varia- 
 tions of its quantity, according to the local tempera- 
 ture of any particular volume of the atmosphere ; for 
 instance, it is shown at page 130, that warm air, 
 either calm, or moving as a breeze, or as a high wind, 
 is capable of evaporating and sustaining in its invisible 
 volume more water than cold air, under similar condi- 
 tions of repose and motion. 
 
 It has been ascertained during most refined, accu- 
 rate, and laborious experiments, conducted both by 
 the meteorologist and the chemist, that a cubic foot of 
 absolutely dry or anhydrous air, i. e. air consisting of 
 Nitrogen, Oxygen, and Carbonic acid, when at the 
 temperature of 33 degrees, or near the " freezing 
 point " of water, does not absorb or sustain more than 
 two grains and one-third of a grain of watery vapour ; 
 whilst at the temperature of 60 degrees, by such in- 
 crease of heat, it will sustain five grains and three 
 quarters of a grain ; and at the temperature of 70 de- 
 grees, by such further increase of heat, it will sustain 
 eight grains. 
 
 This experimental fact immediately accounts for 
 the greater rapidity with which a pool, or other accu- 
 
190 AUTUMN. 
 
 mulation of stagnant water, is " dried away " even 
 by the naturally hydrated atmosphere in warm weather 
 than in cold weather ; and it also, in a great measure, 
 accounts for the more copious deposition of dew from 
 the atmosphere in the one season than in the other. 
 
 In some cases, a parched volume of the atmosphere 
 in motion, as " wind " travelling from one clime to 
 another, over the wide expanse of sea or ocean, incites 
 the rise, and accumulates the burthen of so large a pro- 
 portion of pure watery vapour upon its (< wings," as to be 
 at length unable to sustain the whole ; and then, during 
 its flight or transit, a portion is slowly and gently re- 
 linquished in the mysterious form of clouds. 
 
 These eventually descend as rain upon the earth ; 
 but in other cases, a parched volume or blast of wind, 
 is ordained to sweep over arid sands or deserts, and in 
 place of refreshing these with a copious supply of 
 water, it actually deprives them of their very scanty 
 store of this invaluable fluid for its own hydration, 
 and thus often causes a most intense and almost in- 
 supportable sensation of heat. 
 
 These phenomena are most particularly evident in 
 Eastern climates, and being familiar to the most ig- 
 norant observers, they were chosen by The Saviour 
 of mankind as a medium for conveying a just and 
 powerful reproof to the captious malevolence of be- 
 nighted minds, concerning the utter vanity of physical 
 observation and knowledge, if not combined with 
 full perception, and confession of the transcendent 
 excellency of Faith. 
 
AUTUMN. 191 
 
 " When ye see a cloud rise out of the west, straight- 
 way ye say, There cometh a shower ; and so it is." 
 
 " And when ye see the south wind blow, ye say, 
 there will be heat ; and it cometh to pass." 
 
 " Ye hypocrites, ye can discern the face of the sky 
 and of the earth ; but how is it that ye cannot discern 
 this time ?" 
 
 " Yea, and why even of yourselves judge ye not 
 what is right ?" 
 
 The physical explanation of the phenomena to 
 which this powerful allusion is made, may be thus 
 rendered ; the Mediterranean Sea is situated imme- 
 diately to the west of Judea, and during the preva- 
 lence of a westerly wind, yields sufficient vapour to 
 form a cloud of rain, for the refreshment of the land ; 
 whilst the hot countries of Egypt, Ethiopia, and 
 Arabia, situated immediately to the south of Judea, 
 during the prevalence of a southerly wind, so greatly 
 deprive it of moisture as to parch the land on which 
 it ultimately arrives. 
 
 To minds duly prepared, the observation and study 
 of the " magnificent history of Wisdom and Intel- 
 ligence, which is written in legible characters both 
 in the heavens and on the earth," is an inexhaustible 
 source of happiness ; which can never prove incom- 
 patible with the exalting influence of The Scriptures, 
 since both, emanate from One Omnipotent Being, as 
 faithful messengers, to direct the humble approach 
 of man towards The Throne of His Mercy and of 
 His Power. 
 
192 AUTUMN. 
 
 The Scriptures do not contain a single prohibition 
 regarding the acquisition of wisdom and understanding 
 concerning the phenomena of The Universe ; on the 
 contrary, they first, set forth the rudiments of such 
 philosophy in the circumstantial language of history ; 
 and subsequently, enjoin its search in the sublimest 
 strains of poetry, and extol the pleasures and advan- 
 tages of its discovery in the attractive charms of pro- 
 verb and of song. 
 
 First, as regards the rudiments and goodness of 
 philosophical knowledge; secondly, as enjoining its 
 search ; and, thirdly, as extolling its discovery. 
 
 The Scriptures thus testify : 
 
 I. " In the beginning God created the heaven and 
 the earth," et seq. 
 
 " And God saw everything that He had made, and 
 behold it was very good." 
 
 II. " The works of the Lord are great, sought out of 
 all them that have pleasure therein." 
 
 Worthy, that is, of being inquired into, and studied 
 by all that delight in obedience to His will, and such 
 only, can appreciate His power. 
 
 III. " Happy is the man that findeth wisdom, and 
 the man that getteth understanding." 
 
 The refined joy and happiness of the man that finds 
 pure knowledge, is here to suit human comprehen- 
 sion likened to the ordinary elation and gladness of 
 the man that either directly finds a pure vein of pre- 
 cious metal, or indirectly succeeds in getting or draw- 
 ing it out in purity and value from an ore by his own 
 
AUTUMN. 1 93 
 
 application and labour ; the terms " finding " and 
 getting," as in remote ages, are even now employed 
 for denoting such discoveries. 
 
 The inestimable worth of pure knowledge is then 
 placed in direct and powerful contrast with the insig- 
 nificant value of metallic riches. 
 
 " For the merchandize of it is better than the mer- 
 chandize of silver, and the gain thereof than fine 
 gold." 
 
 Truly inestimable are the varied phenomena presented 
 in the wide realm of Nature throughout the revolving 
 year ; and such as we cannot comprehend, still awaken 
 our minds in the most glowing feelings of gratitude and 
 admiration. 
 
 Thus the physical cause of the blue colour of the sky 
 cannot be satisfactorily explained through the medium 
 of science; and yet at all seasons, we acknowledge 
 its surpassing beauty, more especially perhaps in 
 Autumn. 
 
 The atmosphere immediately incumbent upon the 
 earth, has probably the power of absorbing and retain- 
 ing more of the blue rays of light than that at greater 
 altitudes ; and thus, when we cast our eyes on high, 
 we look through a volume of the densest air, replete 
 with blue light; and so likewise, if we look abroad 
 over an extensive tract of country, the horizon of which 
 is formed by distant hills, they appear blue, or in other 
 words, they partake of the colour of the medium through 
 which they are viewed ; if we journey to them, their 
 
 K 
 
194 AUTUMN. 
 
 blue colour gradually vanishes, and at length their or- 
 dinary colours appear, and now, looking from the hill;* 
 towards the spot from whence we journeyed, it in turn 
 appears hlue. 
 
 " The ridge called ' The Blue Mountains/ in Aus- 
 tralia, another of the same name in America, and many 
 others elsewhere, are not really hlue, for they possess 
 all the diversity of scenery which their climates can 
 give; but to the eye which first discovered them, 
 bent on them generally from a distance, they all at 
 first appeared blue, and they have retained the name." 
 
 The air contained in a spacious hall or room is too 
 small in volume to affect the eye with an impression 
 of blue colour, and all objects appear of their natural 
 tint ; the same as an alabaster figure will appear beau- 
 tifully white when viewed through a thin glass shade, 
 but will gradually appear green, upon being covered 
 with three or four additional shades, although they are 
 of equal thickness and transparency ; and if several 
 more be employed, the vase will at length become 
 invisible. 
 
 The red appearance of the evening and morning 
 sky, so popularly known as indicative of fair and foul 
 weather, was chosen by the Saviour of Mankind, as the 
 medium of a reproof, similar in its force and tendency 
 to that which has already engaged our attention, in 
 humbly endeavouring to present its philosophical inter- 
 pretation. 
 
 :e When it is evening ye say, it will be fair weather, 
 for the sky is red." 
 
AUTUMN. 1 95 
 
 " And in the morning, it will be foul weather to-day, 
 for the sky is red and lowering." 
 
 The astronomer proves, that in consequence of the 
 refractive or light-bending power of the atmosphere, 
 the sun is visible for a considerable time after actual 
 sunset, and also before actual sunrise ; the chemist 
 ascertains the fact, that at actual sunset, the surface of 
 the earth radiates heat, and the watery vapour present 
 throughout a vast height of the atmosphere, imme- 
 diately enters into a state of incipient condensation ; 
 he therefore presumes the glow of light that so often 
 blushes in the sky during a summer or autumnal sun- 
 set, may depend upon the vesicular vapour reflecting 
 the red rays more powerfully than the others, for he 
 discovers, that if light be transmitted through steam 
 mingled with air, and therefore on the verge of con- 
 densation, that it assumes a deep orange or red 
 colour. 
 
 " The red colour of the sky at sunset, is indicative 
 of fine weather ; for although watery vapour is present 
 in the air, it is probably only on the verge of incipient 
 condensation, and not sufficiently condensed to form 
 rain-clouds ; and this slowly progressive transition of 
 vast volumes of the air through the temperature of the 
 dew-point, can only occur in serene weather at sunset, 
 and not at sunrise." 
 
 " The red and lowering appearance of the morning 
 sky, which indicates foul weather, probably depends 
 upon such an excess of vapour being present in the 
 whole atmosphere, that clouds are actually forming in 
 
196 AUTUMN. 
 
 the higher regions, contrary to the direct tendency 
 of the rising sun to dissipate them, they accordingly 
 reflect the red rays of light abundantly, and are consi- 
 dered as announcing a speedy precipitation of rain." 
 
 " In the morning, in fine weather, the strata of the 
 air near the surface of the earth alone, and in the 
 lowest and most sheltered spots, are in a state of abso- 
 lute dampness, the more elevated regions are compa- 
 ratively free from humidity, and the morning light is 
 grey ; the vapours which, during the reversion of the 
 process, might probably reflect the red rays, are not 
 elevated until the action of the sun upon the surface of 
 the earth has continued long enough to impart a sen- 
 sible warmth, by which time the moment of sunrise 
 is past, and the sun has risen above the horizontal 
 vapours." 
 
 The close observance of natural phenomena by our 
 ancestors, gave rise to many sayings and proverbs, of 
 which several have been presented ; and we find another 
 concerning the appearance of the skies that we have 
 just considered. 
 
 " An evening red, and morning gray, 
 Will set the traveller on his way ; 
 But an evening gray, and a morning red, 
 Will pour down rain on the traveller's head." 
 
 The " rainbow," that so frequently adorns and glads 
 the clouded watery heavens, in full display of gorgeous- 
 coloured zones of first-created light, as " the token of 
 the covenant between God and man, that the waters 
 
AUTUMN. 197 
 
 shall no more become a flood to destroy all flesh/' must 
 be esteemed as the most beautiful and magnificent 
 atmospheric phenomenon that we behold throughout 
 the Four Seasons of the revolving year. 
 
 This phenomenon, however, does not admit of ex- 
 planation through the medium of Chemistry, its inter- 
 pretation belongs to the very highest departments of the 
 science of Optics, and there probably we only know it 
 in part : but even such part, if it could be here ad- 
 mitted, would more than occupy the remaining limits 
 that are assigned for the actual chemical phenomena 
 of Autumn and Winter. 
 
 But we are inevitably led for a few moments to quit 
 the direct province of Chemistry, and trespass upon that 
 of Optics, for unfolding the probable physical cause of 
 the rainbow, in concise and intelligible terms. 
 
 The rainbow invariably appears in that part of the 
 heavens which during the day is directly opposite to 
 the sun, and whilst rain is falling between" the dark 
 clouds in the one quarter, and the solar beams in the 
 other ; these, under most circumstances, impinging 
 upon pellucid drops of water, will either directly pass 
 through them in right lines, or if refracted from such 
 course, they will, upon emerging from the drops, 
 immediately resume it, and pass onward as colourless 
 light. 
 
 Under certain natural conditions, which merely to 
 facilitate our inquiry may for the moment be called 
 extraordinary, the solar rays impinging upon drops of 
 water, will not only pass through them, or be simply 
 
198 AUTUMN. 
 
 refracted, as above, but upon emerging from the drops, 
 a portion of the rays will continue to pass onward as 
 colourless light after ordinary refraction ; whilst ano- 
 ther portion deviates from such path, and is further 
 refracted, or broken, into seven extraordinary-coloured 
 rays, or prismatic rays, as mentioned at page 23 of the 
 Introductory Chapter. 
 
 This extraordinary or coloured refraction or analysis 
 of solar light, is frequently presented by drops of 
 morning dew, but in greater perfection by drops of 
 rain, in falling through the atmosphere, between a 
 dark cloud and the brilliant sun, the rays of which 
 entering and emerging from successive drops, are re- 
 fracted into Violet light, which departs farthest from the 
 path that the unaltered rays would have pursued, and 
 into Bed light, which keeps nearest the path that the 
 unaltered rays would have pursued ; thus the external 
 and the internal fringes of the rainbow are formed., 
 and they Include within their zones the remaining co- 
 loured rays in the order of their inherent refrangibility, 
 the Indigo, Blue, and Green, being nearest the Violet, 
 whilst the Yellow, and Orange, are nearest the Red ; thus 
 presenting a perfect rainbow of the seven colours of 
 analysed light. 
 
 Or in more technical terms, the Violet, Indigo, Blue, 
 and Green, rays, are the most refrangible, whilst the 
 Yellow, Orange, and Bed, are the least refrangible rays 
 of solar light ; the rainbow, therefore, is said to pre- 
 sent a magnificent natural example of its analysis ; for 
 the coloured rays cannot be divided into others. 
 
AUTUMN. 199 
 
 When a single and perfect rainbow appears, its inte- 
 rior fringe is Red, and its exterior fringe is Violet ; 
 but a " double rainbow" is most frequent ; a pheno- 
 menon that is, of one bow within another ; and then 
 not only are the colours of the inner and smaller, or 
 Primary bow, more vivid than those of the outer and 
 larger, or Secondary bow, but they are exactly in the 
 reverse order, the interior fringe of the inner bow being 
 Violet, and its exterior fringe being Bed. 
 
 Fig. 42. 
 
 The form of the " double rainbow" the artist has 
 successfully represented in the above engraving, the 
 dark shading of the bows denoting their respective 
 fringes of violet light, as the employment of surfaces 
 to reflect individual colours is impracticable in this 
 department of art ; indeed, when we consider that the 
 effect of an engraving depends upon the total reflec- 
 tion of one portion of colourless light, by the surface 
 
200 AUTUMN. 
 
 of the paper, and the total absorption of another 
 portion by the surface of the ink, it becomes extra- 
 ordinary that simple engravings should convey to the 
 eye any correct notion of the appearances of surround- 
 ing objects. 
 
 The following ancient and popular proverb concern- 
 ing the " rainbow," affords one more example of a 
 refined physical truth appearing in plain homely 
 guise : 
 
 " A rainbow in the morning, is the shepherd's warning, 
 A rainbow at night, is the shepherd's delight." 
 
 " This old proverb is generally correct, as a rainbow 
 can only occur when the clouds containing or depositing 
 the rain are opposite to the sun ; and in the evening 
 the rainbow is in the East ; and in the morning in the 
 West ; and as our heavy rains in this climate are 
 usually brought by the westerly wind, a rainbow in the 
 West indicates that the bad weather is on the road by 
 the wind to us ; whereas the rainbow in the East proves 
 that the rain in the clouds is passing from us." 
 
 " As an indication of wet weather approaching, 
 nothing is more certain than a halo round the moon, 
 which is produced by the precipitated water, and the 
 larger the circle, the nearer the clouds, and conse- 
 quently the more ready to fall." 
 
 All things demand equal attention from him who 
 truly loves and desires knowledge ; thus the foregoing- 
 explanation of the homely proverb emanated from the 
 
AUTUMN. 201 
 
 most enlightened philosopher that ever devoted his 
 talents to the fascinating science of Chemistry. 
 
 Educated in strict accordance with, the inflexible 
 doctrines of " Inductive Philosophy," constantly in- 
 ferring and collecting general results, general facts, 
 and laws, from a number of particular instances care- 
 fully established on actual Experimental evidence, this 
 philosopher proved the utility of Chemistry when judi- 
 ciously applied towards increasing the resources, and 
 adding to the welfare of man ; demonstrated its im- 
 portance as a medium for interpreting the wonders of 
 natural phenomena ; concentrated all its varied rays, 
 by the mirror of truth, into one effulgent star of 
 light, for the moral and intellectual guidance of man, 
 towards " The First Author of Beauty who hath cre- 
 ated them all." 
 
 God, for the fulfilment of His inscrutable purposes, 
 has been pleased to take the spirit of this true philo- 
 sopher to a better and more elevated sphere than the 
 world that it was permitted for a few years to en- 
 lighten and adorn ; the voice that once poured forth 
 fervid eloquence regarding the wonders of the Crea- 
 tion, is hushed, and the hand that demonstrated them, 
 is closed in the silent, cold grave. 
 
 But those words of fervour, and works of skill, are 
 faithfully remembered, and zealously guarded by his 
 disciples who are yet permitted to remain ; and as they 
 follow at a vast distance the footsteps of their master, 
 they endeavour, as he did, to keep the laborious yet 
 certain path that is permanently illuminated by true 
 
202 AUTUMN. 
 
 experiment, and to shun the seductive uncertain mazes 
 that are capriciously lighted by the false fires of theory 
 and hypothesis. 
 
 In cases of doubt and indecision, reliance may always 
 be placed upon the light of experiment, because its rays 
 emanate from the rock of truth; theory and hypothesis 
 " impose upon the imagination like the ' mirage ' of 
 the Egyptian sands, but like this illusion they must 
 pass away ; they may present to the eye, a magnifi- 
 cence as seducing as the ' fata morgana ' oftentimes 
 witnessed on the coast of Calabria, in which the most 
 beautiful landscapes, crowned with picturesque villages, 
 superb palaces, and massy towers, seem to possess a 
 real existence ; all is but an aerial phantom ; the en- 
 chanted scene changes with the least shifting of the 
 light or the ruffling of the sea ; melting away like a 
 dream of the night ; so, ultimately vanish all systems 
 of Philosophy and Science that are not founded on the 
 solid basis of Induction." 
 
 The fleeting form of clouds has been attentively 
 studied by the meteorologist, and the refined instru- 
 ments that are employed in such researches enable him 
 to predict with considerable accuracy the probable state 
 of the coming weather ; although he yet remains in 
 ignorance concerning the manner in which vesicular 
 vapour is formed, or in which rain is relinquished from 
 the clouds. 
 
 In the absence of accurate scientific knowledge, and 
 refined meteorological apparatus, the husbandman in- 
 variably consults the appearance of the evening and 
 
AUTUMN. 203 
 
 morning sky, the actions of animals, the forms of 
 flowers, and is thus enahled to foretell if the weather 
 will be fair, or foul. 
 
 The sky guides him according to the proverbs ; and 
 if, in the morning, cattle low more than usual, and 
 stretch forth their necks, and snuff the air with ex- 
 tended nostrils, he expects rain ; if the chickweed be 
 quite open, and if the trefoil and bindweed stand out 
 boldly, no rain will fall : many flowers besides these, 
 close their petals against the approach of rain, but 
 these are most common, and most easily observed. 
 
 The presence of watery vapour in the air, or more 
 technically the " hydration " of the atmosphere, is 
 imperatively requisite for the welfare of the animal and 
 vegetable creation ; animals cannot breathe, neither 
 can plants grow, in dry or anhydrous air : their exqui- 
 site functions are immediately deranged, suspended, 
 and ultimately destroyed. 
 
 The chemist has now to direct attention to the fact 
 that absolutely pure water is a direct poison to aquatic 
 beings, and for their respiration, the water they inhabit 
 requires mixture with air, or aeration ; precisely the 
 same as the air in which we are placed, for our respira- 
 tion, requires mixture with the vapour of water, or 
 " hydration." 
 
 It has been already stated that pure water evaporates, 
 and collects in the atmosphere as clouds ; these by a 
 recondite power, not understood, yield it back to 
 the earth as showers. For the sake of illustration let 
 us imagine that rain falls into a hollow or basin, near 
 
204 AUTUMN. 
 
 the summit of a mountain, and accumulates as an 
 Alpine lake ; we ascend the mountain, and reach the 
 lake, and then experience something more than mere 
 bodily fatigue ; our breathing becomes difficult, per- 
 haps painful. 
 
 If we examine the water of the lake we find it either 
 very scantily supplied with fishes, or entirely free from 
 them. What is the reason of the oppression in breath- 
 ing that we feel, and the fact regarding the lake that 
 we discover ? As follows : the air is not so abundant 
 upon the mountain summit as it is in the valley ; it is 
 more rare, more attenuated at this elevation, and there- 
 fore our lungs do not receive the supply to which they 
 have been commonly accustomed, either in the valley, 
 or on the level earth : the water of the lake, thus ex- 
 posed to an atmosphere so rare, cannot exert attraction 
 for it, or become sufficiently aerated to support the 
 respiration of fishes. 
 
 Suppose even that aerated water were exposed at this 
 great elevation, it would immediately part with its air, 
 to supply the rarity of the surrounding atmosphere, as 
 it would to supply a vacuum : the following experiment 
 can be made in illustration of this fact. 
 
 Place a large glass, filled with clear river -or spring 
 water, beneath the receiver of the air pump, (page 117;) 
 then exhaust the air from it as already directed ; and it 
 will be found that myriads of small bubbles will rise 
 from all depths of the water ; these were originally 
 dissolved in it, and had no' tendency to escape under 
 the ordinary pressure of the atmosphere, but as the air 
 
AUTUMN. 205 
 
 is exhausted from the receiver, they are freed from 
 pressure, and therefore expand and rise, and ultimately 
 escape to supply the vacuum. 
 
 In place of allowing all the bubbles to escape, re- 
 move the screw, and admit the external air ; its pres- 
 sure will immediately force back those that remain into 
 union again with the water, which will appear pellucid 
 and clear as it did at first. 
 
 A portion of aerated water popularly so called, 
 either natural, as Pyrmont- water, or artificial, as soda- 
 water, after exposure to the air for half an hour, if 
 similarly experimented upon, will evolve more numerous 
 bubbles, than river or spring water ; but such bubbles 
 are not pure air, they are carbonic acid, formerly called 
 " fixed air," in the one case, combined with water 
 naturally by an unknown process, in the other artifi- 
 cially, by the force of machinery ; but in both cases 
 the sudden escape of the greater part of such carbonic 
 acid when the corks of the bottles are drawn, causes 
 the well-known effervescence ; all does not escape, for 
 at the end of half an hour sufficient remains dissolved 
 in the water to present an effervescence when in a 
 vacuum, and thus illustrates the point that we are 
 considering. 
 
 If rain water be boiled, the air that it contained will 
 be nearly expelled, and after allowing the water to cool 
 down to atmospheric temperature in a tightly corked 
 bottle, if we pour it from this, without guggling, into 
 a finger-glass, and then introduce a small fish, it will 
 show signs of distress by raising its head and gasping 
 
206 AUTUMN. 
 
 at the surface, and it would soon die if kept immersed ; 
 if it be removed, and the water poured from the height 
 of two or three feet, from one vessel to another, for a 
 few minutes, upon then immersing the fish it will not 
 show such signs of distress as at first. 
 
 The water, on the one hand, contained no air for 
 exciting the action of the respiratory organs of the fish, 
 it therefore gasped to obtain a supply from the external 
 atmosphere ; but, on the other hand, by pouring the 
 water for a time from one vessel to another, it became 
 aerated, and fitted to yield a supply to the fish when 
 introduced. 
 
 Fishes breathe in consequence of their respiratory 
 organs being fitted to withdraw oxygen, not from the 
 water itself, but from the air, that it is capable of dis- 
 solving and of holding in solution under ordinary 
 circumstances. 
 
 The chemist applies these facts to the explanation 
 of a natural phenomenon ; let us suppose that the 
 unaerated, unproductive water of the lake overflows its 
 bounds, and under the influence of gravitation dashes 
 as a cataract over the mountain side ; each moment 
 that it increases in velocity, it passes into denser and 
 denser regions of the atmosphere, and in the hurry and 
 turbulence of its fall, dissolves air, foams with bubbles, 
 and then flows onwards and throughout the vallies and 
 plains, as a stream or river, sufficiently aerated for 
 supporting the respiration of aquatic beings, and 
 accordingly we now find them in abundance. 
 
AUTUMN. 207 
 
 The description of this beautiful phenomenon may 
 be aided by reference to the engraving, in which the 
 horizontal shading being strong below, faint in the 
 centre, and faintest at the top, may denote as at page 
 122, that the atmosphere is heavy upon the level sur- 
 face of the earth, light at some height above, and 
 lightest at the elevation of the mountain summit. 
 
 Fig. 43. 
 
 Upon this, the unaerated water of the lake is sup- 
 posed to be ; and as it overflows and falls through the 
 successive strata of the atmosphere, as indicated by 
 the successive increase of the shading, it gains more 
 and more air, until upon its arrival in the heaviest air, 
 as indicated by the strongest shading, at the base of 
 the mountain it becomes turbulent with foam. 
 
208 AUTUMN. 
 
 The grandeur of a mountain torrent, cataract, or 
 waterfall, is chiefly referrible to the tremendous velocity 
 of its fall in the denser regions of the air, and the 
 powerful shock with which the water and air incorporate, 
 producing an enormous foam, 
 
 As such water traverses the surface of the earth in 
 its return to the parent ocean, it widens its course and 
 thus exposing a larger surface to the atmosphere, be- 
 comes more powerfully aerated, and likewise by the 
 rippling, the agitation, into which it is thrown by 
 breezes and winds. 
 
 If we fill a vessel with water, thus naturally and 
 wonderfully aerated, and place a fish in it, and then 
 secure the mouth of the vessel with an air-tight cover, 
 the creature will die when its respiration has consumed 
 the certain amount of oxygen that the air contained ; 
 it will die though immersed in water that contains 
 oxygen as an element, bat this is combined with 
 hydrogen, be it remembered, and the respiratory 
 organs of the fish have not the power of separating 
 it from such chemical combination, as they have from 
 its mechanical mixture with nitrogen, which constitutes 
 the chief volume of atmospheric air. 
 
 Fishes demand a constant supply of fresh aerated 
 water, the same as animals demand a constant supply 
 of fresh hydrated air, for both classes of beings are 
 soon destroyed by the mephitic products of their own 
 respiration. 
 
 The lavish abundance of air and water presented 
 throughout Nature, would alone probably ensure the 
 
AUTUMN. 209 
 
 fulfilment of these demands for oxygen, and ages might 
 elapse hefore either of these extraordinary media would 
 become vitiated, or unfitted for the maintenance of 
 life ; but the Creator has made the same beneficent pro- 
 vision for purifying water from the results of the respi- 
 ration of aquatic beings, as He has made for purifying 
 air from those of man and the higher order of animals. 
 
 Everything is miraculously balanced and adjusted 
 throughout the Creation, and displays the power and 
 goodness of God ; and above all branches of science, 
 that of chemistry is particularly favoured in being 
 permitted to become the medium of interpreting so 
 many wonders. 
 
 During the bright weather of Summer and Autumn 
 most plants that grow in ponds, pools, and streams, 
 and particularly those slender green filaments known 
 to the botanist as " conferva rivularis," are covered 
 with myriads of small air globules ; this is a common 
 " observation ;" the chemist devises means of col- 
 lecting thousands of these globules in a glass, and 
 finds that such aeriform volume will cause a lighted 
 taper to burn with far greater brilliancy than it burns 
 in the surrounding atmosphere : this is a simple 
 " experiment ;" he next reasons upon this, and guided 
 by " analogy" tries if all plants of a similar character, 
 when exposed to light, will present the same pheno- 
 menon ; he finds them to do so, and thus establishes 
 a " scientific truth." 
 
 These three essential requisites enabled us to recog- 
 
210 AUTUMN. 
 
 nize the plants of the earth, combining their agencies 
 for purifying the atmosphere from the mephitic results 
 of combustion, and the respiration of man, and the 
 higher order of animals ; they will now enable us to 
 recognize the plants of the water, combining their 
 agencies for purifying it from the mephitic results of 
 the respiration of fishes, and other aquatic beings. 
 
 When under the direct influence of solar light, the 
 slender green filaments of " confervse " have the power 
 of decomposing the carbonic acid, produced by the 
 respiration of fishes, and of eliciting oxygen nearly 
 pure; thus globules of this element, ascending and 
 collecting in the glass, will support the flame of a 
 taper with greater brilliancy than the surrounding 
 atmosphere containing nitrogen. 
 
 Two or three handfuls of " conferva rivularis " col- 
 lected carefully without injuring their fragile structure, 
 may be introduced into a large globular glass " carafe," 
 or " water-flagon," having a long and narrow neck 
 the narrower the better ; then fill the " carafe " witli 
 water from the pool, pond, or stream, in which the 
 plant grew, place one hand over the mouth of the 
 " carafe " to close it firmly, and with the other holding 
 the globular part, invert it ; pass the first hand beneath 
 the surface of three or four pints of water contained in 
 a shallow pan or glass, then withdraw it from the neck 
 of the " carafe ;" no water will escape from this, be- 
 cause the weight of such water is inferior to that of 
 the surrounding atmosphere ; thus the " carafe " will 
 
AUTUMN. 
 
 211 
 
 remain perfectly full, with its globular part containing 
 the " conferva " uppermost. 
 
 As on account of the weight being so much above 
 the narrow support of the mouth, the " carafe" would 
 be liable to fall from this upright position, carry the 
 arrangement to an open window where the sun is 
 shining with its greatest splendour, set the pan upon 
 the window-sill, place a heavy brick against the side 
 of the pan to prevent it from slipping, and then gently 
 move the " carafe" from its upright position still 
 keeping its mouth under water that its globular part 
 may securely rest against the corner of the window- 
 frame, as shown in the annexed engraving. 
 
 Fig. 44. 
 
 This simple arrangement is precisely similar in 
 principle, though upon a larger scale, to the well-known 
 " globe bird-fountain," that is placed in a " breeding- 
 cage," or the " conical bird- fountain " that is placed 
 
AUTUMN. 
 
 outside, with its horizontal neck passing through a 
 hole to the inside of a small bird-cage, and the 
 " carafe" will act similarly to both of these contri- 
 vances. 
 
 For example, the water in each " fountain " is pre- 
 vented from running out by atmospheric pressure ; but 
 as the birds gradually sip away the water from the 
 " cistern" of the one, or the neck of the other, air will 
 gradually bubble up into the globe or cone, and cause 
 the fall of an equal portion of water : as this is gra- 
 dually drank, air will again gradually ascend, water 
 will again descend ; so that, at length, each fountain 
 will be exhausted of water, or " dry," and will only 
 contain air. The great utility of each contrivance is 
 that only a very small surface of water is presented to 
 the surrounding air, and therefore it cannot " dry 
 away," or evaporate with the rapidity that it does from 
 a wide shallow glass, or even from a common i( bird- 
 glass ; " it remains as a refreshing store for the birds 
 for many days without requiring replenishing. 
 
 These " bird-fountains," simple as they may appear, 
 and unworthy of attention as they may be thought, 
 involve the principle upon which all the refined and 
 accurate apparatus is constructed by the chemist for 
 extending his researches regarding the nature of 
 aeriform matters or gases, be they either invisible as 
 Oxygen, or coloured as Chlorine. 
 
 From facts, and contrivances the most simple, have 
 emanated some of the most important and invaluable 
 discoveries and inventions which adorn not only che- 
 
AUTUMN. SI 3 
 
 mislay, but every other experimental science ; but tbe 
 pursuit of chemistry more particularly does not ne- 
 cessarily involve the possession of costly and compli- 
 cated apparatus ; SIMPLICITY, not mystery, is its aim, 
 and by endeavouring to keep this steadily during our 
 inquiry, we have been enabled, and shall yet be ena- 
 bled to conduct many curious and instructive experi- 
 ments with materials of common occurrence. 
 
 The splendid show of costly and beautiful apparatus 
 that appears on the well- arranged table of the public 
 lecturer, is imperatively demanded,, because he has to 
 demonstrate the facts of science to assembled hundreds ; 
 experiments therefore require to be made upon a large 
 scale, with the greatest promptitude, and as far as 
 possible with success, that all the audience may see, 
 and may be simultaneously convinced of the facts under 
 discussion, for the lecture-room is not the arena for 
 individual instruction. 
 
 But in the quiet of the laboratory, much of the appa- 
 ratus of the lecture-table may be dispensed with, and 
 important facts discovered by simple means : thus the 
 grand discovery of the element Oxygen, which, about 
 seventy years since, completely changed the whole 
 aspect of the science of chemistry, was made by em- 
 ploying a globular glass, or flask, about the size of that 
 of the " bird-fountain," and inverted like it into a small 
 " cistern," but instead of containing water, both vessels 
 contained mercury, and in that of the globular glass 
 was placed a portion of a compound from which, when 
 heated by the rays of the sun in August, drawn to a 
 
214 AUTUMN. 
 
 focus in a powerful burning lens, Oxygen was at length 
 evolved, and collected, as the air may be collected, in 
 the " bird-fountain." 
 
 But in the arrangement with the " carafe," water, 
 and " conferva," the artificial concentration of the heat 
 of the sun is not required, its natural splendour alone 
 is necessary ; and after it has beamed upon the " con- 
 ferva" for an hour, the slender filaments of the plant 
 will be studded with beautiful globules of Oxygen ; 
 these gradually increase in size, and then either spon- 
 taneously quit the attraction of the filaments, or will 
 do so upon slight agitation of the " carafe," and as- 
 cending to its upper part, there, after a few hours, 
 by the addition of other globules which continue to 
 rise, all will coalesce into one large bubble, a portion of 
 water of corresponding volume having descended into 
 the glass pan, this water being expelled by the oxygen 
 evolved within, exactly as in the " bird-fountain " it is 
 expelled by air ascending from without. 
 
 Allow the arrangement to remain exposed to the sun 
 throughout the whole summer or autumnal day, to 
 obtain as much oxygen as possible ; kindle a very small 
 wax taper attached to the end of a wire, as at page 57 ; 
 then pass one hand beneath the water to close the 
 mouth of the " carafe," and with the other lift it ; and 
 place it to stand upon the table, as the flask at page 
 58, and as in that the air ascended, so in this, the oxy- 
 gen evolved by the " conferva" will ascend and occupy 
 the neck of the ;< carafe ;" slide away the hand from its 
 mouth, quickly introduce the lighted taper, and its 
 
AUTUMN. 21 5 
 
 flame will burn with far greater brilliancy than it did 
 previously in the surrounding atmosphere. Why ? 
 
 Because the carbon which first was an element of 
 the living bodies of fishes, was converted into carbonic 
 acid by their respiration, and so exhaled as a poison 
 to them, but under the influence of light, the growing 
 plants were enabled to convert it into nutriment for 
 themselves by secreting the Carbon, and thus eliciting 
 pure Oxygen ; and there being no diluent Nitrogen 
 present as in the atmosphere, there is no barrier or 
 impediment to the intensely rapid combination of such 
 Oxygen with the Carbon and Hydrogen of the taper, 
 consequently its flame is greatly enhanced in brilliancy 
 and swiftness of combustion. 
 
 The researches of the chemist warrant the conclu- 
 sion that fresh-water plants, and likewise marine plants, 
 derive the chief, if not the whole portion of their con- 
 stituent carbon from carbonic acid, either absorbed 
 directly by the waters from the atmosphere, or produced 
 by the respiration of fishes; and thus both the vege- 
 tation of the earth and of the waters, may be equally 
 active in keeping the just balance of the atmosphere for 
 the life of man and animals, as for preserving their 
 own proper degree of aeration for the support of aquatic 
 beings. 
 
 The vesicles of the sea- weed called " fucus vesicu- 
 losus," or more commonly " bladder-wrack," when 
 recent, contain air more highly oxygenated than the 
 atmosphere, and after having filled the " carafe " with 
 
210 AUTUMN. 
 
 water, and inverted it as directed, if several of these vesi- 
 cles be punctured with a pin when immersed just below 
 the mouth of the " carafe," and then gently pressed, 
 air may be collected from them, which will support 
 the flame of a taper with greater brilliancy than the 
 external atmosphere. 
 
 Such, then, are the simple experimental illustrations 
 of the miraculous provision that is made in Nature for 
 decomposing the mephitic results of the respiration of 
 fishes, by the vital functions of plants ; and it reveals 
 to us another instance of the mutual dependencies of 
 the two organic kingdoms. Fishes produce and exhale 
 carbonic acid, growing plants stimulated by solar light, 
 decompose such compound, and increase their own 
 structures by absorbing and combining with its car- 
 bon, emitting the oxygen, ready to dissolve again in 
 the water, or to ascend to its surface, and there min- 
 gle in due proportion with nitrogen. 
 
 This mixture the water again absorbs, again its 
 oxygen supports respiration, again carbonic acid is 
 produced by the fishes, again this is decomposed by 
 the plants, and from being mephitic it becomes a 
 pabulum of life : thus incessantly does this wonderful 
 action continue, and furnish a proof of the wisdom and 
 power of the Almighty in providing for the welfare of 
 His creatures. 
 
 It is necessary in the foregoing experiment to have 
 the glass " carafe " as large as possible ; indeed one 
 of the globular " show-bottles of a druggist's shop- 
 
AUTUMN. 217 
 
 window is preferable, if it can be obtained ; plenty 
 of " conferva " also is required ; and if this cannot 
 be easily procured, several bunches of fresh water- 
 cresses," or of " chick-weed," may be substituted ; 
 and thus probably sufficient oxygen will be at length 
 collected for proving its power of enhancing the bril- 
 liancy of the flame of the taper ; but should there 
 not be sufficient for this purpose, the fact of the glo- 
 bules of the element appearing on the leaves of the 
 several plants, will always be manifest in the bright 
 sunshine. 
 
 We now discover the reason that fishes placed in 
 marble basins or glass globes, filled with river water, 
 so frequently become languid and sickly ; they were 
 taken from a pond or stream of water fully and power- 
 fully aerated, and fitted for their respiration by the 
 vital action of growing plants ; they are suddenly trans- 
 ferred into a confined portion of the same water, and 
 in proportion as they consume the oxygen of its 
 aeration, they load it with carbonic acid, and no 
 growing plants being present to decompose this, they 
 must inevitably suffer in health, and will ultimately die 
 if the water be not repeatedly changed. 
 
 It therefore becomes necessary for the life of fishes, 
 in marble basins and glass globes, either to change 
 the water repeatedly, or what is much better, as se- 
 lected from the perfect example of Nature, to intro- 
 duce some aquatic plants, not only to decompose the 
 results of the respiration of the fishes, but to afford them 
 
 L 
 
218 AUTUMN. 
 
 shelter from the solar rays ; for these beautiful crea- 
 tures demand such protection as imperatively as we 
 ourselves ; strange as it may appear, it is nevertheless 
 a fact, that light- coloured or silvery- white fishes espe- 
 cially, although in clear water, are sometimes scorched 
 by solar heat. 
 
 A " silver fish " had long been the brilliant and 
 spotless inhabitant of the clear water of a pond sur- 
 rounded by lofty trees, casting shadows in which it 
 could occasionally derive shelter from the direct rays of 
 the sun; when these trees were ultimately cut down, and 
 the waters thus exposed to the full unmitigated glow 
 of light, the fish shortly appeared with a brown spot 
 upon its back, like a scorch ; this increased in colour 
 and size, and according to the examination of a na- 
 turalist and physiologist, it was certainly a f<r sun-burn," 
 but how produced ? 
 
 As follows : solar radiant heat will pass through air, 
 water, crystal, glass, or any other perfectly transparent 
 substances, without imparting any portion of heat to 
 them, but when the rays impinge upon solid opaque 
 bodies, heat is immediately arrested and absorbed ; 
 thus the silver back of the fish was scorched by its solid 
 tissue absorbing the heat that had passed throughout 
 the water without elevating its temperature. 
 
 A direct experiment can be performed in proof of 
 this curious fact : obtain a very large " gold-fish- 
 globe," wipe its exterior and interior perfectly clean, 
 fill it with the most pellucid water that can be pro- 
 
AUTUMN. 219 
 
 cured, place it to stand upon a sheet of white paper in 
 the bright sunshine, and then with a large glass lens, 
 or " burning- glass," collect the rays of the sun to a 
 focus, (in a manner familiar to every schoolboy,) and 
 direct this focus through the surface of the water in 
 the globe ; the transparent " burning-glass " will not 
 become hot, neither will the transparent water into 
 which its focus or "fire-place" falls; as may be 
 proved by the introduction of the bulb of a thermo- 
 meter painted with white-oil paint, near, but not in the 
 focus. 
 
 If the opaque bulb touch the focus, then the radiant 
 light and heat are immediately absorbed and converted 
 into sensible heat, as the mercury of the thermometer 
 will indicate by rapidly ascending in its tube ; and if a 
 very powerful leus be used, a piece of wood placed in 
 the focus imder water will be charred, or the hand 
 even scorched ; or other solid bodies be so heated, that 
 the water in contact with such surfaces will become 
 warmed, convective currents will be established, and 
 thus indirectly the temperature of the whole bulk will 
 be raised, but neither directly by radiant heat, nor by 
 conduction ; of this latter more hereafter. 
 
 Again, remove the " conferva " or other plant from 
 the " carafe," cleanse its exterior and interior tho- 
 roughly, fill it perfectly full of the clearest water that 
 can be obtained ; then tie a piece of well-moistened 
 bladder closely over its mouth, and holding the neck, 
 turn the globular part upwards ; it will now, though 
 
 L 2 
 
220 AUTUMN. 
 
 full of liquid water, appear like a solid ball of glass ; 
 hold it in the sunshine, and move one hand about, at 
 the distance of a few inches from the part of the globe 
 opposed to that upon which the solar rays impinge, 
 and a powerful focus of heat will soon be discovered, 
 by the pain that the hand experiences ; nay, this focus 
 will kindle a piece of " German tinder," although the 
 glass and the water remain cold. 
 
 Hence the danger of leaving globular " carafes " and 
 " gold-fish- globes " perfectly filled with water, near 
 window- curtains, papers, or " Lucifer matches," dur- 
 ing a brilliant summer day ; the position of the " ca- 
 rafes " and '* globes " might be accidentally such as to 
 direct their burning " foci " upon the inflammable ma- 
 terials ; indeed this actually happened to a box of 
 matches near a globular show-bottle of transparent 
 liquid in a shop window. 
 
 These are a few of the curious discoveries that re- 
 ward the Investigations of the experimentalist, and 
 they cannot fail to awaken his feelings of interest and 
 admiration regarding the extraordinary powers and 
 properties of matter ; we must now turn to other things 
 equally wonderful, and in many cases doubtless equally 
 important, although the exact part that they enact in 
 the vasfc laboratory of Nature may not be as yet com- 
 prehended. 
 
 During Summer and Autumn, we may very fre- 
 quently observe large air-bubbles spontaneously col- 
 lecting, and bursting upon the surface of stagnant 
 
AUTUMN. 
 
 water ; and if we disturb the mud beneath with a pole 
 or rake, many thousands of such bubbles will quickly 
 appear. 
 
 The Chemist has devised means similar in principle 
 to those described, for collecting this exhalation, and 
 upon analysis, he discovers it to be neither atmospheric 
 air nor oxygen, but a gas composed of Carbon and 
 Hydrogen, combustible, and burning with a yellow 
 flame ; in these respects it is identical with the " Fire 
 damp " of coal mines, and closely analogous to the 
 " Gas " obtained from coal for the purpose of artificial 
 illumination ; and therefore to denote that it con- 
 tains the above elements, it is called " Carburetted 
 Hydrogen." 
 
 The Chemist presumes this gaseous compound to be 
 formed in stagnant water by the spontaneous decay or 
 decomposition of its vegetable productions ; and when 
 it is kindled, either by lightning, or some unknown 
 agent, it is probably the cause of the light that so fre- 
 quently appears during Summer and Autumnal even- 
 ings, flickering and dancing over the surface of boggy 
 and marshy soils, presenting the phenomenon called 
 " Ignis fatuus," or popularly the " Jack-o'-Lantern," 
 or the " Will-o'-the-Wisp." 
 
 In this country, the beautiful spontaneousjrlight of 
 the " glow-worm," and that of the common " hundred 
 legged worm" when irritated, are both popularly known ; 
 but in hotter climates the " lantern fly" and " fire fly" 
 exhibit this luminous appearance in a degree yet more 
 remarkable ; nothing certain has been ascertained re- 
 
222 AUTUMN. 
 
 garding the cause of the phenomenon, it is prohably 
 referrible to the slow combustion of Phosphorus which 
 these insects have the power of secreting ; as this light 
 may be imitated by gently rubbing the tip of " phos- 
 phoric paste " of a " Lucifer match " in the dark. 
 
 The decayed or " touch- wood " of old forest trees 
 may be often observed to emit a pale light sponta- 
 neously ; also some kinds of fungi, if struck, as by the 
 foot in walking over them at night ; some flowers, as 
 the tuberose, nasturtium, and marigold, occasionally 
 present flashes of light towards the close of warm 
 evenings. 
 
 The chemist has not discovered the cause of these 
 extraordinary phenomena, and therefore for want of 
 knowledge contents himself with denoting them under 
 the general title of " Phosphorescent" substances." 
 
 Several animal substances are thus " Phosphores- 
 cent " when deprived of vitality, and long before their 
 putrefaction commences ; and of these the flesh of the 
 carp, tench, herring, sole, crab, and lobster, are the 
 most remarkable ; this phenomenon of luminosity is 
 seldom presented by the dead flesh of quadrupeds, 
 and never by that of birds under any circumstances of 
 putrefaction. 
 
 Water has frequently engaged our attention as a 
 most active agent in promoting not only the growth, 
 but when that ceases, the decay of vegetation ; and 
 this is especially the case when the element Nitro- 
 gen enters into the constitution of organized struc- 
 tures. 
 
AUTUMN. 223 
 
 " The doctrine of the proper application of manures 
 from organized substances, offers an illustration of an 
 important part of the economy of Nature, and of the 
 happy order in which it is arranged. 
 
 " The death and decay of animal substances tend to 
 resolve organized forms into chemical constituents ; 
 and the pernicious effluvia disengaged in the process, 
 seem to point out the propriety of hurying them in 
 the soil, where they are fitted to "become the food of 
 vegetables. 
 
 " The fermentation and putrefaction of organized 
 substances in the free atmosphere, are noxious pro- 
 cesses; beneath the surface of the ground they are 
 salutary operations. 
 
 " In this case, the food of plants is prepared where 
 it can be used ; and that which would offend the senses 
 and injure the health, if exposed, is converted by gra- 
 dual processes into forms of beauty and of usefulness ; 
 the fetid gas is rendered a constituent of the aroma of 
 the flower, and what might be poison, becomes nourish- 
 ment to animals and to man." 
 
 It has long been familiar to physicians, that there is 
 produced by wet lands, or by marshes and swamps, a 
 poisonous and aeriform substance, the cause not only 
 of ordinary fevers, but of intermittents ; and to this 
 unknown agent of disease the term " marsh-miasma " 
 has been applied ; nor is such knowledge confined to 
 physic ; throughout the world it is a fact known to the 
 vulgar and even to the less enlightened nations. 
 
 It is familiar to the rural inhabitants of Lincolnshire 
 
224 AUTUMN. 
 
 and Essexr^io refer to the fens of these districts as 
 the source of the agues under which they so commonly 
 suffer ; it is known to the rural inhabitants of certain 
 districts of France, Holland, and Italy, in this last 
 country more particularly, as " malaria ; " it is also 
 known to the uncivilized negroes of Africa. 
 
 The fairest portions of Italy are a prey to this in- 
 visible enemy "malaria;" the fragrant breezes are 
 poison, the dews of its summer evenings are death. 
 the banks of its refreshing streams, its rich and flowery 
 meadows, the borders of its glassy lakes, the luxuriant 
 plains of its overflowing agriculture, the valleys where 
 its shrubs regale the eye and perfume the air, are the 
 appointed regions of this " malaria." 
 
 Death here walks hand in hand with the resources 
 of life, sparing none ; the labourer reaps his harvest 
 but to die ; or, he wanders amid the luxuriance of 
 vegetation a sufferer from his cradle to his grave ; aged 
 even in childhood, and laying clown in misery that life 
 which was but one disease. He is even driven from 
 some of the richest portions of this fertile, yet unhappy 
 country; and the traveller contemplates at a distance, 
 deserts, but deserts of vegetable wealth which man dare 
 not approach or he dies. 
 
 Such is the picture of the noxious influence of these 
 exhalations, which the Creator for some inscrutable 
 purpose has ordained to reign in certain districts of 
 this fair world. 
 
 This " marsh miasma," or " malaria," often exerts its 
 baneful power upon the husbandman in our country, 
 
AUTUMN. 225 
 
 at .a time when his bodily strength and activity are 
 most demanded for the pursuit of his labours ; and 
 therefore he devises all possible means for arresting its 
 sway , cutting down the vegetation, removing the 
 putrefying and corrupting mass, sedulously draining 
 off the stagnant water of marshes ; and thus he can 
 occasionally improve the salubrity of districts within 
 certain limits ; but some districts are so extensive and 
 so contaminated, as to defy amelioration by the utmost 
 exertions of human foresight and labour, and they 
 remain proverbially insalubrious. 
 
 In crowded cities and towns, where the buildings 
 are imperfectly ventilated, badly drained, and scantily 
 supplied with water, if animal or vegetable offal be 
 suffered to accumulate through indolence or neglect, 
 and thus putrefy in the heat of Summer or Autumn, 
 infectious or contagious matters are inevitably evolved 
 or produced, and occasionally display their deadly 
 powers in all the horrors of plague and pestilence. 
 
 The Almighty has not permitted the Chemist to dis- 
 cover the nature or the elements of such attenuated 
 exhalations, they elude all detection ; for if he take a 
 volume of stagnant air from the foul " plague ward ' ' 
 of an Egyptian hospital, where crowds of livid and 
 cadaverous beings are hourly stricken with the agonies 
 of death; his analysis will prove it to contain the 
 exact proportions by weight and by measure of ele- 
 ments and compounds, as those contained in an equal 
 volume of a balmy breeze taken from a free and open 
 English valley, where all are smiling with the ines- 
 
 L 5 
 
226 AUTUMN. 
 
 timable blessing of health, and glowing with its bronzed 
 and ruddy hues. 
 
 But the Almighty has mercifully permitted the Che- 
 mist to discover and to employ the power of destroying 
 both contagious and infectious exhalations, and of 
 thus averting within certain limits, the dreadful judg- 
 ments of plague and pestilence. 
 
 From the atmosphere itself, the Chemist is per- 
 mitted to produce a compound, and from the salt of 
 the ocean, to elicit an element for destroying contagion 
 and infection; these miraculous compound and elemen- 
 tary gifts, have been already mentioned under the 
 respective titles of Nitric acid and Chlorine. 
 
 Nitric acid is a compound of Oxygen and Nitrogen, 
 this latter term implying " generator" or " producer" 
 of Nitre, because the continued passage of electricity 
 through a portion of air, contained in a vessel also 
 holding a solution of potash, eventually produces crys- 
 tals, precisely resembling in shape and composition 
 those of native Nitre, or " salt petre," which consist- 
 ing of Nitric acid and Potash, is called Nitrate of 
 Potash. 
 
 This extraordinary compound is abundantly pre- 
 sented in a crystalline form by certain soils of oriental 
 countries, and the Chemist can obtain Nitric acid from 
 it with much greater facility and in larger quantities 
 than he can do by exciting the direct union of the 
 elements of the air by electricity; but he is led to con- 
 clude, that the word Nitre, as it occurs in Scripture, 
 does not denote the compound now under considera- 
 
AUTUMN. 227 
 
 tio.n, and the following are the facts which lead him to 
 this conclusion. 
 
 " Though thou wash thee with nitre, and take thee 
 much sope." 
 
 And again ; " As vinegar upon nitre, so is he that 
 singeth songs to a heavy heart." 
 
 Nitre, salt-petre, or Nitrate of potash, is unfit for em- 
 ployment as a detergent in washing, neither will it form 
 a soap ; and vinegar poured upon it produces no re- 
 markable effect ; but another crystalline product of the 
 earth, closely resembling it in appearance, is here to be 
 understood by the word Nitre, viz. a natural compound 
 of Carbonic acid and Soda, a Carbonate of soda, which 
 dissolves in a very small quantity of water ; and such 
 solution is used for washing in many parts of Asia, 
 and when mixed with oil it forms soap ; the crystalline 
 substance itself from these two circumstances, and 
 being abundantly found in Egypt and various parts of 
 Asia, is called " soap-earth." 
 
 Upon this " soap-earth," or Carbonate of Soda, if 
 Vinegar be poured, the two substances are found in- 
 compatible with each other ; a foam or effervescence of 
 Carbonic acid is immediately expelled, and as vinegar 
 was well known in the remotest ages, the fact of its 
 action upon ancient nitre, or " natron," or the fact of 
 the opposition between the two substances, is taken as 
 the foundation of a beautiful and powerful metaphor for 
 illustrating the equally extreme incompatibility between 
 songs and a heavy heart. 
 
 Probably the term Nitre was applied to both nitrate 
 
228 AUTUMN. 
 
 of potash and carbonate of soda, from the circumstance 
 of their simultaneous occurrence in eastern countries, 
 and their mutual resemblance in appearance when ex- 
 tracted in a crude state from the earth. 
 
 The chemist discovers that an acid called sulphuric 
 acid to denote that it contains more oxygen than the 
 sulphurous acid with which the flowers were bleached 
 at page 98, is as perfectly incompatible with the Nitre 
 of nitrate of potash, as is the vinegar or acetic acid with 
 the nitre of carbonate of soda ; and when sulphuric acid 
 and nitrate of potash are mingled together in a saucer, 
 and a moderate heat applied, that the sulphuric acid 
 combines with the potash, forming a sulphate of potash, 
 and expels the Nitric acid in fumes combined with 
 water that the former acid contained ; thus making 
 the experiment in an infected atmosphere with a suffi- 
 cient quantity of materials, the hydrated fumes of the 
 nitric acid will destroy the mephitic matters. 
 
 Sulphuric acid frequently occurs native, particularly 
 in the lakes and waterfalls of volcanic districts, but it 
 is artificially formed in the chemical laboratory by 
 burning sulphur mingled with nitre in air, and thus 
 by the intervention of the oxygen contained in the 
 Nitric acid of the Nitre, the fumes which would other- 
 wise be only sulphurous acid, are incited to combine 
 with more oxygen, and become those of sulphuric acid, 
 which immediately dissolve in the water that is simul- 
 taneously presented. 
 
 Salt, which is the great natural source of the element 
 chlorine, may be obtained from the water of the ocean, 
 
AUTUMN. 229 
 
 or from that of brine springs, by exposure of either in 
 large shallow pits to the evaporating action of solar 
 heat, or in pans to the vaporising agency of artificial 
 heat applied beneath, as in ordinary boiling ; in both 
 cases the solid fixed salt will remain. 
 
 Both processes are conducted upon a gigantic scale 
 for supplying salt, which is an essential addition to the 
 food of man and animals ; it is therefore most lavishly 
 presented, not only in the waters of the ocean, or of 
 brine springs, and thus requiring an amount of che- 
 mical knowledge for its extraction, but as a solid crys- 
 talline deposit of vast extent in the strata of the earth, 
 and only demanding mechanical labour for its " get- 
 ting." 
 
 This variety of salt is called " rock-salt," to denote 
 its native, hard, and solid state, whilst the two varieties 
 already named are called " sea-salt," and " bay-salt," 
 the latter term denoting the vessel technically called 
 " a bay,"" in which the brine is pent up, or subjected to 
 the action of heat, or to denote that it was formerly 
 caused to form a small " salt-bay " over a certain tract 
 of land for spontaneous evaporation to ensue. 
 
 Kock-salt is quarried like stone in large crystalline 
 masses, sometimes pure, colourless, and transparent as 
 ice, at others variously coloured by native metallic 
 compounds, or contaminated to a considerable extent 
 by sulphate of lime, or gypsum ; this last variety of 
 rock-salt, upon exposure to moist air, will soon lose its 
 actual saline matter, or chloride of sodium, by the sol- 
 vent power of the watery vapour, which having no 
 
230 AUTUMN. 
 
 such action upon the gypsum, that will remain solid 
 and devoid of taste. 
 
 A natural analysis, or separation of the common-salt 
 from the gypsum is thus effected, similar to the artifi- 
 cial analysis or separation of the salt from the sand in 
 the experiment at p. 43, and knowledge of these facts 
 enables the Chemist to venture upon an interpretation of 
 the following Scripture passage, in which, as in many 
 others, allusion is made to familiar things in order to 
 convey important truths to obdurate minds. 
 
 " If the salt hath lost its saltness, wherewith shall 
 ye salt. It is fit for nothing but to be cast out : and 
 trodden under foot." 
 
 In this case the salt, from its universal employment 
 as a savour to food, being the valuable, and the gyp- 
 sum, from its inapplicability to such purpose being the 
 comparatively worthless portion of the compound mineral 
 product. 
 
 " Can that which is unsavoury be eaten without 
 salt ? or is there any taste in the white of an egg ?" 
 
 This passage evidently proves that the use of salt as 
 taken with food, to confer flavour upon it, was known 
 in the remotest ages, but the reason of its utility in 
 entering from food into the constitution of the blood, 
 and likewise its own composition, have only been de- 
 termined of late years ; the fact as regards composition 
 most concerns this inquiry. 
 
 Unlike Nitric acid from Nitre, Chlorine cannot be 
 directly educed from salt or chloride of sodium, but by 
 the action of sulphuric acid, a produce or compound 
 
AUTUMN. 231 
 
 can be obtained, from which the chemist can educe the 
 element of which he is in search, and employ it as a 
 disinfecting agent. 
 
 Place about a quarter of an ounce of salt in a saucer, 
 and pour upon it twenty or thirty drops of sulphuric 
 acid ; dense white fumes will immediately arise, pre- 
 cisely similar in appearance and chemical composition 
 to those which destroyed the geranium or myrtle at 
 page 97, and having an equal destructive power upon 
 such or other plants ; these fumes were called hydro - 
 chloric acid, and by peculiar management when dis- 
 solved in water by the chemist they constitute the 
 hydrated or liquid hydrochloric acid with which the 
 experiment was made. 
 
 Salt has been repeatedly spoken of as a chloride 
 of sodium, why then does hydrochloric acid, a com- 
 pound of chlorine and hydrogen, appear from salt 
 that contains no hydrogen ? As follows : although the 
 salt contains no elements save chlorine and sodium, 
 the sulphuric acid contains water, and Water contains 
 both Hydrogen and Oxygen : accordingly during 
 this apparently simple experiment a refined chemical 
 change ensues ; the sodium of the salt unites with the 
 oxygen of the water to form oxide of sodium or soda, 
 and this directly unites with the real sulphuric acid to 
 produce sulphate of soda ; whilst the chlorine that was 
 with the sodium, but now emancipated, combines with 
 the hydrogen that was with the oxygen ; and thus the 
 two elements, Hydrogen and Chlorine, produce Hydro- 
 chloric acid ; the result is a product, not an educt. 
 
232 AUTUMN. 
 
 - 
 
 Rub a quarter of an ounce of Salt, with half an ounce 
 of " Red-lead," i. e. an oxide of lead, to fine powder ; 
 place this in an ale-glass; slowly add a teaspoonful of 
 sulphuric acid to a teaspoonful of water contained in a 
 gallipot ; and when this diluted acid is cold, pour it 
 into the ale-glass, stir it with a piece of stick ; and 
 now, in addition to sulphate of soda, as in the last 
 experiment, a portion of sulphate of lead is formed 
 simultaneously with hydrochloric acid, but this acid is 
 immediately de-hydrogen ated by a part of the oxygen 
 of the original oxide of lead ; water is formed, and 
 
 * then Chlorine is truly educed, in the state of a yellow 
 
 ^vapour which arises in the glass. 
 
 For the purpose of fumigation, the chemist generally 
 prefers to educe Chlorine from a compound well known 
 as " Chloride of Lime" more correct would be the 
 expression " Chlorinated Lime : " this compound has 
 the invaluable property, when exposed to an in- 
 fected atmosphere, of slowly evolving chlorine, which 
 mingling with mephitic matters, deprives them of vi- 
 rulence more effectually than even the action of nitric 
 acid. 
 
 The simplest method of proceeding to fumigate a 
 small apartment is to select ten or twelve earthenware 
 flower-pans, and place in each of them six or eight 
 ounces of chlorinated lime ; then arrange these pans, 
 some near the ceiling, others near, or upon the floor, 
 then close the doors and windows, and leave all undis- 
 turbed for a day or two, in the course of which time 
 the carbonic acid of the air will have expelled much of 
 
AUTUMN. 233 
 
 the chlorine from the compound ; the windows of the 
 apartment must then be opened from the outside, and 
 fresh air allowed to sweep through previous to opening 
 the door, for many persons are seriously affected by a 
 very slight inhalation of chlorine ; the chlorinated lime 
 may be then stirred in the pans with a piece of stick, 
 and again left, shut up, for a similar time. 
 
 The whole of the chlorinated lime may next be put 
 into one large deep pan, much larger than is sufficient 
 to hold it ; this is to be placed on the top of a pair of 
 steps, so as to be near the ceiling, and then, having 
 shut the windows, quickly pour about a quart of 
 vinegar into the pan, and immediately quit the room, 
 closely shutting the door. 
 
 The affusion of the vinegar will now liberate all the 
 chlorine that the compound might yet contain, and 
 after a day or two, the room may be entered with the 
 above precautions, and the residue in the pan carefully 
 thrown away. 
 
 In extensive fumigations, chlorine is generally 
 evolved from a mixture of four pounds, by weight, of 
 common salt, one pound of oxide of manganese, two 
 pounds of sulphuric acid, and two of water ; no pre- 
 cautions are required for mixing the two former, but 
 great precautions are required as regards the two 
 latter. 
 
 The water must be placed in an earthenware bowl, 
 and then the sulphuric acid must be added in a very 
 slender stream, the mixture of the two liquids being 
 rapidly promoted by stirring them together with a flat 
 
234 AUTUMN. 
 
 piece of wood ; it must then be allowed to cool before 
 use. 
 
 If sulphuric acid be plentifully and suddenly added 
 to water, the heat evolved by the meeting of the two 
 cold liquids is so great that it will inevitably break a 
 glass vessel, and very likely one of earthenware : why 
 is the heat evolved ? 
 
 Because the water, which is the lightest liquid of the 
 two, when it energetically combines with the sulphuric 
 acid has its density increased, and therefore its capa- 
 city for heat diminished in a far more remarkable 
 degree than in the experiment with water and spirit of 
 wine, as detailed at page 113, and most dangerous 
 accidents have happened to persons in ignorance of 
 this fact. 
 
 The mixture of common salt and oxide of manganese 
 must then be weighed into five portions of one pound 
 each, and placed in as many quart or three pint earthen- 
 ware basins upon the five topmost " treads" of a pair of 
 steps set in the centre of the room, the windows being 
 closed ; then, with a half- pint jug dipped into the cold 
 diluted acid, a quantity of it sufficient to fill about 
 three parts of the jug must be baled out and poured 
 upon the mixture contained in the uppermost of the 
 pans, then a similar quantity upon that in the second, 
 third, fourth, and fifth, as quickly as possible, the 
 operator always taking care to avoid placing his face, 
 either level with, or below the pans, this he can do 
 by standing on another pair of steps, more elevated 
 
AUTUMN. 235 
 
 than the first, and placed close alongside ; he must 
 then quickly descend and quit the apartment, shutting 
 and securing the door. 
 
 Should any chlorine be accidentally inhaled, the 
 readiest means of alleviating the distressing coughing 
 that it produces, is to saturate a lump of sugar with 
 brandy, and a few drops of " sal volatile," and then to 
 hold the sugar in the mouth until it dissolves. 
 
 The basins may remain for two days, then the win- 
 dows of the apartment being opened from the outside, 
 as already directed, when the odour of chlorine is no 
 longer strongly perceptible, the apartment may be en- 
 tered without danger, the basins removed, their ex- 
 hausted contents thrown away, and then they may be 
 again charged and arranged with all former precautions, 
 and left for a similar time, and subsequently removed 
 with the same careful observance. 
 
 The apartment may then be considered to have un- 
 dergone a thorough fumigation, for neither infectious 
 nor contagious matter can insidiously lurk in the pre- 
 sence of chlorine. 
 
 The pans containing the " chlorinated lime/' and 
 the basins containing the mixture of which mention 
 has been just made, are directed to be placed near the 
 ceiling of the room, because the evolving chlorine is 
 more than twice as heavy as the air, and therefore will 
 descend and uniformly mi ogle with it, which is the 
 grand object of the whole proceeding; if, however, 
 the vessels were placed on the floor, the heavy chlo- 
 rine would chiefly repose there as a distinct stratum 
 
236 AUTUMN. 
 
 and not rapidly diffuse its powers throughout the main 
 volume of the air. 
 
 The precaution to be observed by the operator, in 
 proceeding quickly with the addition of the acid, and 
 in keeping his head above, and not at or below the 
 vessels, is in the first place that the evolution of chlo- 
 rine may commence from all within a few seconds, and 
 in the next, that he may avoid inhaling any portion of 
 the descending poisonous element, for a poison it is, 
 although applied for the destruction of another poison ; 
 if he can hold his breath during the few seconds that 
 are required for the addition of the acid and his descent 
 from the steps it will be so much the better. 
 
 The chemist, therefore, discovers an extraordinary 
 fact in illustration of The power by which elements 
 and compounds are controlled, viz., that chlorine in its 
 pure uncombined state is a poison, and a destroyer of 
 poison, whilst in combination with the metal sodium, 
 it forms exactly sixty per cent, of the common salt, 
 which is an absolute requisite of life, and a most pow- 
 erful antiseptic of organic matters. 
 
 The yellow colour of chlorine, its density, its power 
 upon organic and inorganic bodies may be demon- 
 strated by the following experiments, which should be 
 made in the open air, that the deleterious vapour may 
 be instantly wafted away. 
 
 Place two ounces of " chlorinated lime " in a pint 
 wide-mouthed flint-glass bottle, then quickly add a 
 fluid ounce of " hydrochloric acid ;" an evolution of 
 chlorine will immediately ensue, it will expel the air 
 
AUTUMN. 237 
 
 from the bottle and supply its place with its own yel- 
 low vapour, which is now technically said to be the 
 " atmosphere of the bottle/' the yellow will become 
 yet more visible if a sheet of white paper be held be- 
 hind one part of the bottle. 
 
 Immerse a few shreds of red cabbage leaves in a tea- 
 cup half full of boiling water, and thus obtain a fine 
 blue coloured infusion, which when cold, pour into a 
 a tall half-pint ale-glass, then take the bottle contain- 
 ing the chlorine, and holding its mouth over that of 
 die glass, as in the ordinary act of pouring, the heavy 
 chlorine vapour will pour out like water, and not only 
 display its colour in the glass, but upon slight agita- 
 tion it will instantly destroy that of the blue vegetable 
 infusion. 
 
 If a piece of tainted meat be placed in a half pint 
 wide- mouthed bottle, provided with a glass stopper, 
 upon pouring chlorine into it, then closing it, and leav- 
 ing the meat exposed. to the vapour for half an hour, 
 upon shaking it out the taint will be destroyed. 
 
 Twist a piece of thin copper bell-wire into a tolera- 
 bly close spiral around a ruler, then place two leaves of 
 " Dutch gold " (i. e. nearly pure copper) within this 
 spiral ; put half an ounce of " chlorinated lime " into 
 a half pint ale-glass, add half a fluid ounce of hydro- 
 chloric acid, cover the mouth of the glass with a card 
 until the chlorine appears deep yellow, then quickly 
 remove the card, and introduce the spiral, the leaves 
 of metal will instantly kindle and burn with a vivid 
 red light, thus affording an example of combustion 
 
238 AUTUMN. 
 
 without oxygen, and manifesting the intense affinity 
 of chlorine for the metal, with which it forms artificial 
 " chloride of copper," as with sodium it naturally 
 formed " chloride of sodium " or common salt. 
 
 Such then are a few of the important applications of 
 chlorine as a disinfecting agent, and its intense che- 
 mical powers upon other matters. 
 
 The mere burning of incense or pastils, sprinkling 
 " eau de cologne," lavender water, or vinegar in an 
 apartment, will only cover an unpleasant odour, and will 
 not destroy the virulent matter of which it consists ; 
 so burning feathers on a heated shovel, or stirring a 
 basin-full of vinegar with a red-hot poker, although 
 certainly fumes arise in both cases, and such operations 
 are therefore esteemed " fumigations," they are worth- 
 less as disinfectants, the mephitic matter remains in 
 full force, disguised, but not destroyed. 
 
 Solar heat never gains sufficient intensity to destroy 
 infectious and contagious matters, but on the contrary, 
 its natural range under the conditions already stated 
 is rather an active agent in exciting their production ; 
 an artificial heat of 220 degrees, on the other hand, is 
 sufficiently intense to destroy them most effectually, 
 and accordingly articles of wearing apparel, bedding, 
 blankets, curtains, draperies, &c., which might be in- 
 jured in colour and texture by the powerful action of 
 nitric acid or chlorine, may-be disinfected by hanging 
 them in a room heated by an open fire of charcoal in a 
 brazier, the operator taking care not to a remain in the 
 room or to enter it until fresh air has been allowed to 
 
AUTUMN. 239 
 
 sweep through,, to remove the poisonous vapour of car- 
 bonic acid that is invariably produced by the combus- 
 tion of charcoal in air. 
 
 Woollen goods are especially retentive of contagious 
 and infectious matters, and in all doubtful cases they 
 should be burnt without the slightest compunction or 
 hesitation. 
 
 /The action of artificial or fire -heat upon infected air 
 in disarming it of mephitic power, was well known to 
 our forefathers, who during the awful times of plague 
 and pestilence, kindled huge piles of wood or large 
 tar-barrels in the streets of cities ; such fierce combus- 
 tions demanded an enormous volume of air for sup- 
 port, and as it rushed forward, loaded with disease, it 
 became partly heated, partly consumed, and swiftly 
 mounted to higher regions, whilst a strong draught 
 was created through the streets, and eventually drew 
 purer air from the suburbs. 
 
 When the equilibrium of the atmosphere is thus dis- 
 turbed by an extensive combustion, the draught that 
 is produced is of extraordinary power ; this was exem- 
 plified during the burning of Moscow : it is said that 
 the wind, naturally high, was raised by the sudden rare- 
 faction of the air, to a perfect hurricane ; the howling 
 of the tempest drowned even the roar of the conflagra- 
 tion. 
 
 In time of plague, the inhabitants of cities resorted 
 to the vicinity of iron furnaces, metal foundries, and 
 other works emitting fumes of sulphureous acid mat- 
 ters ; these and the high temperature neutralized or de- 
 
240 AUTUMN. 
 
 stroyed the mephitic portions of the air, for infection 
 in such situations was but rarely taken. The vapour 
 of burning sulphur is still used in the East against the 
 plague, but its power is feeble in comparison with that 
 of chlorine and nitric acid. 
 
 Another powerful adjunct in cases of fumigation, is 
 quick-lime ; when the apartment has been subjected to 
 the agency of chlorine or nitric acid vapour, if prac- 
 ticable, the walls, ceiling, and floor should be lime- 
 whited, the lime by its extreme causticity removes all 
 adherent organic matters ; mere white-wash is useless, 
 because it is made of whiting or carbonate of lime, a 
 perfectly neutral compound, having no power upon 
 organic matters. 
 
 Lime-white is active because it is made of quick- 
 lime, which is known by its cracking and becoming 
 very hot when slaked with water, and when mixed 
 with sufficient it should be employed immediately, 
 otherwise it will absorb carbonic acid from the air, and 
 form carbonate of lime, which has no caustic property. 
 
 The chemist can neither isolate the above mephitic 
 exhalations, nor the aroma of plants and flowers from 
 the atmosphere, although he is tolerably certain that 
 abundance of such attenuated matter must be con- 
 tained therein at various seasons ; thus, for example, 
 the flowering of beans frequently loads the air with an 
 insupportable fragrance, and such vegetable perfume 
 is retained by the air with great and persistent force, 
 and wafted by its winds occasionally to extraordinary 
 distances : it is stated that the fragrance of cinnamon, 
 
AUTUMN. 241 
 
 which is abundant in Ceylon, and that of the rosemary 
 growing on the coasts of Spain has been distinctly per- 
 ceptible to persons at sea, even when distant five miles 
 from those shores. 
 
 It must always be borne in mind that the atmo- 
 sphere is not an immoveable volume of gaseous and 
 vaporous constituents, but that it is continually in mo- 
 tion through eonvective currents into which it is 
 thrown by the agency of heat, and if it be rarefied or 
 attenuated in one locality, air that is more dense in- 
 stantly advances to restore the equilibrium. 
 
 Take a familiar example, we kindle a fire in the 
 grate, the air contained in the chimney is immediately 
 rarefied, it ascends, whilst dense air rushes through 
 every crevice of the room to restore the equilibrium, 
 and produces a draught. 
 
 When disturbances in the equilibrium of the atmo- 
 sphere naturally ensue through the influence of solar 
 heat, they are recognized as breezes and winds, and 
 they tend most effectually to disperse the mephitic 
 matters resulting from the decay of organic productions 
 and from respiration and combustion throughout the 
 enormous volume of the atmosphere, in a state so 
 highly attenuated as to be rendered harmless and even 
 to elude detection. 
 
 During The Four Seasons, we have ample oppor- 
 tunities of experiencing the physical force of atmo- 
 spheric motion in every degree ; for example, the gentle 
 zephyr floating the thistle-down, and undulating the 
 corn; the fresh breeze rippling the surface of the 
 
 M 
 
242 AUTUMN. 
 
 stream, and swelling the canvass of the bark ; the tem- 
 pest blast lashing the ocean into waves and appalling 
 the heart of the mariner ; and lastly, the fierce hurri- 
 cane, uprooting the oak of the forest, devastating the 
 harvest of the plain, and overwhelming the works of 
 man with ruin and desolation. 
 
 With few exceptions, during Summer and Autumn 
 an extreme closeness, or oppressive heat, an extraor- 
 dinary transparency of the atmosphere, an unusual 
 traquillity of the animal and vegetable kingdoms, and 
 a painfully acute sensibility of the human ear to acci- 
 dental sounds, may be regarded as certain forebodings 
 of an approaching " thunder-storm." 
 
 This awful and astounding phenomenon is still or- 
 dained to be an occasional visitant of the terrestrial 
 atmosphere, as it was in the remotest ages, when the 
 Psalmist extolling the power of The Almighty, records 
 that " the clouds poured out water, the air thundered, 
 and Thine arrows went abroad. The voice of Thy 
 thunder was in the heavens, the lightnings lightened 
 the world : the earth trembled and shook/' 
 
 In his limited endeavours to reason upon, and if 
 possible to explain, the physical cause of a phenome- 
 non so wonderful and terrible as the thunder-storm, 
 the chemist discovers by experiments, that ,in the ge- 
 nerality of cases, either sudden or extensive changes, 
 regarding either the physical or chemical forms of sub- 
 stances, are attended by the display of the imponder- 
 able agency of Electricity. 
 
 Throughout the whole of this inquiry regarding The 
 
AUTUMN. 243 
 
 Four Seasons, it has been remarked, that an enormous 
 change of water from the state of liquid to that of va- 
 pour, is constantly proceeding from every aqueous 
 portion of the entire globe, and to such physical change, 
 the chemist refers with extreme probability the imme- 
 diate cause of the thunder-storm ; for he discovers that 
 the artificial conversion of water into vapour always 
 developes Electricity, and under certain conditions, de- 
 velopes it with the striking concomitants of vivid light, 
 intense heat, and snapping sound, differing only in 
 degree from natural lightning and thunder. 
 
 The chemist, by his artificial excitation of Electri- 
 city, can cause its spark to accumulate in intensity and 
 power, can direct this for the fusion and combustion of 
 metals, the paralysis or death of organic bodies, and 
 thus imitate upon a microscopic scale, the well-known 
 effects of the resistless flash of lightning from the 
 heavens. 
 
 He discovers that substances, having a redundance 
 of electricity, or being charged with electricity, inva- 
 riably endeavour to communicate or to discharge it to 
 others that are deficient, and when this restoration of 
 equilibrium or discharge is suddenly and extensively 
 effected, it is attended by intense heat and vivid light. 
 
 Further experiments inform the chemist, that such 
 restoration of the equilibrium or discharge of electri- 
 city, may be either arrested, opposed, or facilitated by 
 several distinct substances ; or, as in the case of Heat 
 so in this of Electricity, there are non-conductors, bad 
 conductors, and good conductors. 
 
 M 2 
 
244 A.UTUMN. 
 
 Anhydrous air is a non-conductor, earthy substances 
 are had conductors, water and metallic ores are "better 
 conductors, and pure metals the hest conductors of im- 
 ponderable Electricity. 
 
 The greatly desiccated atmosphere of Summer, and 
 of the first days of Autumn, though not an absolute 
 non-conducting, is an extremely imperfect conducting 
 medium of electricity ; and this agent, by some recon- 
 dite property, appears to accumulate in the atmosphere, 
 probably during the incipient condensation of its 
 watery vapour into the mysterious form of clouds, 
 these clouds are regarded as aqueous volumes highly 
 charged with electricity, floating in the vast and ge- 
 nerally desiccated volume of the air ; or, in other 
 words, a volume of dry air, capable of supporting the 
 clouds, yet incapable of depriving them of their elec- 
 trical charge. 
 
 The clouds endeavour to discharge this electrical 
 surplus to the solid earth and flowing waters ; the air 
 will not conduce to this effort, and eventually the 
 surplus or accumulation in the clouds is so excessive, 
 is so powerful, that it suddenly pierces or disrupts the 
 air by a flash of lightning to the earth and waters. 
 
 This lightning is succeeded by thunder, a sound 
 produced by the immediate and violent collapse of the 
 disrupted air, to effect the restoration of its own equi- 
 librium ; " like as when an arrow is shot at a mark, it 
 parteth the air which immediately cometh together 
 again, so that a man cannot know where it went 
 through," 
 
AUTUMN. 245 
 
 The time which elapses between the flash of light-' 
 n ing and the explosion of thunder, affords the means 
 of calculating the distance of the storm, for light, 
 moving with the incomprehensible velocity of 192,000 
 miles in a second, the time that it takes to traverse 
 any terrestrial distance may be considered as nothing, 
 but sound travels only at the rate of about 380 yards 
 in a second. 
 
 The flash and the thunder are really simultaneous, 
 but the former is instantly seen, whilst the other re- 
 quires a second of time to traverse 380 yards ; there- 
 fore the interval that elapses between the two pheno- 
 mena, being multiplied by this number, will give the 
 distance of the storm. 
 
 Thus, if the flash take place six seconds before the 
 thunder is heard, then 6x3802280 yards, or one 
 mile, two furlongs, and eighty yards, which is the dis- 
 tance of the storm from the observer. 
 
 Let it be particularly remembered, that this calcula- 
 tion regards a discharge of lightning that has hap- 
 pened, and it must not be considered as a measure of 
 the removal of the observer from danger, for other dis- 
 charges may rapidly happen much closer, as thunder 
 clouds are frequently extended over a great extent of 
 terrestrial surface, and very frequently two or three 
 flashes of lightning are seen, apparently simultaneously 
 in the different parts of the atmosphere. 
 
 When lightning flashes in a long irregular angular, 
 gnarled or knotted stream, these appearances announce 
 its passage through an extensive volume of the atmo- 
 
246 AUTUMN. 
 
 sphere ; but when it flashes in a short, straight, or 
 direct line of vivid light, it may be considered to have 
 disrupted a comparatively limited portion of the atmo- 
 sphere. 
 
 In the first case the flash would be seen some time 
 before the thunder would be heard, and in the second 
 case the flash would be instantly followed by the 
 thunder. 
 
 Fig. 45. 
 
 The tree in the back ground is supposed to have de- 
 termined the discharge of lightning from a cloud 
 hovering at a considerable distance, the flash is there- 
 fore long and irregular, and a spectator of the storm, 
 if standing near the tree, would first hear the thunder 
 from the collapse of the air near its summit, then from 
 beyond this, afterwards from a more remote portion, 
 and ultimately from the volume of the cloud, whence 
 the lightning first broke forth ; the thunder, therefore, 
 would not fall upon the ear as one direct and crashing 
 
AUTUMN. 247 
 
 sound, but as an irregular succession of sounds, or 
 loud rumbling noise. 
 
 " This irregularity in the passage of lightning, is 
 sometimes so considerable, that the thunder is actually 
 lost to the ear at one moment, and heard again at 
 another, and this three or four times successively in 
 the same clap ;" and this, conjoined with the reflection 
 of the sound, or its reverberation from mountain, hill, 
 and valley, at one instant, pealing loudly, at another, 
 booming gently, at length murmuring faintly, and ul- 
 timately dying away, are extremely impressive con- 
 comitants and attendants of the original phenomenon 
 of the flash. 
 
 The tree in the fore-ground of the engraving, is sup- 
 posed to have determined the discharge of lightning 
 from a cloud hovering at a little distance, the flash is 
 therefore short and regular, and a spectator of the 
 storm, if standing near this tree, at the moment of the 
 flash, would hear the full thunder of the collapsing 
 air, as one loud and terrible crash, which in a few 
 seconds after, would reverberate from surrounding ob- 
 jects, and ultimately die away in silence. 
 
 When the chemist causes electricity to pass through 
 large and small intervals of air, the vivid sparks in 
 their disruptive transit, present upon a microscopic 
 scale appearances precisely similar to those of exten- 
 sive and limited flashes of lightning. 
 
 An appearance of two distinct flashes or streams is 
 very frequently produced at a considerable distance 
 from each other, when part of a long, sharp, angular 
 
248 AUTUMN. 
 
 flash is hidden by an intervening cloud, and the 
 sudden and universal flash, or " sheet lightning," ap- 
 pears to result from a discharge which is more per- 
 fectly concealed. 
 
 The bright flashes which occur during summer and 
 autumnal evenings, unaccompanied by thunder, are of 
 this kind, and it is supposed that on account of their 
 vast distance from the earth, that the sound of the 
 thunder must be lost in its passage. 
 
 " The appearance of the heavens during a thunder- 
 storm, the manner in which the clouds assemble, and 
 attract and repel each other, the circumstance of their 
 rising against the wind, and traversing the upper 
 regions of the atmosphere in a variety of contrary di- 
 rections, are phenomena, which it is not difficult to 
 explain by reference to the general laws of electricity." 
 
 Many of these have been discovered by the great 
 philosopher of the present day, and regarding his ex- 
 traordinary knowledge of Electricity and Chemistry it 
 has been justly said, that " in point of originality in 
 devising experiments, skill in carrying them into effect, 
 and perspicuity in tracing out, and unravelling the com- 
 plicated relations of the new truths which are elicited, 
 he stands, if not unrivalled, at least unsurpassed." 
 
 Upon known laws of electricity, as excited in the 
 laboratory, the peculiar fringed appearance of a thun- 
 der-cloud may be explained, and also the irregular 
 portions which it projects towards the earth, whilst its 
 upper surface is generally smooth, and well-defined. 
 
 " We sometimes observe that a number of such 
 
AUTUMN. 249 
 
 clouds of small dimensions, coalesce into a larger one, 
 moving swiftly in all directions, and darting flashes 
 from one to the other, whilst the wind rises and often 
 blows in squalls ; the lightning is more frequent as 
 the clouds aggregate, and a great expanse of the 
 heavens often appears in an almost continuous hlaze 
 of light; the thunder at first rumhling in the distance, 
 now approaches with various roaring and rattling 
 sounds, and the rain often falls in torrents. 
 
 " If we watch a severe thunder-storm from the be- 
 ginning to the end, we observe a singular variety in 
 the appearance of the flashes ; the scene is sometimes 
 rendered awfully magnificent, by their brilliancy, fre- 
 quency, and extent, darting sometimes in broad, well- 
 defined lines from cloud to cloud, and sometimes 
 shooting towards the earth, they are often zig-zag and 
 irregular, and sometimes are said to appear as a large 
 and rapidly-moving ball of fire, an appearance usually 
 designated by the uninformed, ' a thunderbolt,' and 
 erroneously supposed to be attended by the full of a 
 solid body." 
 
 Thus the nodular masses that are so frequently 
 found on the sea beach, at the foot of chalk cliff's, are 
 called " thunderbolts," yet they have not fallen from 
 the heavens, but from the cliff's, and when chemically 
 examined, are found composed of sulphur and iron, 
 they are " sulphurets of iron " therefore, and if two 
 masses be violently struck against each other, sparks 
 of fire appear, in consequence of the heat of the blow 
 or collision having enabled both elements to attract 
 
 M 5 
 
250 AUTUMN. 
 
 oxygen from the air and burn ; thus fire was anciently 
 obtained, and the name of*' pyrites," or " fire- stone, " 
 was likewise conferred upon the supposed " thunder- 
 bolt." But let us continue our investigation of the 
 " thunder storm." 
 
 " The voice of the Lord is upon the waters : The God 
 of glory thundereth : The Lord is upon many waters." 
 
 " The voice of the Lord is powerful ; the voice of 
 the Lord is full of majesty." 
 
 In such sublime and rapturous exhortation to the 
 princes of the earth, does the Psalmist set forth the 
 glory of The Omnipotent Ruler of the storm ; and re- 
 garding its awful and astounding grandeur, no man 
 can either feel, or feign indiiference ; yet he does well, 
 that instead of indulging in morbid fear, and of com- 
 municating it to others, endeavours to calm such emo- 
 tions, by reflecting and expounding that the will of 
 God directs the storm, to remind us of our insignifi- 
 cance, which in the pride of our knowledge, and the 
 height of our abundance, we are but too prone to 
 forget. 
 
 It is, however, the imperative duty of every man to 
 exercise his utmost reasoning and inventive faculties 
 for guarding his life, and the lives of others, against 
 the physical power of the lightning, and not with im- 
 piety and presumption to defy the storm. 
 
 In the open air, shelter should not be sought imme- 
 diately under a tree or building, for should they be 
 struck, such a situation is particularly dangerous, if 
 not fatal ; the distance of twenty or thirty feet from tall 
 
AUTUMN. 251 
 
 trees, or lofty buildings, is, on the contrary, an eligible 
 situation ; for should a discharge take place, these 
 prominent bodies are most likely to receive it, and the 
 less elevated bodies in their vicinity may therefore 
 escape uninjured. 
 
 It is quite essential during a thunder-storm, to avoid 
 every considerable mass of water, and even the stream- 
 lets that may have resulted from a recent shower ; for 
 these are all excellent conductors, and the height of a 
 human being when near them, might probably deter- 
 mine the discharge of lightning ; shelter under the 
 arch of a bridge is a comparatively safe situation. 
 
 The conductors and imperfect conductors through 
 which lightning directs its course when it strikes a 
 building, are generally the metallic appendages of the 
 walls and partitions ; the most secure situation is there- 
 fore in the middle of the room, especially when stand- 
 ing on a hair mattrass, or even a thick hearth-rug ; 
 and if a bed be drawn into the middle of the room ; it 
 will afford perhaps the safest of all situations. 
 
 The part of every building least likely to receive 
 injury is the middle story, as the lightning does not 
 always pass from the clouds to the earth, but occa- 
 sionally from the earth to the clouds, a phenomenon 
 called the " returning stroke ; " hence it is useless to 
 take refuge in the lowest story or in a cellar. 
 
 Many instances are recorded in which the basement 
 story has been the only part of a building that has 
 sustained severe injury, the lightning being weakened 
 as it ascended. 
 
252 AUTUMN. 
 
 Whatever situation be chosen, any approach to the 
 fire-place is most dangerous; for the heated air, or 
 even the soot in the chimney, are conductors suffi- 
 ciently good to determine the course of the lightning 
 flash, especially as they are in immediate connexion 
 with the excellent conducting iron work of the grate, 
 fender, and fire-irons ; the same caution is necessary 
 with respect to gilt furniture, bell-wires, and moderately 
 extensive metallic surfaces of every description. 
 
 It is likewise exceedingly dangerous to approach a 
 window for the purpose of closing its shutters, if they 
 have large iron bars or bolts for fastenings; an instance 
 is known of a shock having been suddenly expe- 
 rienced by a female endeavouring to bar a window 
 during a severe discharge of lightning ; the effect lasted 
 a considerable time, but fortunately did not prove 
 fatal. In a carriage, the precaution of keeping at 
 some inches distance from its sides or back is also 
 advisable. 
 
 These particulars have been enumerated from a desire 
 " to supply what useful information the present state 
 of our knowledge may afford, and to diminish that 
 anxiety and fear by which the minds of many arc 
 oppressed during the occurrence of these magnificent 
 but awful phenomena." 
 
 The operation of mysterious agents has always con- 
 siderable effect on the human mind ; and by raising 
 a host of unreal terrors, may suspend the action of its 
 best energies ; but when we are enabled to ascertain 
 
AUTUMN. 253 
 
 something regarding the nature and influence of the 
 powers which surround us, we are prepared to meet 
 their effects with feelings equally remote from vain 
 confidence and useless fear ; and are thus enabled to 
 avoid their dangers effectually and without agitation. 
 
 " Where persons have been killed by lightning, it 
 has generally come upon them so suddenly as to leave 
 no time for precaution ; though it must also be ad- 
 mitted that some have suffered from foolishly ridiculing 
 the idea of danger, and wantonly exposing themselves 
 to the storm, walking out to admire its grandeur, or 
 insisting upon opening the windows to look out and 
 observe it, or standing under a tree for shelter. 
 
 " A severe thunder-storm is always an awful and 
 dangerous phenomenon ; and while, on the one hand, 
 it is the extreme of folly to neglect common precau- 
 tion, or to ridicule those that are alarmed, it is, on the 
 other, equally weak to give way to unfounded appre- 
 hension." 
 
 As the important discovery of Oxygen was made by 
 the employment of the simple form of a " bird-foun- 
 tain," so the astonishing discovery of the identity of 
 lightning with electricity was made by the use of the 
 still more simple means of a common kite; and it 
 likewise proves that men must condescend to attend to 
 the most ordinary things if they would acquire know- 
 ledge, for the design of philosophy is " not to build a 
 capital, or erect a pyramid, to the glory of man, but 
 to found the temple of the universe in the human 
 intellect." 
 
254 AUTUMN. 
 
 At a very early period of the Science of Electricity, 
 experiment had shown that electricity is attracted by 
 points, and if highly excited, it discharges itself with a 
 flash and report ; lightning and thunder exhibited an 
 example of a flash and report ; the atmosphere was 
 known to be susceptible of electrical influence ; all 
 this had been ascertained, but no relation had been 
 established between the cases ; other causes might 
 possibly produce a flash and report ; but the analogy 
 of electricity presented itself strongly to the mind of a 
 true philosopher, who reasoned thus : " The electric 
 fluid is attracted by points ; we do not know whether 
 this property be in lightning, but since they agree, 
 in all particulars in which we can already compare 
 them, it is not improbable that they agree likewise 
 in this." 
 
 " Let the experiment be made." 
 
 He made the experiment, by attaching a pointed 
 wire to the stick of a kite, and upon elevating it in the 
 air during a thunder-storm, as the string became wetted 
 with rain, it conducted electricity from the clouds, 
 which on its arrival at the ground was regularly dis- 
 charged with vivid sparks, and sharp reports, and the 
 analogy converted into an identity. 
 
 This great philosopher was overcome with emotions 
 of awe, at the wonderful discovery that the Almighty 
 had vouchsafed him permission to make regarding the 
 nature of the astounding phenomena of the thunder- 
 clouds ; and as the whole of his previous life had been 
 devoted to the humble pursuit of science, and in en- 
 
AUTUMN. 255 
 
 deavours to cause its principles to <f enrich human life 
 with useful arts and inventions/' he immediately sought 
 to apply this discovery to the protection of dwellings 
 from the terrific effects of lightning, hy elevating upon 
 them metallic rods, in deep connexion with the hu- 
 mid earth, and thus to afford ready continuous paths 
 for the natural flash of electric fire. 
 
 The conduction of electricity, hy metals, unlike that 
 of heat by the same elements, or their alloys, is not 
 progressive, but instantaneous, of which the most ex- 
 traordinary discovery of the present day, the " electric- 
 telegraph," presents the strongest example ; and thus 
 if the electricity be intensely accumulated, and the me- 
 tals in sufficiently large rods or wires, they sustain no 
 elevation of temperature, they undergo no chemical 
 change whilst conducting the charge ; if, on the other 
 hand, the rods or wires are but small, or insufficient to 
 conduct it with extreme facility, not only do they be- 
 come sensibly elevated in temperature, but so intensely 
 heated, that they are excited to combine with the 
 oxygen of the air, and actually to burn, as iron-filings 
 will do when shaken into the heated air arising from a 
 common flame. 
 
 But these filings might have been obtained by filing 
 the bar of a fire-grate, and it does not burn away 
 like them. Why is this ? does it chemically differ 
 from them ? 
 
 No, the difference is merely mechanical ; the con- 
 stituent particles of the bar of iron are strongly bound 
 together into one large and compact solid form ; and 
 
256 AUTUMN. 
 
 although subjected day after day to the burning fuel, 
 the bar conducts away to the adjacent iron and stone- 
 work ; the heat as it is excited by the flames, does not 
 admit of its concentration upon any one particular 
 point of its own surface, and therefore never becomes 
 sufficiently heated to attract oxygen and burn, as it 
 will do immediately and chemically, when its attrac- 
 tion of aggregation is mechanically destroyed by the 
 file. 
 
 Fig. 46. 
 
 So will iron and other metals, when drawn into the 
 slender form of " bell-wires," immediately heat and 
 burn, whilst endeavouring to conduct an intense charge 
 of the electricity of the laboratory, or a flash of light- 
 ning from the heavens ; but in the stouter form of 
 bars or rods, of an inch in diameter, they will in- 
 stantly and perfectly conduct both, and sustain no 
 change. 
 
 Accordingly, rods of such diameter, either of iron 
 or of copper, this latter metal being preferable, though 
 
AUTUMN. 257 
 
 most expensive, are attached to buildings as <c good 
 conductors " for preventing the lightning discharging 
 itself and exerting its destructive power upon the bad 
 or imperfect conductors presented by stone, brick, and 
 wood-work. 
 
 The engraving represents a building furnished with 
 a " lightning conductor," and its construction may be 
 probably understood by the following description. 
 
 On the summit of the roof is firmly fixed a metal 
 bar, two inches square at its base, and gradually 
 tapering upwards to a height of twelve feet, terminating 
 in a perfectly sharp point which is strongly gilt, to 
 prevent its corrosion or oxidation by the air and 
 moisture ; the base of the bar is made two inches 
 square, that it may not be materially swayed from the 
 perpendicular by the force of storms, and to prevent 
 rain from being attracted by its means amidst the 
 wood-work of the roof, which would cause decay ; the 
 square bar is provided just above its base with a conical 
 cap of its own metal spreading six inches all around, 
 which thus will cast the rain drops away from the 
 summit of the roof. 
 
 Immediately above this conical cap, an iron bar of 
 two inches square, and of any convenient length, is 
 firmly secured to project as an arm horizontally, and 
 to its extremity, by a bolt, is united an iron bar 
 of one inch square, which then proceeds in the same 
 slope as the roof, though supported one foot distant 
 from it by several iron staunchions, until it reaches the 
 eaves, where it is bent if necessary to suit the curves 
 
258 AUTUMN. 
 
 and then proceeds perpendicularly, in a line parallel 
 with the wall, though still kept one foot distant by 
 staunchions until it enters the ground. 
 
 As iron will soon rust in damp earth, and as upon 
 the perfect metallic nature and continuity of the bar 
 its utility as a lightning conductor depends ; this ex- 
 tremity, as well as the other pointed and gilt, must be 
 preserved unharmed ; accordingly a channel about one 
 foot in width, and of length according to circumstances, 
 is constructed of brick work, extending horizontally 
 beneath the surface of the earth, and in the centre of 
 this channel the iron bar is bent and laid ; it is then 
 closely packed around with dry wood-ashes, and when 
 the channel is quite filled it is bricked over, and a small 
 pent-house formed around the part of the bar that first 
 enters the ashes from above. 
 
 Fig. 47. 
 
 Upon emerging from this channel, the iron bar is 
 either strongly painted or varnished, then bent into a 
 perpendicular or gently sloping direction according to 
 local circumstances, and carried as far into the damp 
 earth, or, if possible, into a stream of water, as its 
 point extends into the atmosphere ; this lower ex- 
 
AUTUMN. 259 
 
 tremity of the bar is generally fashioned into the form 
 of a sharp trident. 
 
 The " conductor 4 ' is thus completed, and upon the 
 approach of thunder- clouds its point will slowly and 
 silently disarm them of electricity, and conduct it to 
 the earth and water ; and thus restore an equilibrium 
 that otherwise might have been suddenly and vio- 
 lently effected by a flash of lightning destroying the 
 building. 
 
 Although the " conductor" is supported by iron 
 staunchions projecting from the roof and wall of the 
 building, these will not divert the electricity from the 
 " conductor/' for electricity always chooses the direct 
 path that is proffered, and will not leave it, or fly to 
 lateral conductors. 
 
 Ships are protected by " conductors" generally made 
 of copper bars attached to their masts, and carried 
 down in connexion with the water ; and by these 
 " conductors" much fearful damage by lightning has 
 been prevented. 
 
 The chemist, by subjecting a portion of air to the 
 long-continued discharge of electricity, proves that the 
 elements Oxygen and Nitrogen, combine and produce 
 Nitric Acid, which has a very powerful odour and action 
 upon organic matters, as already stated; guided by 
 analogy, he ventures to pronounce that the protracted 
 discharge of lightning through the atmosphere may 
 effect a similar combination of elements, and produce 
 such compound upon a more gigantic scale, and that 
 the peculiar odour which pervades the tumultuous at- 
 
200 AUTUMN. 
 
 mosphere of a thunder-storm may be that of Nitric 
 acid, and, still guided by analogy and by the perfect 
 examples of Beneficial design that he discovers through- 
 out Nature, he ventures yet farther to state that this 
 production of a powerful acid may be destined to aid the 
 commotion of the storm in destroying and removing 
 the mephitic exhalations that arise from organic mat- 
 ters putrefying in the heat of Summer and of Autumn. 
 
 Like every other Natural phenomenon, this of the 
 thunder-storm is evidently productive of good, for when 
 it has passed, the atmosphere directly imparts a sensa- 
 tion of purity and freshness that it did not previously ; 
 animal life revives, vegetation sends forth a more pow- 
 erful aroma, excited probably to exhale more oxygen, 
 and the whole beautiful aspect of the earth, seems to 
 rejoice in the recovery of its wonted tranquillity. 
 
 The occurrence of thunder-storms is always greatly 
 dreaded by the husbandman, not only on account of 
 the extreme probability of the lightning striking his 
 homestead, and thus instantly kindling its well-stored 
 harvest in one consuming flame, but also on account of 
 the usual concomitants of sudden and violent showers 
 of hail and rain which burst from the clouds, and so 
 lacerate and prostrate the standing crops, so tear the 
 fruits and strip the leaves of orchards, that frequently, 
 after the storm has passed, these fragile structures can 
 scarcely, if at all, recover from the shock to meet the 
 bright rays of the sun, and ripen into the maturity of 
 an autumnal harvest. 
 
 The physical cause of these dread concomitants of 
 
AUTUMN. 261 
 
 the thunder-storm, rain and hail, is shrouded in im- 
 penetrable mystery ; no man can " understand the 
 spreadings of the clouds," no man hath 4( seen the 
 treasures of the hail," but the terrible visitations of 
 these agents of Divine power have been experienced by 
 mankind from the earliest ages of the world ; for it is 
 recorded in the Sacred Writings as follows : 
 
 " The Lord sent thunder and hail, and the fire ran 
 along the ground." 
 
 " He maketh lightnings with rain " 
 
 " He destroyed their vines with hail." 
 
 " He smote with hail in all the labours of harvest." 
 
 " The voice of the Lord breaketh the cedars, yea. 
 the Lord breaketh the cedars of Lebanon." 
 
 As in the earliest ages, so at the present time, the 
 countries of the East, and especially in the immediate 
 vicinity of Mount Lebanon, which is nine thousand, 
 six hundred feet in altitude, are yet subject to the 
 foregoing tremendous visitations ; and even in this coun- 
 try they occasionally occur in a scarcely inferior 
 degree. 
 
 Regularly shaped hail-stones and shapeless masses 
 of ice, three, six, and even nine inches in circumference 
 or girt, suddenly shower down from the clouds, and 
 devastate not only the corn-crops and orchards of open 
 plains and vallies, but the exotic flowers and fruits, 
 which are sedulously kept in conservatories, by the 
 refinements of horticulture. 
 
 " The time of the continuance of hail is always very 
 
262 AUTUMN. 
 
 short, generally only a few minutes, and very seldom 
 so long as a quarter of an hour; the quantity of ice 
 which falls from the clouds in so short a time is pro- 
 digious ; the ground "being sometimes covered with it 
 to the depth of several inches. 
 
 " The clouds, from which hail is precipitated, appear 
 to be of very considerable extent and depth ; it has 
 been remarked that they have a peculiar grey or reddish 
 colour, and that their lower surfaces present enormous 
 protuberances, whilst their edges exhibit deep and 
 numerous indentations." 
 
 Fig. 48. 
 
 A mineral, beautifully transparent, colourless, and 
 having the regular form of a six-sided prism, with a 
 six-sided pointed summit, was well known to the an- 
 cients, and they imagined it to consist of water more 
 intensely and compactly frozen than common ice, and 
 therefore incapable of thawing by solar-heat this sub- 
 stance they termed " Crystal ;" the modern chemist 
 discovers it to be the purest form of the earth Silicn, 
 and he employs the word " crystal " to denote any 
 
AUTUMN. 263 
 
 solid substance, either native or artificial, that presents 
 itself in a regular figure, however different such figure 
 may he to that of ancient " crystal." 
 
 Upon examination of a hailstone received upon a 
 soft yielding surface, and thus prevented from shatter- 
 ing by its violent collision with the hard solid earth, it 
 exhibits the crystalline form of a short six -sided prism, 
 having at each end a short six-sided pyramid, one being 
 invariably " truncated/' or cut off as shown in the 
 annexed engraving. 
 
 Fig. 49. 
 
 The known phenomena attendant upon the ordinary 
 transition of water to the state of ice will claim our 
 attention hereafter ; leaving therefore the unknown phy- 
 sical cause of hail and its crystalline form, let us pro- 
 ceed to investigate another phenomenon. 
 
 In addition to the various physical forms of rain, 
 dew, mist, and hail, in which water most commonly 
 descends upon the earth throughout the seasons of 
 Spring, Summer, and Autumn, it sometimes pours 
 down in one gigantic and unbroken liquid column, and 
 then is popularly " the water-spout." 
 
264 AUTUMN. 
 
 The electrician and the chemist, by observation, ex- 
 periment, and analogy, are led to conclude that during 
 certain states of the atmosphere, although a cloud may 
 not be so powerfully charged with electricity as to seek 
 a restoration of its equilibrium by emitting a disruptive 
 flash of lightning to subjacent objects; it may be suffi- 
 ciently charged when at a moderate elevation, that its 
 own entire and mobile volume of aqueous particles, 
 will yield downward in the form of a watery column, 
 through which the inherent electricity seeks a rapid 
 though silent discharge ; the same, to use a very 
 homely simile for conveying an idea regarding the mere 
 attraction and transit as a large flock of cotton nearly 
 saturated with water, when held in one hand, may have 
 its filaments drawn out by the other, in an unbroken 
 form through which by capillary attraction the water 
 will pass in a smooth and silent stream, until its excess 
 has thus drained away. 
 
 An electrical cloud, when thus yielding to the at- 
 tractive or inductive power of the objects over which it 
 hovers, is gradually drawn from its rounded form into 
 that of a fringe, and this gradually accumulates into 
 the form of a well-defined point ; then as the distance- 
 between the cloud and subjacent bodies diminishes, 
 this point becomes more and more elongated, until at 
 length it forms an unbroken conductor, not only for 
 the discharge of the electricity of the clouds, but like- 
 wise for a torrent of its waters ; and these phenomena 
 having ensued, the cloud is found either to have wholly 
 
AUTUMN. 265 
 
 vanished, or to present but a minature semblance of 
 its original form. 
 
 Generally speaking, the electricity of the " water- 
 spout " is not so much to be dreaded as the vast 
 aqueous torrent, that descends with impetuous force 
 upon the dwellings of man and the labours of the field, 
 which are all alike overthrown and prostrated, and swept 
 away by this sudden and concentrated inundation. 
 
 The occurrence of this extraordinary natural phe- 
 nomenon is by no means so common inland, as at sea, 
 and there it displays itself in a yet more striking and 
 remarkable form. 
 
 There, in place of the solid and fixed earth, the 
 liquid and flowing water presents an attractive surface 
 for the floating and mobile vapour of the electric 
 clouds. 
 
 In such case, not only does the electric cloud emit 
 an elongated portion of its volume as a precursor of 
 the full descent, but the level surface of the water si- 
 multaneously gives rise to a mobile pointed wave, and 
 thus by mutual attraction, the former continuing to 
 descend and the latter to ascend, they at length sud- 
 denly coalesce, and form an aqueous conductor for the 
 restoration of the electrical equilibrium ; and having 
 effected this, the waters of the cloud are ultimately re- 
 ceived into the bosom of the ocean, from whence they 
 were exalted by the imponderable agency of heat. 
 
 An idea of the form of this remarkable, and when 
 minutely considered, important phenomenon, may be 
 gained by reference to the engraving on the next page. 
 
266 AUTUMN. 
 
 A sudden and violent concussion of the atmosphere 
 will frequently cause the descending cloud to burst be- 
 fore its union with the ascending wave, and accordingly 
 mariners are in the habit of discharging a gun in its 
 direction, and of thus averting the probability of the 
 " water- spout" extending and engulphing their richly 
 freighted and highly- valued ship. 
 
 Fig. 50. 
 
 A large, stately, firm structure it may be, in compa- 
 rison with the hands by which it was fashioned, but it is 
 a small, lowly, and frail shell, in comparison with the 
 incomprehensibly vast and boundless flood of waters 
 upon which it floats ; it bears not so great proportion 
 to them as the smallest grain of sand bears to the 
 largest artificial globe ; and therefore, instead of con- 
 sidering it as extraordinary that shipwrecks so fre- 
 quently occur, we should rather feel surprise that they 
 do not more frequently happen, and astonishment 
 that in vessels so minute, mariners have been permitted 
 to circumnavigate the gigantic world. 
 
AUTUMN. 267 
 
 " They that go down to the sea in ships, that do 
 business in great waters ; 
 
 " These see the works of The Lord and His wonders 
 in the deep." 
 
 Thus in addition to wonderful phenomena, of con- 
 stant occurrence, as storm, tempest, hurricane and 
 wave, mariners sometimes behold with astonishment 
 and awe, fiery volcanoes suddenly bursting forth from 
 the depths of the ocean ; these are attended by light- 
 ning, thunder, lava, steam and water- spouts, all of 
 them so far as man is permitted to discover being 
 physically caused by the abrupt, violent, and extensive 
 changes which matter is commanded to sustain by 
 " The Creator of the heavens and the earth, the sea 
 and all that in them is." 
 
 Changes, miraculous and perpetual, pervade through- 
 out the creation, and yield an inexhaustible store of 
 materials which are continually presented, withdrawn, 
 and again renewed for mental reflection and experi- 
 mental investigation. 
 
 The vital force displayed by vegetation, from the 
 hour of its germination, and throughout all its suc- 
 cessive periods of growth towards maturity, in obedi- 
 ence to the immutable laws of its Creator, is a subject 
 well calculated to draw attention from the servant and 
 interpreter of Nature. 
 
 In Spring, when a seed is buried in the earth, this 
 medium, on account of the hardness and solidity of 
 its constituent atoms, might be reasonably imagined 
 capable of exerting such rude pressure upon the first 
 
 N 2 
 
268 AUTUMN. 
 
 germs of vegetable life, as to crush it almost in the 
 very moment of its nascence, but experience teaches 
 us that no such injury is sustained. 
 
 When the entire organic structure is once endowed 
 with vitality, its powers become superior to those of 
 inorganic matter ; for example, the " radicle " sends 
 forth soft and tender filaments, yet having sufficient 
 strength during their search of liquid nutriment, to 
 penetrate between hard solid stones, and these fila- 
 ments, in obedience to gravitation, descend beneath the 
 earth to form a firm and steady root. 
 
 The " plumula " simultaneously sends forth delicate 
 and fragile folds having a nearly equal though contrary 
 strength during their search of other nutriment from 
 the air, to part asunder and lift before them, the in- 
 cumbent atoms of their terrestrial prison, and thus to 
 emerge amidst the ethereal treasures of light and heat, 
 under whose combined attraction, the folds burst into 
 full leaves, a perfect plant soon flourishes, and it is 
 destined in due season to " yield seed after its kind," 
 which in its turn will then present the same miracu- 
 lous circle of changes. 
 
 When natural or artificial obstacles of great size, 
 solidity, or weight, are opposed to the comparatively 
 small, slender, and light structure of plants, attraction 
 of gravitation and attraction of cohesion, both combine 
 to render the former of superior power to the latter ; 
 but in such cases, although the organic forces cannot 
 directly penetrate or lift these obstacles, they preserve 
 as closely as possible the direction that they would 
 
AUTUMN. 269 
 
 have pursued, if not opposed, and will recover it at 
 the earliest opportunity. 
 
 The endeavour of plants to remove obstacles op- 
 posed to the ordinary direction of their growth, and 
 failing of it, then gracefully yielding obedience to 
 them, seem to have been first remarked in the case of a 
 basket covered with a flat, square stone, which was ac- 
 cidentally placed in the centre of a growing " acan- 
 thus," the leaves of which being diverted from their 
 original position, assumed a bending beauty of form, 
 as shown in the engraving, and from this it is said 
 originated the elegant Corinthian capital. 
 
 Fig. 51, 
 
 In pure Corinthian architecture the " acanthus '' en- 
 tirely surrounds with its aspiring leaves the " basket" or 
 " vase " of the capital, as if attempting to raise the flat 
 stone or " abacus " that covers the whole, they then 
 turn down and form themselves in graceful " volutes." 
 
 It is occasionally observed that when plants cannot 
 remove solid obstacles, they will actually enclose them 
 
270 AUTUMN, 
 
 within their own structures ; thus, nails and stones have 
 been found imhedded in the trunks of trees, and some 
 Indian nations take advantage of this fact, for the con- 
 struction of their hammers ; they split open the supple 
 stem of a creeping plant, then place an oblong piece 
 of heavy stone in the aperture, and bind it fast with 
 the shoot of another plant of the same kind which is 
 in a growing state ; by the end of twelve months the 
 stone is firmly interlaced, the stem which bears it is 
 cut away, and thus a rude hammer is obtained. 
 
 But returning to the graceful form of the acanthus or 
 other plant when diverted from its original position, it 
 presents more than its mere outward beauty to the vo- 
 tary of experimental science ; for example, remove the 
 stone from the top of the basket, and then it will be 
 seen that all the stems and leaves of the plant, which 
 have crept through the wicker-work and have thus 
 grown in the gloom induced by the opacity of the ex- 
 ternal foliage, are neither vigorous nor verdant like it, 
 but sickly and pale, thus affording another example in 
 addition to those adduced at page 93, of the modifi- 
 cation of vegetable growth and colour when deprived of 
 the free access of solar-light. 
 
 Even one more example of the same kind will be 
 presented, when the languid foliage is carefully freed 
 from its imprisonment, and the basket lifted ; it might 
 have been originally placed upon the grass, near the 
 acanthus or other luxuriant plant, and if this were the 
 case, no grass will be found, but only a circular spot of 
 bare earth, where the basket stood ; because it and the 
 
AUTUMN. 271 
 
 stone being ponderous, crushed the tender blades of 
 grass, and thus injured and at the same time prevented 
 from the restorative agency of imponderable light, they 
 had no alternative but to die, and mingle the results 
 of their decomposition with the earth for supporting 
 the growth of surrounding portions free from oppres- 
 sion, and permitted access to the light of day. 
 
 The darkness intervening between the bottom of the 
 basket and the bare soil, although inimical to the growth 
 of vegetation, is favourable to the life of reptiles and 
 insects ; worms, for example, will appear in abundance, 
 and then quickly shrink, and glide beneath the earth, 
 " centipedes" will rapidly crawl and hide amidst the 
 surrounding grass . or foliage, to shun the newly ad- 
 mitted light; both classes of wonderfully formed beings 
 eagerly seeking localities favourable to their organiza- 
 tion and habitudes. 
 
 If a few of these " centipedes " or " hundred- legged 
 worms" be gently caught upon a leaf and placed in a 
 small card-box from which they cannot escape, this 
 may be taken into a perfectly dark room, and after a 
 few minutes, when the eyes of the experimenter have 
 become accustomed to the gloom, if the insects be dis- 
 turbed or irritated by touching them with a feather, 
 they will generally emit a phosphorescent light, resem- 
 bling that of glow-worms. 
 
 All the foregoing examinations can be made without 
 difficulty, and they corroborate the fact so frequently 
 named during this inquiry, that things of common oc- 
 
272 AUTUMN. 
 
 currence will present scientific information when pro- 
 perly investigated ; let us now direct our attention to 
 the grand and important feature of Autumn. 
 
 " Lift up your eyes and look on the fields, for they 
 are white already to harvest." 
 
 Beautiful indeed is the sight of wide fields of com, 
 with its richly-laden crop gracefully undulating before 
 the autumnal breeze, but " it is infinitely more ani- 
 mating and delightful to see the stately stems fall be- 
 neath the regular and measured stroke of the reaper, 
 whose toil is lightened by the thought that abundance 
 is thus poured, from the lap of earth into the garners 
 of her children, to support them when the hour of un- 
 fruitfulness is nigh." 
 
 " It is a subject worthy the consideration of every 
 one to calculate what a vast quantity of nourishment 
 is by the agency of the vital principle in seeds thus 
 annually abstracted from the atmosphere, tne waters, 
 and the earth, and reduced to a state fit to minister to 
 the sustenance of men and animals. " 
 
 " To secure this precious treasure all persons, young 
 and old, engage in the work of the harvest, and let us 
 hope that there are few who can witness the additions 
 made to our stores of provisions without experiencing 
 a feeling of exultation ending in grateful emotions and 
 thankfulness to Him who promised that " seed-time 
 and harvest should not fail." 
 
 An extraordinary fact is elicited by the researches of 
 the chemist, that no inorganic substances either natu- 
 
AUTUMN. 273 
 
 rally found or artificially formed, though containing 
 the elements oxygen, hydrogen, nitrogen, and carbon, 
 are suited for the support of animal life. 
 
 To constitute food, these elements must have been 
 subjected to the recondite laws and powers of vitality 
 either in the vegetable or the animal creation ; or, in 
 other words, food must consist of organized matter ; 
 all attempts of the chemist to form food by the direct 
 presentation of elements to each other are perfectly 
 futile. 
 
 For the due sustenance of human life, in the vigorous 
 exertion of its manifold functions, a judicious and va- 
 ried admixture of vegetable and animal food, aided by 
 culinary operations, is absolutely indispensable, but to 
 obtain such food the ground must be tilled and cattle 
 must be cherished. 
 
 Grain-bearing vegetables, the chief of which are 
 wheat, barley, oats, maize, rye, rice, millet, beans, and 
 peas, have never been discovered in a natural, or as it 
 is commonly called, a " wild state of growth" ; they all 
 require cultivation by the labour of man, thus power- 
 fully illustrating The Sacred Truth, that the fallen 
 destiny of man is " to till the ground from whence he 
 was taken, and in the sweat of his face that he shall 
 eat bread " 
 
 " Hate not laborious work, neither husbandry, which 
 the Most High hath ordained." 
 
 In former times, when the incessant occurrence of 
 civil and foreign wars distracted men from the labours 
 of husbandry, scarcity of food very commonly re- 
 
 N 5 
 
274 AUTUMN. 
 
 suited, and famine overspread the land ; but since 
 these sanguinary strifes have in a great measure ceased, 
 men have " beat their swords into ploughshares, and 
 their spears into pruning-hooks," and returned dili- 
 gently to their toil, guided by the observations, expe- 
 riments, and analogies of science, and thus rendered 
 capable of reflecting and reasoning upon the pheno- 
 mena that they behold, and of bringing scientific prin- 
 ciples to bear upon the succession of crops and the 
 nurture of cattle, so that a general scarcity of food is 
 at present unknown. 
 
 Supremely blest with " every good and perfect gift" 
 from the bounteous Hand of God, England presents 
 striking examples of the utility of science when judi- 
 ciously applied foi increasing the advantages, comfort, 
 and benefit of man. 
 
 At the same time, sad and heart-rending is the stern 
 fact, that in the very midst of " garners full and 
 affording all manner of store," there is not only 
 " complaining in our streets," but the most appalling 
 cases of misery, of frightful destitution, of utter pros- 
 tration of the corporeal, of partial aberration of the 
 mental faculties, from want of a scanty pittance of 
 food ; nay, dreadful above all, cases of lingering death 
 from absolute starvation. 
 
 " Blessed is he that considereth the poor : the Lord 
 will deliver him in time of trouble." 
 
 " The rich and poor meet together, the Lord is the 
 Maker of them all." 
 
 The philanthropist adorns his country with temples 
 
AUTUMN. 275 
 
 of Christian charity and benevolence, as Public Hos- 
 pitals for the reception and alleviation of suffering hu- 
 manity ; and upon visiting these meritorious works, in 
 manifold cases, the physician can but too surely point 
 out to him that present disease was caused by previous 
 starvation, and that the restorative now required is 
 generous food, rather than the " medicines out of 
 the earth, of which doth the apothecary make a con- 
 fection," although such may need to be simultaneously 
 prescribed by the physician, for " there is a time when 
 in their hands there is good success." 
 
 The exalted science of Medicine enrols amongst 
 its followers many of the best and greatest men of 
 the age, men of expanded sentiments and pure phi- 
 lanthropic feelings towards their fellow-creatures, be 
 they high or low, rich or poor, men who are con- 
 stantly bent upon healing the sick, comforting the 
 afflicted, alleviating the vast and terrible complications 
 of human agonies ; men who humbly, yet steadfastly 
 following the footsteps of their Divine Master, are 
 constantly " going about and doing good." 
 
 " Honour a physician with the honour due unto 
 him, for the uses which ye may have of him ; for the 
 Lord hath created him." 
 
 The physician proves, that for the proper formation 
 and renewal of the solid and fluid portions of the 
 human body, in which the chemist discovers Nitro- 
 gen as a leading element, a due supply of food, con- 
 taining Nitrogen in the form of flesh, is imperatively 
 demanded ; for it is an established scientific truth, 
 
276 AUTUMN. 
 
 that animals fed entirely upon proximate organic prin- 
 ciples not containing nitrogen, invariably sink under 
 such diet, and if its use be prolonged, they will ulti- 
 mately die, with all the symptoms which are attendant 
 upon death from total starvation. 
 
 Although nitrogen is abundantly present in the 
 atmosphere, the chemist discovers that it is never 
 withdrawn from thence or elaborated into the animal 
 body, and that it is always indirectly derived from the 
 organic food taken as sustenance. 
 
 Elest with health and strength, happy indeed is the 
 man that " goeth forth unto his work and to his labour 
 until the evening," and can thus obtain a moderate share 
 of both varieties of necessary food, that will enable 
 him to keep aloof from those who would fain persuade 
 him that " raw vegetables and pure water are conducive 
 to health and longevity ;" or who, during his poverty, 
 would penuriously dole out a minimum of animal 
 food, for the miserable support of the frail earthly tene- 
 ment of his immortal soul, which at length escaping 
 from temporal wrong and oppression, seeks for ever- 
 lasting mercy and repose in the bosom of its God. 
 
 The chemical phenomena attendant upon the nutri- 
 tion of the human body by a proper supply of food, 
 are but little known, and vain is the attempt to bring 
 ordinary laboratory processes forward in aid of such 
 recondite functions of vitality. 
 
 The human body, whilst endowed with vitality, ex- 
 erts an action upon every variety of food that defies 
 imitation by the utmost stretch of chemical skill ; but 
 
AUTUMN. 277 
 
 it is discovered that food undergoes a remarkable 
 change after mastication and mixture with the secre- 
 tions of the salivary glands, and transposition by de- 
 glutition into the stomach. 
 
 A secretion of the stomach called " gastric juice," 
 exerts a powerful solvent agency upon the food, and 
 during digestion reduces it to a- semifluid white matter 
 called " chyme." 
 
 The gastric juice is a most energetic solvent of every 
 kind of food, which of a necessity must be matter de- 
 prived of life ; but it has no action upon the stomach 
 in which it is secreted through the mysterious agency 
 of vitality ; and that vitality is the sole cause of the 
 suspension of the solvent power of the gastric juice, 
 becomes evident after death, for then the stomach, like 
 food, is often found to be corroded and dissolved. 
 
 Chemical analysis of the gastric juice does not mate- 
 rially enlighten experimenters regarding its solvent 
 powers, but it contains a peculiar acid, termed the 
 hydrochloric, probably derived from common salt, na- 
 turally contained in the generality of food and drink, 
 or added to it as a condiment. The small quantity of 
 hydrochloric acid, and of other acids and peculiar 
 principles supposed to exist, are insufficient to account 
 for its power upon food, and it must be referred to the 
 recondite agency of vitality. 
 
 " Chyme," the first product of digestion, may be con- 
 sidered as intermediate with the original food and 
 arterial blood ; from the stomach, this chyme proceeds 
 into the small intestines, and meets with another ex- 
 
278 AUTUMN. 
 
 traordinary secretion termed " bile/' which mingles with 
 it, and very probably confers some alkaline matter ; a 
 chemical change is likewise sustained by the chyme, 
 in consequence of its contact with the bile, for it sepa- 
 rates into two portions, one of which passes into the 
 large intestines, and is ultimately voided as excremen- 
 titious ; the other a milk-white fluid termed " chyle," 
 which is rapidly absorbed by a peculiar set of vessels 
 termed the " lacteals," and by them transmitted to the 
 thoracic duct, and from it to the venous system. 
 
 Upon entering the venous system, the whiteness of 
 chyle is succeeded by a dark purple colour, referable, 
 as it would appear, to the absorption of a superabun- 
 dance of Carbon, which would prove hurtful if retained 
 in the system. 
 
 The Creator has ordained that this purple or venous 
 blood is to be received by the right cavity of the heart, 
 which wondrous organ, by regular pulsations, trans- 
 mits it to the lungs, where, extremely diffused by their 
 peculiar membranous structure, it is exposed to the 
 influence of the air, and the changes immediately ensue, 
 as already mentioned at page 60. 
 
 The blood, thus deprived of its excess of carbon, 
 returns to the left cavity of the heart, as red arterial, or 
 perfect blood, containing a peculiar colouring princi- 
 ple, termed " hsematosyn," and the two other proximate 
 principles already mentioned as fibrin and albumen ; a 
 small proportion of saline matters ; and it is endowed 
 with the power of circulating throughout the system, 
 for the secretion of new parts, and for the removal of 
 
AUTUMN. 279 
 
 such as have performed their functions. Whilst circu- 
 lating throughout the system, the blood is a homo- 
 genous fluid, hut upon removal it spontaneously sepa- 
 rates into a solid and a fluid portion, the former con- 
 taining the colouring principle, and fibrin, the latter, 
 the albumen. 
 
 The human mind has always a tendency to seek 
 into incomprehensible matters ; but incessant and 
 laborious as have been the researches regarding the 
 physical cause of the functions of digestion, nutrition, 
 respiration, and animal heat, very little of real im- 
 portance has been discovered beyond the above state- 
 ment, " though a wise man think to know it, yet shall 
 he be not able to find it." 
 
 Of all the varied productions of Autumn, the corn 
 harvest is of the utmost importance to mankind, and 
 therefore a few general observations upon the che- 
 mical nature of the proximate principles contained in 
 wheat, and to which the nutritive property of good 
 bread may be referred, will claim our attention at this 
 period of our inquiry. 
 
 In " harvest work," the utmost care is taken that 
 the sheaves of corn are perfectly dried by the combined 
 influence of the sun and air, before they are carted 
 from the fields, and housed in barns or stacked in rick- 
 yards ; care is likewise taken to cleanse them as much 
 as possible from tares, thistles, and other succulent 
 plants, which are ordained to accompany the growth 
 of wheat ; because, like hay, all varieties of corn, even 
 when pure, will heat if stacked whilst damp, and with 
 
280 AUTUMN. 
 
 even greater facility, if contaminated by succulent 
 weeds ; whereas if dry, there is no danger of its be- 
 coming heated and musty, and unfit for food. 
 
 The methods of thrashing, winnowing, and grinding 
 the grains of wheat into flour, are too well known to 
 require comment ; but if we turn our attention to the 
 flour, we shall discover a few facts that are not so 
 generally known. 
 
 Knead a portion of flour with water into the size and 
 shape of a dumpling ; then hold it beneath a slender 
 stream of water, and continue to knead ; at first the 
 water will flow away perfectly milk-white, and this 
 may be received in a pail, and set aside ; then the 
 water will gradually become less and less white, until 
 at length it flows unchanged, and leaves upon the 
 hands a grey, tough, elastic substance, very much 
 like bird-lime; it is called Gluten; it is a proximate 
 principle, which existed in the flour, and is educed by 
 this first or simple analysis. 
 
 Gluten, when submitted to ultimate analysis, by an 
 experienced chemist, yields the ultimate elements, 
 Carbon, Hydrogen, Oxygen, and Nitrogen, as at page 
 21 ; and on account of containing the last-named 
 element in considerable abundance, and therefore being 
 nearly identical with the Fibrin and Albumen of the 
 animal body, Gluten is frequently called a vegeto- 
 animal principle, for it gives to articles of diet in 
 which it exists, a nutritive power nearly equal to that 
 of animal food. 
 
 Wheat-flour contains more gluten than that of any 
 
AUTUMN. 281 
 
 other grain, and hence the superiority of wheaten 
 bread over barley bread, or rye and oaten bread ; it is 
 lighter and more digestible. 
 
 The chemist discovers that the warmth of the sea- 
 son materially affects the formation of gluten in wheat, 
 that it is most abundantly found in the wheat of 
 southern climates ; and hence this is peculiarly excel- 
 lent for the manufacture of vermicelli and macaroni, 
 which are very nutritious articles of diet. 
 
 If gluten be perfectly dried, by long exposure to 
 steam heat, it will undergo no change by keeping; 
 but when moist, it will rapidly enter into putrefaction, 
 and exhale the same offensive odour as putrefying 
 flesh, and for the same reason, because it contains 
 Nitrogen, and this combining with Hydrogen, forms 
 the volatile substance called Ammonia. 
 
 Upon examination of the milk-white water that ran 
 from the ball of dough when kneaded to obtain gluten, 
 it will not be found so white as it was, and by gently 
 inclining the pail on one side, to pour it away slowly, 
 a white sediment or precipitate will be found at the 
 bottom ; this is another proximate principle of wheat 
 flour, called Starch; and when correctly analysed, it 
 is found to consist of Carbon, Oxygen, and Hydrogen 
 only, as at page 21, and to present no trace of 
 Nitrogen. 
 
 Starch, when moist, soon becomes acid, from the 
 production of vinegar ; but when dried, it may be kept 
 for years without undergoing change ; it is insoluble 
 in cold water, and only mingles with it mechanic ally > 
 
282 AUTUMN. 
 
 so that by repose it quickly falls to the bottom of the 
 vessel in which the mixture is made ; if boiling water 
 be poured upon a paste of starch, then it dissolves and 
 forms a solution more or less gelatinous, according to 
 the quantity of starch that is present ; and this solu- 
 tion, when cold, if added to one of the element Iodine, 
 in water, will immediately produce a deep blue colour, 
 which is esteemed by the chemist as an exceedingly 
 marked characteristic of starch. 
 
 If a portion of this blue compound, or as it may be 
 called " iodide of starch," be thrown into boiling 
 water, the blue colour instantly disappears, and very 
 seldom returns when the water cools ; hence the expe- 
 rienced chemist, when testing for starch by iodine, or 
 vice versa, always takes the precaution of employing 
 the solutions cold, or he will fail in obtaining the blue 
 colour, even though abundance of both substances may 
 be present. 
 
 Pure starch is perfectly white, but is apt to assume 
 more or less of a yellow tinge in the course of time ; 
 hence the manufacturer of this proximate principle for 
 domestic use, confers upon it a slightly blue tint, by 
 the addition of a small quantity of " smalt," or " oxide 
 of cobalt ;" this renders it perfectly unfit for all re- 
 fined chemical purposes, and for such the pure white 
 starch of wheaten flour, or of arrow-root, must be inva- 
 riably used. 
 
 An aqueous solution of iodine is easily made, by 
 placing one grain by weight of such solid element in a 
 pint bottle filled with rain-water, and leaving it for a 
 
AUTUMN. 283 
 
 few hours ; if, then, a portion of this solution, which 
 has the colour of hrown sherry, be poured into another 
 and smaller bottle, and a few grains of wheat or barley 
 thrown into it, even upon agitation for several minutes 
 no blue colour will be produced, and yet we are cer- 
 tain that the respective grains must contain starcli ; 
 then why does the iodine fail in immediately detecing 
 its presence ? 
 
 For a reason that often presents itself to the chemist 
 during his manifold experiments upon organic and in- 
 organic matter, and that has more than once been pre- 
 sented during our rapid and general inquiry ; viz. that 
 mechanical structure or attraction of aggregation op- 
 poses chemical attraction or affinity, and in the case 
 now presented it is that of the thin hard coating of 
 bran or husk around the grains which prevents the 
 contact of their starch with the iodine. 
 
 Place the mixture of iodine and grains of wheat or 
 barley in a mortar, and crush them with the pestle, 
 thus mechanically destroy their attraction of aggrega- 
 tion, that of the solid iodine being already destroyed 
 by chemical solution, and then, the starch that they 
 contain will meet with the iodine, the two substances 
 will combine, and produce the blue colour, or iodide 
 of starch. 
 
 Again, if perfectly dry iodine, and perfectly dry 
 starch, be rubbed in a mortar, no blue colour will 
 appear, because neither of the substances are suffi- 
 ciently divided by this mechanical proceeding to exert 
 
284 AUTUMN. 
 
 chemical attraction ; but the addition of a few drops of 
 water will effect a chemical division, or a solution of 
 part of the iodine, and then it will immediately and 
 chemically combine with the mechanically divided 
 starch ; it is also probable that a slight solution of the 
 ^/ starch simultaneously takes place. 
 
 Like as with " soda-water powders," consisting of 
 dry tartaric acid and carbonate^6f soda, though both 
 are mechanically divided, they exert no chemical action 
 upon each other; but when thrown into water, they 
 are simultaneously and chemically dissolved, and in 
 such state of solution far exceeding in attenuation the 
 utmost exertion of mechanical comminution ; they are 
 immediately brought into perfect and mutual contact, 
 and then display their chemical incompatibility ; " as 
 vinegar upon nitre," (natron,) by evolving a foam of 
 carbonic acid. 
 
 Bread contains gluten and starch ; the latter may be 
 detected by a very simple experiment : place a thin 
 slice of bread on a plate, and moisten it with an aqueous 
 solution of iodine ; and from being white, or nearly so, 
 it will become dark blue, because in bread, the starch, 
 though still solid, is neither dry, nor protected as it 
 was in the grain. 
 
 If the blue-stained bread be now placed on another 
 plate, and covered with a solution of " ammonia" or 
 strong " hartshorn," the blue colour will vanish, in 
 consequence of a very extraordinary affinity that some 
 of the elements of the ammonia have for the iodine, 
 
AUTUMN. 285 
 
 which is greater than its affinity for the starch ; or in 
 other words, in the one case a compound is produced, 
 and in the next it is decomposed. 
 
 Starch may be decomposed hy the mere application 
 of a moderate heat, as in baking or roasting ; it then 
 becomes brown, and soluble in cold water, and yields 
 no blue colour with iodine ; in fact, the heat has dis- 
 turbed the original arrangement of its proximate ele- 
 ments, Carbon, Hydrogen, and Oxygen, and caused 
 them to group together as Gum ; reference is made to 
 its composition at page 21. 
 
 A piece of bread is insoluble in water, and therefore 
 confers no taste ; if a piece of bread be toasted brown, 
 and then thrown into water, it forms the beverage well 
 known as " toast and water," which has a mucila- 
 ginous taste, and for this reason, the heat of the fire 
 has converted a portion of the original starch of the 
 bread into Gum ; this dissolves in the water, and forms 
 mucilage. 
 
 At the same time, during the toasting of the bread, 
 a portion of its original gluten, starch, and recently - 
 formed gum, are decomposed into volatile matters, 
 which cause the smoking, and peculiar smell of the 
 toast after the first dampness or steam of the bread 
 has passed away, but a portion of carbon does not 
 volatilize, it remains, forming the " charred," or 
 " burnt-toast ;" and this, when thrown into water, 
 forms a dark brown extract, which colours " the 
 water." 
 
 If the bread be more perfectly toasted, so as to be- 
 
286 AUTUMN. 
 
 come very much blackened and burnt, the resulting 
 charcoal is not useless, as might be supposed ; for 
 upon throwing it into a portion of water unfitted for 
 beverage by long keeping, the charcoal will deprive it 
 of all offensive odour and taste, and render it pala- 
 table, yet the theory of this fact is not understood. 
 
 By the long-continued action of diluted sulphuric 
 acid upon starch, the chemist can further derange the 
 natural proportions of its elements, and produce Sugar, 
 a proximate principle likewise consisting of Carbon, 
 Hydrogen, and Oxygen, as shown at page 21. 
 
 A small proportion of Sugar exists in wheaten flour, 
 and likewise another principle called Albumen; but 
 these require a very considerable amount of chemical 
 knowledge for their eduction, and the details of the 
 process would encroach too much upon the prescribed 
 limits of this examination ; reference, however, must 
 be made to the fact, that wheat flour, in addition to its 
 organic principles, gluten, starch, sugar, and albumen, 
 contains notable traces of the inorganic compounds, 
 called phosphate of lime and phosphate of magnesia ; 
 and it is a most remarkable fact, that these inorganic 
 substances are transferred from wheaten and other food 
 in which they exist, into the constitution of the bones 
 of man, and of the higher order of animals. 
 
 The extreme utility of manuring wheat-lands with 
 recent " bone-dust," consists in the fact, that the 
 organic, or tough matter of the bone called Albumen, 
 is extremely prone to putrefy, and thus render soluble 
 the phosphates of lime and magnesia with which it is 
 
AUTUMN. 287 
 
 associated ; these are accordingly rendered into a state 
 suitable for absorption by the rootlets of the growing 
 grain, and are chiefly transferred to the ear, whilst the 
 silica and potash are arrested, to form the glistening 
 straw, as mentioned at page 145. 
 
 Bones, when calcined or burnt, have all their really 
 organic matters, such as albumen, fat, and oil, destroyed 
 and dissipated, and nothing but their inorganic phos- 
 phates remains ; such " bone- ash," although invaluable 
 to the chemist as a source of phosphorus, is not so 
 to the agriculturist, because it is insoluble, and not 
 easily or perfectly received by the rootlets of plants, 
 and therefore it requires solution, or rather decomposi- 
 tion, by the agency of diluted sulphuric acid, before 
 it is added to the soil. 
 
 Bone- ash is the source from whence the chemist 
 elicits all his supplies of phosphorus, about twenty 
 thousand pounds weight per annum, for the manufac- 
 ture of " Lucifer matches ;" he generally effects the 
 decomposition of the bone-ash by submitting it to the 
 action of charcoal and sand at a red heat ; these agents 
 deprive the phosphoric acid of oxygen, and elicit phos- 
 phorus, as the " red lead " deprived hydrochloric acid 
 of hydrogen, and elicited chlorine, at page 232. 
 
 Another most important office of the organic matter 
 of bone, and of animal and vegetable manures .in 
 which nitrogen exists as an ultimate element, is to 
 supply this extraordinary form of matter to growing 
 plants ; hence it is found that wheat, grown upon soils 
 chiefly manured with nitrogenous matters, contains 
 
288 AUTUMN. 
 
 a relatively large proportion of gluten ; and the same 
 remark is applicable to the growth of other vege- 
 tables, for it does not appear that any of them have 
 the power of secreting nitrogen directly from the 
 air ; it enters their living structure indirectly from 
 the decomposition of dead organic matter, and when 
 the season of maturity is attained, such vegetables 
 become the food of animals ; nitrogen enters into 
 the composition of their flesh, and this, conjoined 
 with the use of vegetables as food, aided by proper 
 culinary operations, then enters into the constitution 
 of the human body; at least so it is presumed, accord- 
 ing to the observations and experiments of the ablest 
 physiologists and chemists. 
 
 The use of quick-lime as a manure is on account of 
 its causticity, soon rendering dead organic matters 
 soluble, and fit for the nutrition of growing vegetables ; 
 and having performed this office, it gradually absorbs 
 carbonic acid from the atmosphere, reverts to the state 
 of neutral carbonate of lime, and then sustains the 
 office of absorbing the water of the shower, or the 
 aqueous vapour of the air, by capillary attraction, and 
 thus preserves a reservoir of nutriment for the plants 
 that it supports. 
 
 The offal of the stable and fold-yard is invaluable as 
 manure, because it returns to the soil a very large 
 proportion of the proximate and ultimate elements, 
 that were taken from it by the growth of the hay and 
 corn-crops; it returns them in a state fitted for afford- 
 ing vegetation the support that it demands ; these facts 
 
AUTUMN. 289 
 
 regarding manures are not of such recent date as some 
 persons imagine ; they are to be found in the works of 
 the chemist who first devoted his unrivalled talents 
 to agriculture upwards of thirty years ago, and to 
 whom the agriculturist is deeply indebted for the ra- 
 tional principles upon which he now successfully con- 
 ducts his labours. 
 
 Very few vegetables are destitute of Gum ; it contri- 
 butes to their nutritive powers, and when pure, is 
 wholly soluble in cold or hot water, forming a mu- 
 cilage ; it frequently exudes spontaneously from the 
 stems and barks of trees, as from the plum, cherry, 
 apricot, and almond ; but the substance most popularly 
 known as gum, is the produce of the " acacia vera/' 
 a plant that is very abundant in Morocco. 
 
 As gum exists in vegetables, it appears to have some 
 nutritive properties, and it is said that during the 
 gum harvest the Arabs subsist principally upon it; 
 and moreover, that a large caravan of Abyssinians 
 would have starved, had they not fortunately dis- 
 covered among their merchandize a large stock of gum, 
 upon which one thousand persons subsisted for two 
 months. 
 
 The sweet and luscious taste of fruits may be chiefly, 
 if not exclusively, referred to the presence of the 
 proximate principle well known as Sugar, and it is 
 possessed of considerable nutritive powers; it is so- 
 luble in hot and cold water, forming a syrup, which, if 
 concentrated, will yield four and six sided prismatic 
 crystals as seen in sugar- candy, and thus materially 
 
290 AUTUMN. 
 
 differs in its physical state from gluten, starch, and 
 gum, which are uncrystallizable. 
 
 The composition of all the proximate principles that 
 have been considered, including sugar, will he evident 
 upon reference to page 2J?-; the source of the enor- 
 mous supplies of sugar, is well known to he the 
 <c sugar cane/' or " arundo saccharifera," and there- 
 fore demands no detailed mention here ; the annual 
 consumption of sugar furnished from this plant, and 
 the vast amount of carbon that it contains, are shown 
 at page 82. 
 
 Sulphuric acid has a strong attraction for water, and 
 in combining with it as at page 234, a great elevation 
 of temperature results ; but the chemist discovers that 
 the acid has no attraction for carbon ; now analysis 
 teaches him, that all the proximate principles of which 
 mention has been made, consist of the elements of 
 water, viz., oxygen and hydrogen combined with 
 carbon. 
 
 He therefore reasons as follows, if sulphuric acid 
 be presented to such proximate principles of vegeta- 
 bles, say to sugar for example, it might probably com- 
 bine suddenly with the oxygen and hydrogen or water, 
 and liberate or educe the carbon ; he tries the experi- 
 ment and discovers the truth of his supposition. 
 
 Place a quarter of an ounce of powdered sugar in a 
 small gallipot and add sufficient sulphuric acid to mois- 
 ten it perfectly, stirring the two substances together with 
 a piece of stick ; this will appear as if charred, and it 
 really is so, by the sulphuric acid decomposing it first 
 
AUTUMN. 291 
 
 in preference to the sugar, which will then change into 
 a gum-like mass, and afterwards blacken by the evo- 
 lution of its carbon. 
 
 Or, the experiment may be rendered more striking 
 by moistening another portion of sugar with a few 
 drops of water and then adding the acid, stirring as 
 before ; this purposely added water will combine so 
 energetically with the acid, as to induce the oxygen 
 and hydrogen, or actual water of the sugar, to accom- 
 pany its combination, and the sugar thus decomposed 
 will yield a large mass of carbon. 
 
 The stick should be about one foot long, and the 
 gallipot set upon an earthenware plate, lest it break by 
 the heat of the action, and the operator must not hold 
 his face directly above the arrangement, for sometimes 
 portions of the materials are thrown from the vessel 
 and might do serious injury. 
 
 Sugar has been frequently obtained from the " su- 
 gar-maple " or the " acer saccharinum," also from the 
 " beet-root " or " beta vulgaris," and it may be ex- 
 tracted from many vegetables and fruits that have a 
 sweet taste, but it does not uniformly assume the crys- 
 talline form ; thus, for example, " grape sugar " is 
 not crystalline, neither is " honey sugar," accordingly 
 such varieties of saccharine matter are called " granu- 
 lar sugars." 
 
 A solution of absolutely pure sugar in water will un- 
 dergo no change by keeping for a great length of time, 
 but recently expressed saccharine juice, that of the 
 sugar-cane, for example, will rapidly become acid; 
 
 o 2 
 
292 AUTUMN. 
 
 this is owing to a curious and complicated change that 
 is induced by extraneous matters, which are simulta- 
 neously present in the juice, and therefore the " sugar- 
 boilers " evaporate it as rapidly as possible to obtain a 
 large product of sugar before it spontaneously changes. 
 
 Sugar must be present in all cases of vinous fer- 
 mentation, a process which appears to consist in a por- 
 tion of the carbon and oxygen of the sugar escaping 
 as carbonic acid, whilst the remainder and the whole of 
 the original hydrogen combine to form alcohol. 
 
 In the case of vegetable matters not containing suf- 
 ficient sugar, its formation is induced in them arti- 
 ficially by partial germination; thus, barley is con- 
 verted into malt, or in other words its original starch 
 transmuted into sugar, as that of the " cotyledons " of 
 the bean was changed during germination. 
 
 The process of malting consists in moistening bar- 
 ley with water, heaping it up, and thus inducing ger- 
 mination to a certain extent ; that is, to let the seed 
 grow or vegetate up to that point at which it contains 
 its maximum of sugar : if allowed to continue growing, 
 the sugar at first formed is afterwards consumed by 
 the young plant, so that, at the proper period, vegeta- 
 tion is checked or destroyed by the heat of a kiln, and 
 then the barley is said to be (< malted ;" it has an ex- 
 ceedingly sweet taste. 
 
 The juice of the grape, when first obtained in the 
 " wine-press" is technically called "must," and it will 
 spontaneously ferment, because grape juice contains a 
 peculiar form of " gluten," which extraordinary sub- 
 
AUTUMN. 293 
 
 stance induces this change and production of alcohol 
 in wine. 
 
 An infusion of malt, or " sweet-wort/' on the other 
 hand, does not contain this peculiar gluten, and ac- 
 cordingly a portion of ferment containing nitrogen in 
 the form of " yeast " must be added to induce fermen- 
 tation and the production of alcohol in malt liquor. 
 
 The froth or scum that is so well known to arise 
 upon the surface of fermenting liquors, consists of car- 
 bonic acid gas ; hence the danger of entering a room 
 in which the process is going on, because its atmo- 
 sphere becomes contaminated with the mephitic vapour, 
 which is as eminently fatal to life as the carbonic acid 
 produced by the direct combustion of charcoal in air. 
 
 If a few lighted shavings be thrown into the car- 
 bonic acid arising from fermenting liquor, they will be 
 instantly extinguished, as effectually as though they 
 were plunged into the liquor itself: this curious fact at 
 first only afforded amusement to the philosopher, but 
 he was soon induced to examine it more particularly, 
 and this led him to a general investigation of all kinds 
 of air; in fact, to the foundation of "Pneumatic Che- 
 mistry," and he crowned all his labours by the dis- 
 covery of Oxygen. 
 
 Carbonic acid when cold is much heavier than air, 
 and therefore, if undisturbed by currents or draughts, 
 it will remain as a distinct stratum on the floor of the 
 room in which fermentation is proceeding, and not 
 generally diffuse itself through the whole of the air as 
 it does when ascending hot from a charcoal fire ; ac- 
 
294 AUTUMN. 
 
 cordingly, a person might stand near a fermenting- 
 vat without experiencing giddiness or faintness, the 
 lower part of the hody alone "being immersed in the 
 stratum of cold carbonic acid, but should he stoop to 
 lift any thing from the floor, he would be instantly 
 stupefied or suffocated by this mephitic exhalation. 
 
 Many fatal accidents have happened from forgetful- 
 ness or inattention to these facts, more particularly in 
 large breweries, where, after the liquor has been run 
 off from the vats, men attempt to descend for the pur- 
 pose of cleansing them, and suddenly encounter the 
 invisible yet deadly vapour that still remains. 
 
 The precaution of letting down a lighted candle 
 should never be omitted ; if its flame burn as usual, the 
 atmosphere of the vat is safe ; if it become dim, there 
 is hazard; if it be extinct, there is certain death await- 
 ing the first person who descends. 
 
 It is a well-known fact, that fermentation never en- 
 sues in the grape itself, which if left on the vine, or 
 even after being gathered, shrinks and dries up into 
 raisins, without showing the slightest vinous tendency ; 
 and the cause of this appears to be, that the husk or 
 membrane of the grape is so peculiarly formed as to 
 allow of tho transpiration of water from the pulp, but 
 to arrest the entrance of air or oxygen from without. 
 
 Grapes have been pressed in the vacuum of an air- 
 pump, and the resulting " must " showed no tendency 
 to ferment, but did so instantly upon the admission of 
 the air; hence, a bunch of grapes will become dry 
 raisins if left uninjured, but will yield alcohol, when 
 
AUTUMN. 295 
 
 their membranes are broken to admit the access of 
 oxygen to the gluten they contain. 
 
 The chief bulk of vegetables consists of a principle 
 called Lignin, or woody-fibre, and the diversity of forms 
 in which they present it to the attention of the che- 
 mist, calls forth his wonder and admiration. 
 
 In a dense and compact state, lignin constitutes fo- 
 rest timber ; this is felled in Autumn, and allowed to 
 dry or season ; we then employ it in the construction of 
 our dwellings, its extreme permanence fitting it admi- 
 rably for such purpose, whilst its perfect insolubility 
 in water, and its buoyancy upon that liquid enables us 
 to build ships, and thus to explore the wonders of cli- 
 mates far distant from our own. 
 
 But all kinds of wood are not equally adapted for the 
 latter purpose ; ebony and " lignum vita? " are heavier 
 than water, and will immediately sink through it as 
 stones, whilst oak and pine are lighter, and will float 
 with great buoyancy; the actual proximate principle 
 lignin is of the same density in these heavy and light 
 woods, but in the first it is closely compacted, as the 
 water of a hail- stone, whilst in the latter it is loosely 
 aggregated as the water of a snow-flake, and involves 
 amongst its pores a considerable volume of air. 
 
 If the air be removed from a lump of oak or pine, 
 these will no longer remain buoyant but will sink 
 through water like ebony or " Hgnum-vitaB" ; very 
 simple experiments will prove this fact : for example, 
 boil a piece of oak in water day after day until the air 
 is expelled from its pores, and then it will sink ; or 
 
296 AUTUMN. 
 
 tie a lump of lead to a piece of pine that it may 
 sink in a tall glass filled with water ; place this 
 beneath the receiver of the air-pump, and pro- 
 ceed to exhaust : as this is done, myriads of air-glo- 
 bules will escape from all parts of the wood and 
 emerge at the surface of the water ; maintain the va- 
 cuum until these cease, then admit the air, which will 
 press water into the pores from whence the air-globules 
 escaped; or in other words, will saturate the reti- 
 culated or net- work structure of the wood ; and now 
 upon detaching it from the lead, it will sink with 
 nearly the same facility as that metal when thrown 
 into water. 
 
 During the agonies and struggles of a harpooned 
 whale, the gigantic creature has been known to draw 
 a boat entangled by the harpoon line, to such an ex- 
 treme depth of the ocean, that the pressure of the water 
 forced the air from the wooden planks, and assumed its 
 place, so that the boat when ultimately recovered by 
 the whalers was no longer capable of floating, and in 
 fact was worthless even for the purpose of fuel. 
 
 In varying forms of compactness and strength, lig- 
 nin constitutes a chief part of inferior plants, such as 
 hemp and flax for example ; these admit of being 
 wrought by handicraft into cordage, canvass, and linen, 
 and when these fabrics are no longer applicable to 
 their original uses, they may be converted into paper 
 of inestimable value. 
 
 Delicately elaborated by the Hand of The Creator, 
 this curious proximate principle lignin, constitutes the 
 
AUTUMN, 297 
 
 net-work or skeleton for the reception of the pulp and 
 juices of fruits ; it contributes to their form, and its 
 elements, namely, carhon, oxygen, and hydrogen, slowly 
 yet certainly relinquish their original affinities, and 
 assume those required to produce saccharine matter, 
 during the progress of ripening under the agency of 
 Light and Heat. The chemist obtains absolutely 
 pure lignin from wood, by removing all soluble matters 
 with water, acids, or other solvents, and then he finds 
 it to consist only of the three elements above named, 
 and to be totally dissipated in the form of carbonic- 
 acid and water during the act of combustion. 
 
 But in wood, lignin is associated with portions of 
 earthy, saline, and alkaline matters which the tree, dur- 
 ing its vitality, secreted from the soil; and accordingly, 
 when wood is kindled, its pure lignin changes into 
 carbonic acid and water, whilst the earthy, saline, and 
 alkaline matters being incombustible, remain as white 
 ashes, which under ordinary circumstances are gene- 
 rally very light and easily scattered by the wind; 
 hence the expression in Holy Writ, " He scattereth 
 the hoar-frost like ashes," has reference to the white- 
 ness and lightness of the ashes of wood, which was the 
 chief fuel employed in early ages. 
 
 Upon accurate examination of wood- ashes, the che- 
 mist discovers them to contain the compound already 
 spoken of as pearl-ash or carbonate of potash ; not that 
 it actually existed as such in the wood, but there more 
 probably as acetate of potash, the acetic acid changing 
 into carbonic acid by the action of the fire. 
 
 o 5 
 
298 AUTUMN. 
 
 During the clearing of vast forest tracts, the fallen 
 timher is regarded as an incumbrance rather than of 
 value ; and in order to remove it, enormous piles are ar- 
 ranged and kindled, the lignin and other organic mat- 
 ters are dissipated in flame and smoke, chiefly pro- 
 ducing carbonic acid and the vapour of water, whilst 
 the inorganic matters remain as fixed ashes. 
 
 These, when purified by solution in water, filtration, 
 and evaporation, afford carbonate of potash very nearly 
 pure, and are technically called " Pearlashes ; " the che- 
 mist, knowing that lime has a strong attraction for car- 
 bonic acid, adds lime to carbonate of potash, and thus 
 forms insoluble carbonate of lime, as at page 63, whilst 
 potash or oxide of potassium remains in solution, and 
 then by evaporating the water, solid potash remains, 
 which if heated with iron under certain conditions, 
 gives oxygen to the iron and forms oxide or rust of iron, 
 whilst the potassium is emancipated in its elementary 
 or metallic form, though capable of floating upon 
 water and burning into oxide of potassium or potash, 
 by decomposing the water and combining with its 
 oxygen, of which hereafter. 
 
 The uses of carbonate of potash, as immediately found 
 in the white ashes, or of the potash obtained by the 
 agency of lime, are most numerous ; both are employed 
 in the arts of dying and bleaching, and also in the ma- 
 nufacture of glass ; for oxide of potassium, or potash, 
 as it is' more commonly called, (from the circumstance 
 of the combustion of wood for its production being 
 originally conducted in iron pots,) is discovered to have 
 
AUTUMN. 299 
 
 the power of uniting with oxide of silicium or sil ica, 
 and many other metallic oxides, to constitute glass, 
 either pellucid and colourless, as rock crystal, or tinted 
 with colours as vivid and varied as those which court 
 our admiration and wonder in the amethyst, topaz, 
 ruby, sapphire, and emerald. 
 
 By the employment of pellucid glass, compounded 
 of the oxides of potassium, silicium and lead, in the 
 form of lenses of enormous magnifying power, man has 
 been enabled to construct instruments for penetrating 
 into space, to watch the career of the heavenly bodies ; 
 " the sun that rules by day, the moon that rules by 
 night, and the stars also;" to explain the change of 
 seasons, to predict the return of comets, and gain 
 knowledge regarding the surpassing grandeur and 
 Omnipotence of the God who created, and still upholds 
 the boundless Universe. 
 
 Such are a few of the extraordinary phenomena 
 which are presented upon an examination of wood- 
 ashes, but there are two more facts that may be men- 
 tioned; in Autumn more particularly, harvest-men 
 kindle a pile of sticks upon the ground to make a fire 
 for cooking their food ; and if we examine the circle 
 of embers and ashes next morning, we find them more 
 damp than the soil around : this is contrary to what we 
 might expect : so if we hold a dry glass over the flame 
 of a candle it becomes damp, and this is contrary to what 
 we might expect : what is the reason of these facts ? 
 
 Why, the burning of the wood has produced pearl- 
 
300 AUTUMN. 
 
 ash, and this is deliquescent, as stated at page 137; 
 and although the circle of the soil "became heated, yet 
 during the night it cooled, and the embers and the 
 ashes attracted sufficient watery vapour from the air, 
 to dissolve partially ; they accordingly present an ex- 
 ample of deliquescence from aerial moisture. 
 
 If we collect them and throw them into " hard 
 water," that is perfectly unfit for washing, as it curdles 
 the soap on account of containing a portion of gypsum 
 or sulphate of lime in solution, we shall find, after the 
 lapse of half an hour, that the water has become 
 " soft," even softer than rain-water, that was directed 
 at page 47, to be collected before it touched the 
 ground, in order that it might not dissolve any calca- 
 reous or other matter, but remain as water nearly 
 chemically pure ; but what is the reason that the ashes 
 of the harvest-men's fire have thus softened the hard 
 water ? 
 
 Because the carbonic acid of the carbonate of pot- 
 ash has combined with the lime of the sulphate of 
 lime, to form insoluble carbonate of lime or chalk, 
 whilst the sulphuric acid has combined with the potash 
 to form soluble sulphate of potash, which remaining in 
 solution, with a considerable excess of carbonate of 
 potash, the latter, instead of curdling the soap and de- 
 priving it of oily matter as gypsum would do, renders 
 it all as soluble as it would be if pure or rain-water. 
 
 The practical application of this fact is well known 
 in rural districts, and weeds are burned to obtain the 
 
AUTUMN. 301 
 
 ashes ; the " wormwood " particularly affords them 
 abundantly, and hence its purified ashes are often called 
 " salt of wormwood." 
 
 The reason that the glass does not remain dry when 
 held over the flame as we might expect that it would, 
 is because the hydrogen of the wax, tallow, oil, or gas, 
 combines with the oxygen of the air to produce the 
 vapour of water which the glass condenses, whilst the 
 carbon of such sources of light combines with another 
 portion of oxygen to form carbonic acid which the 
 glass cannot condense, but it may be detected by lime 
 water, as directed in the experiment at page 63. 
 
 One more application of the wood-ashes may be no- 
 ticed : they have the power of preserving iron from oxi- 
 dation or rusting, and hence are employed for protect- 
 ing the part of the lightning-conductor that is carried 
 beneath the soil ; and although the carbonate of potash 
 may become perfectly damp, or even dissolved, yet it 
 will still prevent the rusting of iron or steel. The reason 
 of this is unknown to the chemist, but the fact can be 
 appreciated by all. 
 
 In addition to the numerous mechanical uses of 
 wood, and its chemical use as a source of artificial heat, 
 the chemist discovers that it is capable of a most cu- 
 rious change or transmutation into edible matter, in 
 fact that a kind of bread may be made from wood. 
 
 This is effected by selecting the saw-dust of the least 
 resinous wood, that of beech, for example, washing it 
 with water to remove all soluble matters, and then 
 gently drying it in an oven ; after this it is mixed with 
 
302 AUTUMN. 
 
 marshmallow juice and formed into cakes, which are 
 baked at a high temperature ; and these reduced to fine 
 powder with the addition of a little corn flour and 
 leaven, form a dough which when moulded into loaves 
 and baked constitutes bread more palatable than the 
 bread prepared in times of scarcity from bran and 
 husks of corn. 
 
 It is further discovered that absolutely pure lignin, 
 when heated to redness out of the access of air, so that 
 it cannot enter into combustion, is nevertheless decom- 
 posed, and that its gaseous elements newly arrange 
 themselves with a part of the carbon, to constitute the 
 same acid as that resulting from the spontaneous sour- 
 ing of fermented liquors. 
 
 The same thing happens when ordinary wood is si- 
 milarly treated, and thus an abundant store of acetic 
 acid or vinegar is obtained, which is of great value 
 as an antiseptic ; and the excess of carbon that remains 
 is of equal importance as a fuel. 
 
 Carbon, or charcoal as it is more commonly called, 
 appears as a black porous solid ; and an accurate ex- 
 amination of its habitudes and powers of combination, 
 with other elements, leads to the extraordinary conclu- 
 sion, that the carbon or charcoal obtained from wood, 
 is identical in its elementary habitudes with the highly 
 valued diamond. 
 
 The properties of charcoal obtained from wood are 
 numerous and important ; it undergoes no change by 
 the most protracted exposure to air and water ; and 
 hence engineers and architects submit those parts of 
 
AUTUMN. 303 
 
 timbers that are employed as foundations for works in 
 damp soils, or in the beds of rivers, to the preliminary 
 operation of charring. 
 
 Charcoal, likewise, exerts antiseptic power over ani- 
 mal food; and although inferior in this respect to com- 
 mon salt, nitre, and vinegar, is yet susceptible of much 
 practical utility ; it has also the property of discharg- 
 ing many colours of organic matters, and therefore it 
 is employed for whitening sugar, and other crystalline 
 products of vegetation. 
 
 The utility of charcoal as a fuel is very great, 
 more especially in many processes of metallurgy ; for 
 in consequence of its powerful affinity for oxygen at 
 an elevated temperature, it not only combines with 
 that element from the air, but likewise with the oxygen 
 present in the ore ; and the ore thus deoxidated, relin- 
 quishes its pure metal; a process which has received 
 the name of " reduction." 
 
 "If thine enemy hunger, feed him; if he thirst, 
 give him drink ; for in so doing thou shalt heap coals 
 of fire upon his head." 
 
 This passage is a beautiful metaphor, taken from the 
 ancient practice of smelting ores ; and meaning, not to 
 consume the enemy, (for that would be contrary to the 
 precepts of Christian charity,) but to soften and subdue 
 him as the fire melts and reduces metals. 
 
 Upon tracing lignin as a chief constituent of the 
 bark of trees, the chemist discovers another example of 
 the power and goodness of The Creator. 
 
 Lignin is an exceedingly bad conductor, and there- 
 
304 AUTUMN. 
 
 fore only very slowly permeable by heat or cold ; thus 
 the covering of bark prevents the sap of trees from 
 disturbance in its circulation by sudden changes in 
 the temperature of the air, and secures it the degree 
 most congenial to the performance of its vital func- 
 tions. 
 
 If the bark were not thus created of bad conducting 
 material, trees and plants would suffer from the heat of 
 Summer, and the cold of Winter ; but more especially 
 from the latter, as it would cause their death by the 
 freezing of the sap, a phenomenon sometimes observed 
 during a protracted and rigorous winter ; but it can 
 be prevented in many instances by enveloping the 
 trunks of trees with a thicker coating of woody fibre, 
 in the form of matting, or bands of hay and straw. 
 
 When tropical plants are transported to cold cli- 
 mates, we artificially clothe them with similar mate- 
 rials to prevent them from suffering by the sudden 
 transition, the same as we should endeavour to protect 
 ourselves, by putting on an extra garment upon passing 
 from hot to cold weather. 
 
 By keeping a thermometer plunged in a hole bored 
 in a sound tree during hot weather, it constantly 
 indicated a temperature several degrees below that 
 of the atmosphere ; and during cold weather a tem- 
 perature several degrees above that of the atmo- 
 sphere : and another wonderful fact was also dis- 
 covered, namely, that sap drawn from the tree would 
 freeze at the same temperature as pure water, whilst 
 the sap circulating, in the tree, under vital agency, 
 
AUTUMN. 305 
 
 would not freeze until reduced seventeen degrees be- 
 low the freezing point of water. This point or degree 
 will claim our attention when considering the leading 
 chemical phenomena of Winter. 
 
 It is a generally received and probably correct state- 
 ment, that heat is evolved during germination, heat 
 quite independent of that which is popularly known to 
 be evolved during putrefactive fermentation, as that of 
 damp hay, damp corn, or organic manures ; the tem- 
 perature of plants is very frequently materially above 
 that of the atmosphere, " and all have undoubtedly a 
 power dependent upon vitality of maintaining to a 
 great extent an equable temperature." 
 
 In Summer and Autumn the dense foliage of trees, 
 by its extraordinary non-conducting power, forms the 
 cool shade which at noon-day is so eagerly sought by 
 man and animals from the piercing rays of the sun, 
 and more particularly in oriental climates. 
 
 The chemist discovers that the leaves of some very 
 succulent plants will absorb oxygen in the dark, and 
 again evolve it in the light ; some kinds of the " cac- 
 tus," for example, will absorb more than their own 
 bulk of oxygen, and retain it so tenaciously, that they 
 will not yield it by the action of heat, nor in the va- 
 cuum of ,an air-pump, but immediately do so upon 
 exposure to the imponderable agency of solar- light. 
 
 No satisfactory evidence can be adduced regarding 
 the physical cause of the circulation of the sap in 
 plants, nor even of the general direction of its course; 
 but the most accurate researches which have been 
 
306 AUTUMN. 
 
 made upon this recondite subject, render it probable 
 that the chief ascent of the sap from the roots to the 
 leaves, is in the vascular system of the " alburnum," 
 and outer layers of wood ; and that having performed 
 its functions in the leaves, as shown at page 78, it 
 chiefly descends by the " liber," or inner layer of 
 bark, giving rise to the formation of new wood, and 
 to the separation of gum, resin, and other proximate 
 principles. 
 
 As regards the influence of flowers upon the atmo- 
 sphere, it appears that they deteriorate it to some 
 extent, and particularly during the night; but it is 
 highly probable that much of the oppression which 
 persons frequently experience after remaining in a 
 conservatory, or room filled with flowers, is in the 
 first place referrible to the confined atmosphere being 
 loaded with carbonic acid arising from the tan and 
 soil ; and in the next from the concentrated aroma of 
 the flowers, and not from any material deterioration of 
 air by their agency. 
 
 Some persons are more affected by the aroma of 
 flowers than others ; thus a single hyacinth in a large 
 room certainly cannot deteriorate the air in any appre- 
 ciable degree, and yet its odour may be extremely 
 oppressive, producing even headache and faintness. 
 
 Few persons can bear an atmosphere loaded with 
 aroma, whilst a little is occasionally refreshing; the 
 same as a pocket-handkerchief saturated with otto of 
 rose, soon palls upon the sense, though the first diffu- 
 sion of its odour might have been grateful. 
 
AUTUMN. 307 
 
 In Autumn, during the ripening of fruits, the che- 
 mist ascertains that they in all cases tend to the pro- 
 duction of carbonic acid ; and as in the case of seeds 
 which will not germinate, unless carbon escape from 
 them, as shown at page 65 ; so in this of fruits, they 
 will not ripen unless they can relinquish a portion of 
 their carbon as carbonic acid ; indeed they will ra- 
 pidly die and rot, if their functions in this respect be 
 prevented. 
 
 When fruits rot, they first change a portion of 
 the oxygen of the air into carbonic acid, and then 
 abundantly liberate carbonic acid ready formed, so that 
 during Autumn both the ripening and decay of fruits 
 become sources of carbonic acid in the atmosphere ; 
 this carbonic acid, the leaves of surrounding plants, if 
 healthy, have the power of elaborating into matters 
 conducive to their vitality, under the direct influence 
 of solar-light. 
 
 The seeds committed to the earth a few months 
 since, watered by the gentle showers of Spring, warmed 
 and nurtured by the sun of Summer, have attained 
 their perfect structure during Autumn, and brought 
 forth, some ten fold, others sixty fold, according to 
 the nature and situation of the soil. 
 
 For example : if we now proceed to the plot of 
 earth where the beans were first cast, for affording us 
 the means of investigating the phenomena of germina- 
 tion by the death of one set of their proximate consti- 
 tuents for the quickening of others, we shall find such 
 as remained undisturbed, have now grown up into per- 
 
308 AUTUMN. 
 
 feet plants, with luxuriant foliage ; and from the inter- 
 vening stems are hanging numerous heavy pods, con- 
 taining not each one single hean, but six, or seven, or 
 eight beans, all precisely identical in their physical 
 and chemical characters, with those originally com- 
 mitted to the earth, and into which, by the bursting of 
 the ripe pod, these in their turn will ultimately fall, 
 and remain dormant during the approaching Winter, 
 then will germinate, upon the return of Spring, 
 flourish throughout Summer, ripen during Autumn, 
 and then again, as now, display their multifarious store. 
 
 Fig. 52. 
 
 We shall thus find that the existence of most plants 
 is dependent for its continuance on an inherent law, or 
 principle of producing a seed similar to that from 
 whence it sprung ; the perfecting of this seed is the 
 grand object of the various processes and actions 
 which take place from germination to maturity ; and 
 when it is completed, the end for which the plant was 
 formed is probably accomplished ; it either dies away, 
 upon the seed previously relinquished, to which even 
 
AUTUMN. 309 
 
 in the putrefactive changes of death it affords nutri- 
 ment, as its ultimate elements undergo new arrange- 
 ments ; or in place of thus entirely mingling with the 
 earth, the dead leaves alone are cast upon it, for slow 
 yet certain transition, into the food of future plants, 
 whilst the stem and branches, though denuded, remain 
 unharmed and dormant throughout the rigours of 
 Winter, and resume the full exercise of their vital 
 functions for the reproduction of foliage, flowers, and 
 fruits, as Spring, Summer, and Autumn, appear in un- 
 erring and ceaseless change. 
 
 How miraculous are the foregoing phenomena, and 
 in minds duly prepared, how pure, how exalted, are 
 the feelings of happiness and of faith inspired by their 
 contemplation and investigation ; they direct our 
 thoughts from the present to an hereafter, and are ap- 
 pealed to in Scripture as emblematical of the " resur- 
 rection of the dead." 
 
 " But some man will say how are the dead raised 
 up ? and with what body do they come ? 
 
 " Thou fool, that which thou sowest is not quick- 
 ened except it die ; 
 
 " And that which thou sowest ; thou sowest not that 
 body that shall be, but bare grain, it may chance of 
 wheat or of some other grain : 
 
 " But God giveth it a body as it hath pleased Him, 
 and to every seed his own body," et seq. 
 
 " So also is the resurrection of the dead. It is sown 
 in corruption : it is raised in incorruption," et seq. 
 
 In this general inquiry, it is impossible to dwell 
 
310 AUTUMN. 
 
 upon all the extraordinary matters that are presented 
 to our notice during the season of Autumn ; the mere 
 examination of the proximate principles of vegetables, 
 would of itself occupy more space than is here devoted 
 to the phenomena of all the Four Seasons. 
 
 The rich and varied products of corn-fields, vine- 
 yards, orchards, and gardens, have been gradually 
 elaborated by the recondite powers of vitality from the 
 earth, the waters, and the air, under the genial agency 
 of solar light and heat, directed by the Hand of Om- 
 nipotence, from the dawn of Spring, throughout the 
 noon of Summer, unto the evening of Autumn ; " the 
 trees of the field have yielded their fruit, and the 
 earth has brought forth her increase " for the welfare 
 and comfort of man, during the approaching night of 
 Winter. 
 
 In reference to the power and goodness of God, 
 Who " fixes the mountains, calms the seas, and re- 
 freshes and fertilizes the earth, providing abundance 
 of necessaries for the use of man," well does the in- 
 spired Psalmist exclaim, with rapture : 
 
 " Thou crownest the year with Thy goodness ; and 
 thy paths drop fatness. 
 
 " They drop upon the pastures of the wilderness ; 
 and the little hills rejoice on every side. 
 
 " The pastures are clothed with flocks ; the vallies 
 also are covered with corn ; they shout for joy, they 
 also sing." 
 
 The sun now declines in heat and splendour, the 
 atmosphere becomes chilled, and leaves assume an 
 
AUTUMN. 311 
 
 endless variety of hues, thus presenting beauties even 
 in their decay ; these well-known autumnal tints are 
 presumed to depend upon peculiar acid matters now 
 formed in the leaves, which, acting upon the principle 
 that during summer caused the reflection of green 
 light, so modify it as to produce a reflection of red and 
 yellow light, and various intermixtures of coloured rays. 
 
 The sight of a vast forest, thus variously tinted by 
 the rays of the setting sun, is indeed magnificent ; but 
 the foliage soon loses its vital functions ; the fall of 
 the leaf arrives, and then the chill winds denude the 
 trees, sweeping back their leaves to mingle with the 
 earth, there to elaborate nutriment for the stems they 
 once adorned. 
 
 During Autumn, we frequently see upon meadows, 
 circles of green, much brighter than that of the sur- 
 rounding grass ; these are popularly known as " fairy 
 rings," and probably they are due to the growth of a 
 fungus, which dying away every year, leaves a rich 
 soil, upon which the grass grows more luxuriantly 
 than upon other parts of the meadow ; these rings 
 therefore annually increase in size, and in many 
 localities they present an extraordinary appearance. 
 
 Slight frosts are common towards the close of 
 Autumn, and therefore tender or valuable plants re- 
 quire protection by matting, or other bad conducting 
 covering ; and at this season may be often observed in 
 the fields, marks of footsteps, which appear to have 
 scorched the grass like heated iron ; this phenomenon 
 was formerly regarded with superstitious dread, but 
 
312 AUTUMN. 
 
 can now be explained upon very simple chemical prin- 
 ciples. 
 
 When the grass becomes crisp by frost, it is ex- 
 ceedingly brittle, and the foot of a man, or even of 
 a child, is sufficiently heavy to break it completely 
 down, and effectually to kill it ; therefore when the sun 
 has thawed the frosty rime from the fields, these foot- 
 tracks appear brown and bare, in the midst of the sur- 
 rounding and flourishing green grass. 
 
 Such are a few, and a few only, of the principal che- 
 mical phenomena of Autumn ; and at its close, the 
 frequent occurrence of frost warns us of the approach 
 of Winter. 
 
 During the dark and dreary reign of this, the last of 
 The Four Seasons, we shall still have to extol the 
 power and appreciate the goodness of The Almighty, 
 in providing for the welfare and protection of His 
 creatures, although " the waters are hid as with a 
 stone, and the face of the deep is frozen." 
 
3] 3 
 
 CHAPTER IV. 
 
 WINTER 
 
 " HE casteth forth His ice like morsels ; who can 
 stand before His cold ? 
 
 <l He sealeth up the hand of every man : that all 
 men may know His work." 
 
 Decreasing days, gathering vapours, falling dews, 
 piercing winds and chilling frosts, conclude the train 
 of departing Autumn, and commence that of approach- 
 ing Winter. 
 
 The most remarkable Chemical phenomenon of 
 Winter, is the transition of water from the liquid to 
 the solid state, and therefore its consideration will 
 form the chief subject of this concluding Chapter. 
 
 The Chemist discovers during his manifold experi- 
 ments and researches throughout the varied produc- 
 tions of Nature and of art, that all substances contract 
 
 P 
 
314 WINTER. 
 
 when cooled, and expand when heated ; with the ex- 
 ception of water, which expands when cooled below a 
 certain degree ; this departure from a law so general, 
 or anomaly in the code of laws discovered by man, is 
 productive of the most beneficial effects throughout 
 'the Creation ; but to understand and duly appreciate 
 these, a few preliminary experiments require to be per- 
 formed, on the contraction and expansion of solids, 
 liquids, and aeriform bodies generally. 
 
 Fig. 53. 
 
 First as regards solids; Provide a smooth cylin- 
 drical bar of iron, about one inch in diameter and four 
 inches in length, with a piece of iron wire about a 
 quarter of an inch in diameter and ten inches in 
 length, screwed into one of its ends, the other end of 
 the wire being inserted into a wooden handle ; like- 
 wise a piece of iron-plate about three inches square, 
 with a circular aperture in its centre, that will exactly 
 allow the end of the cylindrical bar to pass through, 
 or to use a more technical expression, that will " gauge 
 the bar." 
 
 Mix together equal weights of finely-powdered ice, or 
 snow and common salt, in an earthen or wooden bowl ; 
 this will form an intensely cold mixture, for a reason 
 
WINTER. 315 
 
 hereafter to be given ; place the cylindrical bar in 
 this for five minutes ; then remove it, wipe it with a 
 cloth, and apply it to the gauge ; it will enter with 
 extreme readiness, and indeed will be perfectly loose, 
 but in the course of a few minutes it will only enter as 
 exactly as it did at the outset of the experiment. 
 
 Ascertain this fact, then withdraw the bar from the 
 gauge, and place it for five minutes over a clear glow- 
 ing fire, so that it may become heated, but not to a 
 degree approaching redness ; then remove it, and apply 
 it to the gauge ; it will be impracticable to cause its 
 entrance, until it is cooled down to the temperature 
 that it had originally. 
 
 In these experiments, the bar of iron is said to con- 
 tract by cold ; and to expand by heat. 
 
 The contraction and expansion of a liquid by cold 
 and heat, may be thus experimentally demonstrated : 
 Pour spirit of wine into a Florence flask, leaving only 
 about half an inch of the neck unoccupied ; with a 
 sharp file make a mark upon the glass, or paste a 
 small slip of paper around it, at the level of the spirit ; 
 then place the flask in the mixture of ice, or snow and 
 salt ; as the spirit cools, it will contract in bulk, and 
 at length remain stationary considerably below the 
 mark; ascertain this fact, then remove the flask, dry 
 it with a cloth, place it to stand upon a ring, as at 
 page 58. As it gradually gains warmth from the 
 surrounding air, the spirit will expand, and ultimately 
 become stationary, exactly at the mark ; now plunge 
 the flask into hot water, the spirit will expand, and rise 
 
 P 2 
 
316 WINTER. 
 
 above the mark ; but upon removal from the hot water, 
 and cooling in the air as before, the spirit will contract 
 to its original level. 
 
 The experiment may be varied: Select a sound 
 cork that will fit the neck of the flask, make a hole 
 through the centre of the cork to admit one of the 
 open ends of a piece of glass tube, about a quarter 
 of an inch in diameter, and from ten to twelve inches 
 in length. 
 
 Fig. 54. 
 
 Pour spirit of wine into the flask until it is brim- 
 full, then insert the cork into the neck of the flask, 
 that the greater part of the length of the tube may 
 stand uppermost; in doing this, a portion of the spirit 
 will rise in it, but a little more may be dropped in, 
 that its level may be about two inches above the cork, 
 and then any portion that has escaped should be wiped 
 away. 
 
WINTER. 317 
 
 The flask should be held by the neck, and not by 
 the bulb, during the insertion of the cork ; and this 
 rule is invariably followed by the chemist, in corking 
 or stoppering all bottles or other vessels that are em- 
 ployed in his experiments, in order that should they 
 break, his hands may not be lacerated by their frag- 
 ments, or corroded by their contents ; it is seldom that 
 the necks of flasks or bottles break, whilst their bulbs 
 and cylinders very frequently do, therefore the necks 
 remain between the fingers of the operator, and do no 
 injury, and the only temporary inconvenience is the 
 loss of the vessels and their contents. 
 
 The flask, prepared as directed, may then be cooled 
 and heated, as above described ; and in consequence of 
 the elongation of its neck by the glass tube, the con- 
 traction of the included spirit by cold, and its expan- 
 sion by heat, will be more perceptible ; and if it be 
 required to demonstrate this fact more plainly, the 
 spirit of wine may be coloured of a deep crimson, by 
 a few grains of cochineal, and a slip of white paper 
 pasted against part of the tube, to render the descent 
 and ascent of the spirit yet more visible. 
 
 The contraction of air by cold, and its expansion by 
 heat, can be shown by an apparatus equally simple in 
 its construction to that just described. 
 
 Make a tea- cup full of blue infusion, as directed at 
 page 237; pour this into a flask ; select a cork that 
 will most accurately fit its neck, then perforate the 
 cork, to admit of an open glass tube, the same dia- 
 
318 WINTER. 
 
 meter as the last, but thrice its length, being passed 
 through until that part which protrudes from the 
 lower end of the cork, when it is inserted into the 
 neck of the flask, will dip about half an inch below 
 the surface of the infusion that it contains. 
 
 If the cork be sound, and the perforation as truly 
 cylindrical as the glass tube, the arrangement is com- 
 plete ; but the perforation can seldom be accurately 
 made with a knife, and therefore the better plan is 
 to bore a hole through the cork with an awl, and 
 then to enlarge this very smoothly with a cylindrical 
 rasp or file, until it fits the glass tube, care being 
 taken, whilst thrusting it through to the length men- 
 tioned, to hold it in a folded cloth, lest it break. 
 
 Fig. 55. 
 
 Suppose the cork and tube inserted into the neck of 
 the flask as above, a very simple test will detect if it 
 be all air-tight, viz. place the upper and open end of 
 
WINTER. 319 
 
 the tube between the lips, and then endeavour to force 
 air down it ; if this can be done easily, and if plenty 
 of air bubbles appear through the infusion, the ap- 
 paratus is leaky ; if, on the other hand, it can only be 
 done with difficulty, and but few bubbles appear, and 
 above all, if upon removing the lips from the tube, 
 the infusion rise in it considerably above the level of 
 that in the flask, and remains stationary, when the 
 flask is held by the neck, the apparatus is " air-tight," 
 and fit for use. 
 
 Should the infusion descend rapidly in the tube, 
 the whole of the upper part of the cork, part of the 
 tube that it immediately surrounds, and the neck of 
 the flask for about a quarter of an inch, must be co- 
 vered with strong glue, or a solution of sealing-wax in 
 spirit of wine, to stop up all pores or fissures ; and 
 when either application is dry or set, the apparatus 
 may be tested by endeavouring to force in air; and if 
 the infusion rise and remain stationary in the tube, the 
 flask being held by its neck, all things are favourable 
 to the success of the following experiment. 
 
 The flask contains a certain volume of air, and it 
 presses v/ith a certain force upon, and sustains a cer- 
 tain column of the infusion ; now plunge the bulb 
 into a vessel containing ice-cold water, its degree of 
 cold will immediately cause the volume of air to con- 
 tract, and diminish its pressure upon the infusion, 
 consequently that in the tube will fall; allow it to 
 do so, until it fall to the level of the main bulk of 
 that in the flask ; then quickly remove this from the 
 
320 WINTER. 
 
 ice-cold water, and plunge it into a vessel containing 
 water that has remained for many hours in the apart- 
 ment in which the experiment is made, and therefore 
 has acquired its temperature ; the volume of the air in 
 the flask will now expand hy the increase of heat, and 
 press upon the surface of the infusion in the flask, 
 and force a portion of it upward in the tube to the 
 same level as that at which it stood previously to 
 being cooled. 
 
 Ascertain these facts ; then remove the flask, and 
 plunge it into a vessel containing water that has just 
 been taken boiling from the fire ; the volume of air 
 will instantly expand by this great increase of heat, 
 and press so forcibly upon the infusion in the flask, 
 as to force a portion of it upward, nay even to the 
 very top of the tube ; when this happens, quickly 
 remove the flask, place it to stand on a ring, as at 
 page 58, and as it cools, the air will gradually con- 
 tract in volume, its pressure will gradually lessen, 
 the infusion will slowly fall, and at length arrive and 
 remain stationary at the original level that it assumed 
 when the flask was plunged into water having the same 
 temperature as that of the apartment. 
 
 This apparatus, or " air- thermometer," will present 
 the same phenomena repeatedly, care being taken, if 
 necessary, to force in a little air as directed; and 
 during experiments with it, as in those experiments at 
 page 56, the included volume of air sustains nothing 
 beyond mere physical contraction by cold, and expan- 
 sion by heat ; it sustains no chemical change in the 
 
WINTER. 321 
 
 proportions of its elementary and compound consti- 
 tuents ; it will support the flame of a taper, as at 
 page 58. 
 
 If the infusion become mouldy or putrid by keep- 
 ing, then the air above it will not support the flame 
 of a taper, because the decomposition of the organic 
 colouring matter has altered the relative proportions 
 of oxygen and nitrogen ; and this is a chemical 
 change. 
 
 Absolutely pure water undergoes no change by any 
 lapse of time if kept in vessels, the materials of which 
 have no attraction for its oxygen or its hydrogen, such 
 as Florence flasks of hard glass, or yet better, bottles 
 of gold or platinum, these metals having the feeblest 
 attraction for oxygen of all known substances. 
 
 The unpleasant odour of rain-water, as it is com- 
 monly collected, depends upon the decomposition of 
 the organic matter that it has washed from the roofs 
 of buildings, or that it has acquired from the casks 
 and tanks in which it is kept, whilst water che- 
 mically pure, or containing metallic compounds in so- 
 lution, will remain unchanged for years, nay for ages, 
 as exemplified by the fact of its natural occurrence 
 within crystals and pebbles of silica, which extraordi- 
 nary substance, thus densely aggregated, has no attrac- 
 tion for water or its elements. 
 
 Silica, when its attraction of aggregation has been 
 destroyed by some occult process in the vast and per- 
 fect laboratory of Nature, is then rendered soluble in 
 water, as exemplified in those extaordinary and won- 
 
 P 5 
 
322 WINTER. 
 
 derful waters, known as the " boiling fountains," or 
 " Geysers," in the vicinity of the volcanoes of Iceland. 
 
 The waters of these fountains gush boiling hot from 
 the earth, and as they fall and evaporate, leave a sili- 
 cious incrustation upon the sides of the natural cavities 
 into which they are received, and upon the surrounding 
 peat, mosses, and grass ; the leaves of birch, and other 
 stinted trees which grow in that severe climate, are 
 also incrusted, so as to appear as white as stone, or 
 petrified, yet preserving not merely their general form, 
 but their minutest fibres, unaltered. 
 
 The petrifying springs of England deposit not silica, 
 but carbonate of lime, upon their courses, and sub- 
 stances that are immersed in them ; for carbonate of 
 lime, although insoluble in pure water, is soluble if it 
 contain excess of carbonic acid; and as this escapes by 
 exposure to the air, the carbonate of lime falls, as an 
 insoluble solid or petrifaction; this can be imitated 
 by the artificial operations of the chemist, but he is 
 ignorant of the natural process by which the pheno- 
 menon of the solution is effected. 
 
 Let us now return to the more immediate object of 
 our inquiry, viz. the contraction and expansion of 
 solids, liquids, and air, by cold and by heat. 
 
 The chemist, by conducting experiments similar in 
 principle to those described, but with refined appa 
 ratus, and with his utmost skill in manipulation, 
 arrives at the conclusion that air, and all aeriform sub- 
 stances, gases, and vapours, when cooled or heated out 
 of the contact of the liquids from whence they were 
 
WINTER. 323 
 
 educed or produced, contract alike, and expand alike; 
 but as regards solids and liquids, he discovers that 
 they have distinct contractions hy cold, and expansions 
 by heat. 
 
 Or in other words, if a definite volume of air at 
 common temperature, i.e. 62 degrees, contract into a 
 less volume by the cold of iced water, and expand into 
 a greater volume by the heat of boiling water, a similar 
 definite volume of chlorine, hydrogen, or carbonic acid, 
 will do precisely the same ; if, on the other hand, a 
 definite bulk of liquid mercury contract into a less 
 bulk by the cold of iced water, and expand into a 
 greater bulk by the heat of boiling water, a similar 
 definite bulk of alcohol, submitted to such variations 
 of temperature, will contract six times, and expand six 
 times more in its bulk than mercury ; and lastly, if a 
 definite mass of iron contract and expand to a definite 
 mass by cold and heat, a similar definite mass of lead 
 will contract and expand three times more in its mass 
 than iron. 
 
 Having conducted these few preliminary experiments, 
 we may now proceed to investigate the extraordinary 
 exception that water presents, to this general law of 
 contraction by cold and expansion by heat. 
 
 Provide a Florence flask, with a long neck, yet ca- 
 pable of admitting the bulb of a delicate mercurial 
 thermometer ; pour water at the temperature of 80 
 degrees into the flask, until about two inches of its 
 neck remain unoccupied ; place the thermometer with 
 its bulb dipping below the surface of the water, that 
 
324 WINTER. 
 
 the scale may rest upon the mouth of the flask; then 
 make a mark, as already directed, on the glass at the 
 level of the water, and lastly, lift the flask into a quart 
 jar, containing a mixture of ice and salt sufficient to 
 surround the bulb. 
 
 As the water cools from 80 degrees, it will contract 
 and fall in the neck of the flask, like the spirit in a 
 former experiment ; let the thermometer be closely 
 observed all this time ; the water will continue to con- 
 tract, until it attains the temperature of 40 degrees, 
 and at that moment the water, instead of continuing 
 to contract, will slowly expand, and rise in the neck of 
 the flask, until the thermometer indicates a cold of 32 
 degrees, and then the water will congeal or freeze; 
 mark the level of this newly-formed ice upon the neck 
 of the flask, then immediately withdraw it from the 
 cold mixture, wipe it dry, and place it on a ring, as 
 already directed. 
 
 This is a remarkable experiment, and the knowledge 
 that emanates from its accurate investigation is of 
 great importance ; the water, when it contracts by 
 cold to the temperature of 40 degrees, is said by the 
 chemist to attain its maximum of density ; he means 
 by this expression, that if it be cooled below 40 de- 
 grees, or heated above 40 degrees, that its contraction 
 and expansion will be similar. 
 
 Suppose, for example, the ice in the flask of the last 
 experiment be allowed to thaw, the thermometer after 
 some hours will indicate when the temperature of the 
 water has risen from 32 degrees to 40 degrees ; or has 
 
WINTER. 325 
 
 attained its maximum of density ; as it becomes 
 warmer it will expand, and upon attaining the tem- 
 perature of 48 degrees, it will rise to the same mark, 
 or he of the same bulk as it was at the cold of 32 de- 
 grees or in other words, at 8 degrees above 40, the 
 maximum of density, or at 8 degrees below, water is 
 of the same bulk. 
 
 With this incontrovertible fact in Chemistry we are 
 enabled to venture upon an interpretation of the tran- 
 sition of water from the liquid to the solid state during 
 the natural cold of Winter. 
 
 If water, like other congelable liquids, continued to 
 contract in bulk, and to increase in density until it 
 froze, large bodies of water, instead of only being su- 
 perficially frozen in Winter, would become solid masses 
 of ice. Let us select a fresh water lake as an ex- 
 ample ; in Winter, the earth, as already stated, (page 
 69,) is warmer than the air; the heat is accordingly 
 withdrawn from the surface of the water by the cold 
 breezes that blow over it ; the water thus cooled, in- 
 creases in density and falls, whilst warmer water 
 ascends, to undergo a similar abstraction of heat in its 
 turn ; and these descending and ascending, or convec- 
 tive currents, continue, until the entire bulk of the 
 water has attained the temperature of 40 degrees, 
 its maximum of density and temperature perfectly con- 
 genial to aquatic beings. 
 
 The cold breezes still blow over the surface of the 
 lake, still abstracting heat, but instead of causing the 
 water to contract or become heavier, as it would every 
 
326 WJNTER. 
 
 other liquid, it actually causes it to expand and become 
 lighter, so that cold water fairly floats upon warm 
 water, with no more power of sinking through it than 
 a film of oil would have. 
 
 This stratum of light cold water, cannot communi- 
 cate depression of temperature to the warmer water be- 
 neath, because it has no conducting power, and con- 
 vective power is out of the question, it therefore re- 
 mains floating until cooled by the breezes to 32 de- 
 grees ; at this temperature it has parted with so much 
 heat, that it can no longer remain liquid, and therefore 
 becomes a solid sheet of ice. 
 
 Over this newly formed surface the winds may con- 
 tinue to blow, with their greatest intensity of winter 
 cold, but it shields the liquid water upon which it re- 
 poses from their chilling agency, and preserves it im- 
 mutably at the temperature of 40 degrees, whatever 
 may be the cold of the ambient air, for ice is a non- 
 conductor. 
 
 The temperature of the surface of the ice may fall 
 many degrees below 32 degrees, but the water beneath 
 remains at 40 degrees ; accordingly fishes dwell se- 
 curely in these warm liquid depths until the heat of 
 spring dissolves the icy shield, and then they rise upon 
 the surface of the emancipated waters. 
 
 Had The Creator ordained that water should tho- 
 roughly cool to its freezing point, by direct conduction 
 of cold from the air, then on the first approach of Win- 
 ter it would congeal into one entire and solid mass of 
 ice, to the destruction of aquatic beings. 
 
WINTER. 327 
 
 But The Creator, in His Power and Goodness has 
 conferred upon water habitudes with cold and heat, 
 perfectly distinct from those of other liquids ; it expands 
 at an immutable degree of cold, and therefore the re- 
 sulting ice, though solid as a stone, is lighter than the 
 liquid water upon which it floats and protects from 
 congelation ; thus, " By the breath of God frost is 
 given, and the breadth of the waters is straightened ; ' 
 thus, " the waters are hid as with a stone ;" thus are they 
 " clothed with ice as with a breast-plate," to call forth 
 our admiration and Gratitude towards God, even in 
 the season of Winter". 
 
 This miraculous transition of flowing water into so- 
 lid ice, is therefore not an abrupt or sudden phenome- 
 non ; if it were, vast and incalculable derangement of 
 the economy and order of the whole Creation would 
 inevitably ensue : on the contrary, it ensues with a de- 
 gree of regularity and slowness, invariably proportionate 
 to the depth of the water, exposed to the cold blasts of 
 Winter. 
 
 Considerable time, therefore, elapses before the en- 
 tire bulk of water is cooled to 40 degrees by con- 
 vective currents ; and until it be so cooled, and its ex- 
 pansion by continued cold effected, it will not freeze. 
 
 Thus the chemist discovers, that some deep lakes 
 are never frozen, because the cold of the ambient air 
 has been unable to establish the full agency of convec- 
 tion throughout the vast bulk of their waters, even 
 during the most severe and protracted winter ; again, 
 when a sheet of ice has formed upon more shallow 
 
328 WINTER. 
 
 waters, it increases its mass with extreme slowness, 
 and rarely gains a thickness at all proportionate to their 
 main bulk ; it is, comparatively speaking, but a film ; 
 because ice is incapable of conducting cold with facility 
 from its upper to its lower surface. 
 
 Kivers and streams resist congelation longer than 
 lakes, and pools, because their tides and currents inter- 
 fere materially with the cooling influence of the air ; 
 and the water of the ocean in temperate climates, yet 
 more effectually resists such change, on account of its 
 enormous bulk, extreme depth, and large quantity of 
 saline matter ; this alone prevents it from freezing un- 
 til the temperature falls to 27 degrees, or 5 degrees be- 
 low the freezing point of fresh water. 
 
 Within the arctic circle the surface of the ocean is 
 seldom warmer than 27 degrees, and therefore in the 
 decline of Summer it soon attains this temperature, 
 and congelation proceeds so rapidly, that in the space 
 of a few hours, a sheet of ice of an inch in thickness 
 is formed ; then the cold continuing, this increases, 
 until it attains a thickness of several feet, and covers 
 the waters with an impenetrable barrier. 
 
 An experiment can be made to prove that saline 
 matter present in water, causes it to resist congelation 
 at 32 degrees ; add common salt, to half a pint of 
 water, as long as it will dissolve ; this is indicated, 
 when after stirring or shaking the solution, a very con- 
 siderable quantity of the solid salt falls or precipitates 
 to the bottom of the vessel in which it is contained ; 
 pour off the liquid, and if necessary, let it run through 
 
WINTER. 329 
 
 a piece of fine muslin to render it clear ; it is strong 
 brine, or chemically speaking, a saturated solution of 
 chloride of sodium. 
 
 Select a bottle that will hold all, or part of this 
 solution, and another that will hold an equal quan- 
 tity or bulk of fresh water ; place these bottles in a 
 mixture of ice and salt ; they are thus exposed to the 
 same degree of cold, and the water will freeze at 32 
 degrees, but the brine will remain liquid at this tem- 
 perature, and many degrees below it, as the introduc- 
 tion of a thermometer will prove. 
 
 The chemist, by discovering that saline matter pre- 
 sent in water thus causes it to resist congelation, is led 
 to consider the ocean as being an enormous magazine of 
 heat ; and that it enacts an important part, in yielding 
 heat, for the mitigation of the inland cold of Winter. 
 
 Several curious and instructive experiments can be 
 made regarding the phenomenon of the congelation of 
 fresh water : in the first place, provide a cylindrical 
 glass about two inches in diameter, and fifteen inches 
 high, open at one end and closed at the other by a 
 broad " welt," or foot, upon which it will stand firmly. 
 
 Into this glass, pour water at 40 degrees, until with- 
 in four inches of its brim, then introduce a few lumps 
 of clean ice which will float upon the water, and at the 
 same time raise its level coincident with that of the 
 brim of the glass ; allow this arrangement to remain 
 for a few minutes that the ice may slowly thaw. 
 
 Whilst this thawing is proceeding, detach the deli- 
 cate thermometer from the brass column of the " hygro- 
 
330 WINTER. 
 
 meter," page 182, and to its upper part attach a slen- 
 der string about eighteen inches long, and by this care- 
 fully allow the thermometer to descend, through the 
 water, to the bottom of the cylindrical glass, and note 
 the temperature, probably 40 degrees, that is indicated. 
 
 Then gradually draw the string, to raise the bulb of 
 the thermometer into the water resulting from the thaw 
 ing of the ice; and its entrance into this peculiar stratum 
 of water, will be known by its indicating a temperature 
 of about 33 degrees. Why is this curious phenome- 
 non presented ? 
 
 Because ice-cold-water, or nearly ice-cold-water, is 
 lighter than the warmer water, upon which it floats 
 like a film of oil ; again, allow the thermometer to de- 
 scend 'from this stratum, and its mercury will ascend 
 by the action of the comparative warmth to which it is 
 subjected ; again, cause the thermometer to ascend, 
 and its mercury will descend by the action of the com- 
 parative cold to which it is subjected ; and thus the 
 extraordinary yet important conclusion is obtained, 
 that within certain ranges of thermometric temperature, 
 cold water will float upon warm water instead of vice 
 versa, as in the case of all other liquids. 
 
 This experiment being concluded, the water may be 
 poured away from the jar, and then the following ar- 
 rangement can be made, in further illustration of the 
 lightness of ice-cold-water and ice, and the non-con- 
 ducting power of water. 
 
 Select a well-shaped flower-pot, the upper part of 
 which is from six to seven inches in diameter ; then 
 
WINTER. 331 
 
 with a circular rasp, enlarge the aperture of its lower 
 part, until it will just admit of the entrance of the cy- 
 lindrical glass, that its brim may stand a quarter of an 
 inch above the level of the brim of the flower-pot. 
 
 A piece of broad tape, about three feet long, must 
 be wound tightly around the part of the glass that pro- 
 trudes from the lower part of the flower-pot ; and then 
 coated with a thick mixture of plaster of Paris, to unite 
 the surfaces firmly, and form a water-tight joint ; 
 this will be effected in the course of an hour or two, 
 by the hardening or setting of the plaster ; the glass 
 may then be placed to stand as before, but supporting 
 the flower-pot around its upper part. 
 
 Fig. 56. 
 
 Thrust a ball of lamp-cotton or a thin sheet of 
 crumpled paper into the mouth of the glass ; then fill 
 the space in the flower pot with a mixture of finely 
 powdered ice, and salt, as already directed, and should 
 the arrangement seem likely to fall on account of such 
 
332 WINTER. 
 
 a considerable and enlarged weight being placed so 
 much above the small or limited point of support 
 afforded by the glass, a heavy brick must be placed on 
 opposite sides of its "welt," or foot, and thus render 
 its position firm and upright. 
 
 Remove the temporary stopper of cotton or paper, 
 taking great care that none of the mixture of ice and 
 salt fall into the glass, then pour water at common 
 temperature into it, until within an inch of its brim. 
 
 This simple arrangement will enable us to imitate 
 with rapidity, upon a microscopic scale, the phenome- 
 non that proceeds with slowness throughout the gigan- 
 tic laboratory of Nature, during Winter, because in 
 both cases the source of cold is applied at the surface 
 of the water, only in the artificial case it is derived 
 from a mixture of ice and salt, and in the natural case, 
 from winds of extremely low temperature. 
 
 Take the suspended thermometer, as already em- 
 ployed, and immerse it at different depths of the water 
 from time to time, and remark that it indicates the 
 power of the cold mixture in reducing the temperature 
 uniformly down to 40 degrees, because those portions 
 of water in immediate contact with the source of cold, 
 lose heat, contract, and therefore fall, whilst warmer 
 portions ascend ; they in turn become cooled and fall ; 
 convection, and not conduction, is thus established, 
 until the entire bulk of the water is cooled to 40 de- 
 grees, or its point of maximum density. 
 
 Having attained this maximum of density, the pro- 
 
WINTER. 333 
 
 cess of further cooling is no longer extended through- 
 out the entire bulk of water, but is confined to that 
 portion only in immediate contact with the source of 
 cold, which continues constant it is true, but in place 
 of producing a greater contraction of the water, now 
 induces expansion ; this will be immediately detected 
 by the water rising nearer the brim of the glass. 
 
 Thus the cold water is lighter, and floats upon the 
 warmer that is heavier ; the thermometer, which indi- 
 cates 40 degrees at the bottom of the glass, will soon 
 indicate a cold of 32 degrees at or near the top ; and 
 when this happens, the water can no longer remain 
 liquid, but will congeal into a solid cylinder of ice, ex- 
 tending from the top to the bottom of the mixture of 
 ice and salt, whilst the water from the lower part of the 
 flower-pot to the base of the glass, will remain liquid ; 
 because it is of the higher temperature of 40 degrees, 
 and is incapable of conducting cold. 
 
 If the arrangement be now dismantled, by pouring 
 away the mixture of ice and salt, and wiping the out- 
 side of the glass cylinder dry with a cloth, not only 
 will the danger of its fracture be prevented, but the 
 mass of ice that it encloses will be distinctly seen. 
 
 If the source of cold be applied around the lower part 
 of the glass cylinder when filled with water at common 
 temperatures, the effect is very different, for the cool- 
 ing below 40 degrees renders the water lighter ; it as- 
 cends, whilst warmer water descends, becomes cool in 
 its turn and ascends ; thus convection is established 
 throughout the entire bulk of water, or thus its entire 
 
334 WINTER. 
 
 bulk is cooled to 32 degrees, and it will become solid 
 ice throughout its entire bulk; an effect limited to 
 the mere surface of the water in the last experiment, 
 and which, as already stated, represents what happens 
 in Nature where the cold is always superficial, and ice 
 being lighter than water, floats upon its surface. 
 
 If the weight of a bulk of Water be = 1000, the 
 weight of a similar bulk of Ice will be = 940, or 
 in other words, its inherent or particular weight is 
 less than that of Water ; accordingly, the chemist 
 says that the Specific Gravity of Ice is less than the 
 Specific Gravity of Water ; he denotes by this technical 
 expression, the comparison of the weights of equal 
 bulks of different substances, inreference to some fixed 
 standard : let us endeavour to understand his precise 
 meaning. 
 
 Suppose a measure so accurately constructed, that 
 its capacity is exactly equal to a Cubic foot ; suppose 
 the tare of this vessel be accurately taken, and that it 
 be perfectly filled with pure water at the temperature 
 of 62 degrees, this bulk, measure, or cubic foot of 
 water, will weigh 1000 ounces avoirdupois ; this weight 
 is adopted as a Standard of Unity, because Water may 
 be obtained, though not absolutely pure, yet sufficiently 
 pure and abundant for all practical purposes. 
 
 If the water be removed from this cubic measure, 
 and its place supplied with Sea-water, 28 ounces 
 will generally be required as an addition to the 1000 
 ounces, before an equilibrium is effected, so that the 
 weight of a cubic foot of sea water will be 1 028 ounces. 
 
WINTER. 335 
 
 If the sea-water be removed and a solid block of ice 
 be accurately wrought to fit the cubic measure, 88 
 ounces must be taken from the 1 028 to effect a ba- 
 lance, therefore a cubic foot of ice will weigh 940 
 ounces. 
 
 Sea-water is therefore heavier, and Ice lighter, than 
 Water; and the numbers 1028 and 940, directly ex- 
 press their relative weights to it, or their Specific Gravi- 
 ties, the one being 28 thousandths heavier, and the 
 other 940 thousandths lighter than water, or more con- 
 cisely expressed by decimals, as thus : Specific Gravity 
 of Water = 1.000 of Sea Water = 1.028, and of Ice 
 = 0.940. 
 
 Thus, having fixed upon Water as a Standard, and 
 proceeding to ascertain the Specific Gravities of va- 
 rious liquids and solids, the chemist discovers that 
 very few of them exactly coincide with each other ; for 
 example, Spring- water, containing a small amount of 
 chloride of sodium and sulphate of lime, has a Specific 
 Gravity, or for the sake of brevity, S. G. 1.001. 
 
 Water of the Dead Sea containing much chloride 
 of sodium, chloride of magnesium, and chloride of cal- 
 cium, S. G. 1.211; Water saturated with chloride of 
 sodium, forming Brine, S. G. 1.220; these differ- 
 ences in Specific Gravities being dependent upon the 
 fact of a greater actual weight of matter being con- 
 tained within the same bulk in some cases than in 
 others ; thus, all saline substances, such as chloride of 
 sodium, chloride of magnesium, and carbonate of 
 potash held in solution by water, increase its Specific 
 
336 WINTER. 
 
 Gravity, until it is saturated or can dissolve no more ; 
 thus, Spring-water is a weak solution, and its Specific 
 Gravity barely exceeds that of water, Sea-water is a 
 strong solution, Water of the Dead Sea a stronger so- 
 lution, and these both exceed the S. G. of Spring water, 
 whilst Brine, which is the strongest solution of them 
 all, in fact a saturated solution of chloride of sodium, 
 exceeds even the S. G. of the Water of the Dead Sea. 
 
 All common acids when they saturate water, likewise 
 increase its Specific Gravity : we have already employed 
 three of these; viz., Hydrochloric acid S. G. 1.210, 
 Nitric acid S. G. 1.500, and Sulphuric acid S. G. 1.840, 
 this being nearly twice the S. G. of Water. 
 
 When water is added to dilute these concentrated acids, 
 as in the case of sulphuric acid, at page 234, the S. G. 
 of the mixture, is materially lower than 1.840, though 
 invariably higher than 1.000, or the Water standard. 
 
 Ammonia is an alkaline vapour, and when it saturates 
 water, the solution, in place of becoming heavier, be- 
 comes lighter, in fact, from being 1 .000, it is reduced 
 to .875, and this is about the S. G. of alcohol or spirit 
 of wine. 
 
 The fact that equal bulks of different liquids have 
 different weights, may be thus experimentally illus- 
 trated : take the tare of an ounce narrow-mouthed vial, 
 then fill it with water, and ascertain the weight of 
 such water in grains ; pour it away, and fill the bottle 
 with sea water, ascertain its weight, which will be 
 materially greater than that of the water ; then with the 
 spirit of wine, which will be lighter ; and so on with 
 
. WINTER. 337 
 
 other liquids, very few of which will be found to 
 agree in their Specific Gravities. 
 
 If the experiment be made with Mercury, a very 
 common pair of scales should be employed, because its 
 extreme weight would break the strings or bend the 
 beam of a delicate balance such as the chemist uses in 
 accurate experiments, and render a valuable instru- 
 ment perfectly worthless. 
 
 Suppose the experiment made with Mercury, and 
 with Spirit of Wine, the following formula will discover 
 the Specific Gravities of these liquids compared with 
 that of Water. 
 
 Divide the weight of the Mercury, and of the Spirit 
 of wine, decimally by the weight of the Water, which 
 the bottle originally held; thus, suppose it originally 
 held 425 grains of Water, and it be found to hold 5737.5 
 grains of Mercury, and 350.5 grains of Spirit of wine. 
 
 5737.5 -r 425 = 13.5, the Specific Gravity of Mercury ; 
 and 350.5 ^- 425 = 0.824 the Specific Gravity of Spirit of Wine. 
 
 A very homely yet tolerably accurate method is often 
 adopted for ascertaining when brine is sufficient]}' 
 strong for the preparation of meat for salting, or of ve- 
 getables for pickling ; it consists in the fact, that an 
 egg will sink to the bottom of spring or river water, 
 but will float upon the surface when as much common 
 salt is added as the water can dissolve ; the egg 
 thus becomes a " hydrometer," or measurer of liquid 
 strength, and upon this simple principle a refined* in- 
 
 Q 
 
338 
 
 WINTER. 
 
 strument, bearing that name, is constructed for ascer- 
 taining with celerity and accuracy, the specific gravi- 
 ties of saline solutions, acids, worts, and of spirituous 
 liquors more particularly. 
 
 Fig. 57. 
 
 The above engraving shows the usual form of the 
 hydrometer, which is constructed of glass or metal, 
 according as it is intended to be employed for taking 
 the specific gravities of corrosive or neutral liquids. 
 
 It consists of a hollow bulb in the form of an egg, with 
 two stems of unequal length,'the longest proceeding from 
 the larger, and the shortest from the upper end ; this 
 latter, has a small bulb at its extremity, and it is either 
 originally made sufficiently heavy, or is ballasted within, 
 by a globule of mercury or a few small shot, that it 
 may cause the larger bulb and stem to float upright 
 when plunged into a liquid, just the same as the piece 
 of lead that is nailed on the keel of a school-boy's boat, 
 
WINTER. 339 
 
 causes it to float with its mast upright on the water of 
 a pond ; this is the form of the " hydrometer." 
 
 The tall cylindrical glass for the experiments, described 
 in pages 329, and 331, is technically called a "plain 
 hydrometer glass ;" if it have a lip on its brim for the 
 convenience of pouring, it is called " a lipped hydrome- 
 ter-glass;" this form is not so convenient for the above 
 experiments, as the lip interferes with the accurate 
 fitting of the flower-pot around the cylindrical part 
 of the glass, but is very advantageous when it is to be 
 employed for holding any liquid the specific gravity of 
 which is to be denoted by the " hydrometer." 
 
 Suppose the "hydrometer- glass" nearly filled with 
 water, and the "hydrometer "immersed with the shorter 
 stem and small bulb downwards, the instrument will 
 gradually sink until the large oval bulb, and part of 
 the longer stem, become immersed ; a mark is there- 
 fore made upon it, coincident with the surface of the 
 water ; this is a " standard mark/' and indicates the 
 depth to which the " hydrometer " will always sink in 
 pure water, having a specific gravity of 1.000, at 62 
 degrees of temperature ; a number of equal divisions be- 
 ing marked above and below this " standard mark," 
 the depth to which the longer stem sinks will show 
 whether any other liquid into which the " hydrometer " 
 is plunged, is lighter or heavier, or has a specific gravity 
 below or above that of water. 
 
 Thus, in Alcohol, it would sink so low as to sub- 
 merge nearly the whole of the longer stem, the same 
 as the egg would sink through spring water, whilst in 
 
 Q 2 
 
340 WINTER. 
 
 the water of the Dead-sea, it would rise so high as to 
 leave the " standard mark " considerably above the 
 liquid surface, the same as the egg would float upon 
 the brine. 
 
 By repeated immersions of the "hydrometer" in 
 liquids and solutions, the specific gravities of which 
 have been previously determined by accurate weighing 
 in the " specific gravity bottle," real specific gravities 
 may be marked on the stem of the instrument, and thus 
 immediately read off with rapidity, and with sufficient 
 accuracy for all ordinary purposes. 
 
 Another familiar example of the case in point, is the 
 fact, that it is much easier for a person to swim in sea 
 water than in river water, because the human body, 
 like the egg on brine, is buoyed up in a greater degree 
 in the one case than in the other ; and, indeed, if a 
 boat were so laden as to float with safety on the water 
 of the ocean, it would sink upon arriving on the water 
 of a river. 
 
 This may be proved by placing the school-boy's 
 boat upon brine, and gradually and evenly loading it 
 with sand until it just floats level with the solution's 
 edge ; then carefully lifting up the boat, and gently 
 placing it upon river water, it will instantly sink. 
 
 Many other extremely beautiful and instructive ex- 
 periments can be made by very simple means for illus- 
 trating this important subject of Specific Gravity; for 
 example, place the pipe of a "wine-strainer" in an 
 ale-glass, that it may quite touch the bottom, then pour 
 down brandy sufficient to occupy half the capacity of 
 
WINTER. 341 
 
 the glass, and having done so, slowly pour down suffi- 
 cient water to occupy the remaining half, and then re- 
 move the "strainer;" the difference between the spe- 
 cific gravities of the two liquids will be strikingly 
 shown, by the coloured brandy floating on the colour- 
 less water ; and yet further demonstrated, if a lump of 
 white wax, about the size of a hazel-nut, be placed 
 upon the brandy, the wax being of greater specific 
 gravity than it, will sink ; but being of less specific 
 gravity than the water, will float upon its surface. 
 
 Fig. 58. 
 
 Let the tall "hydrometer" glass be thoroughly 
 cleaned and dried ; then select a piece of pewter, cop- 
 per, or glass tube, about two inches longer than the 
 glass, and having a bore about the size of a goose- 
 quill, and if such cannot be obtained, a hollow reed, 
 or even a piece of large pipe vermicelli may be substi- 
 tuted ; one end of the tube, whatever be its material, 
 is to be placed at the pipe of a small glass funnel 
 
342 
 
 WINTER. 
 
 and secured by glueing a strip of calico around it, the 
 object being to elongate the pipe of the funnel, that 
 it may touch the bottom of the " hydrometer glass," in 
 which it is to be placed, as here shown ; the globes 
 at the bottom of the glass will be described hereafter. 
 
 Fig. 59. 
 
 Place half a pint of rain water in one finger glass, 
 and half a pint in another ; add to the one as much 
 " White vitriol," i. e., sulphate of zinc, and to the other 
 as much " Blue-vitriol " i. e., sulphate of copper, as it 
 will dissolve, or in other terms, obtain saturated solu- 
 tions of these substances, which are known to the che- 
 mist as " Salts," although they differ from " common 
 salt" in chemical composition, and all physical proper- 
 ties, save those of solidity and solubility in water. 
 
 By stirring these salts, then, from time to time, in 
 the course of a few hours the desired point of satura- 
 tion will be gained, and it is indicated by a consider- 
 able proportion of each remaining un dissolved. 
 
WINTER. 343 
 
 Mould three lumps of wax into the size of hazel- 
 nuts ; take one of these, and introduce into it a few 
 shot, that will render it sufficiently heavy to sink 
 through water, but yet to float upon the solution of 
 "blue vitriol;" this is easily done after a few trials : 
 take another lump, and introduce into it a few more 
 shot, that will render it sufficiently heavy to sink 
 through the solution of " blue vitriol," but yet to float 
 upon the solution of " white vitriol; " then wash these 
 lumps of wax in water and dry them with a cloth. 
 
 Make a cork ball, and select a leaden bullet, of the 
 same size as one of the lumps of wax ; heat the bullet 
 slightly, and rub a piece of wax upon it to form a thin 
 coating, or it may be " black- leaded." 
 
 Place all the lumps of wax, the cork ball, and the 
 bullet at the bottom of the "hydrometer-glass," as 
 shown in the engraving ; colour about four fluid ounces 
 of strong alcohol of a fine crimson, with a few grains of 
 cochineal; this forms what is called a "tincture," to 
 denote that it is a solution of colouring matter, in spirit 
 or alcohol, instead of in water. 
 
 Strain the " tincture " from the dregs, through a 
 piece of fine muslin, and gently pour about half into 
 the funnel ; it will descend through the long pipe into 
 the glass, and the cork ball will float on it ; next, slowly 
 pour in about the same bulk of water, and the plain 
 lump of wax will rise and float on it ; then, with the same 
 precaution, pour in about the same bulk of the solu- 
 tion of " blue vitriol," and the lump of wax containing 
 the least shot will rise and float on it ; proceed similarly 
 
344 WINTER. 
 
 with the solution of " white vitriol/' and the lump of 
 wax containing the most shot will rise and float on it; the 
 leaden bullet alone remaining ; but, lastly, upon pour- 
 ing in mercury, the bullet will rise and float upon its 
 surface, as buoyantly as the cork upon the tincture or 
 the lumps of wax upon the other liquids. Remove 
 the funnel and the arrangement will present the extra- 
 ordinary appearance of five distinct liquids contained 
 in one glass, in the exact order of their specific gravi- 
 ties ; and five solid masses floating at different heights ; 
 the liquids keep so perfectly distinct that a casual ob- 
 server might think it was a glass, banded, at intervals, 
 with crimson, blue, and silver. 
 
 Fig. 60. 
 
 The surface of the bullet is covered with wax, or 
 black-leaded, to prevent the lead from dissolving in the 
 mercury, for which it has a strong attraction ; and the 
 great specific gravity of the mercury is shown, not only 
 
WINTER. 345 
 
 by the lead floating on it, but by its supporting the 
 weight of all the other liquids; some days will elapse 
 before they mingle, and then no repose will cause their 
 separation. 
 
 Substances insoluble or nearly insoluble in water, 
 have mostly a greater specific gravity than it ; thus as 
 regards the earths, viz., Silica S. G. 2.660, Alumina 
 S. G. 2.000, Lime S. G. 2.300, Magnesia 2.300 ; and it 
 is on account of the great Specific Gravities of these 
 earths and likewise of their natural compounds, that 
 they chiefly -subside with rapidity or precipitate from 
 water when mechanically diffused throughout it by the 
 force of inundations, or floods, the effects of which 
 have engaged our attention at page 143. 
 
 But earths and their compounds are not the heaviest 
 solid forms in comparison with water as a standard : 
 the elementary metals best known surpass them all, as 
 the following statement will prove. 
 
 Zinc S. G. 7.000, Iron S. G. 7.780, Copper S. G. 
 8.890, Silver S. G. 10.470, Lead S. G. 11.350, Mer- 
 cury S. G. 13.500, Gold S. G. 19.25, and Platinum 
 S. G. 21.00, this last metal being the heaviest sub- 
 stance eiiher natural or artificial that the chemist has 
 discovered. 
 
 Some idea of the relative Specific Gravities of solids 
 may be gained by the performance of the following 
 simple experiments ; take the tare of a tin cup capa- 
 ble of holding about an ounce of rain-water, and then 
 ascertain exactly how many grains this water weighs ; 
 it will afford a standard of comparison : pour away the 
 
 Q 5 
 
346 WINTER. 
 
 water, dry the cup perfectly, remove all weights ex- 
 cepting those of the tare from the scale, fill the cup 
 with fine Sand, and ascertain its weight ; then proceed 
 similarly with fine filings of the following metals, viz.. 
 Tin, Zinc, Iron, and Lead, and it will be discovered, 
 although all their bulks are nearly equal to that of 
 Water, their weights greatly surpass it; and by finding 
 how many times the weight of the water is contained 
 in each of their respective weights, an approach to their 
 respective Specific Gravities will be obtained. 
 
 A more accurate proceeding is to obtain a solid 
 cylinder of sandstone, and of each of the metals, ex- 
 actly equal in bulk to the capacity of the tin cup ; 
 then having ascertained the weight of water that it will 
 hold, to remove the cup and all weights from the scale 
 and simply to weigh the cylinders in succession, and 
 then calculate how many times the weight of the water 
 is contained in their respective weights; thus their 
 Specific Gravities will directly appear, and will be 
 nearly coincident with those already stated as belong- 
 ing to these solid substances. 
 
 These remarks regarding Specific Gravity, must not 
 be carried farther at present ; let us return to the fact 
 from whence they emanated, namely, that the specific 
 Gravity of Water being = 1.000, that of Ice is = 0.940, 
 or in other words, Ice is lighter than Water. 
 
 Whatever fluctuations may happen in the density of 
 the atmosphere, they produce no fluctuations in the 
 degree of temperature at which liquid water becomes 
 solid ice, or in more popular terms, the degree at which 
 
WINTER. 347 
 
 water freezes ; and the Chemist avails himself, of this 
 immutable fact, in the construction of the thermome- 
 ter that we have employed so frequently during this 
 examination of the chemical phenomena of the Four 
 Seasons. 
 
 When the bulb and tube of the thermometer are sup- 
 plied with a proper amount of mercury, it is immersed 
 in melting ice, until the mercury contracts and be- 
 comes stationary ; a mark is made upon the tube at 
 this point ; and whenever the instrument is again ex- 
 posed to the same degree of cold, the mercury will 
 descend to the same point. 
 
 If the thermometer be plunged into boiling water, 
 (under certain conditions to be described,) the mercury 
 will expand, and rise, and at length become stationary; 
 a mark is then made upon the tube at this point ; and 
 generally speaking, at any future time it will rise to 
 this mark when plunged into boiling water. 
 
 If the thermometer be immersed in a mixture of ice 
 and salt, the mercury will contract and descend far 
 below the point that it indicated in the melting ice, 
 and this it will do at any future time ; the mixture of 
 ice and salt was formerly imagined to cause the ab- 
 sence of all heat, or to be " absolute cold ;" it was 
 therefore taken as the " zero," or commencement of 
 the thermometric scale of degrees, perfectly arbitrary 
 in their magnitude, but thirty- two of them included be- 
 tween " zero" and the " freezing point" and one hundred 
 and eighty between it and the " boiling point" of water ; 
 so that 32 degrees became the thermometric expression 
 
348 WINTER. 
 
 for the " Freezing Point," and 212 degrees for the 
 ''Boiling Point." 
 
 The freezing point of water is immutable, but not 
 so the boiling point ; it is subject to variations from 
 fluctuations in the local density of the atmosphere, 
 and is therefore determined upon the thermometer 
 scale, when the mercury in the barometer stands at 30 
 inches ; this height indicates the mean pressure of the 
 atmosphere, or announces that it is exerting a pressure 
 of Fifteen pounds upon every square inch of surface ; 
 under such pressure, pure water boils at 212 degrees. 
 
 If the atmosphere become more dense, the boiling 
 point will be elevated ; if it become more rare, the boil- 
 ing point will be depressed ; the Barometer indicates 
 these aerial fluctuations ; its mercury is highest during 
 clear, bright days, and lowest during the prevalence of 
 moisture; all persons are familiar with this fact, for 
 the instrument is constantly examined during the Four 
 Seasons ; but many, when informed minutely concern- 
 ing the construction of the barometer and the prin- 
 ciple of its action, cannot readily understand why the 
 mercury, or f< the glass," to use the favourite expres- 
 sion, " falls when the day is dull and wet/' and as 
 they say " the air is heavy with water." 
 
 The Chemist can present a solution of this seeming 
 difficulty or anomaly. It is true that water is about 
 eight hundred and fifteen times heavier than air, but 
 in this state of liquid density it does not exist in air ; 
 it exists as vapour, lighter than air in about the pro- 
 portion of ten to sixteen"; and accordingly air, satu- 
 
WINTER. 349 
 
 rated with such vapour, is specifically lighter than a 
 similar volume nearly anhydrous or dry, and as a con- 
 sequence, is unable to counterpoise or balance so tall 
 a column of mercury. 
 
 On the plate of the household Barometer, or 
 " weather-glass/' the centre is marked FAIR, above 
 this SET FAIR, yet higher, VERY DRY, then below, 
 FAIR, is CHANGE, below it, KAIN, then MUCH KAIN, 
 and lastly STORMY ; these marks are entitled to no 
 attention, and they never receive it from scientific ob- 
 servers, who know that the instrument can only indi- 
 cate the actual weight of the air, and it is expressed by 
 the numbers 31, 30, 29, 28, and their decimal subdi- 
 visions marked upon the scale. 
 
 If the favourite words of the instrument are to be 
 relied upon, they actually state that similar changes 
 of weather can never take place in any two situations. 
 For example; suppose two excellent barometers, alike 
 in every respect from the hand of the same maker ; 
 they are suspended side by side in his workshop, and 
 the rise and fall of the mercury in the one, exactly tal- 
 lies with the rise and fall of that in the other. 
 
 They are purchased by two persons, one resident on 
 a hill, the other in an adjacent valley; each baro- 
 meter is placed in the house of its owner, consequently 
 one is at a greater altitude from the level of the sea 
 than the other. 
 
 The owners of these Barometers meet, upon a fine 
 bright day, he from the hill- top prognosticates wet, be- 
 cause " the glass is low at RAIN ;" whilst he from the 
 
350 WINTER. 
 
 valley predicts a continuance of fine weather, because 
 " the glass is high at FAIR ;" both losing sight of the 
 different circumstances under which the instruments 
 are placed. 
 
 The weather is the same on the hill and in the val- 
 ley ; but the weight of the air is not, it is less on the 
 one locality than in the other, and to this cause alone 
 is the discrepancy between the indications of the baro- 
 meter to be referred ; bring them side by side in either 
 situation, they will immediately agree as they did in 
 the workshop of the instrument-maker, be the weather 
 fair or foul ; restore each to its place again, and they 
 disagree, although each is correctly indicating the 
 weight of the air in its locality. 
 
 The Barometer and the Thermometer are two dis- 
 tinct instruments, and have distinct principles of ac- 
 tion ; the one indicates fluctuations in the weight of 
 the atmosphere alone, the other changes in its tempe- 
 rature, or in that of surrounding objects. 
 
 Let us now return to the curious phenomena at- 
 tendant upon the freezing of water in Winter ; the 
 Chemist discovers that the formation of ice is attended 
 with most powerful expansion, and of its effects several 
 familiar examples will readily present themselves; 
 we frequently find water in our bottles, not only densely 
 frozen during frosty weather, but the bottles broken, 
 or pipes for the conveyance of water split and rent 
 asunder; if we reflect upon these occurrences for a 
 moment, we must be convinced that a great force is 
 brought into action during the congelation of water. 
 
WINTER. 351 
 
 It is common to say, " that the hottles and pipes 
 are broken by the frost;" true, not however by the 
 mere cold of the frost, but by the expansion of the 
 water in freezing, which these vessels, and others of 
 far greater strength, are unable to withstand ; this can 
 be proved by experiment. 
 
 Boil half a pint of water to expel the air that it 
 contains ; allow it to cool down to the temperature of 
 the atmosphere ; in the mean time select a thick glass 
 bottle, that will hold about four ounces, and a sound 
 cork that will fit its neck accurately ; pour the cold 
 water into the bottle until it is quite full ; then fold a 
 thick cloth several times around it, and holding this 
 firmly with one hand, thrust the cork into the neck of 
 the bottle with the other, to the perfect exclusion of 
 every bubble of air ; secure the cork by tying it down 
 with string, and carefully wipe away any water that 
 may adhere to it or the neck of the bottle. 
 
 The use of the cloth is to prevent the hands from 
 being wounded, should the bottle break during the 
 insertion of the cork ; but suppose this has been done 
 without accident, it must be dipped into hot cement, 
 made by melting four parts of rosin and one part of wax, 
 so that it may be firmly cemented to the neck of the 
 bottle. 
 
 When the cement is cold, place the bottle in a mix- 
 ture of ice and salt, to cover it completely ; this intense 
 cold will not cause any fracture, but in the course of 
 a few minutes, a sharp crack will be heard, which an- 
 nounces, that the water has frozen, expanded and 
 
352 WINTER. 
 
 broken the bottle, as will be evident upon removing it 
 from the mixture. 
 
 Provide a bottle of wrought iron, about one inch in 
 diameter, four inches long, and an eighth of an inch 
 thick, having a female screw cut in its neck, and a 
 male screw plug to fit this accurately ; fill the bottle 
 with boiled water, insert the plug as tightly as pos- 
 sible, and then submit it to cold, as last directed ; 
 when the water freezes, it will expand and burst the 
 iron. 
 
 Many excellent and remarkable experiments have 
 been made upon this expansive force of water in freez- 
 ing ; cast-iron bomb-shells, thirteen inches in dia- 
 meter and two inches tbick, were filled with water, and 
 their apertures or fuse-holes firmly plugged with iron 
 bolts ; thus prepared, upon exposure to the severe cold 
 of a Canadian winter, between four and nineteen de- 
 grees below " zero," at the moment that the water 
 froze, the iron plugs were violently thrust out, and the 
 ice protruded, and in some instances the shells burst 
 asunder; thus demonstrating the enormous interior 
 pressure unto which they were subjected, by water 
 assuming its solid state. 
 
 Our attention must now be directed to the beneficial 
 effects that result throughout Nature from this expan- 
 sive force freezing of water. 
 
 During Spring, Summer, and Autumn, fertile soils 
 by capillary attraction absorb and retain water for the 
 support of their produce ; during Winter, a portion of 
 this water at the surface of the soil freezes, and by its 
 
WINTER. 353 
 
 expansive force thrusts the individual particles apart, 
 and so holds them apparently as solid clods of earth ; 
 hut as the warmth of Spring returns, the icy cement 
 dissolves from its interstices, the clods crumble down 
 so minutely divided, as materially to lessen the labour 
 of the husbandman in preparing the soil for seed. 
 
 The rounded, or weather-worn aspect, the degrada- 
 tion or decay of many rocks, more particularly those 
 of lime-stone and sand-stone, may be referred to the 
 exertion of this singularly powerful agency of water ; 
 it is absorbed into their fissures and pores by capil- 
 larly attraction, as already shown ; and when it freezes 
 during Winter, it expands and detaches successive 
 fragments, so that the original sharp abrupt outline is 
 gradually rounded, and softened down. 
 
 Again, as regards slate-rocks, the strata of which 
 repose upon each other like a number of cards placed 
 at a certain angle or inclination, when water freezes in 
 their fissures, fragments are detached ; and thus freed 
 from restraint, they glide down the sides of the parent 
 mass, and accumulate as an enormous heap of ruin at 
 its base. 
 
 During an extremely severe Winter the sap of trees 
 becomes frozen, and the expansion attendant upon 
 such change is said to rend them asunder with loud 
 cracking or explosion ; we also observe illustrations 
 of this phenomenon upon a minor scale, by flag-stones 
 and pavements, suddenly starting from a level posi- 
 tion, and the mortar of walls peeling away in flakes ; 
 and masons being aware of this fact, never undertake 
 
354 WINTER. 
 
 work requiring mortar or cement during the continu- 
 ance of frost, or in the course of a few hours it would 
 be destroyed. 
 
 If a large cubical piece of Bath-stone be perfectly 
 saturated, by boiling it in water, upon taking it out 
 and exposing it to the frosty air, the manner in which 
 its particles scale away may be soon discovered. 
 
 When masons and bricklayers anticipate the setting 
 in of frost, they invariably cover the new work with 
 thick layers of straw, or matting, which being of non- 
 conducting power, prevents the water in the cement 
 or mortar from freezing and producing injury by its 
 expansion. 
 
 It is a very common practice during Winter to sur- 
 round water-pipes with thick hay-bands and straw- 
 bands, or to cover them with stable-manure, and thus 
 prevent the freezing of water, and the rupture of the 
 pipes, which otherwise might ensue. 
 
 In a service-pipe a few feet beneath the surface of 
 earth, water will seldom freeze unless the cold be ex- 
 tremely severe ; but the part of the pipe which emerges 
 from underground into the open air, as in passing 
 from the street-main across a kitchen area ; being thus 
 exposed, the metal, by its good conducting power, will 
 soon chill the water, and cause its own rupture ; hence 
 such part of the service-pipe either requires to be 
 bound round with hay, straw, or other non-conducting 
 material, to prevent freezing ; or if the tap at the ex- 
 tremity of the pipe in the house be left partly open, 
 the water, instead of remaining stagnant, and thus 
 
WINTER. 355 
 
 becoming frozen, will constantly flow, and oppose in 
 a great measure the cooling power of the surround- 
 ing air. 
 
 In conducting the experiment regarding the conge- 
 lation of water at page 323, the thin flask does not 
 generally hreak when ice forms, because the neck 
 being open, admits of the expansion ; if a considerable 
 portion of water freeze in this, and particularly if it 
 gradually become narrow towards the mouth, the ice 
 acts as a solid plug to the water beneath, opposes its 
 expansion upwards ; therefore it is exerted in all direc - 
 tions around, and the flask is certainly broken ; hence 
 the necessity of applying the freezing-mixture more 
 around its bulb than its neck. 
 
 In the experiment with the " Cryophorus," at page 
 136, the instrument should be removed from the 
 freezing-mixture the moment after the ice has formed 
 upon the surface of the water in the upper bulb ; for 
 if this be not perfectly spherical, the farther congela- 
 tion of the water will generally break it by the expan- 
 sion that we have been considering. 
 
 During the natural cold of Winter, when a glass 
 " carafe " containing water breaks, generally speaking 
 this happens if it be nearly filled with water, the freez- 
 ing of that in the neck, acting as a barrier against the 
 subsequent expansion of the portion in the bulb, when 
 it freezes ; but it sometimes happens that the glass 
 escapes fracture, because the cold air, like the freezing- 
 mixture simultaneously enveloping it upon all sides, 
 quickly reduces the whole temperature of the water to 
 
356 WINTER. 
 
 the freezing point, and the open mouth admits of the 
 total expansion ; or in other words, the ice will rise 
 towards it in preference to exerting pressure upon the 
 interior of the bulb ; and again, if the " carafe " be 
 only half full of water, its fracture seldom ensues, 
 because there is plenty of room for expansion. 
 
 As in the experiment at page 219, we obtained a 
 heating focus, by allowing the solar rays to fall upon 
 liquid water, so shall we be enabled to obtain a like 
 result with solid water ; or in other words, we can form 
 a " burning lens " of ice. 
 
 Obtain a hemispherical mould of tin-plate, in fact a 
 bowl about eight or nine inches in diameter ; place 
 it to stand either upon a shovel full of hot sand, or 
 upon the rim of a saucepan containing boiling water ; 
 then select a block of the most transparent ice that can 
 be obtained, considerably larger than the bowl, and 
 with a hammer chip away the solid angles of the block, 
 so that it will just enter the bowl. 
 
 Of course the thawing of the ice will immediately 
 commence, and it must be suffered to proceed until it 
 has completely taken the hemispherical shape of the 
 bowl; the block of ice must then be removed, and 
 placed with its hemispherical part upwards, so that its 
 base may stand upon a flat, tin-plate, heated either by 
 sand or water, as directed; the object now being to 
 thaw the excess of base away, exactly level with the 
 zone or circumference of the hemisphere ; thus a 
 " plano-convex lens " is obtained. 
 
 During the process of its formation, the operator may 
 
WINTER. 357 
 
 protect his hands from being numbed, by a thick pair 
 of woollen gloves, and now still wearing these, carry 
 the " ice-lens," and present its plane surface to the 
 rays of the sun, at an open window, upon the sill of 
 which is placed a piece of German tinder ; move the 
 lens about, at the distance of a few inches from this, 
 and at length it will kindle; thus proving that the 
 solar rays have been collected to a focus, and have lost 
 no heat in their passage through the cold ice at 32 
 degrees. 
 
 Thus even in the Arctic regions, the rays of the sun 
 have been collected by a lens of ice, in sufficient inten- 
 sity to kindle gunpowder ; in this country ice can 
 always be obtained, and the experiment can be made 
 during Spring, Summer, Autumn, and Winter. 
 
 Let us now direct our attention to other properties 
 of solid-water or ice. 
 
 The antiseptic power of ice is extraordinary, as the 
 following remarkable natural example will prove : in 
 the year 1803, at Yakoust, on the banks of the river 
 Lena, in Siberia, the body of a mammoth slowly ap- 
 peared from a mountain of ice in which it had been 
 entombed and preserved from decay, according to all 
 probability, from the time of The Deluge ; the animal 
 was sixteen feet in length, nine feet in height, and the 
 flesh was in such excellent preservation, that not only 
 did the bears and wolves devour it with eagerness, but 
 the inhabitants of the district actually cut it up as food 
 for their dogs. 
 
 Knowledge of this antiseptic power of ice is of great 
 
358 WINTER. 
 
 importance to us for the artificial preservation of 
 animal food; such provision packed in ice will not 
 undergo decomposition, because the water that it natu- 
 rally contains as a leading proximate constituent, is 
 rendered solid or frozen by the low temperature ; and 
 in such state, although still consisting of Oxygen and 
 Hydrogen, it is incapable of promoting those changes 
 or new arrangements of the ultimate elements of or- 
 ganic matter which are called putrefactive, as it is ca- 
 pable of doing in the liquid form. 
 
 Such frozen provision, if very slowly thawed, and 
 immediately submitted to culinary operations, becomes 
 wholesome food ; if not, it rapidly putrefies, as it would 
 in a recent state. 
 
 During the Winter in Russia, large and beautifully 
 transparent blocks of ice are quarried from the surface 
 of the frozen Neva, and stored up in cellars for the pre- 
 servation of food; oxen and sheep are slaughtered, 
 dismembered, and allowed to freeze ; the joints are af- 
 terwards packed in casks $nd sent to market; and 
 although so hard as to require an axe to break them, 
 the flesh softens by the thawing of the ice when im- 
 mersed in cold water and is fit for cooking. 
 
 Large quantities of salmon are shipped from Scot- 
 land packed in boxes with ice ; indeed so important 
 are its antiseptic powers, that of late years it has been 
 imported from some of the lakes of North America ; 
 the chief employment of ice is by fish-merchants, for 
 the preservation of their stock during the heat of Sum- 
 mer, because the animal fibre of fish is exceedingly 
 
WINTER. 359 
 
 prone to putrefy, by a very moderate elevation of natural 
 temperature. 
 
 Confectioners, likewise, employ large quantities of 
 ice for obtaining a sufficiently low temperature for 
 making ice-creams, water-ices and other luxuries of 
 the table, which are so grateful during the heat of 
 Summer; and the collection of ice for all the above 
 purposes affords active employment for many poor yet 
 industrious persons, during the chill season of Winter. 
 
 Accordingly, upon the first intelligence that ponds 
 are frozen over in the vicinity of London, folks who 
 are stirring at daybreak may see parties of men and 
 boys, proceeding with crow-bars, forks, rakes, poles, ropes 
 and nets ; in carts, wagons, and vans of every grade 
 and denomination, in search of ice ; a luxury to the'rich, 
 but a treasure to the poor ; as by its collection, although 
 a chilling, comfortless, and hazardous task, they earn 
 a small pittance, which carefully expended upon the ne- 
 cessaries of life, will enable them to keep distress and 
 famine from their cheerless abodes, for a short time at 
 least, during the Winter that brings no festivity with- 
 in their walls. 
 
 The ice thus collected is carted to the shops of fish- 
 mongers and confectioners, and received in their e ' ice^ 
 houses ; " the construction of these receptacles for the 
 preservation of the ice, throughout the Four Seasons, 
 depends upon strictly scientific principles, and there- 
 fore demands a general description in this inquiry. 
 
 The sole object is to prevent the accession of heat to 
 the ice,and therefore an "ice-house," or "ice-well," 
 
360 WINTER. 
 
 is generally formed at a considerable depth in the non- 
 conducting earth, especially in the metropolis, where 
 the surface is of such great value. 
 
 To construct an "ice-house," or more correctly 
 speaking, an " ice-well/' a cavity is dug in the earth, 
 in the shape of an inverted cone, and then huilt around 
 with thick hrick-work, like a well as shown in the ac- 
 companying sectional engraving. 
 
 Fig. 61. 
 
 At the bottom of the cone, a cart-wheel is laid flat, 
 to serve as a grating, and immediately beneath this, 
 proceeds a small brick drain, sloping gradually towards 
 the main sewer or larger street drain. 
 
 About the middle of the small drain, as shown above, 
 a small tank is placed, and a large flat paving tile, or 
 slab of stone, descends from the upper part of the 
 course of brick-work constituting the small drain, to 
 
WINTER. 361 
 
 within a few inches of the bottom of the small tank, 
 and this is half full of water. 
 
 The upper part of the cone is covered with a dome of 
 brick-work, in the centre of which is an aperture, of 
 any size most conveniently suited to the whole struc- 
 ture ; and the horizontal part of the engraving, which 
 proceeds from the white space on the left hand, de- 
 notes a brick work passage, having two or three doors, 
 by which access can be gained to the interior of the 
 " ice-well ;" this is charged with ice, as follows. 
 
 The aperture in the dome of the well is opened, as 
 also the doors of the passage, and a truss of clean straw 
 unbound and thrown down evenly upon the cart wheel ; 
 the cart loads of ice are then emptied upon the street 
 pavement, and the ice is rapidly broken by clubs and 
 mallets, into fragments small enough to pass through 
 the aperture in the dome ; these fragments are rapidly 
 shovelled down, and when a sufficient quantity has 
 thus fallen, one or two men, according to the size of 
 the well, descend, and beat the ice firmly together with 
 heavy wooden rammers, something like paviours' ram- 
 mers ; more ice is then shovelled down and beaten ; 
 and so on, until the well is perfectly and compactly 
 filled ; the workmen then pass out through the side 
 door. 
 
 The aperture of the dome is then accurately closed 
 by a slab of stone, which rests upon a ledge, formed 
 for its reception ; the shaft above this is several feet in 
 extent ; and its top, or mouth, is covered with another 
 slab of stone, level with the pavement ; thus, a con- 
 
 R 
 
362 WINTER. 
 
 siderable column of air is closely imprisoned or ren- 
 dered stagnant, between the upper and lower slab ; and 
 this air, by its non-conducting power, cuts off the ac- 
 cess of heat to the dome of the ice-well. 
 
 The door in the brick- work of the ice -well is then 
 closed, and the space between it and the next door, 
 closely filled in with straw ; this second door is then 
 closed, and the space between it and the third door 
 similarly filled, and so on until all are closed ; the 
 air, and the straw thus confined, cut off the access of 
 heat to the ice in this direction ; and thus the opera- 
 tion is finished. 
 
 Notwithstanding all these precautions, a portion of 
 the ice will thaw ; but the water from this thawing fil- 
 ters down through the remaining ice, through the straw, 
 and between the spokes of the wheel into the small 
 drain, and as it accumulates in the small tank, it over- 
 flows and passes to the sewer ; at the same time, the 
 slab of stone or paving tile, forms an effectual barrier 
 against the admission of warm air from the sewer, so 
 that by all .these contrivances the ice is kept as per- 
 fectly as possible from obtaining heat, and the chief 
 mass of it remains throughout the Summer. 
 
 A considerable thawing of the ice takes place when 
 the doors are opened for obtaining such portions as 
 may be required for use ; on this account, and also of 
 the great trouble that is required for removing the 
 straw barriers, and shutting one door before another is 
 opened, the proprietors of these " ice-wells" never open 
 them more frequently than is absolutely necessary. 
 
WINTER. 363 
 
 A small quantity of ice maybe preserved, by placing 
 it in a thick wooden box with a tight cover, and hav- 
 ing four wooden clump-feet, about two inches high, to 
 stand within another box, so that a space of two 
 inches may intervene between its sides and cover ; this 
 second box is then closed and provided with simi- 
 lar clump feet, and placed in a third, leaving the same 
 intervening space ; this may be placed in a fourth, and 
 the last closely shut down ; thus, by the non-conduct- 
 ing power of the wood, and of the intervening air, the 
 ice will be prevented from thawing for a very consi- 
 derable time ; and so it may be by folding it in several 
 yards of thick flannel. 
 
 During extremely cold weather, fish-ponds are so 
 firmly frozen over, that the sheet of ice forms a perfect 
 barrier against the access of the atmosphere to the yet 
 liquid water beneath ; and accordingly fishes would 
 eventually perish, not by cold ; but by the mephitic re- 
 sults of their own respiration, as at page 208, for solar 
 light is feeble in Winter, and rendered yet more feeble 
 by passing through the ice; the aquatic plants are 
 not stimulated to exert their miraculous decomposing 
 powers upon carbonic acid, it therefore accumulates, 
 and proves fatal, unless we break holes through the 
 ice ; and then we immediately remark, how eagerly the 
 fishes swim towards these, and directly breathe the 
 newly admitted air ; exactly the same as we ourselves, 
 after long confinement in a close room, the air of which 
 has been gradually vitiated by our own respiration, 
 
 R 2 
 
364 WINTER. 
 
 gladly advance to the window and throw up the sash, 
 and thus admit the fresh air to relieve our faintness. 
 
 These holes in the ice require to be kept open from 
 day to day, during the continuance of the frost, that the 
 mephitic results of respiration may partly escape, or 
 chiefly that the fishes may come to the surface and 
 breathe ; drawn there by necessity, they eagerly seize 
 all baits that may be introduced by the fishermen, who 
 are aware of this fact, and accordingly turn it to pro- 
 fitable account. 
 
 In the case of very deep and extensive ponds natu- 
 rally formed, we may generally, if not invariably re- 
 mark, that they are not frozen over with one conti- 
 nuous sheet of ice, of uniform thickness and opacity ; 
 but in many parts circular patches, several feet in diame- 
 ter, consisting of extremely fragile and transparent ice, 
 are readily visible : and in others, even large circles of 
 perfectly liquid water ripple in the winter blast ; these 
 phenomena announce the power and goodness of The 
 Creator, and the miraculous provision which He has 
 made for the protection of His wondrous works. 
 
 Although the cooling of the entire bulk of the water 
 of the pond might have proceeded, by the intensity of 
 the cold, to the degree required for the formation of 
 one uniform sheet of ice, it must be remembered, that 
 the pond thus deprived of receiving water from the 
 clouds above, is not deprived of receiving water from 
 the earth beneath ; springs of water are constantly 
 gushing through its bed, the temperature of this water 
 
WINTER. 
 
 365 
 
 is many degrees above that of the pond ; it therefore 
 swiftly rises, and coming into contact with the lower 
 surface of the ice, commences its work of thawing those 
 spots immediately above the spring from whence it as- 
 cended; these spots become thinner and thinner, so 
 that fishes can easily burst a barrier so frail, and gain 
 not only access of fresh air, but a more genial tempe- 
 rature than that of the main bulk of the surrounding 
 water ; or if they do not burst it, the winter wind will 
 do so, and thus free them from imprisonment ; or if 
 neither force thus operate, the still ascending warm 
 water will at length dissolve the icy barrier, within 
 prescribed limits, and thus free the creatures from the 
 oppression under which they temporarily suffered. 
 
 But this is not the whole of the miraculous provi- 
 sion that is made by The Creator ; He, for the fulfil- 
 ment of a recondite purpose, may ordain the cold of 
 Winter to be so protracted, and so intense, as to con- 
 geal the entire surface of the water into one sheet of 
 ice, of uniform thickness, and thus prevent the access 
 of the atmosphere ; then He ordains the earth to cease 
 the supply of water from its springs, and to exert its 
 own property of attracting a portion of the water inha- 
 bited by the fishes ; thus it is gradually drained from 
 beneath the ice ; which, yielding to the pressure of the 
 superincumbent atmosphere, slowly bends to the ut- 
 most verge of its own elasticity ; and at length sud- 
 denly cracks and admits the air. 
 
 The important fact to be borne in mind regarding 
 the congelation of water, is this : when ice has formed, 
 
3G6 WINTER. 
 
 it matters not how much below 32 degrees the winds 
 of Winter may descend ; the liquid water, shielded by 
 the ice, will maintain the invariable temperature of 
 40 degrees; persons who have accidentally broken 
 through the ice, and become immersed in the water, 
 generally remark after escaping from such an unplea- 
 sant situation, " how much warmer the water felt than 
 the air ! " indeed, when the air is at or below zero, if 
 we break a hole through the ice, the water at 40 
 degrees sends forth warm vapour, which immediately 
 condenses in the cold air into minute crystals, and ap- 
 pears like white smoke. 
 
 An appearance of this kind is often seen hovering 
 over marshes and brooks, and more particularly over the 
 Greenland seas ; it is there called " frost smoke," and in 
 all cases is formed by the sudden congelation of aque- 
 ous vapour ; this phenomenon ceases when the surface 
 of the water, and the incumbent air, become cooled to 
 the same degree. 
 
 The vapour exhaled from our lungs is perfectly in- 
 visible on a hot Summer day, because the air is too 
 warm for its condensation ; if we breathe into a cold 
 glass, it becomes dimmed by the condensation of the 
 vapour, to the liquid state of water ; and, upon an in- 
 tensely cold Winter day, the vapour from our lungs be- 
 comes solidified into frost ; occasionally, in Lapland, 
 when the door of an apartment in which persons are 
 assembled is suddenly opened, and a blast of cold air 
 admitted, the watery vapour exhaled by their respira- 
 tion, is instantly frozen into flakes. 
 
WINTER. 
 
 367 
 
 In the early days of Winter, and at various times 
 during its continuance, whilst the land may happen to 
 be soft, the deep foot-prints of the husbandman, the 
 deeper hoof-marks of cattle, and the ruts of heavy 
 wheels, all become filled with the water of the next 
 ensuing shower ; this, from the strong contrast of the 
 dark soil, glistens in the solar rays, like spots, patches, 
 and threads of silver, and forms a pleasing feature of 
 the wintry landscape. 
 
 If the shower be succeeded by a sharp frost, then 
 all these little pools and streams are frozen ; and be- 
 ing thus assimilated in whiteness and other physical 
 characters, to the surrounding heavy " rime," they no 
 longer strike the observer with their former bright sil- 
 very contrast ; but reveal other beauties, if he conde- 
 scend to the examination of things so lowly, and this 
 he must do, if he wish to interpret Nature. 
 
 Within many of these foot-prints, hoof-marks, or 
 wheel-ruts, the ice will be in the form of beautiful crys- 
 tals, crossing each other at angles of 60 and 120 de- 
 grees, thus forming an icy net work, through the in- 
 terstices of which the dark soil is seen ; within others, 
 again, the ice will be in the form of one perfect crystal- 
 line film ; if either form be broken away, not the slight- 
 est trace of liquid water can be found ; the cavities are 
 all perfectly dry, and yet we must feel assured, that the 
 delicate crystals or the fragile film, cannot contain the 
 whole of the water in a solid form. Can the chemist 
 account for this ? 
 
 He can, as follows : in all these small cavities the 
 
368 WINTER, 
 
 water was cooled by the frosty air, though in some 
 with more slowness than in others ; accordingly, in the 
 first case, crystals of ice formed at the sides, gradually 
 accreted and individually shot across the water, and 
 would have entirely covered its surface, had not ano- 
 ther agent been simultaneously active ; namely, the 
 capillary attraction of the soil, which drew away or ab- 
 sorbed the water with rapidity superior to the cooling 
 influence of the air ; and thus the slightest subsidence 
 of the water beneath the nascent, or newly-formed crys- 
 tal, of course prevented its farther increase ; this ca- 
 pillary attraction at length absorbed the whole of the 
 water from such cavities, leaving a crystalline net- work 
 of ice. 
 
 In the second case, crystals of ice formed with ra- 
 pidity superior to the power of capillary attraction, and 
 thus accreted into one entire sheet ; but this, however 
 thin it might be, prevented cold from penetrating to the 
 water beneath, so that capillary attraction alone re- 
 mained, silently, yet certainly active, and at length 
 drew away the whole of this liquid water, leaving the 
 film of ice suspended in the cavities, at the point of its 
 formation. 
 
 These beautiful phenomena, for such they are, al- 
 though of such common occurrence, are chiefly displayed 
 upon light calcareous soils, which are not very retentive 
 of water ; whilst in the foot-prints, hoof-marks, and 
 wheel-ruts, on compact clayey soils, which are ex- 
 tremely retentive, the crystalline net-work seldom oc- 
 curs, but only the icy film ; and if this be broken, water 
 
WINTER. 369 
 
 appears beneath, as no rapid means for its escape was 
 afforded by capillary attraction. 
 
 It is a favourite amusement with country boys, to let 
 the air escape from these cavities, with a sharp sound, 
 by suddenly thrusting the end of a stick through the 
 film of ice, which is popularly called " cat's ice," pro- 
 bably in allusion to a smooth and fair appearance, upon 
 which, generally, but little dependence can be placed. 
 
 Stagnant water, or water only subject to compara- 
 tively slight disturbances, universally presents the phe- 
 nomenon of the formation of ice upon its surface, as 
 now fully described ; but in rapid and impetuous 
 streams the formation of ice, when it occurs, is often 
 very different, indeed exactly the reverse. , 
 
 " In direct opposition, as it would seem, to the 
 hitherto discovered laws of the propagation of heat, or 
 cold, the ice in running water frequently begins to 
 form at the bottom of the stream instead of the top ; 
 and this fact, while it is received with doubt by some, 
 even among the scientific, is frequently attested by 
 those whose business leads them to observe the phe- 
 nomena connected with rivers." 
 
 " Millers, fishermen, and watermen find that the 
 masses of ice with which many rivers are crowded in 
 the winter season, rise from the bottom or bed of the 
 stream ; they say that they have seen them come up 
 to the surface, and have also borne them up with their 
 hooks ; the under part of these masses of ice, they have 
 found covered with mud or encrusted with gravel, thus 
 bearing plain marks of the ground on which the ice 
 
 K 5 
 
370 WINTER. 
 
 had rested ; this form of solid water is popularly called 
 " Ground-ice." 
 
 The formation of " Ground-ice " occurs only when 
 the temperature of the whole bulk of the running wa- 
 ters is reduced to near 32 degrees, and that of the atmo- 
 sphere is considerably below such point; it is pre- 
 ceded by a long continuance of a clear state of the sky, 
 " but while forming under the continuance of a cloud- 
 less sky, its increase is impeded during the day; but 
 when a densely clouded state of the sky occurs, and 
 continues for twenty four hours, the ice becomes de- 
 tached from the bottom and floats down the stream." 
 
 Should the temperature of the air continue low, with 
 a clouded sky, or become lower, the ground-ice is not 
 renewed; but the river or rapid stream, is speedily 
 frozen over at its surface, in the usual manner. 
 
 The formation of " Ground-ice " only ensues, natu- 
 rally, upon the rugged rocks and stones which form 
 the beds of rapid streams ; but when other solid objects, 
 such as branches, and moss more especially, are ar- 
 tificially placed beneath these waters, the formation 
 of the ice is copiously induced upon them ; and this 
 fact, combined with the previously stated aspect of the 
 sky, furnishes a clue to the explanation of the pheno- 
 non. 
 
 During our inquiry regarding the chemical pheno- 
 mena of Spring, Summer, Autumn, and part of Win- 
 ter, we have learned these facts ; viz. that the tempera- 
 ture of the earth in this season, is greater than that 
 of air ; that radiant heat will pass through transparent 
 
WINTER. 371 
 
 media, without increasing their temperature ; and that 
 a cloudless sky is essential for radiation to ensue, and 
 that it will ensue with the greatest rapidity from rough 
 surfaces ; let us now venture upon the application of 
 these facts to the phenomenon of " ground-ice." 
 
 The heds of the rivers or streams already mentioned, 
 consist of rugged rocks and stones ; these contain a 
 certain degree of heat, and part with it, not by con- 
 duction, not by convection to the water, but by direct 
 radiation through it to the cloudless sky ; thus losing 
 heat, they quickly cool the water in their immediate 
 contact, and suddenly freeze it in films upon their sur- 
 faces ; which films remain so long as radiation and the 
 cloudless sky continue, but radiation ceases when 
 clouds appear. 
 
 The solid surfaces then communicate sensible heat 
 to the ice, or the clouds may send forth radiant heat 
 downwards through the water to the ice ; which unlike 
 common ice, is not smooth and glassy, but rough and 
 porous ; therefore capable of converting radiant into 
 sensible heat, in a degree sufficient to cause thawing to 
 take place ; and therefore the detachment of part of the 
 ice from the solid rocks and stones, and its floating 
 upon the surface of the water ; it there opposes all fur- 
 ther radiation from below, and by actual contact, cools 
 the water until a perfect sheet of ice is formed as usual. 
 
 Let us now turn to the contemplation and investiga- 
 tion of another beautiful attribute of Winter, that dis- 
 plays the wisdom and power of God : 
 
372 WINTER. 
 
 " Great things doeth He which we cannot com- 
 prehend ; for He saith to the snow, be thou on the 
 earth." 
 
 " By his commandment he maketh the snow to fall 
 apace ; as birds flying he scattereth the snow ; and the 
 falling down thereof is as the lighting of grasshoppers, 
 the eye marvelleth at the beauty of the whiteness 
 thereof; and the heart is astonished at the raining of it " 
 
 Fig. 62. 
 
 Snow thus eloquently and impressively described, 
 very probably depends for its formation upon the gra- 
 dual congelation of watery vapour in clouds amid the 
 higher and colder regions of the air, where its capacity 
 for heat is increased by expansion ; the water thus be- 
 coming solidified, loses the support of the air, and the 
 newly-formed crystalline snow-flakes, in obeying the 
 attraction of gravitation, descend, and cover the earth 
 with a mantle of spotless white. 
 
WINTER. 373 
 
 This perfectly conceals the lowly remnants of vege- 
 tation from our sight, but we have reason to be grate- 
 ful for its presence ; the chemist discovers that snow 
 is solid water in loosely compacted crystalline flakes, 
 the beautiful form of which may be readily determined 
 by catching them on a piece of black cloth, or on the 
 top of a black hat, and immediately examining them 
 with a high magnifier ; they will be found to present 
 the regular figures as shown in the engraving ; and 
 these may be regarded as the framework or skeleton 
 of the solid six-sided prism into which water is more 
 compactly frozen to constitute hail. 
 
 Like more massive ice, snow is a bad conductor 
 of cold ; it therefore protects seeds, bulbs, and roots 
 from the chilling winds that sweep over its surface, as 
 effectually as the shield of ice protects the beings of 
 the wave ; in fact, vegetable productions are thus pre- 
 served from intense cold by snow flakes, as they would 
 be by a fleece of wool. 
 
 Thus in the beautiful and impressive language of 
 Scripture, " He giveth snow like wool." 
 \ This passage refers to the similarity between flakes 
 o\ ? snow and fleeces of wool, in whiteness and light- 
 ness ; and also to their similarity in power of preserv- 
 ing warmth around the bodies which they shield and 
 clothe. 
 
 Snow is a great, preservative against the effects of 
 cold ; wheat will continue growing beneath deep snow, 
 whilst every blade would be killed by hard frost with- 
 out snow ; beneath the surface the temperature of 
 
374 WINTER. 
 
 snow is very little colder than 32 degrees, whilst the 
 air above is frequently 20 or 15 degrees. 
 
 If a piece of ground be left covered with snow, and 
 another contiguous piece of ground be swept clean, 
 after a day or two, upon digging both, it will be found 
 that the frost has penetrated very considerably below 
 the surface of the piece unprotected by the snow ; 
 indeed it is recorded, in illustration of this protecting 
 power of snow, that in " Holland, during the cold 
 winter of 1776, the surface of the earth was frozen to 
 the depth of twenty- one inches on a spot of garden 
 ground, kept free from snow, but only to nine inches 
 on an adjacent spot, covered with four inches of 
 snow." 
 
 " In the northern regions, snow lying twelve feet 
 deep during Winter, preserves the vegetables which are 
 destined to adorn the Summer, although the cold may 
 be many degrees below zero." 
 
 The Esquimaux have learnt to convert snow into 
 building materials, by which means they can raise a 
 dwelling for their families in a few hours ; a dwelling 
 which, from the purity of the material of which it is 
 composed, the elegance of its construction, and the 
 translucency of its walls, gives it an appearance superior 
 to a marble building. 
 
 Having selected a spot where the snow is sufficiently 
 compact, they commence by tracing out a circle of 
 from eight to fifteen feet in diameter, proportioned to 
 the number of occupants the hut is to contain. 
 
 They then prepare a number of oblong slabs of snow, 
 
WINTER. 375 
 
 of six or seven inches thick, and about two feet in 
 length, which are tenacious enough to admit of being 
 moved without breaking, or even losing the sharpness 
 of their angles. 
 
 These slabs, which have a slight degree of curvature 
 corresponding with the circular foundation, are piled 
 upon each other exactly like courses of hewn stone, 
 and care is taken to make them fit closely to each 
 other, by running a knife adroitly along the under part 
 ancl sides, and to cut them so as to give the wall a 
 slight inclination inwards. 
 
 Tier after tier is thus laid on by one man standing 
 within the wall, who is supplied with material by one 
 or more assistants from without. 
 
 But for the better convenience of transmitting this 
 supply to the workman, when the wall has attained a 
 height of five or six feet, a hole is cut on the south 
 side close to the ground. 
 
 Thus they continue labouring till they have brought 
 the sides nearly to meet in a perfect and well-con- 
 structed dome, sometimes nine or ten feet high in the 
 centre ; and this they take particular care in finishing, 
 by fitting the last block or key-stone very nicely in the 
 centre, dropping it into its place from the outside, 
 though it is still done by the man within ; the people 
 outside are in the mean time occupied in throwing up 
 snow with the snow- shovel, and in stuffing in little 
 wedges of snow where holes have been accidentally 
 left. 
 
 The builder next proceeds to let himself out, by en- 
 
876 WINTER. 
 
 larging the hole on the south side into the form of a 
 Gothic arch, intended as a doorway, three feet high, 
 and two feet and a half wide at the bottom ; commu- 
 nicating with which he constructs two passages, each 
 from ten to twelve feet long, and from four to five feet 
 in height, the lowest being that next the hut. 
 
 The roofs of these passages are sometimes arched* 
 but more generally made flat by slabs laid on horizon- 
 tally ; in first digging the snow for building the hut, 
 the workmen take it principally from the part where 
 the passages are to be made, which purposely brings 
 the floor of the latter considerably lower than that of 
 the hut, but in no part do they dig till the bare ground 
 appears. 
 
 The work just described completes the walls of a 
 hut, if a single apartment only be required ; if several 
 families are to reside under one roof, the passages are 
 made common to all, and the first apartment, in that 
 case made smaller, forms a kind of ante-chamber, from 
 which the entrance is through an arched doorway, five 
 feet high, into the inhabited apartments ; when there 
 are three of these, which is generally the case, the whole 
 building, with its adjacent passages, forms a tolerably 
 regular cross. 
 
 For the admission of light into the huts, a round 
 hole is cut on one side of the roof of each apartment, 
 and a circular plate of fresh-water ice, three or four 
 inches thick, and two feet in diameter, let into it. 
 The light is soft and pleasant, like that transmitted 
 through ground glass, and is quite sufficient for every 
 
WINTER. 377 
 
 purpose ; if fresh- water ice be not within reach, melted 
 snow is poured into a vessel, and thus frozen into a 
 transparent plate. 
 
 When after some time these edifices become sur- 
 rounded by drift, it is only by the windows that they 
 can be recognised as human habitations, and but for 
 them, one might walk completely over them without 
 suspecting the little hive of human beings that is com- 
 fortably established below. 
 
 The next thing to be done is to raise a bank of snow 
 two feet six inches high, all round the interior of each 
 apartment, except on the side next the door ; this bank, 
 which is neatly squared off, forms their beds and fire- 
 place, the former occupying the sides, and the latter 
 the end opposite the door ; the passage left open up to 
 the fire-place is between three and four feet wide. 
 
 The beds are arranged by first covering the snow with 
 a quantity of small stones, over which are laid their pad- 
 dles, tent-poles, and some blades of whalebone ; above 
 these they place a number of little pieces of net- work, 
 made of thin slips of whalebone, and lastly a quantity 
 of twigs of birch ; their deer-skins, which are very nu- 
 merous, can now be spread without risk of their touch- 
 ing the snow ; and such a bed is capable of affording 
 not merely comfort, but luxurious repose, in spite of 
 the rigour of the climate. 
 
 With the lamps lighted, and the hut full of people 
 and dogs, a thermometer placed on the net over the 
 fire indicates a temperature of 38 degrees ; when re- 
 moved two or three feet from this situation, it falls to 
 
378 WINTER. 
 
 32 degrees ; and placed close to the wall, stands at 23 
 degrees ; the temperature of the open air at the time 
 being 25 degrees below zero. A greater degree of 
 warmth than this, produces extreme inconvenience by 
 the dropping from the roofs. This they endeavour to 
 obviate by applying a little piece of snow to the place 
 from which the drop proceeds ; and this adhering, is 
 for a short time an effectual remedy ; but for several 
 weeks in the Spring, when the weather is too warm for 
 these edifices, and still too cold for tents, they suffer 
 much on this account. 
 
 The interior appearance of these habitations is ren- 
 dered more beautiful when they are situated on the 
 ice, which, being cleared of the snow, presents a floor- 
 ing of that splendid blue, which is perhaps one of the 
 richest colours in Nature. 
 
 As the Spring advances, the snow walls melt and 
 freeze alternately, forming innumerable icicles, which 
 reflect the light like radiant diamonds ; although this 
 is very beautiful, it is a source of great trouble to the 
 poor inhabitants, whose lungs become affected from 
 repeated colds and coughs ; for this reason, although 
 the houses are formed of snow, coolness is the object 
 always kept in view; and from the inexhaustible build- 
 ing materials always at hand, but little time and labour 
 is required to effect any alterations or additions that 
 may be requisite to effect the purpose. 
 
 Equal in beauty to the snow-houses are those con- 
 structed of fresh-water ice ; when this material is em- 
 ployed, it is collected in large transparent slabs, which 
 
WINTER. 379 
 
 are arranged in somewhat an octagonal form, and 
 plastered together with snow ; the roofs of some are 
 formed of walrus skins, and others have the regular 
 dome-tops of snow ; these dwellings are so transparent, 
 that even at some paces distance it is possible to dis- 
 tinguish those who stand within them, yet they are so 
 completely air-tight as to be perfectly warm ; a pas- 
 sage of the same pure material forms the entry to 
 the hut. 
 
 The " red-snow " which is sometimes found in the 
 Arctic regions, seems to derive its colour from the 
 presence of oxide of iron, in a state of extremely mi- 
 nute division, and a resinous vegetable principle of an 
 orange-red colour, belonging apparently to some lichen, 
 of which too the iron may form one of the immediate 
 principles ; the colouring matter penetrates to various 
 depths, and appears in the form of globules, varying 
 from one thousandth to one three thousandth part of 
 an inch in diameter. 
 
 In Italy, snow is collected with as much assiduity as 
 ice in England ; the country surrounding the city of 
 Naples is too flat and too warm to allow snow to re- 
 main on the ground in sufficient quantity to be col- 
 lected ; but the chain of the Apennines, traversing 
 Italy from north to south, furnishes an inexhaustible 
 supply. 
 
 A few of the loftiest of these mountains have their 
 summits above the line of perpetual congelation, as 
 mentioned when investigating the capacity of air for 
 heat at page 123; accordingly they are clothed with 
 
380 WINTER. 
 
 snow throughout all the changes of the Four Seasons ; 
 but in the greater part of the range below the line of 
 perpetual congelation, the snow of Winter melts about 
 the month of May. 
 
 The Neapolitans excavate deep pits or wells on the 
 sides of the mountains, or select any natural caves 
 which may be found ; and into these they throw, 
 during the winter season, thick pure layers of snow, 
 collected from the mountains ; each layer is pressed 
 firmly before another is added, and thus the pits, wells, 
 or caves, are completely filled ; when this is done, a 
 large quantity of straw, or of dried leaves, placed upon 
 the upper layer of the snow, preserves it, as in the 
 case of the ice in the " ice well," from the heating 
 influence of the external air ; and as the cavities are 
 either artificially made, or selected from such as natu- 
 rally exist on the northern aspect of the mountain, to 
 avoid as much as possible the direct rays of the sun, 
 and are moreover at a very great elevation ; they main- 
 tain a very low temperature, even during the intense 
 heat of summer. " Sometimes a fall of snow will 
 take place in a valley, or in an inhabited spot at the 
 side of a mountain ; and in such case the peasants 
 hasten out, and with an exuberance of joy at such a 
 welcome occurrence, collect the snow, and place it in 
 pits." 
 
 When the Summer arrives, the snow- diggers proceed 
 to the pits, extract it, and bring it into the city, where 
 it is sold at a regulated price, for the purpose of cool- 
 ing water, and other beverages. 
 
WINTER. 381 
 
 As an example of the bad conducting power of 
 earthy substances, in the form of porous dust and 
 scoria, it may be mentioned that the shepherds, in the 
 higher regions of Mount Etna, are accustomed to pro- 
 vide water for their flocks, by strewing a layer of vol- 
 canic sand a few inches thick over the snow ; and this 
 earthy matter effectually prevents the heat of the sun 
 from penetrating ; the snow is withdrawn, and allowed 
 to thaw in its direct beams, and thus form water, 
 better than none certainly, but not well fitted for the 
 support of life, as it is unaerated. 
 
 The reflection of heat by white, and its absorption 
 by black surfaces, may be well illustrated in Winter, 
 by remarking that the snow will remain for many 
 hours without thawing in the sunshine ; but if its 
 surface be lightly covered with black mould, the 
 thawing will rapidly commence, because in the one 
 case the heat is reflected, and in the other it is 
 absorbed. 
 
 If the pieces of cloth employed in the experiment at 
 page 158 be spread upon snow, when the sun shines 
 their different absorptive power as regards solar heat, 
 will be illustrated, by the black piece and the darker 
 pieces thawing more snow, and therefore sinking 
 deeper than the white piece and the lighter pieces. 
 
 In England and Scotland, snow storms sometimes 
 come on suddenly, accompanied by high winds, which 
 drift it into heaps ; and in these, sheep are particularly 
 liable to be enclosed, and either smothered or starved 
 to death ; such accidents often happen in the moun- 
 
382 WINTER. 
 
 tainous districts of the north of England and in Scot- 
 land, where vast flocks of sheep are reared. 
 
 " These animals will, however, live a considerable 
 time, though deeply buried in snow ; they appear to 
 fall into a half torpid state, and the shepherd finds a 
 part of his flock living when he had supposed them all 
 to be dead ; in such cases, however, the sheep which 
 survive are so much weakened, that they generally 
 become diseased, and die in the Spring/' 
 
 Throughout The Four Seasons, the Almighty like- 
 wise, " by His great power He maketh the clouds 
 firm, and the hailstones are broken small." 
 
 So far as the cause of hail can be discovered, it 
 appears to depend upon the sudden congelation of 
 rain-drops in falling through a stratum of cold air. 
 The hail- stones thus formed are more dense and com- 
 pact than snow-flakes from vesicular vapour ; they 
 more promptly cleave through the air, and strike the 
 earth with great violence. 
 
 Unlike snow, hail is frequent in Spring, Summer, 
 and Autumn, from some recondite cause, and is dreaded 
 by 'the husbandman, on account of the devastation that 
 it produces upon growing crops ; but these heavy 
 showers of hail and rain are instrumental in tending 
 to restore the electrical equilibrium between the earth 
 and the air, after its disturbance by the long-con- 
 tinued heat of the season, as already mentioned when 
 considering the phenomena of the thunder storm ; thus 
 we have reason to be grateful to Providence for " Fire, 
 and hail, snow and vapours, stormy wind fulfilling 
 
WINTER. 383 
 
 His word." In Winter, again, " The hoar-frost also as 
 salt, He poureth upon the earth, and being congealed, 
 it lieth on the top of sharp stakes;" this beautiful 
 phenomenon appears to result from the condensation 
 of watery vapour into exceedingly fine drops, and their 
 subsequent slow congelation into solid particles more 
 minute than those of snow flakes. These particles 
 falling through the air, are received by leafless branches, 
 evergreens, blades of grass, stakes, fences, roofs, and 
 other natural and artificial solid objects, which act as 
 points of support, or nuclei ; around such they accrete 
 like crystals of salt, and charm the eye with their 
 beauty, their silvery whiteness. 
 
 But in our temperate climate, these delicate crystals 
 of water only glitter for a brief time in the beams of 
 the wintry sun ; then liquify and vaporize by its heat, 
 and thus return again to the air. 
 
 The beautiful phenomenon of hoar-frost upon 
 branches and leaves may be artificially imitated in 
 the following arrangement. -Procure a few drams of 
 crystalline "benzoic acid;" it is a peculiar acid ob- 
 tained from " gum-benzoin," or more popularly " gum- 
 Benjamin;" and even this will answer the purpose to 
 some extent, if its pure acid cannot be obtained. 
 
 Clean the glass shade and plate that were employed 
 in the experiment described at page 97, by washing 
 them with water, and carefully drying them with a soft 
 cloth ; then place the plate to warm before the fire in 
 the usual manner, and likewise a shallow tin dish or 
 
384 
 
 WINTER. 
 
 pan, about two inches in diameter, to become much 
 hotter upon the top bar of the grate. 
 
 In the meantime, select a branch of " arbor-vitse," 
 that will easily pass into the glass shade; mould a 
 lump of clay, and stick the end of the branch in this, 
 to support it upright ; take a crystal or two of the 
 benzoic acid, and drop this substance into the hot 
 tin ; and if it quickly volatilize, the temperature is 
 sufficiently high ; if it do not, the tin must remain 
 longer, until the volatilization of another portion of 
 the acid will rapidly ensue. 
 
 Fig. 63. 
 
 Heat two thick copper penny-pieces red hot; take 
 them out with the tongs, and set them one upon the 
 other in the middle of the hot dinner-plate ; then set 
 the heated tin upon the copper coins. Place the lump 
 of clay, with the branch of " arbor vitee," to stand 
 near them, quickly fill the tin with " benzoic acid,' 7 
 and cover the whole arrangement with the cold glass 
 shade. 
 
WINTER. 385 
 
 The "benzole acid" will immediately volatilize, and 
 its vapour coming into contact with the branch, will 
 be chilled by it, and condense upon it in the form of 
 beautiful and delicate snow-white crystals, closely re- 
 sembling hoar-frost. The preceding engraving shows 
 the arrangement for this extremely pretty and instruc- 
 tive experiment. 
 
 It is called " Sublimation," from a Latin word sig- 
 nifying " high," or " exalted/' and it may be chemically 
 defined as the conversion of a solid into vapour by 
 heat, and the subsequent conversion of that vapour 
 into a solid by cold ; but the change is merely physical, 
 and not chemical, meaning that the " acid " undergoes 
 no change of composition ; thus if " gum benzoin " 
 were employed, its pure volatile acid would sublime 
 and condense on the branch, leaving the fixed matters 
 of the gum below, and by such " sublimation " the 
 pure acid with which our experiment is made, was 
 originally obtained by the chemical operator. 
 
 In the laboratory of Nature, the process of " subli- 
 mation" is not discovered upon a scale so gigantic 
 as that of " evaporation," for very few solid substances, 
 unless artificially extracted from natural sources, are 
 volatile to any great extent by the ordinary changes of 
 temperature during the Four Seasons ; but in the 
 vicinity of those extraordinary mountains called " vol- 
 canoes," sublimation proceeds with regard to " brim- 
 stone," or sulphur ; it is probably raised in vapour by 
 the subterraneous heat of volcanic fire ; and as this 
 vapour is exhaled through the cracks and fissures of 
 
386 WINTER. 
 
 the soil, it condenses by the cold air into transparent 
 yellow crystals, and into opaque yellow amorphous 
 masses j and these collected by the industry of man, 
 constitute all the supplies of "native sulphur" that 
 are demanded for the production of sulphuric acid' 
 and the manufacture of gunpowder, the latter an 
 invaluable agent for removing the solid rocks which 
 oppose the " getting" of mineral treasures, but un- 
 fortunately too frequently employed as a frightful 
 agent for the slaughter of thousands of our fellow men. 
 
 The tremendous and destructive effects of gunpow- 
 der are referrible to the sudden and intense combina- 
 tion of the sulphur and charcoal with the oxygen of 
 the nitrate of potash that the composition contains ; 
 and the consequent production and evolution of many 
 thousand times the bulk of the charge of powder, of 
 highly heated elastic gases, and vapours of great pro- 
 jectile force. 
 
 Returning to the experiment, from whence these re- 
 marks originated : upon removing the branch of " ar- 
 bor vitse " thus beautifully encrusted with crystals re- 
 sembling " hoar-frost," it must be observed, that it 
 cannot be kept exposed to the air, as the acid will gra- 
 dually volatilize ; but it may be preserved for a consi- 
 derable time beneath a glass-shade, in a cold room ; 
 and in this situation, if the crystals ultimately drop 
 off, they may be all collected and sublimed again upon 
 the branch, as at first ; or upon a bunch of red flowers, 
 either natural or artificial. 
 
 It will then exhibit a very close resemblance to the 
 
WINTER. 387 
 
 beautiful phenomenon, that took place on the twen- 
 tieth of March of the present year; when the beau- 
 tiful pink and crimson blossoms of almond trees, were 
 suddenly covered with white and delicate crystalline 
 flakes of snow. 
 
 At the same time vegetation was exceedingly for- 
 ward ; many trees had put forth leaves, and these ex- 
 posing great surface for the reception of the snow 
 flakes ; the whole feature of the landscape was far more 
 striking than it is ever presented upon leafless branches 
 during the depth of Winter. 
 
 The chemist discovers that substances capable of 
 assuming the crystalline form, will generally adhere to 
 porous or rough surfaces in preference to such as are 
 compact or polished ; he accordingly introduces sticks 
 and strings into various solutions of salts, and these 
 act as nuclei for the accretion of crystals ; the most 
 familiar examples of this kind that can be presented, 
 are crystals of "verdigris " on sticks, and of " sugar- 
 candy " upon strings. 
 
 In Nature, the same fact is observable ; for during 
 the congelation of water, the crystals of ice form first 
 upon the stones, grass or moss, at the borders of the 
 pond or stream, and then gradually proceed across the 
 surface. 
 
 During the last experiment, the crystals of " ben- 
 zoic acid " were found to be more abundant upon the 
 rugged branch of the (( arbor vitse' than upon the 
 smooth interior of the glass shade ; and in Nature the 
 same thing happens, for the crystals of water or " hoar- 
 
 s 2 
 
388 WINTER. 
 
 frost " are found more plentifully deposited upon leaf- 
 less branches, and grass plats, than upon stone pave- 
 ments and gravel-walks; and these two latter sur- 
 faces may be perfectly free from " hoar-frost " whilst 
 a few withered leaves, straws, or feathers, lying upon 
 them, will be beautifully encrusted with such crystals. 
 The delicate and elegant frost-work, resembling 
 trees and landscapes, which forms upon the inside of 
 window panes, results from the congelation of the va- 
 pour of water contained in the air of the apartment ; 
 and the same beautiful appearance displays itself upon 
 the glasses of a close carriage, from the congelation of 
 the moisture exhaled by the lungs of its occupants. 
 
 Fig. 64. 
 
 The appearance of hoar frost upona window-pane, 
 may be artificially imitated by dissolving half an ounce 
 of " Epsom salt," i. e., sulphate of magnesia, in a wine- 
 glass full of hot water, and then spreading this solution 
 with a sponge, evenly over the surface of the pane of 
 glass ; as it cools, so it will crystallize in very beauti- 
 ful arborescent or tree-like forms ; and by this simple 
 proceeding, window panes are now very commonly 
 
WINTER. 389 
 
 " frosted," in preference to the more expensive and ha- 
 zardous method of rendering them opaque by grinding. 
 
 Two winters ago, at day-break, the flag- stones of the 
 foot pavement of London exhibited the most splendid 
 example of this crystalline form of water ; the crys- 
 tals were arranged, interwoven, and interlaced, in an 
 endless variety of the most delicate and intricate 
 figures that it is possible for the imagination to conceive ; 
 a very slight thaw having occurred in the night, the 
 film of water, was suddenly frozen, by the frost setting 
 in at dawn. 
 
 Sometimes, during a severe frost, by an occult pro- 
 cess in the vast laboratory of Nature, heavy showers of 
 rain suddenly fall ; the drops are immediately frozen, 
 and then trees, hedgerows, eaves of houses, and other 
 solid objects, present a most beautiful appearance ; they 
 are coated with ice and icicles which reflect and refract 
 the sunbeams in a variety of gorgeous colours. 
 
 If the conflagration of a building happen during a 
 severe frost, the water employed to quench the flames, 
 is frequently frozen as it dashes and trickles over the 
 walls, and forms brilliant icicles pendant from the pa- 
 rapet, portico, balconies, and window-frames. 
 
 The formation of icicles depends upon the succes- 
 sive congelation of drops, or slender streams of water ; 
 and in Nature they sometimes accumulate so greatly 
 upon trees, that the branches break beneath the load, 
 and thus much damage ensues. 
 
 The vicissitudes of The Four Seasons are continually 
 changing the physical state of water, yet never altering 
 
390 WINTER. 
 
 its actual composition ; for if the chemist experiment 
 upon equal weights of this compound, in its three phy- 
 sical states of liquid, solid, and vapour, he invariably 
 educes from them all, Oxygen and Hydrogen in the 
 definite weights, already stated. 
 
 Leaving, for a time, the effect of natural and artificial 
 cold upon water, let us briefly examine the habitudes of 
 this wonderful liquid when subjected to the action of 
 artificial heat, as in the familiar process of boiling. 
 
 Why should the heat be invariably applied beneath 
 the vessel containing the water, and never upon the 
 surface of the water ? The answer to this apparently 
 simple question involves the greatest refinements of 
 chemical science. 
 
 It has been already stated, that water is a non-conduc- 
 tor of heat, and this fact has been experimentally proved 
 in several cases ; therefore, if heat were directly applied 
 to its surface, the portions of water constituting such 
 surface would soon become elevated, by mere heat of 
 contact, to the boiling point ; and this boiling film, 
 having less specific gravity than that of the colder por- 
 tions below, would float upon them ; whilst they can- 
 not derive heat from it on account of their non-con- 
 ducting power. 
 
 For example, let the iron heater of the tea-urn be 
 heated red hot, and then by means of its hook, held 
 that its end may touch the surface of water contained 
 in a large tall glass ; the heat will instantly cause the 
 surface to boil furiously, whilst the beneath water 
 will remain cold ; nay, even a piece of ice, tied to a 
 
WINTER. 391 
 
 heavy bullet, and previously placed in the water at the 
 bottom of the glass, will not thaw, although the sur- 
 face of the water at a few inches above, is in a state of 
 full ebullition. 
 
 Then, if water were a conductor of heat, it should 
 all fairly boil, when the heat is applied above, as we 
 know that it does when applied below ; the theory of 
 its ebullition, in the latter case, is as follows. 
 
 The heat is conducted through the vessel, and thus 
 expands the water that it first reaches ; the portions 
 thus expanded, are of greater temperature and of less 
 specific gravity than others above, they accordingly 
 ascend, the same as a lighter fluid through a hea- 
 vier, they impart heat to these portions by contact ; 
 and thus losing temperature, they gain specific gravity ; 
 they fall, again acquire heat, and diminish in specific 
 gravity ; they again ascend, and thus by carrying heat, 
 or by convection instead of conduction, ascending and 
 descending or convective currents are established, until 
 all portions of the water are equally heated to a degree 
 at which it can no longer remain liquid ; then vapour 
 or steam simultaneously escapes from all portions, va- 
 porization rapidly ensues, or in plainer terms, the water 
 boils. 
 
 The whole of the water can never boil when the heat 
 is applied at its surface, because convection, or ascend- 
 ing and descending currents cannot be established, the 
 heated film, that in the other case is a convective film, 
 is in this, a heated non-conducting film. 
 
 A very beautiful experiment regarding the ascent of 
 
392 WINTER. 
 
 heated water and the descent of cold, can be made 
 without much trouble, by attending to the following 
 directions. 
 
 First, boil about two gallons of clean rain-water, in 
 a clean tin saucepan for about an hour, then remove 
 the vessel from the fire, cover it closely and allow the 
 water to cool down to common temperatures. 
 
 Select a piece of glass-tube four feet long, about the 
 twentieth of an inch thick, having a bore half an inch in 
 diameter, and perfectly clean ; if not so, it can be 
 cleaned by passing a long string with a little cotton 
 fastened to one end, several times through the tube. 
 
 Place a hand near each extremity of the tube, and 
 thus hold it horizontally, that its centre may be at a 
 distance of four or five inches above the heated air 
 ascending from a large argand gas-burner, or above 
 that of a bright charcoal fire in a small chafing dish 
 or brazier ; turn the tube round and round between 
 the hands, that it may conduct the heat, or warm 
 gradually at its centre, then continuing to turn, bring 
 it lower and lower, or nearer the source of heat, and 
 let it become fairly red-hot for about four or five 
 inches; the hands will soon detect that it is soft and 
 yielding, and by gently drawing them together in the 
 same manner, as for bending a cane, the glass tube, or 
 " cane " as it is technically called, will bend from its origi- 
 nal straight form, and by still keeping this yielding por- 
 tion in the heat, and still gently drawing the hands 
 together, the tube will assume the form of a " syphon," 
 having its limbs parallel to each other, though about 
 
WINTER. 393 
 
 four inches apart, and like a syphon, one of these 
 limbs should he about four inches longer than the 
 other : this is managed by heating the tube originally a 
 little beyond its true centre ; if, however, they should 
 be of equal length, the matter can be remedied, of 
 which hereafter. 
 
 Having wrought the tube into this shape, place its 
 open ends in a box or jar that its bend may stand 
 uppermost and thus slowly cool in the air ; and when 
 it is sufficiently cold to handle, it must be removed, 
 and again heated in the following manner. 
 
 Hold the tube horizontally that about four inches of 
 its longest end may become red-hot and soft, then by 
 gently pressing against this with a sound piece of char- 
 coal, or a stick of deeply charred wood, form it into a 
 bend, exactly parallel with the first, though not quite 
 so large ; and this being done, place the first bend to 
 stand in the box or jar, that the second may now cool. 
 
 When it is cold, remove the tube and place it flat 
 upon the table, and very probably the straight limb 
 of the tube will now appear the longest ; if such be 
 the case, take a sharp three-edged file, and gently make 
 a deep cut across this, then hold the red-hot heater of 
 an Italian iron on the cut for half a minute, and if 
 the tube do not crack, remove the iron and touch the 
 file mark with the wetted tip of the fore-finger, this 
 sudden cold will cause it to fly across, and by a very gen- 
 tle pull, a piece will be thus cut off, and the limbs of 
 the syphon will bear the same proportion to each other 
 as shewn in the next engraving. 
 
394 
 
 WINTER. 
 
 Select a thin earthenware basin, large enough to 
 admit the two ends of the syphon, when placed in it 
 with its large bend uppermost; then remove it, and fill 
 the basin with a portion of the boiled rain-water, and 
 stain this deeply with the well-known dye called 
 "Saxon blue ;" this being done, select a very shallow 
 pan that will hold the syphon when laid flat within it, 
 pour the remaining uncoloured boiled rain-water into 
 this, in order that the syphon may be perfectly filled, 
 and every bubble of air excluded. 
 
 Fig. 65. 
 
 Then place a finger of each hand beneath the water, 
 and close each end of the syphon ; thus lift it, and 
 when both ends are fairly immersed beneath the sur- 
 face of the coloured water in the basin, remove the 
 fingers, and the syphon will remain full on account of 
 atmospheric pressure, as in the case of the "bird- foun- 
 tain " and the " carafe " at page 212. 
 
 The basin thus containing the syphon must be now 
 placed upon a ring supported on three feet, a small 
 tripod, and the syphon very gradually raised into a 
 perpendicular direction, so that the orifice of its straight 
 
WINTER. 
 
 395 
 
 end may be half an inch below the surface of the 
 coloured water : it may be supported at this elevation 
 by a string attached to its upper bend, and fastened 
 to any convenient support above, as to the arm of a 
 chandelier, suspended from the ceiling of a room. 
 
 Fig. 66. 
 
 Although the whole arrangement occupies much 
 time in description, and even in its performance, it is 
 worthy of both, on account of the instructive result 
 that it will afford, the object being to prove that hot 
 water is lighter, and therefore will ascend through 
 cold water, which is heavier ; let the flame of a 
 spirit lamp be applied to the bottom of the basin, in a 
 line perpendicular with the straight end of the syphon ; 
 and in the course of a few minutes will be presented 
 the phenomenon, of which we are in search, and which 
 is represented in the above engraving. 
 
 The coloured water at the* bottom of the basin be- 
 
396 WINTER. 
 
 comes expanded by heat, and rises towards the colder 
 surface ; no portion of such ascending water can enter 
 the bent end of the syphon, because its orifice points 
 upwards, but a portion can enter the other, as its end 
 is directed downwards ; accordingly, the warm blue 
 water will be observed gradually stealing up this tube, 
 whilst its cold colourless water is gradually falling 
 down the other, the warm blue water continues rising ; 
 one limb of the syphon now contains blue, the other 
 colourless water; the heat of the lamp continues; 
 the blue water reaches the bend, passes over, becomes 
 cooled, and descends through the colourless, to the 
 coloured in the basin, and thus both limbs of the 
 syphon are filled with blue water, and the experiment 
 in illustration of ascending and descending or con- 
 vective currents is concluded. 
 
 It may here be remarked that the object of boiling 
 the rain-water is to expel the air from it, for if this 
 precaution were neglected the subsequent evolution of 
 air-bubbles in the syphon would materially interfere 
 with the successful result that is desired. 
 
 Thus in every case where heat is applied beneath 
 the vessel containing water, that extraordinary liquid 
 is elevated to its boiling point by convective currents : 
 now let us enquire the degree of heat that is required 
 for this phenomenon to ensue. 
 
 Plunge the bulb of a mercurial or " Brewing ther- 
 mometer '' into rain-water contained in a tin cup, then 
 apply the flame of a spirit lamp, and as the water 
 gains heat by convection, the mercury will gradually 
 
WINTER. 397 
 
 rise until the water boils, and then it will remain 
 stationary about 180 degrees above the "freezing 
 point," or as it is marked upon the scale 212 degrees ; 
 this is called the " boiling point of water." 
 
 Experimenting at different times with water in a 
 state of ebullition, the chemist discovers that its boil- 
 ing point is liable to much variation, being sometimes 
 materially above, and at others below " 212 degrees." 
 
 Searching for the cause of this variation, he detects 
 the invisible though certain agency of the air, which 
 considered as an entire volume, though of constant 
 weight, is liable to local variations in its density, 
 chiefly by the agency of solar heat, and that it presses 
 with greater weight upon the earth at some times than 
 at others. When the pressure of the air is equal to 
 that of fifteen pounds upon every square inch of sur- 
 face opposed to its action, artificial heat can cause 
 water to boil at 212 on earth at the level of the sea. 
 If the pressure of the air increase, or if it diminish 
 from this, which is conventionally termed its " standard 
 pressure," the boiling point of water is elevated in the 
 one case and depressed in the other, because in the 
 former case, the heat has to oppose the pressure of the 
 air, which is tending to preserve the water in a liquid 
 state, and in the latter the heat has not so much pressure 
 to contend with, but the rarity of the air rather aids its 
 conversion of the water into vapour. 
 
 Further experimenting upon this curious and im- 
 portant phenomenon, the chemist discovers that at 
 various heights and depths from the surface of the 
 earth, water sustains an alteration in its boiling point 
 
398 WINTER. 
 
 dependent upon the rarity or density of the air ; which, 
 as already mentioned, decreases in weight as it as- 
 cends from the level earth. Accordingly upon the 
 summit of a mountain J5.781 feet above the level of 
 the sea, water will boil at 180 degrees, instead of 212 
 degrees, as at the Jevel of the sea ; -a temperature in- 
 adequate for the preparation of food. 
 
 At the bottom of a mine 1,650 feet below the level 
 of the sea, water will boil at 216 degrees, a temperature 
 better suited for the preparation of food, by extracting 
 all its soluble nutritious matters, than the ordinary 
 boiling point upon the level earth, and very much 
 better than that upon the mountain summit. 
 
 The freezing point of water is immutable, whatever 
 variations may ensue in the pressure of the air, but 
 The Almighty has ordained the boiling point of water 
 to sustain changes in its temperature, and to be 
 highest on the surface, or below the surface of the 
 earth, where its utility is most required for man. 
 
 The chemist, therefore, when speaking of 212 de- 
 grees as the " boiling point of water," means that such 
 is the thermometric temperature required for the 
 vaporization of water by artificial heat, when the ex- 
 periment is made with absolute water in a metallic 
 vessel on the earth at the level of the sea, and when 
 the atmospheric pressure is equal to fifteen pounds 
 upon every square inch, or is at " mean pressure," 
 which the "barometer" denotes when its column of 
 mercury stands at thirty inches, and under such cir- 
 cumstances the thermometer is graduated. 
 
WINTER. 399 
 
 The manner in which the hoiling point of water is 
 affected by diminution or increase of atmospheric 
 pressure may be experimentally demonstrated by very 
 simple means. 
 
 If a portion of water not sufficiently hot to scald 
 the hand be poured into an ale-glas^ and placed upon 
 the plate of the air-pump, a,nd covered with the 
 receiver, as at page 177, upon exhausting the air, and 
 thus freeing it from pressure, the water will boil as 
 briskly as though set over the flame of a lamp, thus 
 artificially imitating the phenomenon that naturally 
 ensues, when water is gently heated on the summit of 
 a lofty mountain ; but the boiling will stop if the 
 action of the pump be suspended, because then it be- 
 comes subjected to the pressure of its own vapour 
 which fills the receiver, and the amount of heat yet 
 retained by the water is insufficient to raise it into 
 further vapour against this pressure, which is exactly 
 equivalent to that of the external atmosphere under 
 which the water had ceased to boil before it was 
 subjected 7 to the experiment. 
 
 The action of greater pressure upon water actually 
 boiling under that of the atmosphere may be proved 
 by making the following arrangements : pour away the 
 spirit of wine from the flask employed in the experiment 
 at page 316; then wash the flask with water, drain it, and 
 pour in about a quarter of a pint of rain-water, suspend 
 the flask over the heated air of a gas flame, or let it be 
 held by the fingers protected with a thick worsted glove, 
 over the flame of a spirit-lamp, that the water may boil. 
 
400 WINTER. 
 
 Select a bladder about the size of the flask, and 
 after soaking it in water, cut off its neck, so that an 
 aperture will be made large enough to admit the upper 
 part of the glass tube that belongs to the cork, as used 
 in the experiment with the flask at page 316; secure 
 the neck of the bladder around the tube by tying it 
 firmly with thread, and this being done, blow the blad- 
 der full of air. 
 
 When the water in the flask boils, insert the cork 
 very quickly and firmly, and then compress the blad- 
 der, the boiling will instantly cease ; allow the bladder 
 to expand, and the boiling will instantly recommence. 
 Why? 
 
 Because the water was boiling at first at a tem- 
 perature of 212 degrees under ordinary atmospheric 
 pressure, but by compressing the bladder the pressure 
 was suddenly increased, and the same degree of ther- 
 mometric temperature was insufficient to create steam 
 against this, thus closely imitating what happens in 
 the depth of the mine ; the heat would eventually in- 
 crease and be superior to this pressure, the water would 
 boil at a higher temperature as in the mine, but the 
 experiment might be attended with danger by the 
 bursting of the flask ; when, on the other hand, the 
 air in the bladder was allowed to expand, its pressure 
 became the same as that of the external atmosphere, 
 and the water retaining sufficient heat, formed steam 
 equivalent to this, or in other words, it boiled at its 
 usual temperature of 212 degrees. 
 
 As few liquids are alike in their specific gravities, so 
 
WINTER. 401 
 
 very few are alike in their boiling points, even when 
 experimented upon at the level of the sea, and under 
 the mean pressure of the atmosphere ; thus the boiling 
 point of "brine," or saturated solution of common salt, 
 is 12 degrees above that of absolute water, or 224 de- 
 grees; the boiling point of ordinary spring-water is 
 hardly one degree above that of absolute water, or 213 
 degrees ; and it is found that in proportion as saline 
 substances are dissolved in water, so does the boiling 
 point become higher and higher, and this quite inde- 
 pendent of fluctuation in atmospheric pressure. 
 
 Thus if pure water be boiling at 212 degrees, and 
 the barometer standing at 30 inches, if common- salt 
 be gradually added, as it dissolves so will the mercury 
 in the thermometer gradually rise, and at length be- 
 come stationary at 224 degrees, when the water is 
 saturated with the salt. 
 
 On the other hand, Alcohol and Ether have boiling 
 points lower than that of water under like circum- 
 stances of pressure, the former boiling at J 80, and the 
 latter at 98 degrees; accordingly such liquids will 
 boil vehemently in an exhausted receiver; but the 
 experiment cannot be advised as their vapours cor- 
 rode or dissolve the oiled-silk valves of the pump, 
 and quickly render a valuable instrument perfectly 
 useless. 
 
 Knowledge of the fact regarding the difference be- 
 tween the boiling points of water and of alcohol, 
 enables the chemist to separate them from each other ; 
 take, for example, the combination of these liquids, 
 
402 WINTER. 
 
 originally made in the experiment detailed at page 113 ; 
 place it in the copper-boiler of one of those small 
 models of " stills " that are now so commonly sold ; 
 fix on the " still-head," insert its " beak " into the 
 " worm-pipe," fill the " worm-tub " with cold water ; 
 apply a lighted lamp beneath the " boiler/' and place 
 a small glass at the end of the " worm-pipe " that 
 comes through the lower part of the " worm-tub." 
 
 The heat of the lamp will effect repulsion between 
 the chemically combined liquids; the alcohol requiring 
 the least heat for its ebullition., will first rise in vapour ; 
 this will condense in the cold worm-pipe, and trickle 
 into the glass ; and by receiving the drops from time 
 to time upon a folded slip of blotting-paper, and hold- 
 ing this to a flame, the alcohol will kindle and burn 
 with a very pale flame ; at length the drops so received 
 will not kindle ; and this fact announces that all the 
 alcohol has separated or distilled, and the drops now 
 consist of water that is boiling and distilling, therefore 
 the process must be stopped, for the separation or ana- 
 lysis is effected, the alcohol being in the glass, the 
 water remaining in the " boiler." 
 
 Pour the alcohol thus " rectified " but not abso- 
 lutely anhydrous into a vial containing half its bulk 
 of dry pearl-ash ; shake it three or four times, then let 
 it remain undisturbed ; the pearl-ash, on account of 
 its strong attraction for water, and its want of attrac- 
 tion for the alcohol, will abstract the former, and pro- 
 duce a solution upon which the latter will float on 
 account of its small specific gravity : let this be de- 
 
WINTER. 403 
 
 canted into the " boiler" previously emptied and 
 dried as also the " worm-pipe ;" add half an ounce of 
 quick- lime ; apply the gentle heat of the lamp ; the 
 lime will arrest or hold back any water that had escaped 
 the pearl-ash, whilst the vapour of the alcohol will 
 rise and condense into drops of " absolute " or pure 
 alcohol. 
 
 The process of separating alcohol from water, or one 
 liquid from another to a certain extent, by the mere 
 application of heat, is extremely ancient, and is tech- 
 nically called " Distillation/' from a Latin word signi- 
 fying " to drop ; " and it may be chemically defined 
 as the conversion of a liquid into vapour by heat, and 
 the subsequent conversion of that vapour into a liquid 
 by cold ; in this respect it differs from " Sublimation," 
 but yet agrees with it in the fact of the change being 
 merely physical and not chemical. 
 
 Thus the chemist is enabled to obtain pure water 
 from brine, sea-water, or river water, the " absolute" 
 water distilling away from the saline and earthy mat- 
 ters that are not volatile at the same temperature ; 
 exactly as in the last experiment, the " volatile" alcohol 
 distilled away in the first place from the comparatively 
 " fixed" water, and in the second from the more per- 
 fectly "fixed" lime. 
 
 The evaporation of water from the earth, and its 
 subsequent fall in drops as showers, is a grand and 
 important example of " distillation," proceeding in the 
 vast laboratory of Nature. 
 
 Water has the invaluable property of invariably 
 
404 WINTER. 
 
 maintaining its chemical composition, however vio- 
 lently its physical form may be changed, by the artificial 
 application of cold or heat to the state of solid ice or 
 elastic steam ; and if the latter be prevented in its 
 escape from the water, by which it is generated, as by 
 closing the vessels in which the experiment is made, 
 the water rises far above its ordinary boiling point, 
 and the steam, partaking of such increase of tempera- 
 ture, acquires an enormous elastic force, and hence is 
 employed as the motive power of the steam- engine, a 
 machine that is working wondrous and strange changes 
 upon the physical, moral, and intellectual condition of 
 mankind. 
 
 Constructed of astonishing accuracy and strength 
 by the skill of modern engineers, we behold the con- 
 densing steam-engine " thrusting its giant arm amid 
 the solid strata of the globe, excavating spacious 
 galleries and mines, drawing forth the rivers which 
 inundate and encumber them ; tearing from the rock 
 the boundless mineral wealth therein deposited by 
 nature," hurling it to the surface, assisting in its 
 reduction to the metallic state, and its subsequent 
 manufacture into countless forms for the use of the 
 arts. 
 
 " We see the steam-engine uniting power with deli- 
 cacy: we see it twisting, with equal success, the 
 immense folds of cable, and the gossamer filaments 
 of delicate lace." 
 
 We see it as applied to the manufacture of paper, 
 producing with celerity sheets of paper of the most 
 
WINTER. 405 
 
 even and perfect texture, and any number of miles in 
 length that may be required ! Then, again, as applied 
 to the printing-machine, by which we are rapidly sup- 
 plied with cheap and beautiful publications. 
 
 We observe the application of the same agent to the 
 reduction of iron from the ore; and its formation into 
 the endless variety of states demanded by the civil 
 engineer, for satisfying the calls of the wealthy and 
 enterprising capitalists of this nation. 
 
 In one year alone, the steam-engine produced one 
 million eight thousand tons of cast and wrought iron, 
 the value of which amounted to nearly seven millions 
 sterling, furnishing employment to forty thousand 
 men, and consuming three million tons of coal. 
 
 Its application to calico-printing has summoned 
 into activity the skill of two hundred and thirty thou- 
 sand workmen, who in one year produced by its 
 agency eight millions and a half pieces of calico, and 
 they received for their labour capital to the amount of 
 two millions four hundred thousand pounds sterling. 
 
 Lastly we see the steam-engine applied to ships, the 
 perfection of steam navigation, the speed with which 
 the beautiful machinery of the condensing engine pro- 
 pels a magnificent vessel over the waters of the wide 
 Atlantic, causing its arrival on the shores of the New 
 World in less time than was formerly required to sail 
 from one extremity of the United Kingdom to the 
 other. 
 
 The Almighty was pleased to prolong the life of the 
 great, good, and amiable philosopher, who, after long 
 
406 WINTER. 
 
 and laborious study, perfected this mighty invention, 
 to the advanced age of fourscore years and four ; and 
 then " expressing his gratitude to Providence for that 
 length of days and exemption from infirmity which 
 rendered the evening of his life cheerful and serene, 
 he yielded up his soul in the calmest tranquillity, and 
 passed without pang or struggle from the bosom of his 
 family to that of his God." 
 
 The wondrous invention bequeathed to us his coun- 
 trymen is a monument upon which his name is en- 
 graven, and never can it be effaced or forgotten ; 
 better far than the gorgeous monument of sculptured 
 marble, and moulded bronze, which time crumbles or 
 corrodes into dust, and ultimately mingles with its 
 parent earth. 
 
 " The true end of all science is to enrich human life 
 with useful arts and inventions." What can be a more 
 magnificent illustration of this precept than the inven- 
 tion just alluded to, or its modification into the high- 
 pressure locomotive engine and its present employ- 
 ment upon the iron roads, which ramify throughout 
 the empire, drawing in its giant train with incredible 
 velocity sumptuous carriages laden with thronging 
 hundreds of passengers ? 
 
 The steam-engine, in all its details and bearings, 
 forms a most important and interesting subject for our 
 reflection. 
 
 But to return more immediately to the chemistry of 
 the water, whose vapour is the motive power of every 
 modification of this miracle of art. 
 
WINTER. 407 
 
 The chemist discovers, upon examining the host of 
 metals enumerated at page 4, that some of them have 
 more attraction for oxygen than others; indeed so 
 intense, that they cannot be exposed to the air, or any 
 other mixture or compound containing that element, 
 without immediately tarnishing, rusting, or oxidizing. 
 
 He farther discovers, that a change so sudden, 
 regarding the physical and chemical characters of such 
 metals and oxygen, developes the imponderable agency 
 of Electricity in its utmost artificial degree of power ; 
 and this conducted by wires of the least oxidizable 
 metals, into water, immediately causes repulsion be- 
 tween its elements, or resolves it into Oxygen and 
 Hydrogen, in the above definite proportions of weight 
 and measure ; this extraordinary experiment is techni- 
 cally called the " electrolysis of water." 
 
 It furnishes the only method that is known of simul- 
 taneously eliciting both the elements of water ; and as 
 the manipulations requisite for the success of the ex- 
 periment can be learned from the generality of many 
 popular works on the rudiments of Electricity and 
 Chemistry, reference is made to these, if such in- 
 formation be desired ; whilst we can proceed with a few 
 examples of the evolution of Hydrogen from the de- 
 composition of water, that are not so generally known, 
 yet most intimately connected with this inquiry re- 
 garding the principal chemical phenomena of the Four 
 Seasons. 
 
 Fill a Florence flask with rain-water, and invert it 
 into a basin containing water, exactly after the method 
 
408 WINTER. 
 
 described for the " carafe " at page 211 ; obtain three 
 or four globules, about the size of peas, of the metal 
 Sodium ; these will be presented, by the vendor, in a 
 small vial, containing a portion of colourless, or light 
 yellow-coloured liquid ; it is a native compound of 
 Carbon and Hydrogen, called " naphtha," from an 
 oriental word, signifying to " pour out or to exude," 
 as this liquid does from the soil on the banks of the 
 Caspian Sea ; and as " naphtha " contains no oxygen, 
 it forms an invaluable liquid coating or medium for 
 preventing the globules of sodium from combining 
 with oxygen until the moment that such effect is willed 
 by the operator. 
 
 Let one of the globules of the metal be taken out on 
 the point of a knife, then placed on blotting paper, 
 and cut into four pieces ; in doing this, its metallic 
 splendour will appear for an instant, but then will tar- 
 nish or become dull white, on account of its combining 
 superficially with oxygen from the air, and forming 
 Oxide of sodium or Soda. 
 
 As such, combined with carbonic acid, it is found 
 in ancient " nitre," or " natron/* constituting native 
 carbonate of soda ; and as such again it is obtained 
 by the combustion of marine plants, and is found in 
 their ashes, the same as oxide of potassium or potash 
 is obtained by the combustion of wood, and is found 
 in the resulting ashes as carbonate of potash, which 
 engaged so much of our attention at page 297. 
 
 From the ashes of marine plants Sodium is ultimately 
 obtained, in a manner similar to potassium from wood 
 
WINTER. 409 
 
 ashes ; and thus the chemist is presented with the ex- 
 traordinary fact, that the plants of the ocean and of the 
 earth contain each a metal brilliant as silver, but having 
 the two strongest attractions for oxygen of all simple 
 or compound matters : let us take advantage of this 
 fact in the case of Sodium, for decomposing a portion 
 of the water in the Florence flask. 
 
 The globule being cut into four pieces, press each of 
 these upon the blotting-paper to absorb the naphtha ; 
 then fold each separately, yet tightly, in a very small 
 piece of dry thin glazed paper, stained of a bright yel- 
 low, with tincture of turmeric root; grasp the lower 
 part of the bulb of the flask with one hand, and thus 
 lift it so that its neck may be about an inch beneath 
 the surface of the water, near one side of the glass in 
 which it is inverted ; then take one of the packets of 
 sodium between the finger and thumb of the other 
 hand ; plunge it quickly beneath the water, and when 
 directly beneath the mouth of the flask, relax hold of 
 the packet, and although containing a solid metal, 
 yet like solid ice it will rise to the water at the top 
 of the flask, because it is lighter than^ water, its 
 actual specific gravity being nearly the same as that 
 of ice, viz., Water, S. G.= 1.000; Ice, S. G. = 0.940 ; 
 Sodium, S. G. = 934. 
 
 This is another extraordinary fact; but one yet 
 more extraordinary will soon present itself: as the 
 water creeps through the paper by capillary attrac- 
 tion, and comes into direct contact with the so- 
 dium, myriads of minute air bubbles will exude 
 
 T 
 
410 WINTER. 
 
 from the pores and folds of the paper, with a rapidity 
 increasing every moment, and at last a globule of the 
 metal will burst forth, like a bead of silver ; but it will 
 float upon the water, whilst myriads of air bubbles 
 will surround it on all sides ; the globule will diminish 
 in size, and when very minute, and just before it 
 vanishes, it may very probably become red-hot ; the 
 air bubbles coalesce into one large bubble, as did 
 those of oxygen, evolved by the "conferva" in the 
 "carafe" at page 214. 
 
 In this experiment, as indeed in all others where 
 intensely active agents are employed, the face of the 
 operator should not be held directly above, or very 
 near the vessels or apparatus, lest an explosion hap- 
 pen ; but suppose the experiment successfully performed 
 thus far, let the remaining packets of sodium be simi- 
 larly introduced one by one, and when the last has 
 presented the extraordinary phenomenon, pass a cork 
 through the water, to close the mouth of the flask, 
 and then place it to stand on a ring as at page 57, 
 as the aeriform matter in that experiment, or as the 
 oxygen in * that with the "carafe" at page 214 as- 
 cended, so will the aeriform matter of this experiment 
 ascend into the neck of the flask. 
 
 Let the apartment be darkened ; then, having kin- 
 dled an extremely small taper, or even a small splinter 
 of wood, remove the cork, and introduce the flame of 
 either substance ; the aeriform matter, unlike oxygen, 
 will not support the flame, but will itself kindle, and 
 burn with an extremely pale and lambent flame. 
 
WINTER. 411 
 
 What is the theory, or the explanation, of this expe- 
 riment ? 
 
 Beautiful, and instructive, even beyond the stage 
 already gained, but up to it as follows. 
 
 The myriads of air bubbles were those of hydrogen 
 gas, for which sodium has no attraction or affinity ; and 
 Hydrogen, though itself inflammable, will not support 
 the combustion of the taper or splinter of wood ; but 
 sodium has an intense attraction for the Oxygen of 
 the water, and combined with it to form Oxide of 
 sodium or Soda, which now remains dissolved in a 
 portion of the undecomposed water, and being alkaline, 
 has changed the yellow colour of the turmeric paper 
 to brown ; so that the experiment presents two results, 
 the eduction of elementary Hydrogen by the decom- 
 position of Water, and the production of compound 
 Soda, by the union of elementary Oxygen and Sodium. 
 
 Let the water be now poured from the flask into a 
 perfectly clean basin. Set this in an oven moderately 
 heated, leaving the door open, that the whole of the 
 water may evaporate, and then at the bottom of the 
 basin will be found a minute portion of a white, solid, 
 acrid, and caustic substance, that will immediately 
 redden a moistened piece of turmeric paper most 
 powerfully, or change a blue infusion of cabbage bright 
 green ; it is the solid and nearly anhydrous oxide of 
 sodium or soda, exactly similar in constitution to the 
 dull white tarnish produced when the globule of so- 
 dium was originally cut in the air, though in this case 
 
 T 2 
 
412 WINTER. 
 
 produced by the oxygen, not of the air, but of the 
 water. 
 
 The Hydrogen, as it burnt from the neck of the 
 flask, had its flame supported by the Oxygen of the 
 surrounding air ; and in so burning, actually formed 
 the vapour of water ; and if the experiment be re- 
 peated with about twice as much sodium as that already 
 directed, all being in small pieces, sufficient hydrogen 
 may be collected to fill more than the neck of the 
 flask ; then, by proceeding as before, and applying 
 the smallest possible flame of a splinter of wood, to 
 kindle the hydrogen, and instantly holding a clean, 
 cold, and dry wine-glass over its lambent flame, the 
 glass, instead of remaining dry, as might be reasonably 
 anticipated, will become dim with moisture ; because 
 its cold surface condenses the hot vapour of the Water 
 that is produced by the combination of the Hydrogen 
 with the Oxygen of the air. 
 
 If a globule of sodium be thrown upon the surface 
 of water contained in a large shallow plate, the evolu- 
 tion of hydrogen will proceed as in the flask, but it 
 may now be directly kindled by approaching the 
 globule with a small flame, and thus the curious phe- 
 nomenon of a ball of fire floating on the water will be 
 presented. 
 
 If a globule of sodium be thrown upon hot water, 
 the decomposition is so intensely rapid, that the 
 evolved hydrogen will spontaneously inflame, thus 
 illustrating the chemical fact, that light and heat are 
 
WINTER. 413 
 
 the usual concomitants of intense chemical combi- 
 nation between two or more substances. 
 
 Potassium has a greater affinity for oxygen than 
 even sodium is found to possess ; in fact, it has 
 the most intense affinity for that element of any 
 elementary or compound substance. It is, there- 
 fore, preserved in " naphtha," and it is likewise the 
 lightest solid known,, its Specific Gravity being only 
 0.865. It might be used in the experiment with the 
 flask, but is rather dangerous, as its action often rises 
 beyond control, and an explosion happens. However, 
 a globule may be thrown on a plate filled with cold 
 water ; it will float, and spontaneously inflame with a 
 purple light, this colour being apparently due to the 
 combustion of a portion of the vapour of the metal, 
 in addition to that of the hydrogen of the decomposed 
 water. 
 
 Potassium will as rapidly decompose solid water or 
 ice ; for example, make a small hole in a lump of ice 
 and drop into it a globule of potassium, the purple 
 flame will instantly appear, a deep hole will be melted 
 in the ice, and the liquid that it now contains is a 
 strong solution of oxide of potassium or Potash, and 
 it will act upon turmeric paper, or infusion of cabbage, 
 like soda, because it is likewise an alkaline oxide. 
 
 Reasoning upon the extraordinary powers of the se 
 two metals, potassium and sodium, in so energetically 
 combining with oxygen, in whatever form it may be 
 presented to them, the chemist is led by analogy to 
 imagine, that volcanic eruptions, both on land and at 
 
414 WINTER. 
 
 sea, may probably ensue from masses of these or other 
 metals of the earths, suddenly coming into contact 
 with oxygen or other elements, for which he knows they 
 have intense attraction, and thus combining, displaying 
 combustion upon a magnificent and awful scale. 
 
 If the chemist compare the measures or volumes of 
 the definite weights of these extraordinary elements of 
 water, he discovers them to bear the proportion of one 
 to two, or in other words, One volume of Oxygen and 
 Two volumes of Hydrogen, and farther ascertains, that 
 upon exciting these to combine, they form not Three 
 volumes, or their sum total, as might be anticipated, 
 but only Two volumes of the Vapour of Water, or, to 
 employ his technical expression of this extraordinary 
 fact, the Three volumes of the Elements condense into 
 Two of the Compound. 
 
 This fact bears analogy to that discovered by the 
 simple experiment at page 114, where equal bulks 
 of Water and of Alcohol contracted very considerably, 
 or condensed by chemical union ; for such it was, and 
 no repose, no lapse of time, will cause the separation 
 of the two liquids from each other, according to their 
 specific gravities, as at page 341. Once chemically 
 combined, they can only be separated by chemical 
 agents of which hereafter. 
 
 But, as in the case of their mutual combination, 
 heat was evolved, so in this of the more energetic 
 union of Oxygen and Hydrogen, the chemist discovers 
 that heat is evolved of intensity sufficient to soften, 
 melt, and burn, the most refractory earths, ores, and 
 
WINTEK. 415 
 
 metals ; in fact, the union of Oxygen and Hydrogen 
 affords him a degree of heat scarcely inferior to that 
 of electricity, and a brilliant flash that rivals both it 
 and lightning. Another extraordinary fact next pre- 
 sents itself; although the compound, at the instant of 
 its formation, is in the state of Two volumes of Va- 
 pour, this, upon cooling, sustains a most excessive 
 condensation into y^go-th part, to form liquid water ! 
 
 To impress upon the mind of the young student 
 this extraordinary fact regarding the enormous volume 
 of gaseous elements that are included in a drop of 
 water, let 845 peas, all similar in size, represent the 
 One Volume of Oxygen, and 1690 similar peas repre- 
 sent the Two Volumes of Hydrogen; then 1690 more 
 peas would represent the Two volumes of the Vapour 
 of Water, which the Three Volumes form, and a Single 
 pea will represent the drop of water that results from 
 its condensation. 
 
 It is some little trouble to count so many peas ; but 
 once accurately done, the three heaps may be preserved 
 in three bottles, and are extremely useful for illustrating 
 the fact at any future time. 
 
 Knowledge of the composition of Water is of great 
 importance in chemistry, it enables philosophers to ex- 
 plain many phenomena that were formerly mysterious, 
 and affords an excellent example of a compound differ- 
 ing in all its habitudes from those of its elements. 
 
 Thus, gradually, have we discovered the leading cha- 
 racters of Carbonic acid, Water in its three physical 
 
416 WINTER. 
 
 states, and the elements Oxygen and Hydrogen ; one 
 more experiment will enable us to discover the leading 
 character of Nitrogen, and then our chain of inquiry 
 will he complete. 
 
 Take the flask employed in the experiment with the 
 sodium at page 407, wash and dry it thoroughly; this 
 last operation is best effected by holding it near a fire, 
 with its mouth downwards, until the bulb becomes 
 very hot, then inserting the nozzle of a pair of bellows 
 to blow out the steam ; when this is effected, place the 
 flask upon a flannel and let it cool for an hour at 
 least ; this is essential. 
 
 Obtain a stick of Phosphorus about an inch long, 
 shake it from the vial full of water in which it is 
 kept, into a cup, then remove it from this by stick- 
 ing the point of a knife into it, and press it with 
 a dry cloth; gloves should be worn during this 
 proceeding, and a large basin of water placed near, 
 so that if the phosphorus spontaneously inflame, 
 which it will do by moderate heat or friction, it may 
 be extinguished by the affusion of water ; and so may 
 its flame upon the gloves, should such accident ensue ; 
 but suppose the phosphorus be successfully dried 
 upon the cloth, and the flask perfectly cold, by means 
 of the point of the knife, lift the phosphorus into the 
 flask, cork it tightly, and then place the neck, thus 
 corked, beneath the surface of water contained in a 
 finger glass, as already directed, and leave it at rest for 
 twenty- four hours. 
 
 During this time, the phosphorus will slowly com- 
 
WINTER. 417 
 
 bine with the oxygen of the air that the flask contains ; 
 and if the apartment be darkened at the outset of the 
 experiment, the beautiful lambent light, like that of 
 the glow-worm, attendant upon this slow combustion 
 of the phosphorus, will be visible ; when the time has 
 expired, still keeping the neck of the flask under water, 
 withdraw the cork, the phosphorus will fall into the 
 finger glass, but water will rise from this a very con- 
 siderable height into the neck, and even part of the 
 bulb of the flask. Why is this ? what is there in the 
 flask to pull up the water ? it only rose about half an 
 inch in the experiment at page 56, then why this ex- 
 treme rise ? 
 
 In the experiment to which allusion is made, the 
 flask contained air, and it being subjected to a slight 
 compression by the weight of the water, a very little 
 water only ascended ; so that the volume of the air in 
 the flask was very nearly of the same density as that of 
 the external air ; but heat being applied, some of the air 
 escaped, and upon subsequent cooling, water ascended 
 to supply the place of such portion of expelled or ab- 
 stracted air ; ascended, like that in the flask from which 
 the cork has just been withdrawn, but in this experi- 
 ment there is more to be considered. 
 
 The atmosphere consists of about one volume of 
 Oxygen, and four volumes of Nitrogen; and during 
 the inclusion of the phosphorus in the flask, it has 
 slowly combined with, or withdrawn the one volume of 
 Oxygen, to form a few drops of Phosphorous acid; the 
 air would have entered to supply this deficiency had 
 
 T 5 
 
418 
 
 WINTER. 
 
 not the neck of the flask been corked, and placed un- 
 der water, to keep it air-tight ; so that now less than 
 the original volume of the air is in the flask, and upon 
 removing the cork, the external atmosphere pressing 
 upon the surface of the water in the finger glass, forces 
 a portion of it upwards to supply such deficiency, and 
 at the same time to indicate its extent, the remaining 
 aeriform matter is pure Nitrogen, for which phospho- 
 rus has no attraction under these circumstances ; 
 thus, the air is analysed, its Oxygen or supporter of 
 combustion being combined with the phosphorus, 
 and its Nitrogen, or non-supporter of combustion,, 
 liberated. 
 
 Fig. 67. 
 
 Replace the cork, then lift the flask, place it on a 
 ring, and introduce a lighted taper ; the flame will bo 
 extinguished, as effectually as though it were plunged 
 into water, and thus we obtain evidence of the leading 
 character of Nitrogen. 
 
WINTER. 419 
 
 Such are a few of the extraordinary phenomena re- 
 garding the properties of elementary and compound 
 matter, that reward the investigations of the diligent 
 student of the delightful science of chemistry; the 
 pleasure derived from this department of knowledge, 
 concerning the wonders of the Creation, is unceasing ; 
 and so varied that it never satiates the sense, at the 
 same time it is far removed from the low gratifications 
 of sense in another respect ; while those hurt the health, 
 debase the understanding, and corrupt the feelings, 
 this elevates and refines our nature ; teaching us, 
 whilst contemplating the wonders by which we are sur- 
 rounded, and which are so essential for our welfare, to 
 acknowledge the Omnipotence of The Hand by which 
 they were created, and are perpetually governed. 
 
 At this inclement season of the year, when the trees 
 are bare, the streams fast bound in icy fetters, the sky 
 obscured by tempests, and the chilling winds howling 
 around our dwellings, we become fully sensible of the 
 comforts of an " English fireside ; " and the examina- 
 tion of the chemical phenomena that it likewise pre- 
 sents, will be found to bear most intimately upon much 
 of our previous inquiry, regarding the habitudes of 
 solids, liquids, and gases, with cold and heat. 
 
 The materials generally laid in a fire-grate are paper, 
 wood, and coal ; and there is much philosophy in this 
 seemingly simple arrangement; for these substances 
 are placed in the order of their combustibility, they are 
 all closely allied in chemical composition, they differ 
 
420 WINTER. 
 
 materially in physical form ; paper being fragile, wood ' 
 tough, and coal brittle. 
 
 A lighted match applied to the paper, instantly causes 
 its inflammation ; this kindles the wood, which does not 
 burn so rapidly on account of its greater aggregation, 
 and therefore allows sufficient contact of its flame, to 
 excite the combustion of the more closely aggregated 
 coal ; this soon ensues, the fire burns well, the smoke 
 and vapour swiftly ascending through the chimney. 
 
 At first sight there appears no reason why a fire 
 might not be kindled as readily at the top of the grate 
 as at the bottom, but daily experience shows us this 
 cannot be done, and for a very simple reason, which 
 may be illustrated as follows. 
 
 Fold a long strip of paper into the form of an ordinary 
 " allumette," kindle one end of this, hold it horizon- 
 tally, and the flame will immediately ascend powerfully 
 from its upper side ; and however it may be held, the 
 flame will always ascend, and most rapidly when the 
 paper is held with its kindled part pointing downwards ; 
 do these simple matters appertain to chemical philo- 
 sophy ? they do, and for the following reason. 
 
 The flame cannot burn without air, and as it chemi- 
 cally withdraws Oxygen from such portions of this 
 wondrous medium as are in immediate contact with it, 
 this action mechanically disturbs the natural equili- 
 brium of unchanged or fresh portions, at some distance 
 around and below ; these, accordingly, move swiftly 
 onward and upward, to supply the deficiency occa- 
 
WINTER. 421 
 
 sioned by the flame ; and it consisting of volatile mat- 
 ter, is urged by the force of such moving air, into a 
 pointed or pyramidal form. 
 
 The dangerous and fatal accidents that have hap- 
 pened, more particularly to females, by their thin dresses 
 catching fire, afford sad illustrations of the invariable 
 ascent of flame. 
 
 In the case of dresses catching fire, persons gene- 
 rally are greatly alarmed and lose their presence of 
 mind, and therefore run wildly to and fro, ( thus fanning 
 the flames into their utmost intensity ; the prudent 
 plan is, to lie down upon the floor, and roll the hearth 
 rug around the body to exclude the air, and thus ex- 
 tinguish the flames ; or, if there be any bystanders at 
 the time of the accident, the cloak of one or the coat 
 of another, thrown around the body of the sufferer, will 
 instantly quench the flames. 
 
 A simple experiment may serve to impress this use- 
 ful fact upon the mind ; spread a sheet of paper flat 
 upon a board, kindle the four corners of the paper, 
 and observe how slow, how imperfect will be the com- 
 bustion ; and to what a small extent the flame will rise ; 
 because the air has only access to the upper part of the 
 paper, and cannot enter below to urge the flame to its 
 full pointed intensity of height ; as it will do the in- 
 stant that the sheet of paper is lifted upright, by taking 
 hold of one corner with the tongs. 
 
 But in either case, the flame may be perfectly and 
 safely quenched, by spreading a thick cloth over it to 
 prevent the access of air; it should be particularly 
 
422 WINTER. 
 
 borne in mind, that no common flame can burn with- 
 out access of air ; but now, to continue our investiga- 
 tion regarding the philosophy of applying such flame 
 to the lower strata of fuel in the " fire grate." 
 
 It is a well-established fact, that all substances, 
 not even excepting water, after a certain degree is 
 passed, under the influence of heat increase their 
 mass, bulk, or volume, and diminish in their specific 
 gravity ; they, accordingly, in the case of mobile liquids, 
 gases, and vapours, have an immediate tendency to as- 
 cend through colder and heavier portions of their own 
 nature, or in many cases of other liquids, gases, and 
 vapours, of totally different nature ; thus, if the hand 
 be held some inches above a flame, great heat will be 
 felt, for the products of combustion, namely, Watery 
 vapour and Carbonic acid, are both intensely hot, both 
 specifically lighter, and therefore ascending through 
 the colder, heavier air ; if the hand be held under the 
 flame, little more than actual heat of radiation will be 
 felt upon its palm, whilst its back will feel cold, by the 
 fresh air ascending to supply the place of the escaping 
 products of combustion. 
 
 Let the thermometer with its blackened bulb, em- 
 ployed in the experiment at page 156, be held some 
 distance above, and then the same distance beneath a 
 horizontal flame, and in the former position it will in- 
 dicate a much greater temperature than in the latter. 
 
 The reason, then, of kindling the fuel in a grate at 
 the lower bars, is that the flame may assume its pointed 
 form, and ascend, with its own heated products ; which, 
 
WINTER. 423 
 
 gradually drying and heating the wood, and it in turn 
 the coals, induces their combustion ; then all the pro- 
 ducts ascend through the chimney, and emerging 
 from it into the air, if it he calm will continue ascend- 
 ing for a considerable height as one unbroken column, 
 whilst fresh air enters the room, to supply the fire, still 
 urging the ascent of its flame and heated products. 
 
 If, on the other hand, the fuel were laid in an inverted 
 order, the paper being uppermost, this upon being 
 kindled would immediately obey the impulse of the 
 air, and ascend in flame with such rapidity, that the 
 wood, unless extremely thin, would be prevented from 
 gaining sufficient heat to burn ; and then in turn, it 
 would pass away with rapidity, without kindling the 
 solid coals. 
 
 In all ordinary cases of the employment of coals as 
 fuel, a portion of carbon passes away unburnt, in the 
 ascending draught of actual products of combustion ; 
 and this carbon constitutes the chief part of the black 
 smoke, yet being highly heated, it generally floats for 
 a considerable time in the air. 
 
 Remark the dense volumes of smoke that issue from 
 the lofty stacks of steam-engines, breweries, and gas 
 works ; how far they travel, through the calm air, and 
 do not appear to blend with it ; the watery vapour and 
 carbonic acid that they contain, do really blend and 
 dissolve in the air, but the unburnt carbon cannot 
 do so, it therefore remains mechanically diffused for a 
 considerable time, until it becomes so cooled as to fall 
 in the form of " blacks." 
 
424 WINTER. 
 
 On the other hand, remark the dense white cloud of 
 steam that issues from a railway engine, with what 
 force it ascends a considerable distance in the air. and 
 then forms small clouds ; but these immediately va- 
 nish and do not travel like the carbon of smoke, be- 
 cause they consist of nearly pure watery vapour, and 
 chemically dissolve in the air, without altering its trans- 
 parency ; the same as a lump of white sugar will dis- 
 solve in water, without altering its pellucid appearance. 
 
 Smoke, therefore, presents an example' of the 
 mechanical diffusion of a substance ; and steam, an 
 an example of the chemical solution of a substance in 
 the atmosphere ; again, the dust of Summer, and the 
 snow flakes of Winter, floating in air, present exam- 
 ples of " diffusion ; " and when they fall, of " precipi- 
 tation " from such medium ; but the solid dust can 
 never return into the air, save by its mechanical im- 
 pulse ; whilst the snow flakes, by first changing from 
 their solid state to that of vapour, by the warmth of 
 the air, chemically return into its vast and capacious 
 volume. 
 
 Eeturning to the chemical phenomena presented by 
 an ordinary fire, we find it a point of the utmost im- 
 portance, that the products of combustion and the smoke 
 should have free escape, and that it is absolutely 
 necessary to admit as much air into the room as the 
 flame consumes; if this be prevented, by nailing 
 leather around the doors, or placing sand bags at their 
 thresholds, or upon the window frames, the smoke, in- 
 stead of ascending, will be forced into the room by a 
 
WINTER. 425 
 
 current of air descending from the chimney-pot, to 
 supply the deficiency of that in the room. 
 
 The admission of cold or fresh air to the lower part 
 of the fire, without occasioning the inconvenience of a 
 draught, is one of the most difficult problems for 
 practical solution that can be presented, and probably 
 the simplest plan is to carry an open tube from the 
 hearth into the external air ; at all events, the fresh air 
 should gain admission at or near the floor, and not at 
 or near the ceiling of a room ; the latter situation is 
 the most suited for its escape when heated and vitiated 
 by the combustion of candles and gas, and the respi- 
 ration of the inmates of the apartment. 
 
 The greater heat of the air near the ceiling of a 
 room in comparison with that upon the floor, is di- 
 rectly felt by any person ascending a pair of steps ; as 
 for example, to reach a book from the highest shelf of a 
 library ; and a further proof of the tendency of heated 
 air to ascend to the ceiling, is presented by the fact 
 of its plaster appearing darker in some parts than 
 in others, and for the following reason. 
 
 The heated air carries dust and fine soot to the ceil- 
 ing, the air itself readily escapes through the porous 
 plaster that is simply spread upon the laths, but leaves 
 its dust and soot behind, and thus discolours the plas- 
 ter ; but through the more compact plaster upon the 
 laths, where they are actually nailed to the joists, it 
 cannot pass nor deposit dust, and accordingly such 
 parts remain white or of their original colour. 
 
 The fact of heated air thus ascending and remaining 
 
426 WINTER. 
 
 at the upper part of a room, furnishes a hint as to the 
 most judicious construction of a "fire-place," and it 
 would he a matter of some difficulty to point out any 
 part of our domestic edifices which exhibits such a 
 total ahsence of rational or scientific principles as an 
 ordinary "fire-place" and its appendages. 
 
 Nothing is more common than to see large ill-con- 
 trived grates, placed at a considerable height from the 
 hearth-stone, and in many cases actually half way be- 
 tween it and the mantel-piece, beneath a capacious 
 chimney; the absurdity of such an arrangement be- 
 comes obvious upon the slightest reflection. 
 
 In a grate so situated, the burning fuel radiating 
 heat into the room, will only warm the air at or about 
 its own level, and then the chief part of such warm air 
 will quickly ascend through the ample chimney ; the 
 remainder will ascend to the ceiling, and this on ac- 
 count of the under- current of cold air that is entering 
 the room at the floor in order to restore the equilibrium, 
 and in so doing produces the disagreeable and dan- 
 gerous effect of a " draught." 
 
 A person seated in front of such a fire, burning in 
 such a fire-place, would be perfectly scorched from his 
 face to his knees by the radiant heat, whilst his legs 
 and feet would be especially cold from immersion 
 in the under-current of cold air, or the "draught;" 
 to prevent this, sand-bags are placed at the bottom of 
 the doors, every chink and cranny, even the very key- 
 hole is stopped, and then, to employ the popular ex- 
 pression, "the fire will not draw," the smoke rolls 
 
WINTER. 427 
 
 down in sooty volumes into the room for the reason 
 above described. 
 
 Accordingly the door or the window must be par- 
 tially opened to admit the entrance of fresh air ; this, 
 after a time, will compel the smoke to return into its 
 proper channel, but every article of furniture contained 
 in the apartment, and most particularly the draperies, 
 remain strongly impregnated with the unpleasant odour 
 of the smoke ; and if after having cleared the room, 
 the door or window be closed, in the course of a few 
 seconds the smoke will enter it again, and fill it ex- 
 actly as before, so that there is no alternative but to 
 keep one or both partially open, and the inmate of the 
 apartment will very shortly suffer from the effects of a 
 " severe cold." 
 
 Air is not a conductor of heat, and only admits 
 of its temperature being elevated by convective cur- 
 rents ; if a person proposed to warm a room by placing 
 the fire-grate near the ceiling, such proposition 
 would be deemed perfectly absurd ; but the ordinary 
 situation of this receptacle for burning fuel is almost 
 absurd, because it is actually placed at a consider- 
 able height from the floor, and therefore the result 
 approximates in no slight degree to that which would 
 ensue, if it were placed near the ceiling, namely, keep- 
 ing the air at that elevation excessively hot, and the 
 air upon the floor intensely cold, for warm air will 
 float upon cold air, in artificial volumes, the same as 
 hot water will float upon cold water in artificial bulks. 
 
 In order to warm an apartment to any comfortable 
 
428 WINTER. 
 
 temperature, by a common open fire, the grate should 
 be placed as close to the hearth- stone as possible ; it 
 should be wide and shallow, its sides of stone or fire- 
 brick, and the whole aperture for its reception con- 
 tracted from its usual width, and lowered from its 
 usual height, and a tube provided for the admission of 
 the external air to the lower part of the grate. 
 
 By this proceeding, heat will radiate upwards from 
 the shallow surface of the burning fuel, as also laterally 
 and downwards ; and by the latter rays of heat being 
 arrested and absorbed by the hearth-rug, carpetting, 
 and articles of furniture, they impart heat to the 
 draught of air that may enter beneath the door; it, 
 therefore, instead of proceeding in a strong cold draught 
 directly to the fire, becomes diffused in its passage, 
 convective currents are established ; and the " fire 
 drawing well," a genial temperature is soon established 
 throughout the air of the apartment. 
 
 It frequently happens, that in defiance of every con- 
 trivance, the smoke will not ascend properly, on ac- 
 count of the extremely tortuous and narrow form of 
 the chimney, or its chimney-pot being less elevated 
 than that of another neighbouring chimney, and ac- 
 cordingly a slight wind will blow the smoke from the 
 latter down the former. 
 
 A similar result will also take place when the fire is 
 extinguished in the grate to which the shortest chim- 
 ney belongs, more especially if the apartment be con- 
 nected with another, by folding doors, as a dining- 
 room with a drawing-room in many modern houses, 
 
WINTER. 429 
 
 and a fire kindled in the grate of the latter ; for as its 
 smoke ascends, the external air will prefer freely 
 entering the apartments, through the large cold chim- 
 ney of the dining-room, and introducing at the same 
 time the neighhouring smoke, to seeking a limited 
 entrance beneath the doors, from the hall or passage. 
 
 Architects, generally speaking, bestow very little 
 attention upon these matters, but sacrifice comfort to 
 the smooth appearance of their favourite plans of con- 
 struction; and when the dwelling is completed, they 
 appear suddenly to recollect that it requires genial 
 warmth, to render it habitable in winter, and accord- 
 ingly commence every kind of strange internal altera- 
 tion, and external disfigurement, for ultimately effecting 
 this most essential purpose. 
 
 It is an extremely injudicious plan to " set," as it is 
 technically called, iron grates firmly in brick or stone- 
 work ; they may certainly remain steady for a time, 
 but very shortly cracks, and fissures appear in the 
 plaster of the " setting," and they become, not only 
 unsteady, but unsightly, and for the following reason. 
 
 The first fire that is kindled within the grate, 
 expands its iron-work, exactly as the iron bar was 
 expanded by heat in the experiment at page 314 ; but 
 not the brick setting to an equal degree ; accordingly, 
 the powerful expansion of the former thrusts the latter 
 away in all directions simultaneously, at the same time 
 cracking the brittle plaster. As the fire decays, the 
 iron-work rapidly contracts to its original dimensions, 
 leaving the setting where it was thrust ; a chink, there- 
 
430 WINTER. 
 
 fore, appears between its edge and that of the iron- 
 work ; and this process being continued day after day, 
 the plaster ultimately falls out, and the grate becomes 
 unsteady and unsightly. 
 
 An elegant marble mantle-piece is very frequently 
 bulged or distorted from its proper position, and some- 
 times broken, on account of the expansions and con- 
 tractions of the bars of iron that are inserted at its 
 back to hold the several parts together ; thus the very 
 means adopted with the view of giving permanence or 
 stability, are active agents to the exact contrary. 
 
 Many examples might be adduced of injury that is 
 caused by the expansion and contraction of substances 
 when subjected to alternations of heat and cold, but 
 the following may suffice for this inquiry. 
 
 Sky-lights, glazed with plate or thick crown-glass, 
 when suddenly heated by the sun from without, or by 
 strong gas flames from within, are- very liable to frac- 
 ture on account of unequal expansion and imperfect 
 conduction ; and if a shower suddenly covers their 
 surfaces, then the fracture results from unequal con- 
 traction and imperfect conduction. 
 
 A very large pier-glass was fixed as usual over the 
 drawing room mantel-piece ; the fire grate was piled 
 with fuel ; this was kindled, and the apartment closely 
 shut up for several hours ; then, upon opening the 
 door, which was immediately opposite the fire-place, 
 the pier-glass suddenly shattered to fragments, much 
 to the dismay of the person who entered ; the occur- 
 rence was perfectly accidental, but is thus explained : 
 
WINTER. 431 
 
 the pier-glass gradually, and without injury, gained 
 the temperature of the room, but the sudden rush of 
 cold air from the hall, when the door was opened, 
 chilled its surface, and caused contraction, and fracture. 
 
 When hot water is suddenly poured upon a thick 
 pane of glass, its upper surface is heated, and greatly 
 expanded before the heat is conducted to its lower 
 surface, which for a time remains as cold as it was 
 originally ; an unequal tension is thus established ; 
 the upper surface endeavours to bend in fact, does 
 bend as a slight arch, but soon causes a total fracture 
 by its want of extreme flexibility. 
 
 It would lead into a field of inquiry far too extensive 
 for the present general purpose, to detail the principles 
 upon which ornamental fire-places, and closed stoves, 
 are constructed, as also the contrivances for permitting 
 the escape of foul or vitiated, and the entrance of fresh, 
 or pure air ; suffice it to say, that the main fact requiring 
 attention in warming by heated air, is to admit a large 
 volume, moderately heated and hydrated, that may 
 slowly and equably diffuse itself throughout an apart- 
 ment, and not to admit a small volume, intensely 
 heated and anhydrous, by which proceeding, instead 
 of the whole volume of the air in an apartment being 
 of a temperature nearly equable, scorching blasts would 
 occur in one part, and freezing draughts in another. 
 
 It must be granted that the practical application of 
 scientific principles to the methods of warming and 
 ventilating domestic edifices, and public buildings, is 
 
432 WINTER. 
 
 always very difficult, and frequently utterly abortive ; 
 and therefore, after incurring great inconvenience and 
 enormous expense, in modern hot-air stoves, the " Old 
 English Fire-side" is at length eagerly sought, al- 
 though the snow-flakes may descend the capacious 
 chimney, whilst the " yule log " hlazes upon the 
 hearth. 
 
 The extraordinary substance, popularly known as 
 " coal," which is so invaluable in this country as fuel, 
 upon analysis presents the chemist with the same 
 elements as wood, and occasionally a small amount of 
 Nitrogen ; and this fact has led many philosophers to 
 imagine that coal consists of the remains of gigantic 
 forests, that were overthrown and buried at the time of 
 " The Deluge." 
 
 The extreme importance of coal as fuel consists in 
 the fact of its being extremely hard and compact, and 
 therefore incapable of burning away with great or un- 
 profitable rapidity ; a lump of coal placed upon a fire 
 is some time before it kindles perfectly ; whilst a 
 shovelful of fine coal-dust thrown on the fire will 
 instantly kindle as one large and occasionally dan- 
 gerous flame ; thus affording another illustration of 
 chemical affinity being promoted when attraction of 
 aggregation is overcome. 
 
 When a fire of coal is in perfect combustion, 
 a fine yellow flame blazes steadily upon its surface ; 
 this is due to the combustion of the Hydrogen 
 and a part of the Carbon ; and the latter element 
 
WINTER. 433 
 
 being solid, is the cause of the great light of the flame, 
 for that of pure gaseous hydrogen, as we have already 
 discovered, is extremely lamhent and pale. 
 
 Chiefly from the lumps of coal that are close against 
 the hottest bars of the grate, suddenly issue forth 
 hissing streams of greenish-yellow vapour ; and often 
 kindle, as jets of brilliant yellow flame, or may be 
 kindled by a slip of lighted paper ; how are these pro- 
 duced ? 
 
 The iron bars becoming heated, conduct heat to the 
 interiors of the lumps of coal, and there causes its de- 
 composition into volatile vapour or gas, which cannot 
 burn for want of air, but at length accumulates in 
 sufficient quantity and force to break through the 
 weakest parts of the coals, and issue into the air, and 
 then it either escapes unburnt as greenish-yellow va- 
 pour, or kindles at the heat of the surrounding glowing 
 coals, or at that of the lighted paper, and burns as a 
 yellow flame. 
 
 Chemically speaking, when coal is heated out of the 
 access of air, it is chiefly resolved into a large volume 
 of gas, called " carburetted hydrogen," though con- 
 taining more carbon than the gas obtained from the 
 stagnant water of ponds and pools, as described at 
 page 221 ; and from observance of this apparently tri- 
 vial fact by the chemist, has originated the gigantic 
 manufacture of " coal gas " for the illumination of our 
 cities, towns, and dwellings. 
 
 The discovery of coal-gas was made by a chemist 
 upwards of a century ago, but it was considered as a 
 
 u 
 
434 WINTER. 
 
 mere curiosity of the laboratory, and its practical ap- 
 plication as an excellent means of artificial illumina- 
 tion, was not entered upon until within the last five- 
 and-thirty years ; the merit of this gigantic under- 
 taking is divided amongst a host of the most eminent 
 men, whose names adorn the scientific annals of our 
 country, and who must be considered as the great 
 benefactors of mankind, for the bright illumination 
 of our cities and towns has contributed a most im- 
 portant share towards the prevention of many hor- 
 rible deeds of darkness. 
 
 The merit of first conducting upon a comparatively 
 large scale the examination of the different varieties of 
 coal, the production of gas, its quantity, its purifica- 
 tion, its illuminating power, and the construction of 
 the argand-burner for its combustion, is solely due to a 
 philosopher of the present day, who, educated in the 
 same school of Inductive philosophy as his great pre- 
 decessor, has adorned the science of Chemistry with 
 numerous discoveries and experiments, more particu- 
 larly in those departments relating to the recondite 
 functions of organized beings, and to the extraordinary 
 nature of organized products; and whose extensive, 
 varied, and sound information concerning the whole 
 science, and clear explicit manner of teaching its facts 
 by lectures, is certainly without parallel ; and whose 
 " Manual is the best collection and arrangement of 
 chemical science existing." 
 
 The expressions used by a pupil regarding his 
 master in the chemistry of the " olden time," are here 
 
WINTER. 435 
 
 copied, with sincerity and gratitude, by a pupil, as ap- 
 plicable to his first instructor in the chemistry of the 
 present day ; " he is a man not of words, but of 
 deeds ; a philosopher who eminently seeks to render 
 science popular and intelligible to all capacities." 
 
 Returning to the fuel, from whence the vivid jets of 
 gas issued and led to the above passing notice of its 
 discovery and applications, we discover that when the 
 volatile hydrogen and part of the carbon are thus con- 
 sumed, the yellow flame ceases, and the remaining car- 
 bon, containing no volatile matters, but generally con- 
 taminated with earthy matters, then enters into com- 
 bustion, constituting the glowing of the cinders, and 
 producing carbonic acid alone, which being invisible, 
 the fire is said to " burn clear ;'* this is more particu- 
 larly the case during a " frosty night," because the 
 external air being extremely cold, and that of the 
 room extremely warm in comparison, the latter rushes 
 towards the fire, or fans or blows it with greater force 
 in its rapid endeavour to escape through the chimney 
 to the cold air without, than it does when there is not 
 so great a difference between the temperature and the 
 specific gravity of the interior and the exterior atmo- 
 sphere. 
 
 Upon the surface of the red-hot glowing cinders, a 
 beautiful pale blue flame often appears ; it results from 
 the carbonic acid that is formed near the lower por- 
 tions of the fuel in its ascent through the upper, com- 
 bining with more carbon, and producing an inflam- 
 mable compound, called " carbonic oxide ; " the same 
 
 u 2 
 
436 WINTER. 
 
 flame also appears upon brick and tile kilns, which 
 are heated by coal ashes ; and in such situations it has 
 been occasionally mistaken for the " ignis fatuus." 
 
 The blue flame is supported by the oxygen of the 
 air combining with the excess of carbon, so that car- 
 bonic acid is again produced ; and this is the reason 
 that a piece of paper cannot be lighted with readiness 
 on the top of a " cinder-fire," the heat may be suffi- 
 cient to char the paper, but it cannot inflame, because 
 it is enveloped by the carbonic acid, which is slowly 
 rising ; if this be quickly dissipated by the breath, or 
 by suddenly opening the door, the paper thus freed is 
 fanned into flame by the contact of the air. 
 
 If the piece of paper be held amidst the glowing cin- 
 ders near the bottom bars of the grate, where the fresh 
 air first arrives it will generally kindle immediately, 
 but will not do so if the cinders are only dull red hot, 
 because such degree of heat, though capable of pro- 
 ducing volatile matter from the paper, is incapable of 
 kindling such product ; indeed it requires a white heat 
 for its accension ; this is obtained either by fanning 
 the fire, or blowing it with the bellows, to excite more 
 rapid chemical affinity between the elements of the 
 fuel and the oxygen of the air. 
 
 We frequently hear of thatched buildings, barns, 
 and hay-ricks being accidentally set on fire, from the 
 wadding of a gun incautiously discharged near them, 
 and lodging in the thatch ; the wadding may not be 
 hot enough to do this immediately, but by remaining 
 in the thatch or hay for a time, it is fanned by the 
 
WINTER. 437 
 
 wind into flame, and then instantly establishes an ex- 
 tensive conflagration. 
 
 The bright and dark spots presented in a " clear 
 glowing cinder fire,' 1 depend upon the intensity of the 
 combustion of some parts of the fuel being greater 
 than others ; and these are liable to great variations, 
 by the draught of air proceeding towards the fire ; and 
 whilst watching such variations, the imagination soon 
 becomes active in discovering grotesque resemblances 
 between the forms of the fuel and those of familiar 
 objects. 
 
 When the fire that has afforded so much information 
 is " burnt out," the ashes in the grate consist of car- 
 bon and a small portion of earthy matters ; the carbon 
 is capable of burning in a very strong heat, and the 
 ashes are accordingly collected as fuel for tile and 
 brick kilns. 
 
 The utility of coal as a source of artificial heat and 
 light needs no comment ; the wisdom and beneficence 
 of The Almighty, displayed in the occurrence of exten- 
 sive strata of coal where forest fuel is scarce, calls forth 
 our admiration and gratitude. 
 
 In this country, " a land whose stones are iron," 
 these ores could not be obtained without the aid of 
 coal, to produce steam as the motive power of the 
 engine, and draw them forth from the mine ; neither 
 could they be reduced to the metallic state, without 
 the agency of coal and limestone. We accordingly 
 find that The Creator has associated the ore of iron 
 
438 WINTER. 
 
 or the " iron-stone" with the very agents required for 
 its extraction and reduction. 
 
 But the incessant demands that are made upon these 
 subterranean stores of treasure, compel the miner to 
 descend to greater depths, and to encounter greater 
 perils, than were originally needed; and most particu- 
 larly on account of the air of the mine heing rendered 
 inflammable and explosive, by a gaseous exhalation of 
 carbon and hydrogen, similar in composition to the 
 " carburetted hydrogen" of stagnant waters, as men- 
 tioned at page 221 ; this in coal mines is called " The 
 fire-damp," to distinguish it from the natural exhala- 
 tion of carbonic acid gas, that frequently occurs in 
 limestone and chalk quarries, which is not inflam- 
 mable, but produces suffocation, and is called " The 
 choak-damp." 
 
 " The fire-damp " was long unconquerable, and the 
 most terrific explosions, attended with dreadful loss 
 of human life and destruction of machinery, were of 
 extremely frequent occurrence ; but The Almighty, who 
 ordained its presence in the mine, permitted the great 
 philosopher to whose memory a feeble tribute has 
 been paid during this inquiry permitted him, to re- 
 flect, examine, and experiment upon its habitudes and 
 composition, and ultimately to succeed in perfectly 
 effecting its subjection. 
 
 From the statement at page 125, it will be evident 
 that flame requires a very high temperature for its 
 existence, or else spontaneous combustion would be 
 
WINTER. 439 
 
 common during the heat of summer: and from the 
 statement at page 71, it will be learned that metals 
 are the best conductors of heat which are known to 
 man. 
 
 These two facts were reasoned upon by the philoso- 
 pher thus ; as flame requires a high heat for its ex- 
 istence, and as metals are the best conductors of heat, 
 they, when applied to flame, should conduct away its 
 heat, and cause extinction. 
 
 The experiment was made with success, and its 
 practical application immediately followed, for safely 
 illuminating a mine contaminated with " Eire-damp ;" 
 the flame of a candle being surrounded with metallic 
 gauze, through the apertures of which the " Fire- 
 damp " passed, kindled at the flame, burned within the 
 gauze prison, but could not escape from it as flame to 
 explode the surrounding atmosphere, because the good 
 conducting power of the metal deprived it of heat ; 
 and thus was a fiery enemy converted into a fettered 
 slave. 
 
 The principle of this invaluable invention of the 
 " safety lamp," may be experimentally demonstrated 
 by the following simple arrangement ; indeed it is the 
 form in which a flame was first protected from kindling 
 the " fire-damp " of a coal mine. 
 
 Provide a cylinder of fine wire gauze, such as is 
 used for sieves and window-blinds ; let it be about ten 
 inches long, two inches in diameter, and closed at one 
 end with wire- gauze ; take a lump of soft clay, and 
 mould it around the middle of a candle; light its 
 
440 WINTER. 
 
 wick ; then cover it with the wire- gauze cylinder, that 
 the lower edge may be firmly pressed and imbedded in 
 the lump of clay. 
 
 Fig. 68. 
 
 Unscrew the burner of a gas-lamp, and substitute 
 for it a piece of flexible gas tubing, about two feet 
 long, and half an inch in diameter; make the joint 
 perfect, by tying it round with leather and string, and 
 then bend the tube horizontally ; turn on the gas, and 
 allow it to blow from the tube against the part of the 
 wire gauze that is imbedded in the lump of clay, by 
 which the arrangement is held in the hand. 
 
 Immediately upon the entrance of the gas, which is 
 closely analogous in chemical nature to " fire-damp," 
 it will kindle at the flame of the candle, and by moving 
 the wire- gauze nearer or farther from the pipe, the 
 combustion within will assume various degrees of 
 intensity, but the flame will not escape to kindle the 
 gas that is issuing from the pipe, and which artificially 
 
WINTER. 441 
 
 imitates a natural " blower " of " fire-damp " in a coal 
 mine. 
 
 To the " safety-lamp " we are indebted for nearly all 
 the coal that enables us to enjoy the comforts of an 
 " English fire-side ;" and the gas that illuminates our 
 dwellings and streets during the long darkness of 
 winter nights ; and for nearly all the iron that is em- 
 ployed in the stupendous works of engineering, for 
 which our country is so pre-eminent. 
 
 " The safety-lamp," the certain source of. large 
 profit, the great philosopher and philanthropist pre- 
 sented, with characteristic liberality, to his country- 
 men ; the words are remembered in which, when 
 pressed to monopolize the benefit of the invention by 
 patent, he declined to do so, in conformity with the 
 high-minded resolution which he formed upon ac- 
 quiring independent wealth, of never making his sci- 
 entific eminence subservient to pecuniary gain. 
 
 " I have enough for all my views and purposes ; 
 more wealth might be troublesome, and distract my 
 attention from those pursuits in which I delight. 
 
 " More wealth could not increase my fame or my 
 happiness.'' 
 
 Such was the man, the philosopher, the philan- 
 thropist, who, like the improver of the steam-engine, 
 " with the force of an original genius early exercised 
 in philosophical research, enlarged the resources of his 
 country, increased the power of man, and rose to an 
 eminent place among the illustrious followers of sci- 
 ence and the real benefactors of the world." 
 
 u 5 
 
442 WINTER. 
 
 Where is the national monument to his memory V 
 In vain do we seek it in cathedral or ahhey, and yet in 
 one of these hallowed spots it surely should be found, 
 " not to perpetuate a name which must endure while 
 the peaceful arts flourish, but to show that mankind 
 have learnt to honour those who best deserve their 
 gratitude." 
 
 When the greater portion of the volatile constituents 
 of coal are expelled by the action of artificial heat, 
 with only limited access of air, it becomes " stifled 
 coke ;" and this consisting chiefly of solid carbon, is a 
 form of fuel eminently calculated for the reduction of 
 iron, and other metals from their ores ; it burns with 
 extreme steadiness, and great intensity of heat, and 
 contains no sulphur, which " gas-coke " invariably 
 does ; hence the peculiar odour of burning brimstone 
 emitted from ordinary coke fires, if the draught of the 
 chimney be not powerful and rapid. 
 
 The mass of the globe hitherto explored, consists of 
 the oxides of the metals, Aluminum, Silicium, Cal- 
 cium, and Magnesium, and their combinations with 
 each other, and with various acids, as mentioned at 
 page 17. These are popularly called earths, and they 
 do not admit of reduction to the metallic state by 
 charcoal, coal, or coke. Accordingly, they are invalu- 
 able for the artificial construction of furnaces, for the 
 reduction of the ores of ordinary metals, that are found 
 naturally imbedded in them. 
 
 Some of the metals either found upon or beneath 
 the surface of the earth, are so nearly pure or ele- 
 
WINTER. 443 
 
 mentary, as to admit of immediate application to use- 
 ful and ornamental purposes ; Platinum, Gold, Silver, 
 and Mercury, for example; whilst others, as Iron, 
 Copper, Tin, and Lead, are found combined with non- 
 metallic elements, and require chemical skill for their 
 reduction before they admit of application to the pur- 
 poses of life. 
 
 The former are called "native metals," the latter 
 " metallic ores ;" many of both were known at a very 
 early period, for in the Book of Numbers is a passage 
 remarkable for containing the names of the metals 
 then in common use, viz. : 
 
 " Only the Gold and the Silver, the Brass, the Iron, 
 the Tin, and the Lead." 
 
 And again, in the Book of Deuteronomy, it is 
 written : 
 
 " A land whose stones are iron, and out of whose 
 hills thou mayest dig Brass." 
 
 The opinion of the most learned commentators con- 
 cerning this passage, is corroborated by science, viz., 
 that the word " Brass " either means " Copper," or the 
 most abundant ore of that metal, called " copper 
 pyrites," or " sulphuret of copper," which is dug out 
 of the earth, and is precisely similar to brass in its 
 colour and lustre. 
 
 Brass is not a metal, but an alloy, or compound of 
 Copper and Zinc, and it has never been discovered in 
 a native state ; it was, and is, artificially formed by 
 melting Copper, or its ore, with that of Zinc; although 
 this metal was not formerly known, pure and elemen- 
 
444 WINTER. 
 
 tary as it is at present, its lapideous ore was well 
 known, and used in metallurgical operations. 
 
 That much was ascertained regarding the art of 
 working metals in the earliest ages, will be evident 
 upon perusing the first Books of Holy Writ ; mention 
 is made of " the iron furnace," and of the metal itself, 
 as employed for swords, knives, axes, and tools for 
 cutting stones, and the lavish employment of all the 
 metals in the construction of the Tabernacle and the 
 Temple. 
 
 Of late years, the nature and properties of the metals 
 have been most attentively studied by the chemist, and 
 he is enabled to obtain them pure, or extract them 
 from their ores with great precision, and in vast abun- 
 dance ; and in consequence of the excellent conducting 
 power, even of some of the most common metals, they 
 become invaluable for the construction of vessels in 
 which water may be converted into vapour with ex- 
 treme facility, to constitute the motive power of the 
 steam engine. 
 
 Culinary utensils, of metal, enable us to prepare 
 food more economically and perfectly than could be 
 done in vessels of earthenware, or other imperfect con- 
 ducting materials ; and if it were not for the metals, 
 we should be reduced to the condition of those Indian 
 tribes who are yet unacquainted with them, who make 
 rude vessels of the bark of trees, sewn together with 
 thongs, to hold water, in which the food is placed, and 
 then the water is heated to its boiling point by the 
 successive immersion of red-hot stones. 
 
WINTER. 445 
 
 In the earliest ages of the world, it is reasonable to 
 conclude that man sought repose from his labour soon 
 after sunset ; but, in the course of his numerous opera- 
 tions upon matter, he would soon discover that the 
 combustion of various organic productions might be 
 employed, not only as sources of artificial heat, but of 
 light. 
 
 It is impossible to determine how the wonderful 
 phenomenon of combustion was originally displayed 
 to man ; but one thing is certain, that he soon became 
 aware of its power, and that it engaged his attention 
 on account of its beauty and utility. 
 
 From this inquiry regarding the Chemistry of the 
 Four Seasons, which is now drawing to its close, it is 
 evident that the chemist is permitted to effect wondrous 
 and strange changes upon the various forms of organic 
 and inorganic substances that are presented in the vast 
 laboratory of Nature ; and although he may mix and 
 unmix, combine and decompose, gather and scatter, 
 be it remembered that he can neither annihilate nor 
 destroy. The power of annihilation and destruction is 
 vested in the Hand of The God who created all things. 
 
 The phenomenon of combustion appears to contra- 
 dict this assertion regarding the non-destruction of 
 matter ; for no expression is more common than that 
 of " destruction by fire ;" yet, when accurately con- 
 sidered, this destruction is only found to be apparent, 
 and not real. 
 
 Fire was anciently regarded as a peculiar, distinct 
 
446 WINTER. 
 
 principle or element, having a specific or inherent 
 power of destruction ; and in this sense it repeatedly 
 occurs in many of the most sublime and forcible pas- 
 sages of Holy Writ ; but science has been permitted 
 to discover that Fire, so far from being an element, is 
 the invariable result of intense chemical attraction be- 
 tween two or more substances. 
 
 During ordinary combustion, the elements of the 
 combustible or inflammable substance exert affinity 
 for the oxygen of the air, and produce compounds 
 which, in the generality of cases, are gaseous or va- 
 porous, and therefore elude observation ; but they ad- 
 mit of detection by the chemist, and from them he can 
 educe or draw forth elements, the sum total of which 
 exactly equals the original weight of the combustible 
 substance ; therefore, when a substance is burned, or 
 apparently destroyed by fire, its physical form alone is 
 changed ; but its elements are perfectly unchanged, or, 
 in other words, the elements of the combustible have 
 been induced by elevation of temperature to relinquish 
 their original affinities, and to assume new, but definite 
 arrangements. These, in all ordinary cases, are car- 
 bonic acid and watery vapour. 
 
 Such compounds are ordained to travel throughout 
 the Creation ; and under the recondite powers of vi- 
 tality, are decomposed, and their elements secreted into 
 the form of woody fibre, and other organic matters, 
 and thus again presented as fuel, which again produces 
 the same compounds, and so on, perpetually travelling, 
 
WINTER. 447 
 
 and illustrating, at every change of their affinities, the 
 indestructibility of matter, and the wisdom and power 
 of the Creator. 
 
 All substances of organic origin are combustible, 
 but all are not equally fitted for employment as sources 
 of light and heat; the chemist extending his researches 
 regarding the oils expressed from seeds, or obtained 
 from animals, discovers them to be precisely similar 
 as to the number and nature of their elements, viz., 
 Carbon, Oxygen, and Hydrogen, the latter element 
 being in great excess or abundance, and conferring 
 extreme inflammability upon their vapours ; but they 
 do not contain Nitrogen ; if this element were present, 
 in vegetable and animal oil or fat, these proximate 
 principles could not be advantageously used as sources 
 of artificial light, because, during combustion, in ad- 
 dition to the production of carbonic acid and water, 
 a considerable portion of Ammonia would be produced, 
 and its odour would be as intolerable and fatal as that 
 emitted by burning or putrefying flesh. 
 
 The organic matters used for artificial light, be they 
 liquid as oil, or solid as fat, require to be raised into 
 vapour, before they will burn ; this is effected by the 
 capillary attraction of the cotton wick of a lamp or 
 candle, which raises the liquid oil, or melted fat, to its 
 upper or red-hot portion, where it vaporizes, and then 
 burns with a brilliant and useful flame. 
 
 Wood is invaluable as fuel, because it does not con- 
 tain nitrogen, and the same remark is applicable to 
 many of the best kinds of coal ; some do contain a 
 
448 WINTER. 
 
 small portion ; but little inconvenience is experienced 
 from the production of Ammonia, in the manner after 
 Which such coal is usually hurned, it heing soon dif- 
 fused throughout the enormous volume of the atmo- 
 sphere, and likewise neutralized hy acids that are 
 simultaneously formed during the wonderful pheno- 
 menon of combustion. 
 
 On account of heat being evolved during combustion, 
 a notion is entertained by some physiologists that the 
 heat of the animal body depends upon the burning of 
 the carbon of food, and a statement is made that the 
 " human frame is an apparatus eminently fitted for 
 combustion, or, a species of natural stove." 
 
 " God created man in His own image, in the image 
 of God created He him." 
 
 The body of man " is fearfully and wonderfully 
 made, in knowledge too excellent for attainment;' 
 and it does not behove philosophy to denote a recon- 
 dite work that contains a portion of the Divine Es- 
 sence, by the common name of a laboratory furnace 
 for the combustion of coal. 
 
 The very different sensations that we experience 
 upon touching different substances, having similar 
 temperatures, depends upon their relative conducting 
 powers ; thus, in a room, a thermometer applied to a 
 silver cup, a glass tumbler, an earthenware basin, and 
 a wooden box, indicates that they are all alike in tem- 
 perature; but upon placing the hand in contact \\ith 
 these different objects in succession, the cup feels cold, 
 the glass comparatively warm, the basin warmer, the 
 
WINTER. 449 
 
 box warmest; because the metal draws or conducts 
 from the hand heat with the greatest swiftness, the 
 glass next, then the earthenware, and lastly the wood ; 
 which is so bad in conducting power, that the heat of the 
 hand remains almost at its original point of contact. 
 
 If we step out of a warm bed, and place our feet upon 
 a carpet, they are not chilled ; if we do so upon a floor- 
 cloth, they feel icy cold, the one surface being a bad, 
 and the other a good conductor ; hence the popular ex- 
 pression of " a warm carpet," and " a cold floor-cloth," 
 although both are of precisely the same temperature ; 
 but they differ in texture, and they also differ in con- 
 ducting power. 
 
 The temperature of the Arctic regions is frequently 
 sufficiently low, i. e., 52 degrees below tc zero/' to freeze 
 mercury upon mere exposure ; thus in one of the ex- 
 peditions to those inhospitable climes of ice, a baro- 
 meter was accidentally broken, a man held out his hands 
 to catch the valuable mercury ; not only did the intense 
 cold freeze the metal immediately, but the frozen mass 
 conducted so much of the natural heat from his hands, 
 that they were frost bitten and soon mortified. 
 
 In this country, the cold of Winter is often suffi- 
 ciently intense to produce dangerous effects upon the 
 living body, it appears to destroy its irritability, and to 
 deprive it of heat ; a person feels an irresistible inclina- 
 tion to sleep ; he yields, though against his will, and 
 while lost in insensibility his limbs stiffen ; if thus 
 asleep he be brought into a warm room, the sudden 
 transition causes his death, but if he be rubbed in the 
 
450 WINTER. 
 
 snow he may often recover ; the following directions, 
 regarding persons apparently frozen to death or se- 
 verely frost bitten, are important to be remembered. 
 
 Rub the body with snow, ice, or cold water ; restore 
 warmth by extremely slow degrees ; it is highly dan- 
 gerous to apply heat rapidly, because mortification may 
 take place, since the vessels of the body are too much 
 weakened for the immediate resumption of their ordi- 
 nary functions. 
 
 The metal Mercury is always liquid, even during the 
 most intense cold of Winter in this climate, and for its 
 congelation the chemist is compelled to employ a com- 
 plicated yet powerful means of artificial cold ; he then 
 discovers the curious fact that mercury contracts in 
 freezing, so very considerably, that its specific gravity 
 is increased from 13.500 to 15.500. 
 
 Accordingly, if one bottle be filled with Mercury and 
 another with Water, and the mouths of each firmly se- 
 cured, upon placing them simultaneously in a powerful 
 artificial cold, the mercury, when it freezes, will form 
 a lump that can be shaken about in the bottle ; whilst 
 the water when it freezes, will burst the bottle in which 
 it was confined. 
 
 Water is inadmissible as a thermometric liquid, on 
 account of its anomalous expansion when cooled below 
 40 degrees ; and the two liquids with which thermo- 
 meters are usually filled, are Mercury and Alcohol ; 
 the former requiring a temperature of 640, for its 
 ebullition is particularly suited for indicating ranges 
 above 212 degrees; but on account of its freezing 
 
WINTER. 451 
 
 at 45 degrees below " zero," it cannot be employed 
 for any lower ranges of temperature ; whilst Alcohol, 
 which boils at 180 degrees, is unfit for high ranges ; 
 but eminently suited for low ranges of temperature, as 
 it has never been frozen by natural or artificial cold. 
 
 When a volume of air is perfectly tranquil, at an ele- 
 vated or a low degree of temperature, its power of com- 
 municating heat to the body, in the one case, is very 
 feeble ; and its power of abstracting it in the other, is 
 extremely small ; and this appears to depend upon the 
 non-conducting power of this wondrous medium, to 
 which reference has been so frequently made during 
 our inquiry regarding the chemical phenomena of The 
 Four Seasons. 
 
 Thus, the confined air of a room may be heated 
 to 260 degrees, i. e., 48 degrees above the boiling point 
 of water ; and a person may walk into and out of this 
 atmosphere with impunity, though any attempt to re- 
 main in it generally occasions difficult breathing, and 
 a painful sensation about the eyes, but the skin remains 
 parched and dry. 
 
 In some processes, demanding a high temperature, 
 the air of a chamber is often heated to 300 degrees ; 
 and the workmen, who are used to it can enter and re- 
 main several minutes without much inconvenience. 
 
 The temperature of the atmosphere in the Arctic re- 
 gions has been observed as low as 55 degrees below 
 " zero," during a calm ; and at this extreme degree of 
 cold, Mercury readily froze, yet not the slightest incon- 
 venience was suffered from exposure to the open air 
 
452 WINTER. 
 
 by a person well clothed, if he remained still ; but if he 
 walked rapidly, and thus put the air in motion, it ab- 
 stracted heat from the body and produced the most 
 painful sensation of cold. 
 
 As confined air is a bad conductor of heat and cold, 
 the terms being merely relative, we immediately dis- 
 cover the use of " double windows " and " double 
 doors," both in Summer and Winter ; the stratum of 
 air enclosed between these contrivances, preventing ac- 
 cession of heat in the one instance, and of cold in the 
 other ; this fact has been already illustrated in the case 
 of the plants, at page 101. 
 
 The terms " heat and cold " are in popular use, and 
 denote the relative state of the body with regard to the 
 temperature of surrounding objects ; thus we may ima- 
 gine an atmosphere so intensely cold, that a mass of 
 ice would impart a sensation of heat ; and on the other 
 hand, an atmosphere so intensely hot, that" a flask of 
 boiling water would impart a sensation of cold. 
 
 The sensation of heat and cold may be produced, 
 by the same substance, at the same time and at the 
 same temperature ; for example, place three basins 
 upon the table, pour into one of these ice-cold water, 
 into another water at 50 degrees ; and into the third 
 water at 100 degrees; plunge the left hand into the 
 ice-cold water, and the right hand into that at 100 de- 
 grees, let them remain for about a minute, then sud- 
 denly plunge both into the water at 50 degrees, the left 
 hand will feel warm, and the right hand feel cold. 
 
 The left hand had heat abstracted from it by the 
 
WINTER. 453 
 
 ice-cold water, and therefore experienced the sensation 
 of warmth, by the communication of heat, when plunged 
 into water at 50 degrees ; whilst the right hand had 
 heat communicated to it hy the water at 100 degrees ; 
 and therefore experienced the sensation of cold by the 
 abstraction of heat from it when plunged into water at 
 50 degrees. 
 
 If the air be a non-conductor of heat, why should it 
 instantaneously expand by the application of that agent, 
 as in the experiments detailed at pages 56 and 57 ; 
 or why, as those who have ascended with balloons 
 tell us, should the enormous" volume of gas, in the 
 silken globe, instantaneously expand when it emerges 
 from a dark cloud into bright sunshine ? 
 
 The expansion cannot result from conduction, ra- 
 diation, or convection, the latter power being placed 
 quite out of the question as regards the balloon, because 
 its upper part is the first that meets the heat ; whereas, 
 the reverse condition is necessary for the establishment 
 ofconvective currents: the following explanation of 
 the phenomenon, both as regards the " air thermome- 
 ter " and the " gas balloon " is probably correct. 
 
 The individual atoms of air in immediate contact 
 with the interior of the glass flask, or the individual 
 atoms of gas in immediate contact with the interior of 
 the silk globe, are suddenly expanded by the mere heat 
 of contact, into many times their original volume ; they 
 do not transmit this heat instantly to other atoms, yet 
 they do transmit the pressure, that results from their en- 
 largement of volume in all directions, instantaneously; 
 
454 WINTER. 
 
 room must be afforded, the whole is a mobile vo- 
 lume, and the whole thus appears to expand by the ac- 
 cession of heat to the atoms of air or gas, which con- 
 stitute the film, as it were, in contact with the glass 
 flask or the silk globe. 
 
 When a heated solid, such as the " iron-heater of 
 the tea-urn," is suspended in the air, several causes 
 are active in lowering its temperature ; one may be an 
 extremely feeble conducting power of the air, which in 
 all practical matters needs not to be regarded ; another 
 is extremely powerful radiation from the actual mass 
 of the body ; another is the rapid convection that it 
 establishes by mere contact with the air, and these two 
 causes chiefly effect a reduction of temperature or ac- 
 celerate the cooling of the solid body. 
 
 The constant agitation of the air by convective cur- 
 rents, may be proved by admitting a sunbeam through 
 a hole in a window shutter into a perfectly dark apart- 
 ment, and then all the motes contained in the air, 
 pierced by the light, will be observed in commotion ; 
 or the effect may be heightened by throwing a little 
 dust of " lycopodium " in the path of the ray ; these 
 small particles of matter indicate the agitation and un- 
 steadiness of the air, by being mechanically carried in 
 its currents, the same as feathers thrown in the open 
 air denote the direction of the wind, or straws thrown 
 upon running water betray the course of its stream, 
 though it may appear motionless. 
 
 As the air, and all gases, are thus so extremely sus- 
 ceptible of alterations in their volumes, by fluctuations 
 
WINTER. 455 
 
 in natural or artificial temperatures, it becomes a mat- 
 ter of great difficulty to ascertain their specific gravi- 
 ties with correctness ; and such experiments can only 
 be performed by most experienced chemists, but the 
 following statement may convey a notion regarding the 
 proceeding. 
 
 In taking the specific gravities of gases and vapours, 
 the chemist does not generally refer these to the 
 " Water standard," as with liquids and solids, but to 
 an " Aerial standard," namely, the atmosphere itself, 
 at a temperature of 62 degrees, and at the mean baro- 
 metric pressure of 30 inches. To explain this proceed- 
 ing in simple terms let us suppose as follows : 
 
 A glass globe is selected, exhausted of its air, and 
 its " tare " accurately taken ; air is then admitted to 
 fill the globe, and it is found to weigh 1000 parts; 
 the mercury in the barometer standing at 30 inches, 
 and that in the thermometer at 62 degrees ; thus indi- 
 cating that the air is at its mean pressure, and at its 
 mean temperature. 
 
 The volume of air, thus weighing 1 000 parts, is then 
 perfectly exhausted from the globe, and its place sup- 
 plied with an equal volume of Oxygen, under precisely 
 the same conditions of pressure and temperature ; but 
 this volume of the elementary gas will weigh 1111 
 parts ; it is therefore heavier than the air, or its specific 
 gravity, as compared with air, is as one and one hun- 
 dred and eleven thousandths to one thousand, or 
 decimally thus: S. G. of Air = 1.000, or Unity; 
 S. G. of Oxygen =1.1 11. 
 
456 WINTER, 
 
 The chemist removes the Oxygen, and supplies its 
 place with an equal volume of Chlorine ; hut this will 
 weigh 2470 parts ; it is more than twice the specific 
 gravity of the Air, or decimally thus : S. G. of Chlo- 
 rine =2.470. 
 
 The place of the Chlorine is then supplied with a 
 volume of Carbonic acid, and it will weigh 1500 parts; 
 it therefore is exactly one and a half times heavier 
 than air, or its S. G. is = J .500. 
 
 Proceeding in this manner with Nitrogen, its vo- 
 lume will not weigh even 1000 parts, hut only 972 
 parts ; it is therefore lighter than air, or its S. G. is = 
 0.972. 
 
 Lastly, if the globe be filled with Hydrogen, its 
 volume will not weigh even 972 parts, but only 69 
 parts ; it is therefore lighter than either Nitrogen or 
 Air, or its S. G. is= 0.069 ; and as Platinum is the 
 heaviest, so is Hydrogen the lightest form of pon- 
 derable matter. 
 
 Observation, experiment, and analogy, tend to ex- 
 cite our wonder, admiration, and gratitude, regarding 
 the miraculous provision that is made by the Almighty 
 for the protection of His creatures. 
 
 How admirably adapted to their purposes are the 
 substances provided for the clothing of animals, and 
 which man strips from them to form garments for his 
 own protection ! Animals are preserved from the 
 piercing blasts of winter by clothing which retains 
 nearly the whole of their vital heat ; what is its com- 
 position ? 
 
WINTER. 457 
 
 Almost incredible is the answer of the chemist, 
 namely, that it consists of the ultimate elements of 
 the atmosphere, Nitrogen, Oxygen, Hydrogen, and 
 Carbon most wonderfully, most mysteriously elabo- 
 rated under the influence of vitality, protecting and at 
 the same time adorning. 
 
 " Clothing which grows from the bodies of animals, 
 in quantity suiting the climate, the season, and repro- 
 ducible if partially destroyed by accident ; in hot cli- 
 mates, the coat of quadrupeds is short and thin, but 
 it thickens with increasing latitudes, and yields soft 
 and abundant fleeces." 
 
 " At the poles it is externally shaggy and coarse, 
 internally shorter and fine, as in the skin of the arctic- 
 bear ; how defensive is the fur of amphibious ani- 
 mals, the beaver for example ; how abundant and 
 smooth upon birds, as feathers shutting up the heat of 
 their" warm blood, and opposing no resistance to the 
 air through which they fly !" 
 
 " The birds of very cold regions have plumage 
 almost as bulky as their bodies ; and those which live 
 much in the water, have additionally both a defence of 
 oil on the surface of the feathers, and the interstices 
 of the ordinary plumage filled with delicate down, a 
 bad conductor, which abounds particularly on the 
 breast, as it in swimming first meets and divides the 
 cold wave." 
 
 " Then there are animals with warm blood which 
 live in the water ; for example, the whale, seal, and 
 
 x 
 
458 WINTER. 
 
 walrus ; but neither hair nor feathers oiled would have 
 been a fit clothing for them ; they accordingly derive 
 protection from the cold water, by the enormous 
 amount, of blubber or fat which surrounds their bodies ; 
 it is a non-conductor." 
 
 The bad conducting power of the earth as regards 
 heat and cold, has been already mentioned ; and hence 
 in Winter, springs of water never freeze ; they become 
 remarkable features in a snow-clad country, the warm 
 liquid water gushing from the earth, and flowing for a 
 considerable distance before the cold air can chill and 
 bind it in icy fetters. 
 
 Throughout the Creation everything is admirable, 
 everything is beneficently fitted for its destined pur- 
 pose ; and the more that we learn, the more do we wish 
 to learn, for we soon become sensible of the extreme 
 insignificance of our knowledge, when we compare it 
 with the contents of the mighty volume that is un- 
 folded for our perusal. 
 
 " He sendeth forth His word and melteth the 
 snow." 
 
 As we discovered the transition of flowing water into 
 solid ice to be a slow and gradual process, so shall we 
 discover that the conversion of solid ice into flowing 
 water is unattended by sudden and abrupt disturbance 
 of physical state, and thus gain another proof of the 
 wisdom and beneficence of The Creator, and of the 
 miraculous order and harmony of His works. 
 
 A few experiments of the chemical laboratory will 
 serve as introductory to the extraordinary phenomena 
 
WINTER. 459 
 
 attendant upon the liquifaction or thawing of ice and 
 snow. 
 
 Place a lump of clean dry ice in a basin ; carry this 
 into a warm room, at the temperature of 70 degrees 
 for example ; the thaw of the ice will commence, and 
 continue ; immerse the bulh of a thermometer into 
 the water resulting from the thawing or liquifaction ; 
 it will indicate 32 degrees ; and will again and again 
 do so, whilst a particle of ice remains; when it va- 
 nishes, the water will gradually acquire the tempera- 
 ture of the room. 
 
 During the progress of thawing, heat must be enter- 
 ing and unbinding the ice ; but, strange to say, it does 
 not confer the slightest temperature, it merely causes 
 liquifaction, or, in other words, the sensible heat of 
 the room combines with the ice to produce liquid 
 water, and is then rendered insensible to the ther- 
 mometer. 
 
 By what term does the chemist denote this extraor- 
 dinary habitude of heat ? He denotes it as combined 
 heat, hidden heat, or more commonly Latent heat ; 
 and discovers most important results of its agency 
 throughout the realms of Nature and the provinces of 
 Art 
 
 Select two wide-mouthed bottles, of the same size, 
 and resembling each other in all other respects as 
 nearly as possible ; put into one bottle a pound of 
 small pieces of ice at '32 degrees and pour into 
 the other a pound of water at 33 degrees ; place a 
 thermometer in each bottle, and carry them both into 
 
 x 2 
 
460 WINTER. 
 
 a room having a temperature of 47 degrees, and set them 
 side by side, as at page J 06 ; they are thus placed under 
 similar circumstances as regards the heat of the room; 
 and they differ only in the physical nature of their 
 contents, the one holding solid, and the other liquid 
 water. 
 
 Preserve the air of the room undisturbed by draughts, 
 observe the thermometers occasionally, and note the 
 progress made by the contents of the bottles in heat- 
 ing; if the liquid water arrive at 40 degrees in the 
 course of an hour, the ice will not melt into water, 
 and attain the same temperature, until twenty- one 
 hours later. 
 
 The heat of the room is uniform all this time, but 
 twenty- one times more of it is required in the one case 
 than in the other to produce the thermometric tempera- 
 ture of 40 degrees ; or, to place this easily- ascertained, 
 yet extraordinary fact, in another point of view, sup- 
 pose that, during the twenty-one hours the water re- 
 ceived heat, as regularly as during the first hour, 
 namely, 7 degrees, or from 33 to 40 degrees, the whole 
 heat would be expressed by twenty- one times seven, 
 or 147 degrees ; the difference between the gain of tem- 
 perature by the ice and by the water, with equal acces- 
 sions of heat, is, therefore, 140 degrees ; hence 140 
 degrees become the expression for the amount of 
 thermometric temperature which disappears, which is 
 hidden, or rendered latent during the liquifaction of 
 ice : heat enters the ice, rendering it liquid, but does 
 not produce the slightest rise of temperature. 
 
WINTER. 461 
 
 Let us proceed further \vith the investigation of 
 Latent Heat. Mix one pound of snow at 32 degrees., 
 with one pound of water at 172 degrees; the snow 
 will immediately melt, and two pounds of water will of 
 course result, but of what temperature ? One hundred 
 and two degrees, or half way between the two original 
 extremes, we might reasonably answer ; but the intro- 
 duction of the bulb of a thermometer will indicate the 
 temperature to be only thirty-two degrees, or, in other 
 words, the water is ice-cold. 
 
 Thus the warm water, in cooling from 172 degrees 
 to 32 degrees, loses 140 degrees of heat, which heat 
 converts the snow into liquid water most assuredly, 
 but produces no elevation of temperature. Such is 
 the remarkable fact thus elicited by actual experiment, 
 and, therefore, the Chemist is in the habit of stating 
 liquid water to be a compound of ice, and 140 degrees 
 of heat. 
 
 The effect of heat upon any form of solid water, ice, 
 snow, hail, frost, is not to raise thermometric tempera- 
 ture during thawing, but merely to produce flowing 
 water ; then, this being wholly effected, rise of thermo- 
 metric temperature immediately ensues, and proceeds 
 until it acquires that of the source of heat. The most 
 acute, the most profound reasoning, could not enable 
 us to predict such an extraordinary result ; but it is 
 only one of the many wonders brought to light by 
 chemical experiment, and from it the Chemist dis- 
 covers the following general law : 
 
462 WINTER. 
 
 "That in all cases of liquifaction, a quantity of 
 heat, not indicated by, or sensible to, the thermometer, 
 is absorbed or disappears ; and that such heat is with- 
 drawn from surrounding bodies, leaving them com- 
 paratively cold. 1 ' 
 
 This may be strikingly illustrated in melting a solid 
 substance by the intervention of some chemical affinity, 
 without the direct application of heat. 
 
 Thus for example, for the solution of salts, such as 
 nitre and common- salt, to ensue in water, they must 
 be melted, and they actually melt in the latent heat 
 that the water contains, and therefore the act of solu- 
 tion is attended by cold. 
 
 If an ounce of finely -powdered nitre be placed in an 
 ale-glass filled with water, and then solution rapidly 
 promoted by stirring, the introduction of the bulb of 
 a thermometer will denote depression of temperature, 
 and so will the exterior of the glass, for it summons 
 the watery vapour present in the atmosphere to con- 
 dense upon its surface as dew ; a " dew-point" is thus 
 obtained by the solution of the salt, as by the evapo- 
 ration of the ether in the experiment with the " hygro- 
 meter, ' at page 185. 
 
 The chemical constitution of water is not altered by 
 its transition into ice, neither is its affinity for various 
 substances suspended by such change ; and although it 
 may feel cold to the touch, it contains latent heat ; 
 indeed two lumps of ice have been fairly melted by 
 rubbing them against each other. 
 
 When finely powdered ice or snow is mechanically 
 
WINTER. 463 
 
 mingled with finely- powdered common salt, the two 
 substances instantly exert chemical attraction for each 
 other ; they melt, heat is absorbed during such liqui- 
 faction, and the resulting solution or brine, has a tem- 
 perature thirty-two degrees below the original tempe- 
 rature of the ice, or in other words, the mercury of the 
 thermometer falls to the " zero" of its scale, when its 
 bulb is plunged into this " freezing mixture," that has 
 been so frequently employed as a convenient source of 
 artificial cold, throughout the present inquiry. 
 
 Advantage is frequently taken of this strong che- 
 mical attraction between salt and frozen water, for 
 removing hard trodden snow from foot pavements; 
 the salt is merely sifted or sprinkled on its surface, 
 and in the course of a few minutes liquifaction ensues; 
 the brine is then swept away, and the pavement effec- 
 tually cleansed, it is true, but likewise cooled down to 
 zero, and therefore chills the air much below its ordi- 
 nary winter temperature. 
 
 If we have been walking along the streets for some 
 distance upon snow, the feet become gradually inured 
 to its temperature ; but coming suddenly upon pave- 
 ment recently cleansed by salt, its intensity of cold in 
 comparison with that we have quitted, becomes pain- 
 fully sensible, to the feet, especially if clad in thin- 
 soled shoes. 
 
 Confectioners, by employing a mixture of ice and 
 salt, are enabled to obtain a low temperature even in 
 the very height of summer, for the production of ices 
 
464 WINTER. 
 
 for the table ; and the salt may be recovered from the ~ 
 brine by evaporation, as at page 48, and employed 
 over and over again for the same purpose, because it 
 sustains no change in its chemical constitution. 
 
 A very simple yet extremely instructive experiment, 
 regarding the intense cold of this " freezing mixture/' 
 may be performed at any season of the year as follows : 
 pour a large spoonful of water upon the middle of a 
 wooden trencher ; place the polished tin canister, that 
 was employed in the experiment at page 1 54, to stand 
 in this little pool ; then fill the canister with the 
 " freezing mixture ;" adjust its cover, and insert the 
 thermometer through its aperture. 
 
 In the course of a very few seconds, the bright 
 polish of the canister will become dim with moisture, 
 because the warm air around wafting against its cold 
 surface is reduced to the " dew-point," and compelled 
 to deposit dew ; but the cold is more than sufficient to 
 effect this, the thermometer indicates " zero " and ac- 
 cordingly, in the lapse of a few more seconds, a kind of 
 white smoke will surround the canister ; it consists of . 
 myriads of crystals of hoar-frost, into which the dew 
 is compelled to change ; it is exactly analogous to the 
 " frost-smoke" mentioned at page 360, and in the 
 course of some minutes will thickly encrust the outside 
 of the canister, which simultaneously acts as the means 
 of their formation and the nucleus for their support, 
 and likewise for reducing the temperature of the water 
 upon which it was originally placed, to the " freezing 
 
WINTER. 465 
 
 point ;" so that now, taking hold of the knob of the 
 cover, and lifting it, the canister will be found frozen 
 to the trencher. 
 
 " That the heat which becomes insensible or latent 
 during the liquifaction of ice and other solids, remains 
 in the liquid and is not lost, is shown by the circum- 
 stance of its being again emitted, or given out, during 
 their congelation. 
 
 " If a vessel of warm water be exposed in a very 
 cold atmosphere, the temperature rapidly sinks to the 
 freezing-point, and then it begins slowly to congeal ; if 
 kept in the same situation, heat is of course abstracted 
 as before; but the thermometric heat remains stationary 
 at about thirty-two degrees, till the whole is frozen ; 
 after .which the temperature of the ice begins to 
 sink." 
 
 Perhaps the result of this experiment is more ex- 
 plicitly stated as follows : If, when the thermometer 
 is at twenty-two degrees, we expose a vessel full of 
 Water at fifty- two degrees to the open air, and beside 
 it another vessel full of Brine, at the same tempera- 
 ture, with thermometers in each ; we shall find that 
 both of them gradually lose heat, and are cooled down 
 to 32 degrees. 
 
 After this the Brine which does not freeze till 
 cooled down to four degrees continues to cool with- 
 out interruption, and gradually reaches twenty-two 
 degrees, the temperature of the air ; but the pure water 
 remains stationary at thirty-two degrees ; it freezes 
 indeed, but very slowly, and during the whole process 
 
 x 5 
 
466 WINTER. 
 
 its temperature is thirty-two degrees ; now why 
 should one liquid refuse to give out heat and not the 
 other ? 
 
 Is it not much more probable that the water, as it 
 freezes, gradually gives out the heat which it had ab- 
 sorbed during its liquifaction ; and that this evolution 
 maintains the temperature of the water at thirty-two 
 degrees, notwithstanding what it parts with to the air 
 during the whole process ? 
 
 It is easily shown that water, while congealing, is 
 constantly imparting heat to the surrounding air ; for 
 a delicate thermometer suspended above it is constantly 
 affected by an ascending stream of air less cold than 
 the air around." 
 
 The chemist adduces this fact as another example of 
 a miraculous provision, that is beneficially made by the 
 Creator, to mitigate the rigour of Winter, by ordaining 
 that water during its congelation should yield up its 
 stores of latent heat to the ambient air, and thus gra- 
 dually reconcile animated beings to this wondrous and 
 important physical change. The latent heat would be 
 useless if it remained in the solid water, and is there- 
 fore ordained to escape where its presence is needed. 
 
 That latent heat present in a liquid, and insensible 
 to the thermometer, becomes sensible if the liquid 
 assume the solid state, may be shown by the following 
 experiment during any season : Add crystals of sul- 
 phate of soda to a pint of boiling water, until a consi- 
 derable portion of the salt remain un dissolved ; then 
 filter this hot saturated solution through a piece of 
 
WINTER. 467 
 
 fine muslin, into a perfectly clean finger-glass, until it 
 be nearly filled. 
 
 Place the glass upon the mantel-shelf, that it may 
 not be shaken, as it would be if left on the table by 
 the vibration of the floor close the door and windows 
 of the apartment, that the surface of the solution may 
 not be ruffled, nor become dusty ; in fact, take all 
 necessary precautions to keep the glass steady, and the 
 solution clean. 
 
 In the course of a few hours, the solution will have 
 cooled to the temperature of the apartment, and gene- 
 rally speaking, without depositing crystals; or in 
 other words, the crystallization of the sulphate of soda 
 is in this case suspended, as that of water may some- 
 times be when kept unruffled and reduced to a low 
 temperature. 
 
 Note the temperature of the air, then gently plunge 
 the bulb of the thermometer into the solution, and 
 very probably crystals will instantaneously form around 
 it as a nucleus, and gradually extend until the whole 
 contents of the finger-glass assume the form of one 
 solid crystalline mass ; if this happen, the thermometer 
 will indicate a very considerable increase of tempera- 
 ture ; and indeed this will be immediately detected by 
 the hand, upon grasping the outside of the finger- 
 glass. 
 
 Why does the heat become sensible ? Because the 
 sulphate of soda cannot assume the crystalline form 
 unless it combine with fifty per cent, of water ; and 
 during this sudden transition from one state to another, 
 
468 WINTER. 
 
 the latent heat that existed to maintain the liquid, is 
 now expelled, or rendered sensible, as not needed to 
 maintain the solid form. 
 
 The crystals of sulphate of soda that were originally 
 dissolved to form the solution, contained nearly 
 the same amount of water as those now deposited, 
 although they might have felt perfectly dry to the 
 touch ; but if exposed to the air for a few hours, their 
 surfaces, instead of remaining transparent and glassy, 
 will become opaque and pulverulent ; and so will the 
 newly-formed crystals, if they be set to drain in a 
 sieve. 
 
 The chemist calls the water thus solidified or com- 
 bined with crystals, " water of crystallization ;" and 
 in the case that we are considering, it is not combined 
 with a very high degree of attraction ; so that upon 
 exposure of the crystals to the air, a portion dries out 
 from them, and they become pulverulent, or are tech- 
 nically said to " effloresce." 
 
 They may be preserved by placing them in air satu- 
 rated with aqueous vapour, as in the arrangement at 
 page 52 ; and thus the chemist manages to keep spe- 
 cimens of most " efflorescent salts ; " such as attract 
 water from the atmosphere, or are " deliquescent," he 
 keeps in accurately- stopped bottles ; others again that 
 undergo no change by ordinary exposure to the air ; 
 he keeps in papers or boxes, and calls them " per- 
 manent salts." 
 
 The suspended crystallization of sulphate of soda is 
 rather uncertain ; sometimes crystals will form as the 
 
WINTER. 469 
 
 solution cools ; at others upon touching it with the 
 thermometer ; at others again it will not do so unless 
 briskly stirred with the bulb ; very often the merest 
 agitation of the air will determine the formation of 
 crystals, and as often it will fail in so doing ; but the 
 phenomenon, if it do not occur by any of the above 
 means, will immediately and invariably happen when 
 a minute crystal of sulphate of soda is dropped into 
 the solution. 
 
 No satisfactory explanation has been offered regard- 
 ing the suspended crystallization of this solution ; it 
 is not a solitary instance, for six or seven other salts 
 are known to present the same phenomenon ; the sul- 
 phate of soda has been chosen on account of its cheap- 
 ness and abundance; the crystals may be dissolved 
 and employed over and over again. 
 
 If a pound of carbonate of soda, and a pound of 
 sulphate of soda, both in crystals, (popularly known as 
 " Soda" and Glauber's salts") be melted together in a 
 saucepan and then poured into a shallow earthenware 
 flower-pan, the liquid as it cools will congeal into a 
 crystalline mass, resembling ice in appearance and 
 nearly in hardness; such composition, made upon a 
 large scale, would form an "artificial ice" capable of 
 supporting skaters, though requiring more bodily ex- 
 ertion from them on account of the skate-irons cutting 
 it more readily than actual ice. 
 
 Ice will not form above 32 degrees, but once formed, 
 its temperature may be reduced by natural or artificial 
 means, even below the freezing point of mercury ; 
 
470 WINTER. 
 
 this fact is often neglected ; but it should be borne 
 in mind, else the student would run into serious error, 
 by supposing that every lump of ice, hail-stone, snow- 
 flake, or crystal of hoar-frost, has only a temperature 
 of 32 degrees ; such temperature, it is true, is abso- 
 lutely necessary for the formation of these physical 
 forms of water, but they are all subject to its subse- 
 quent reduction by the continued cold of Winter. 
 
 Inattention to this fact would render the graduation 
 of a thermometer useless ; if the bulb of the newly- 
 formed instrument were simply plunged amidst pow- 
 dered ice or snow, and the point to which its mercury 
 or spirit contracted by such cold, were marked upon 
 its stem as the freezing point of water, the temperature 
 of the ice or snow might in fact be " zero," or even 
 many degrees below ; so that the instrument, if subse- 
 quently plunged into boiling water, for obtaining the 
 other " fixed point," and the space between these di- 
 vided or graduated into 180 degrees, the instrument 
 would be false in its construction, and never could in- 
 dicate temperature with truth. 
 
 On the other hand, the experienced chemist has dis- 
 covered that the freezing-point of water is the melting 
 point of ice, and that so long as a particle of ice re- 
 main, the water produced by the thawing of previous 
 portions will maintain the same temperature ; he there- 
 fore allows a mass of ice to thaw, and places the bulb 
 of the thermometer in the resulting water, in full con- 
 fidence of obtaining the true " freezing point," and 
 then subsequently proceeds with the graduation. 
 
WINTER. 471 
 
 As the great amount of heat required for the liqui- 
 faetion of ice and snow, is withdrawn from the atmo- 
 sphere, its temperature falls very considerably ; and 
 hence the popular expression of " a cold thaw " is ex- 
 plained on philosophical principles. 
 
 Ice to become liquid water, renders latent 140 de- 
 grees of heat; but this water to become steam at 21 2 
 degrees, renders latent no less than 960, nay, some 
 experimenters say, 1000 degrees of heat; it matters 
 not how fierce may be the fire, or how vehement the 
 ebullition of the water in an open vessel, its tempera- 
 ture, and that of the steam will never exceed 212 de- 
 grees, so long as the barometer indicates 30 inches 
 as the atmospheric pressure, the excess of heat from 
 the fire is rendered latent in the steam, and insensible 
 to the thermometer. 
 
 When steam, having a thermometric temperature of 
 212 degrees, impinges upon a cold surface, and con- 
 denses into the state of liquid water, it relinquishes its 
 latent heat, which then becomes sensible to the ther- 
 mometer. 
 
 Hence, in the process of distillation, the steam 
 coming into contact with the upper part of the cold 
 " worm-pipe " is condensed, and its latent heat being 
 received by the surrounding cold water, elevates its 
 temperature ; and it may also be observed, that such 
 heated water will float upon the yet colder portion be- 
 low for a considerable time ; if, however, the distilla- 
 tion be protracted the whole of the water in the " worm- 
 tub " will acquire the temperature of the steam, and 
 
472 WINTER. 
 
 will be unable to condense it any longer, so that steam 
 will freely issue from the lower end of the worm pipe 
 instead of the liquid drops as at the outset of the 
 process. 
 
 It is on account of steam thus containing such an 
 enormous store of latent heat, that its power of scald- 
 ing the body is so great ; for whenever steam comes 
 into contact with a surface colder than itself, it con- 
 denses and its latent heat becomes sensible. 
 
 If we conjoin this fact with that already stated re- 
 garding the cold produced during evaporation, we shall 
 be enabled to explain why it is possible to " blow hot 
 and cold with the same breath." 
 
 By gently blowing, or rather breathing upon our cold 
 hands, they instantly condense the watery-vapour of 
 the breath, and its latent heat becomes sensible, the 
 hands are warmed ; by forcibly blowing upon our 
 hands, the watery vapour has no time to condense, but 
 the blast incites evaporation from the skin, or abstracts 
 heat from it, so that the hands are cooled. 
 
 When a fog occurs during Autumn or Winter, the 
 well-known increase in the temperature of the atmo- 
 sphere is referrible to the latent heat that existed in 
 the watery vapour, becoming sensible during its con- 
 densation or change to the liquid state; and if wind 
 subsequently occur, it is accompanied by decrease of 
 temperature, because heat is absorbed or rendered la- 
 tent by the water, for its evaporation or change into 
 the state of vapour. 
 
 Thick and substantial walls in the interior of houses, 
 
WINTER. 473 
 
 become damp, and often very wet, in certain states and 
 changes of weather ; they are so massive as to retain 
 an acquired temperature for a long time, and during a 
 winter's frost become cooled throughout ; upon a sud- 
 den thaw attended by a very humid state of atmosphere, 
 the vapour or moisture of the air is condensed in the 
 liquid state upon these cold surfaces, because they 
 abstract its heat and consequently cause it to run down 
 in the form of water. 
 
 A most extraordinary fact is discovered by the che- 
 mist during his researches concerning the conversion 
 of water into vapour ; namely, that whatever may be 
 the temperature of such vapour, it invariably contains 
 the same quantity of heat. 
 
 The details of this discovery cannot be touched upon 
 in this general inquiry, but a few examples of the fact 
 may be presented, and when accurately and minutely 
 considered, they display much to excite our wonder and 
 astonishment regarding the habitudes of water with 
 heat, and the important part enacted by this extraor- 
 dinary compound, in all its physical states throughout 
 The Four Seasons. 
 
 A certain weight of steam having a thermometric 
 temperature of 212 degrees, if condensed at 32 degrees, 
 gives out 180 degrees of its original sensible heat, and 
 950 degrees of latent heat; so that the whole amount 
 of heat contained in the steam is equal to 1130 
 degrees. 
 
 The same weight of steam at 250 degrees of thermo- 
 metric temperature, similarly condensed at 32 degrees, 
 
474 WINTER. 
 
 gives out 218 degrees of sensible heat, and 912 degrees 
 of latent heat, so that the whole amount of heat 
 contained in the steam, is again equal to 1130 degrees. 
 
 Lastly, the same weight of steam at 100 degrees of 
 thermometric temperature, similarly condensed at 32 
 degrees, gives out 68 of sensible heat, and 1062 de- 
 grees of latent heat ; so that the whole amount of heat 
 contained in the steam, as in the two former instances, 
 is equal to the constant number of 1130 degrees. 
 
 Upon these incontrovertible facts, a law is established 
 to the effect, that in proportion as the sensible or 
 thermometric heat of steam is increased, so its insensi- 
 ble or latent heat is decreased ; and in proportion as 
 its sensible heat is decreased, so its latent heat is in- 
 creased. 
 
 Carrying forth the results of these experiments into 
 the vast laboratory of Nature, the chemist is led to the 
 conclusion, that similar weights of the vapour of water, 
 produced by the different temperatures of Spring, 
 Summer, Autumn, and Winter, contain a similar and 
 a constant amount of heat ; and without this agent, 
 so miraculously treasured by the Almighty, in the va- 
 pours and floods, the air and the earth, as already 
 shown, the animated creation could not exist. 
 
 Let us now remark and appreciate the beneficial re- 
 sults which ensue throughout Nature by the operation 
 of the unerring laws that we have been considering 
 and endeavouring to illustrate by experiment. 
 
 The ice and snow of Winter do not suddenly change 
 into floods, upon the first accession of heat from the 
 
WINTER. 475 
 
 sun of Spring ; did they so change, the earth and its 
 productions would be immediately inundated by the 
 emancipated waters ; on the contrary, The Hand of 
 Infinite wisdom ordains, that each mass of ice, each 
 flake of snow, each pearl of frost, shall slowly absorb 
 and render latent, a certain amount of heat and thus 
 gradually become liquid water instead of suddenly 
 changing into a destructive torrent. 
 
 And when the long imprisoned waters are freely un- 
 bound by the genial warmth of Spring, and are ex- 
 posed to the heat of Summer and the glow of Autumn, 
 they display the same Beneficence of The Creator in 
 the adjustment of their temperature to animated be- 
 ings, as they manifested during the cold of Winter. 
 
 Warm winds now glide over the liquid surface of 
 the lake chosen as our example at page 325 ; the sur- 
 face water gains heat by contact, but loses specific 
 gravity, or in other words, floats upon the colder water 
 beneath ; the temperature of the surface may be 62 
 degrees, whilst that of the depth remains at 40 degrees ; 
 no sudden elevation of temperature can ensue from 
 conducting power, the fishes become slowly inured to 
 the change that at length is established, by the me- 
 chanical agitation of winds and breezes. 
 
 In concluding this rapid inquiry regarding the prin- 
 cipal phenomena of The Four Seasons which admit of 
 elucidation through the medium of the Science of 
 Chemistry, it becomes necessary to imprint upon the 
 mind of the young student of Nature, the magni- 
 tude of the Earth, as compared with the size of man ; 
 
476 WINTER. 
 
 and then instead of his feeling surprise that so many 
 of its vast phenomena yet remain uninterpreted, he 
 will rather wonder that The Creator has permitted so 
 many to he discovered. 
 
 The Earth is 8000 miles in diameter ; the atmo- 
 sphere is calculated to he 50 miles in altitude ; the 
 loftiest mountain peak is calculated to he 5 miles above 
 the level of the sea, for this height has never been 
 visited by man ; the deepest mine, that he has formed 
 is 550 yards ; and his own stature does not average six 
 feet. 
 
 Therefore, if it were possible for him to construct a 
 globe 800 feet or twice the height of St. Paul's cathe- 
 dral in diameter, and to place upon any one point of 
 its surface an atom of j^th of an inch in diameter, 
 and y^-th part of an inch in height, it would correctly 
 denote the proportion that he bears to the earth upon 
 which he stands. 
 
 If he would condescend to bear in mind the fact of 
 his own insignificance in comparison with the magni- 
 tude of his dwelling place, that he is but a mere atom 
 in the stupendous scale of Creation, it would act as a 
 salutary check to the dogmas that he so frequently pro- 
 nounces, regarding the causes that MUST be operating 
 above, and below the huge surface of the earth, because 
 he finds such, and such, phenomena, after climbing upon 
 a natural hillock, or creeping within an artificial burrow. 
 
 How magnificent is the language of Scripture when 
 extolling the Omnipotence of God and the grandeur of 
 His works ! 
 
WINTER. 477 
 
 " It is He that sitteth upon the circle of the earth, 
 and the inhabitants thereof are as grasshoppers ; that 
 stretcheth out the heavens as a curtain, and spreadeth 
 them out as a tent to dwell in. 
 
 " Behold the nations are as a drop of a bucket, and 
 counted as the small dust of the balance ; behold he 
 taketh up the isles as a very little thing." 
 
 Upon due reflection concerning these important and 
 astounding matters, we are immediately led to exclaim 
 with The Psalmist, " Lord, what is man that Thou art 
 mindful of him, or the son of man that Thou regardest 
 him !" 
 
 Yet has The Almighty, " The Father of Lights, in 
 Whom is no variableness neither shadow of turning," 
 in His abundant goodness vouchsafed to man " certain 
 knowledge of the things that are, namely, to know 
 how the world was made, and the operation of the 
 elements." 
 
 " The beginning, ending, and midst of the times; 
 the alterations of the turning of the sun and the change 
 of seasons." 
 
 We have thus endeavoured to trace a few of the 
 wonderful phenomena of The Four Seasons which 
 admit of interpretation through the medium of the 
 science of Chemistry, from the Spring, when all Nature 
 is bursting into life, to the Summer, when glowing 
 with beauty and sweetness ; then to the Autumn, 
 teeming with all the purposes for which this vitality 
 and perfection were called into being, and finally to 
 the Winter, when it is shrouded in sleep and repose. 
 
4 78 WINTER. 
 
 We have seen that " every thing is beautiful in his 
 season," that every thing displays the power and good- 
 ness of God. 
 
 " All the works of The Lord are good ; and He will 
 give every needful thing in due season." 
 
 " So that a man cannot say, this is worse than that, 
 for in time they shall all be well approved." 
 
 The study of Chemistry and of all the high sciences 
 is well suited to keep down a spirit of arrogance and 
 intellectual pride, "for, in disentangling the pheno- 
 mena of the material world, we encounter things which 
 hourly tell us of the feebleness of our powers, and ma- 
 terial combinations so infinitely beyond the reach of 
 any intellectual analysis as to convince us at once of 
 the narrow limitation of our faculties. 
 
 " In the power of grasping abstract truth, and in 
 the power of linking together remote truths by chains 
 of abstract reasoning, we may be distinguished from the 
 lower order of the beings placed around us ; but in the 
 exercise of these powers, we bear perhaps no resem- 
 blance whatsoever to The Supreme Intellect. 
 
 " Applied to an Almighty Being with the attribute 
 of ubiquity, in whose mind all things past and to come 
 co-exist in eternal presence, time and space have no 
 meaning, at least in that sense in which they are con- 
 ditions of our own thoughts and actions. 
 
 " To Him all truth is as by intuition; by us, truth is 
 only apprehended through the slow and toilsome pro- 
 cess of comparison ; so that the powers and capacities, 
 forming the very implements of our strength are also 
 
WINTER. 479 
 
 indications of our weakness ; in some of our capaci- 
 ties, we may, perhaps, exhibit a faint shadow of a por- 
 tion of our Maker's image ; but in the reasoning power, 
 of which we sometimes vainly boast, we bear to him no 
 resemblance whatsoever. 
 
 " Simplicity of character, humility, and love of truth, 
 ought therefore to be and generally have been 
 among the attributes of minds well trained in philo- 
 sophy." 
 
 " After all that has been done since the thoughts of 
 man were first turned to the phenomena of the mate- 
 rial world after all the boasted discoveries of science, 
 from the first records of civilization, down to our own 
 days those glorious passages of The Old Testament, 
 (JOB xxxviii.,) contrasting the power and wisdom of 
 God in the wonders of His creation, with man's impo- 
 tence and ignorance, have still, and ever will continue 
 to have, not merely a figurative or poetical, but a lite- 
 ral application." 
 
 When " God answered out of the whirlwind" con- 
 cerning the mighty works of His Omniscience and Om- 
 nipotence, when He deigned to hold direct converse 
 with man, to convince him of human ignorance and 
 imbecility. 
 
 The wonderful and beneficial phenomena of The 
 Creation which are acknowledged and appreciated even 
 by the most unenlightened and obdurate minds, in 
 this unapproachable language are displayed and set 
 forth in a series of the most sublime and powerful me- 
 taphors, that are instantly apprehended, and carry con- 
 
480 WINTER. 
 
 viction to the soul of man that " He that built all 
 things is God." 
 
 " Before such an Interrogator we can only bow in 
 humble adoration." 
 
 " The study of the laws of Nature may strengthen 
 and exalt the intellectual powers ; but strange must 
 be our condition of self-government and tortuous our 
 habits of thought if such studies be allowed to co-exist 
 with self-love and arrogance and intellectual pride." 
 
 " There are yet hid greater things than these ; for we 
 have seen but a few of His works." 
 
 Although the amount of scientific knowledge at the 
 present day may be justly called great, yet it is as no- 
 thing in comparison with the magnitude of the objects 
 of The Creation, and while it shall please God to con- 
 tinue us in this world where so much is to be done, and 
 so little to be known, we must employ the talents en- 
 trusted to our care with unremitting zeal and humble 
 confidence, and wait with patient expectation for the 
 time in which the soul returning to the bosom of its 
 God, " shall be satisfied with Knowledge." 
 
481 
 
 APPENDIX, 
 
 CONTAINING 
 
 The Names of the Discoverers, Historians, and Nar- 
 rators of the principal Facts which are embodied 
 in this Work. 
 
 
 AGRICOLA first described Bismuth. 
 
 ALISON records the hurricane produced during the con- 
 flagration of Moscow. 
 
 ALLEN and PEPYS ascertained the quantity of carbonic 
 acid that is exhaled by a healthy adult in twenty-four 
 hours ; they also made important experiments regarding 
 Priestley's discovery of the renovation of vitiated air by 
 growing plants. 
 
 APPLEGATH and COWPER applied the steam-engine to 
 the printing-machine. 
 
 ARCHIMEDES is supposed to have discovered what is 
 now termed the " specific gravity of gold." 
 
 BACON, LORD, must be considered as the founder of 
 " Inductive Philosophy," real knowledge being in his view 
 
 y 
 
482 APPENDIX. 
 
 " not a couch whereupon to rest a searching and restless 
 spirit ; or a terrace for a wandering and variable mind to 
 walk up and down with a fair prospect ; or a tower of state 
 for a proud mind to raise itself upon ; or a fort, or com- 
 manding ground for strife and contention ; or a shop for 
 profit and sale, but a rich store-house for the glory of The 
 Creator and the relief of man's estate." 
 BALARD discovered Bromine. 
 
 BALDWIN made several experiments upon phosphores- 
 cent substances. 
 
 BANKS, Sir J. remarked the fact of the sun-burn on the 
 back of a silver-fish, when exposed to sunshine after the 
 felling of the trees around the pond. 
 
 BASIL VALENTINE discovered the metal Antimony. 
 BERARD accurately examined the changes sustained by 
 the atmosphere during the ripening and decay of fruits. 
 BERGMAN introduced methods of analysing Waters. 
 BERTHOLLET proposed chlorine as a bleaching agent. 
 BERZELIUS discovered Selenium. First obtained pure 
 Silicium. Discovered Thorium. Discovered Zirconium. 
 
 BERZELIUS and HISINGER discovered the metal 
 Cerium. 
 
 BLACK, DR. discovered the composition of Chalk, 
 First proved that the thermometer affords no correct insight 
 into the absolute quantity of heat necessary to produce a 
 given temperature ; or in other words, that bodies have 
 different capacities for heat. Discovered the amount 
 of heat that becomes latent during the thawing of ice and 
 the liquifaction of other substances. Discovered the latent 
 heat of steam. 
 
 BOYLE, HON. ROBERT, corroborated Van Helmont's 
 original experiment with the willow tree. Improved 
 
APPENDIX. 483 
 
 the air-pump, and rendered it an available apparatus 
 for philosophical research. Made the first accurate 
 researches concerning the exhaustion and condensation of 
 air. Records the fact of aroma being retained by the air 
 with persistent force, and travelling with it many miles out 
 to sea. Introduced the form of the air thermometer, as 
 shown at page 318. " Turned his mind with much 
 earnestness to the construction of a scale for thermometers, 
 and seems to have had it in contemplation to set out with 
 the temperature at which water begins to freeze ;" but he 
 did not prosecute this inquiry, fearing that many objec- 
 tions would be raised against its practice. 
 
 BRADLEY and ROEMER discovered the motion of light 
 to be progressive, and that it is about eight minutes and 
 thirteen seconds in passing from the sun to the earth. 
 
 BRANDE made numerous and highly important ex- 
 periments regarding the chemistry of organic bodies. 
 Discovered the presence of Nitrogen in the Alkaloids 
 or active principles of Barks, Opium, &c. Made the 
 first accurate experiments upon a large scale, regarding 
 the destructive distillation of coal, its produce, the purifica- 
 tion of the gas, and its illuminating power. 
 
 BRANDT discovered Cobalt. Discovered Phosphorus. 
 First pointed out the characters of Arsenicum. 
 
 BRAUN discovered that mercury might be frozen by 
 artificial cold. 
 
 CALLIMACHUS first observed the beauty of the acanthus 
 diverted from its original position of growth ; and invented 
 the Corinthian capital. 
 
 CANTON made many experiments upon phosphorescent 
 light. 
 
 CAVENDISH, HON. H., demonstrated the composition of 
 
484 APPENDIX. 
 
 nitric acid ; and its formation by the passage of elec- 
 tricity through confined air. Discovered the composi- 
 tion of salt-petre or nitrate of potash. First examined 
 the nature of Hydrogen. Discovered the composition of 
 Water. 
 
 CELSIUS introduced and 100 degrees to denote the 
 freezing and boiling point of water ; this is the most philo- 
 sophical scale, and commonly employed on the continent. 
 
 CHAPTAL probably originally proposed the employment 
 of chlorine as a bleaching agent in the arts. 
 
 CHRISTISON investigated the action of poisons upon 
 plants. 
 
 CLAYTON discovered that inflammable gas might be ob- 
 tained by the distillation of coals* 
 
 COURTOIS discovered Iodine. 
 
 CRAWFORD made numerous experiments upon the capa- 
 city of bodies for heat. 
 
 CRONSTEDT discovered Nickel. 
 
 CROUNE was probably the first to discover that Water 
 expanded when cooled to a certain degree ; but the Floren- 
 tine academicians accurately examined the phenomenon. 
 
 CULLEN discovered that cold was produced by the eva- 
 poration of ether and alcohol at common temperatures. 
 
 DALTON investigated many of the phenomena concerning 
 the evaporation of water. 
 
 DANIELL ascertained the rate of the evaporation of 
 water, during different states of the atmosphere. Invented 
 the only accurate hygrometer, for ascertaining the actual 
 amount of watery vapour present in the atmosphere. 
 Brought the barometer to its present state of perfection 
 and excellence. 
 
 DARCET discovered that diamonds might be burned ; 
 
APPENDIX. 485 
 
 Lavoisier corroborated the experiment, and ascertained 
 that carbonic was produced, as from the combustion of 
 charcoal. 
 
 DAVY, SIR H., discovered Barium, Boron, Calcium, 
 Lithium, Magnesium, Potassium, Sodium, Strontium. 
 The composition of Common-salt, and that Lime, Sand, 
 Clay, Magnesia, Potash, Soda, were oxides of metals. 
 Suggested the existence of Fluorine. Demonstrated 
 the nature of Chlorine. First devised methods of ana- 
 lysing soils. Discovered that some soils heat and cool 
 more readily than others. Pointed out the doctrine of 
 the proper application of manures. Ascertained the 
 composition of the gas emitted from the mud of stag- 
 nant waters. Discovered silica as the coating or cloth- 
 ing of grasses, and melted a wheat-straw into a globule 
 of glass, by intense heat. Explained the philosophy 
 of the old proverb regarding the morning and evening rain- 
 bow. Discovered the existence of water in crystals and 
 pebbles of silica. Investigated the nature of flame, the 
 combustion of " fire-damp," and crowned his masterly 
 researches by the discovery of the Miners' Safety Lamp. 
 
 DELHUYART discovered Tungstenum. 
 
 DESCOTILS and TENNANT simultaneously discovered 
 Iridium. 
 
 DREBBEL and SANTO RIO divide between them the 
 honour of the discovery of the thermometer. 
 
 FAHRENHEIT discovered that upon mixing ice and salt, 
 an intense degree of cold is produced. Introduced 32 and 
 2 12- degrees to denote the freezing and boiling point of 
 water ; and this scale is universally adopted in England. 
 
 FARADAY corroborated the fact discovered by Caven- 
 
 Y 3 
 
486 APPENDIX. 
 
 dish, of the formation of nitric acid by the action of elec- 
 tricity upon air. Has made the greatest number of 
 discoveries in Electricity of any philosopher. Discovered 
 that Chlorine, Hydrochloric acid, Nitrous oxide, Carbonic 
 acid, and Ammonia, that were formerly thought to be per- 
 manent gases, as Oxygen, Hydrogen, and Nitrogen, rather 
 merit the title of vapours, as all of them may be condensed 
 into liquids by pressure and cold, and some even to the 
 solid state, by the greatest artificial reduction of tempera- 
 ture that can be obtained. 
 
 FLORENTINE ACADEMICIANS (the) constructed the 
 first instrument to which the term "thermometer" can 
 properly be applied ; and it closely resembled the arrange- 
 ment represented at page 316. 
 
 FONTANA constructed an instrument called the " eudio- 
 meter," for examining the goodness or fitness of air for 
 the support of life. 
 
 FORBES ascertained the probable physical cause of the 
 red colour of the morning and evening sky. 
 
 FOURDRINIER and DONKIN applied the steam-engine 
 to the manufacture of paper. 
 
 FRANKLIN drew lightning from the heavens, and 
 proved its identity with electricity artificially excited ; he 
 also proposed the attachment of conductors to buildings. 
 Probably first made the experiment with the nine pieces of 
 cloth, placed upon snow exposed to sunshine. 
 
 GAHN discovered Manganesium. 
 
 GAHN and SCHEELE decomposed Bone-earth. 
 
 GALILEO first suspected that the air was a ponderous 
 body. Probably invented the condensing syringe. 
 
 GALVANI and VOLTA engaged in a controversy regard- 
 
APPENDIX. 487 
 
 ing muscular motion ; and one of the consequences of their 
 difference of opinion was the discovery of the intimate 
 relation between chemistry and electricity. 
 
 GAY LUSSAC discovered Hyponitrous acid. Proposed 
 the form of the lightning conductor, or " paratonnere," 
 that is represented in this work. 
 
 GEBER, in the seventh century, first made the substance 
 called " red-precipitate," (oxide of mercury,) from which 
 Oxygen gas was obtained by Priestley in 1774. 
 
 GEOFFROY constructed the first tabular forms for ex- 
 pressing the force of chemical affinity. 
 
 GLAUBER discovered that vinegar might be obtained by 
 distilling wood, at a red heat, he also gives the first direc- 
 tions for obtaining spirit of salt, i. e., hydrochloric acid ; 
 and likewise sulphate of soda, hence the latter is known as 
 " Glauber's salt ;" "he was a most industrious man, cast 
 in the true mould of an experimental chemist." 
 
 GRAHAM accurately determined the expansibility of 
 liquids by heat. 
 
 GREGOR discovered Titanium. 
 
 GREY and WALL probably made the first remarkable 
 experiments concerning electrical attractions and repul- 
 sions. 
 
 HALES experimented upon the motion of sap in plants, 
 and their powers of transpiring watery vapour. In- 
 vented the revolving ventilators that are commonly used 
 for allowing heated and vitiated air to escape from rooms. 
 
 HALLEY is regarded by several writers as entitled to the 
 merit of fixing upon the boiling point of water, as a stand- 
 ard of graduation for the mercurial thermometer. 
 
 HANCKWITZ first obtained phosphorus upon a large 
 
488 APPENDIX. 
 
 scale, and sold it as a chemical curiosity, at the rate of one 
 hundred shillings an ounce. 
 
 HARRIS perfected the lightning conductors for ships. 
 
 HARVEY discovered the circulation of the blood. 
 
 HATCHETT discovered Columbium. Made the first accu- 
 rate experiments concerning the hardening principle of 
 shell and bone. 
 
 HIELM discovered Molybdenum. 
 
 HIGGINS originally laid the foundation of the theory of 
 definite proportions, for the essential facts which have been 
 subsequently followed up and worked out by later chemists, 
 are to be found in his works, dated 1789. 
 
 HISINGER and BERZELIUS discovered Cerium. 
 
 HOME, Sir E., made the experiments regarding the ab- 
 sorption of heat by the skin of the Ethiopian. 
 
 HOOKE discovered the two fixed points for the gradua- 
 tion of the thermometer. Suspected that nitre contained 
 a principle analogous to that in the atmosphere which sup- 
 ports combustion. 
 
 HULLS, BELL, and FULTON, divide the honour and 
 merit of applying the steam-engine to navigation. 
 
 HYPATIA, a female celebrated for her acquirements in 
 literature and science, towards the end of the fourth 
 century, is said to have invented the " hydrometer " for 
 ascertaining the purity of Water. 
 
 INGENHOUZ ascertained the relative conducting powers 
 of the metals regarding heat. Devised experiments in illus- 
 tration of conductors and non-conductors of heat. 
 
 IRVINE made several important experiments regarding 
 the capacity of bodies for heat. 
 
 KING furnished the accurate account of the manner in 
 
APPENDIX. 489 
 
 which the Esquimaux huild their snow-houses he was 
 one of the party who went out in the Arctic Land Expe- 
 dition in search of Ross. 
 
 KLAPROTH discovered Uranium. Accurately examined 
 Titanium. Accurately examined Tellurium. 
 
 KUNKEL made several experiments upon phosphorescent 
 substances. 
 
 LABARRAQUE proved v the great power of chlorinated 
 lime, and chlorinated soda as preventives of putrefaction 
 and as disinfectants. 
 
 LAPLACE made a series of important experiments upon 
 the capacity of bodies for heat. 
 
 LAVOISIER discovered the composition of gypsum. De- 
 monstrated the atmosphere to be chiefly a mixture of nitro- 
 gen and oxygen. 
 
 LESLIE discovered that water might be frozen, by the 
 cold produced during its evaporation. Made the first accu- 
 rate researches upon radiant heat, as regards the man- 
 ner in which its reception and retention may be affected by 
 surfaces. 
 
 LOWITZ made many important experiments concerning 
 the effects of artificial cold upon substances. 
 
 LYELL gives the account of the preservation of snow 
 from thawing by the non-conducting power of volcanic 
 dust. 
 
 MACBRIDE suspected the presence of carbonic acid in 
 the atmosphere. Discovered that vegetable and animal 
 substances yield carbonic acid gas, by putrefaction and fer- 
 mentation. 
 
 MARCET accurately examined sea-water from various 
 parts of the world, 
 
 MAYOW found that bodies during combustion increased 
 
 y 5 
 
490 APPENDIX. 
 
 in weight, and referred the phenomenon to their " fixa- 
 tion," (combination,) of " nitro aerial particles," (oxygen,) 
 from the atmosphere.' 
 
 MORVEAU originally proved that hydrochloric acid gas 
 and chlorine might be used as disinfectants. 
 
 MOSANDER discovered Lantanum. 
 
 MULLER discovered Tellurium. 
 
 NEWTON, SIR I., by his sagacious views regarding me- 
 chanical and chemical attractions, destroyed the ancient 
 notions that the particles of bodies were held together by 
 hooks, rings, points, and wedges : he says, " I use the 
 word attraction to signify any force by which bodies tend 
 towards one another, whatever may be the cause." Op- 
 tics, book iii., query 31. Explained the probable physi- 
 cal cause of the rainbow, and analysed light by a prism of 
 glass. Hinted that the diamond, and water, both con- 
 tained inflammable matter. Suggested that the melting 
 point of ice should be taken as the commencement of the 
 thermometric scale, but HOOKE made the discovery that 
 in melting ice, and boiling water, the mercury of a ther- 
 mometer, always contracted and expanded to certain marks. 
 
 NICHOLSON and CARLISLE first decomposed water by 
 electricity and obtained both its elements. 
 
 OTTO GUERICKE first publicly demonstrated the enor- 
 mous pressure of the atmosphere upon an exhausted vessel. 
 Invented the air-pump. Invented the meteorological toy 
 now familiarly known as the " weather-house." 
 
 PARACELSUS first mentioned Zinc. 
 
 PASCAL proved that the atmosphere decreases in its den- 
 sity in proportion to its altitude. Proposed the employ- 
 ment of the barometer as a "weather-glass." 
 
 PEPYS ascertained the important fact, that the leaves of 
 
APPENDIX. 491 
 
 plants are ever active in decomposing the carbonic acid of 
 the atmosphere. 
 
 PRIESTLEY discovered Nitrous and Nitric oxide. Dis- 
 covered Oxygen, by heating a compound formerly called 
 " red precipitate," in the focus of a burning lens ; this 
 compound is now known to consist of oxygen and mercury ; 
 these were repelled or unbound by the heat, and the gaseous 
 oxygen obtained free, whilst the mercury mingled with that 
 contained in the flask in which the experiment was made. 
 Priestley thought the newly-discovered gas was air deprived 
 of some combustible matter, and he therefore named it " de- 
 phlogisticated air ;" it was named Oxygen by the French 
 chemists on account of its producing acids, but it is not the 
 universal acidifying principle, for many acids do not con- 
 tain a trace of this element. Discovered the action of plants 
 upon vitiated air. Discovered the evolution of oxygen by 
 aquatic plants growing in water containing carbonic acid ; 
 that the presence of light was necessary to this change, that 
 in sunshine it was most rapid, and that it was in a great 
 measure independent of warmth. 
 
 REY discovered that several metals, when heated in air, 
 increase in weight ; this is due to their combination with 
 oxygen ; the results were formerly named " calces," under 
 the idea that the metals changed into earth like lime or 
 " calx," these are now called " oxides." 
 
 REAUMUR introduced and 80 degrees to denote the 
 freezing and boiling point of water, this scale is rarely used 
 in England. 
 
 ROEBUCK devised the apparatus for producing sul- 
 phuric acid in large quantities at a cheap rate. 
 
 ROEMER and BRADLEY calculated the velocity of light at 
 192,000 miles in a second. 
 
492 APPENDIX. 
 
 RUMFORD experimented upon the radiation of heat. 
 
 RUTHERFORD first examined pure Nitrogen. 
 
 SANTORIO and DREBBEL divide between them the ho- 
 nour of the discovery of the thermometer. 
 
 SAXJSSURE discovered the peculiar form of vesicular va- 
 pour of the mists on the Alps. 
 
 SCHEELE discovered chlorine. Ascertained that common 
 air is a mixture of two distinct gaseous substances, one of 
 which is capable of supporting combustion ; this, accord- 
 ingly, he called " empyreal air ; " the other being neither 
 capable of supporting combustion nor animal life, he called 
 ** foul air ; " these are the Oxygen and Nitrogen of modern 
 chemists. Demonstrated that silica and alumina are two 
 perfectly distinct bodies ; he likewise discovered that soda 
 might be obtained from common salt. " First noticed 
 the distinction between heated air and heat emanating 
 in straight lines," or, in modern terms, the difference be- 
 tween convective currents and radiation of heat : he says, 
 " represent to yourself a little hillock of burning coals ; in 
 this case, the heat darting from this hillock all around, is 
 that which may be reflected by a metallic polished plate ; 
 that, on the contrary, which rises upwards and may be 
 driven by winds to and fro unites with air. I call the first 
 kind by way of distinction Radiant Heat." 
 
 SCHRADER analysed the seeds of wheat, rye, barley, and 
 
 oats, and ascertained the quantity of earthy matter which 
 
 each contained, and made elaborate experiments upon the 
 
 absorption or secretion of such matters by growing plants. 
 
 SEFSTROM discovered Vanadium. 
 
 SEGUIN experimented upon the transpiration of mois- 
 ture from the human body. 
 
APPENDIX. 493 
 
 SINGER gave the best and most explicit directions for 
 ensuring personal safety during a thunder-storm. 
 
 SM EATON brought the air-pump to its present state of 
 perfection. 
 
 SMITH, DR. C., proved the invaluable property of nitric 
 acid vapour as a disinfectant. 
 
 STAHL invented the name " phlogiston," by which he 
 denoted a common principle of combustible bodies ; it is 
 expunged from modern chemical nomenclature. 
 
 SMITHSON ascertained the form of hail-stones and snow- 
 flakes. 
 
 STROM EYE R discovered Cadmium. 
 
 TENNANT discovered Osmium. Made many useful ap- 
 plications of chemistry to agriculture. Probably disco- 
 vered, certainly first made, chloride of lime or chlorinated 
 lime, under the name of oxymuriate of lime, as a bleach- 
 ing material. 
 
 TENNANT and DESCOTILS simultaneously discovered 
 Iridium. 
 
 THOMSON constructed elaborate tables regarding the ex- 
 pansion of liquids by heat. 
 
 TORRICELLI discovered the Barometer. 
 
 TREVETHIC constructed the high-pressure steam-engine. 
 
 VAN HELMONT first employed the term "gas;" it is 
 now used to denote all aeriform matters which are different 
 in chemical constitution to the atmosphere, though re- 
 sembling it in the physical property of permanent elasticity 
 or power of resisting transition into the liquid or solid state 
 by pressure or cold. He made the remarkable experiment 
 concerning the growth of a willow tree in a limited quan- 
 tity of earth, watered for several years with distilled water ; 
 
 z 
 
494 APPENDIX. 
 
 the tree originally weighed five pounds ; not fifty pounds, 
 as generally stated. 
 
 VAUQUELIN discovered Chromium. 
 
 WARD discovered the fact that plants would grow and 
 nourish in a confined portion of air. 
 
 WATT proposed chlorine as a bleaching agent. Was 
 probably the first philosopher who observed that mois- 
 ture was deposited upon a cold surface when held over 
 the flame of inflammable air, (hydrogen.) Made the 
 first capital improvements upon the steam-engine, and it 
 may be regarded as a machine upon which science and art 
 have lavished their choicest resources. 
 
 WELLS, DR., discovered the physical cause of the beau- 
 tiful natural phenomenon of dew. 
 
 WILLIAMS made the experiments upon the rupture of 
 iron bomb-shells, when the water contained in them was 
 frozen. 
 
 WOHLER discovered Glucinum. Discovered Yttrium. 
 Accurately demonstrated the nature of Alumina. 
 
 WOLLASTON discovered Palladium and Rhodium. In- 
 vented the " cryophorus" . 
 
 WOOD made known Platinum in Europe. 
 
 WOODWARD experimented upon the transpiration of 
 water by plants. 
 
 
495 
 
 Acknowledgment of the quotations which occur through- 
 out the Chemistry of The Four Seasons. 
 
 Page 21, Magazine of Popular Science ; 25, Treatise 
 on Heat, Society Diffusion Useful Knowledge ; 42, 43, 
 44, 45, Davy's Lectures on Agricultural Chemistry ; 
 86, Mag. Pop. Sci. ; 89, Priestley's Experiments on 
 Air ; 90, Sir J. Pringle's Discourse to the Royal Society ; 
 95, 96, Brande's Manual of Chemistry; 104, 105, 
 Davy's Lect. Ag. Chem ; 146, Introduction to Practical 
 Organic Chemistry, anonymous ; 156, Brande's Manual ; 
 157, 159, Lardner's Cyclopedia; 160, Sir E. Home, 
 Philosophical Transactions ; 172, Lardner ; 194, Arnott's 
 Elements of Physics; 195, 196, Forhes' Annals of 
 Philosophy; 200, Davy's Salmonia ; 202, Treatise 
 on the Objects, Pleasures, and Advantages of Science ; 
 223, Davy's agricultural Chemistry ; 225, Macculloch 
 an Malaria ; 248, 249, Brande's Manual ; 252, Singer's 
 Elements of Electricity ; 253, Brande's Manual; 253, 
 2nd quotation, Bacon's Novum Organon ; 254, Frank- 
 lin on Electricity ; 272, Anonymous ; 369, Chronicles 
 of the Seasons ; 374, Mitchell's Natural Philosophy ; 
 375, Polytechnic Magazine ; 380, Chronicles of the 
 Seasons : 404, Arago ; 457, Arnott ; 465, Thomson ; 
 478, Sedgwick. 
 
 THE END. 
 
 LONDON: 
 
 PRINTED BY G. J. PALMER, SAVOY STREET, STRAND. 
 

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