....... f f ,f 111 SMI:: EEASON WHY COLLECTION OF MANY HUNDREDS OP REASONS FOR THINGS WHICH, THOUGH GENERALLY BELIEVED, ARE IMPERFECTLY UNDERSTOOD. A BOOK OF CONDENSED SCIENTIFIC KNOWLEDGE FOR THE MILLION. BY THE AUTHOR OF 'INQUIRE WITHIN," This collection of useful information on " Common Things" is put in the interesting form of " Why and Because," and comprehends a familiar explanation of many snb- jaets which occupy a large space in the philosophy of Nature, relating to air, animals, atmosphere, caloric, chemistry, ventilation, inateria medica, meteorology, acoustics lectricity, light, zoology, etc. NEW YORK : DICK & FITZGERALD, PUBLISHERS, N:. 18 ANN STREET. it PREFACE. WE are all children of one Father, whose Works it should be out delight to study. As the intelligent child, standing by his parent's knee, asks explanations alike of the most simple phenomena, and of the most profound problems ; so should man. turning to his Creator, continually ask for knowledge. Wot because the profession of letters has, in these days, become a fashion, and that the man of general proficiency can best work oat his success in worldly pursuits ; but because knowledge is a trea- sure which gladdens the heart, dignifies the mind, and ennobles the soul. The occupation of the mind, by the pursuit of knowledge, is of itself a good, since it diverts from evil, and by elevating and refining the mind, and strengthening the judgment, it fortifies us for the hour of temptation, and surrounds us with barriers which the powers of sin cannot successfully assail. It is not contended that the mere acquisition of knowledge will either ensure a good moral nature, or convey religious truth. But both religion and morals will find in the diffusion of knowledge a ground- work upon which their loftier temples may discover an acceptable foundation. The man who comprehends the order of Nature, and tha immutability of Divine law, must of necessity bring himself in some degree into accordance with thai order, and under submission tc the law : hence the tendency of knowledge will always be found to harmonise the fragment with the mass, and to subvert tin evil to the good. The troubles of the world have arisen from the want of know- ledge, not frcm the possession of it. And in proportion as man becomes an intelligent and reflective being, he will be a better creature in all the relations of life. If these benefits, vast and incalculable as they are, be the real tendency and result of knowledge, why is ignorance allowed to remain, and why h the world still distracted by error? It is because the moral and intellectual qualities of man are, like all creations and gifts of God, the subjects of development, whose law is progression. We can aid human improvement, but we cannot unduly hasten it. Whenever man has sprung too rapidly to a conclusion, he has alighted upon error, and has had to retrace his steps. The greatest philosophers have been those who have clung to the demonstrative sciences, and have held that a simple truth well ascertained, is greater than the grandest theory founded upon questionable premises. Newton made more scientific revelations to mankind than any other philosopher ; and his discoveries have borne the searching test of time, because he snatched at nothing, leaped over no chasm to establish a favourite dogma ; but, by the slowest steps, and by regarding the merest trifles, as well as the highest phenomena, he learnt to read Nature correctly. He discovered that her atoms were letters, her blades of grass were words, her phenomena were sentences, and her complete volume a grand poem, teaching on every page the wisdom and the power of an Almighty Creator. When he observed an apple fall to the ground, he asked the " Reason Why ;" and in answer to that enquiry, there came one of the grandest discoveries that has ever been recorded upon the book of science. With that discovery a flood of light burst upon the human mind, illustrating in a far higher degree than had ever previously been conceived, the vastness of Almighty Power. Why should not each of us enquire the "Reason Why" regarding everything that we observe? Why should w men- PBEFACB. V tally grope about, when we may tee our way? When addressed iu a foreign tongue, we hear a number of articulated sounds, to which we caa attach no meaning; they convey nothing to the mind, make no impression upon the indwelling soul. When those sounds are interpreted to us, in a language that we can understand, they impart impressions of joy, hope, surprise, or sorrow, because the words convey to us a meaning. In like manner, if we fail to understand Nature, its beauties, its teachings are lost. Everything speaks to us, but we do not understand the voices. They come murmuring from the brook, trilling from the bird, or pealing from the thunder; but though they reach the ear of the body, they do not impress the listening spirit. Every flower, every ray of light, every drop of dew, each flake of snow, the curling smoke, the lowering cloud, the bright sun, the pale moon, the twinkling stars, speak to us in eloquent lan- guage of the great Hand that made them. But millions lose the grand lesson which Nature teaches, because they can attach no meaning to what they see or hear. " THE REASON WHY" is offered as an interpreter of many of Nature's utterances. Great care has been taken that these in- terpretations may be consistent with the latest knowledge, obtained from the highest sources. If the author finds that his work is accepted for the good of those who seek not only to know, but to understand, he will make it his constant care to rgad the Book of Nature, and to add to the pages of this volume whatever interpretations the progress of enquiry and discovery may demand md supply. INDEX, AND INDEX LESSONS. ISSIT The numbers refer to the Questions. The Index Lessons do not UOA respond with the Chapters, but are designed to bring together in their alpha- betical connection, all the Questions and Answers upon each particular subject included in tJie work. LESSON I. Acids, vegetable, whence are they obtained 1256 Actinism, what is it 652 Actinism, what effect has it upon vegetation 559 Actinism, at what season of the year is it most abundant ... 560 Aerial spectra, what is the cause of 527 Affinity, what is the attraction of 777 Air, why do we breathe it 4 Air, what is the composition of it 12 Air, what is its state after it has been breathed 13 Air, is that sent from the lungs light or heavy 14 Air, is it a good or bad conductor of heat 150 Air, why is a still summer said to be sultry 171 Air, why does it feel cooler when in motion, than when still ... 175 LESSON II. Air, when is it hot enough to des- trovlife 179 Air, why is it often excessively hot in chalk districts 219 Air, is it heated directly by the sun's rays 221 Air, why does it ascend the chim- ney ;. 240 Air, why does it fly through the doors and windows towards the fire place 241 Air, what does the motion of it in our rooms illustrate 242 A Ir, why does it become charged with watery vapour 346 Air, when is it said to be saturated with vapour 430 Air, what proportion of water is Air capable of holding in the form of vapour 431 Air, what is its woigM relative to that of water ., W/7 LESSON III. Air, which is heavier, dry or va- porised 697 Air-pistol (or pop-gun), why does pressure applied to the handle propel the cork 854 Air- pistol, vjhy must the handle be drawn out before the cork is placed in 855 Air, why does fresh impart a healthy appearance 915 Albumen, what is it 899 Alkalies, what are they , 33 Amber, or electrum, what is it ... 564 Animals, how is their greater warmth in winter provided for 168 Animal forms, why are there so many 1029 Animal furs, why do they become thicker in the winter 1035 Animals, why have carnivorous, long pointed teeth 1038 Animals with long necks, why have they large throats 1049 Animals, why camnot flesh-eaters live upon vegetables 1071 Animals, why can ruminating recover the food from their paunches 1089 Animals, why can ruminating keep the cnewed from the un- chewed food in their stomachs 1090 Animals, why do the smaller animals breed more abundantly than the larger onea 1094 Animals, domestic, why may change of weather be expected when they are restless 1107 Animals, plants, and minerals, what are thi differences between them 1141 Animals that graze, why do thfi? drop the tender blades, but leave the tall graSs 1989 TiTl QUESTIONS FORMING A COMPLETE INDEX. LESSON V. LESSON VII. Animals, distribution of 132 Barometer, why does its rise de- Arms and hands, why do we see note the approach of fine blue marks upon them 89 Arms and legs, why does it require the influence of the will to set weather 708 Baroincter, how does it enable us to calculate the height of the them in motion ... ... ... 94' mountains _ 701 Arms and legs, whv are they made subject to the will 949 Barometer, when does it stand highest 701 Ascending, what is the cause of Barometer, when does it stand bodies 775 lowest 705 Atmosphere, how is it heated ... 232 Barometer, what effect has heat Atmospheric humidity, why does it sometimes form clouds, at upon the if)" 7 Barometer, what effect has cold others form dews, fogs, mists, &c. 409 Atmospheric pressure, ho\v high upon the 70S Balloons, why do they ascend in will it raise water 652 air 830 Atmosphere, what is the 639 Atmosphere, to what height does it extend 639 Balloons, why do air balloons become inflated 831 Balloons, why do they sometimes Atmosphere, what is tho amount burst when they reach a high of its pressure 641 altitude 832 Atmosphere, what is the propor- tion of watery vapour in the ... 642 Atmosphere, why are its upper regions intensely cold 444 Atmosphere, what is the greatest height ever reached in the ... 648 Bat and ball, what principles of natural philosophy arc illus- trated in the play 867 Bats, why have they hooked claws in their wings 1079 Bats, why do they fly by night ... 1080 LESSON VI. LESSON VIII. Atmospheric pressure, what is the Bats, why do they sleep during total amount on the earth's winter 1081 surface 644 Atmosphere, what is the amount Beds, why should they be raised two feet from the ground ... 15 of its pressure upon ihc human 3ed-rooin windows, why are they body 645 sometimes covered with ice Atmosphere, why do we not feel crystals 344 its pressure 646 Jeer, why will it not run out of Atmosphere, to what extent may a cask until a hole is made at its pressure vary 702 Attractive agent, what is an ... 70 Attraction, what is it 772 the top 660 Jeer, why does it get flat 805 iees, why have they stings ... 1101 Attraction, how many kinds are Joes, why may we expect flue there 773 weather when bees wander far Aurora Borealis, what is the cause from their hives 1114 of 590 Jectles, why are they called "coleoptera" 1319 Bananas or plantains, where are Jeetles, why have they hard horny they cultivated 1220 wing-cases 1320 Bark Peruvian, where is it pro- duced 122.8 Jeetles, whv have many of them hard horns 13:21 Barometer, what is a 691 Barometer, why docs it indicate Jile, why does it separate nutri- tious from innutritions matter 884 the pressure of the atmos- Jirds, why have water-fowls ihere 692 feathers of a close and smooth Barometer, why is it also called a texture 1033 "weather-glass" 693 Barometers, why are they con- structed with circular di;ils ... C94 Barometer, why does tho hand Jirds, why are they covered with feathers 1030 Jirds, why does black down grow under their leathers on this change its position when the mercury rises or falls 695 Barometer, why does tapping its approach of winter 1036 Jirds, why have they hard beaks 1040 jirds, why are their beaks face cause the hand to move C96 Baroincter, why does its fall de- -aote the approach of rain ... 699 generally long and sharp ... 1041 Jirds, why are their bones hollow 1(169 Birds, why do they 'ay eggs ... 1061 QUESTIONS FOBMING A COMPLETE INDEX. LESSON IX. LESSON XII. Birds, why have those with long legs short tails 1052 Birds, why have aquatic web- Bones, why are those of the arms and legs formed into long shafts 935 Bones, why are those of the feet feet ... 1059 and hands numerous and small 938 Birds why have those that swim and dive short legs 1060 Birds, whv have some deep rough notches on the under surfaces of their feet ... ... 10c Botanical geography ... ... 1203 Brain, why is it placed within the skull 926 Bread-fruit trees, where are they Birds, whv have they gizzards ... 1072 Birds of prey why have they no gizzards ...1084 natives of ... ... ... ... 1223 Breathing, is it a kind of combus- tion 17 Breaths, have people ever been Birds, why may wet and thunder be expected when they cease to sing 1121 poisoned by their own 24 Breezes, why are summer said to be cool 170 Birds of passage, why, if they Breezes, what is the cause of sea arrive early, may severe weather arid land 235 be expected 1121 Birds, geological distributionof... 1326 Birds, tamenessof in unfrequented Bubbles, why do they ascend in the air 236 Bubbles, why do they fall, after countries 1327 having ascended 237 Birds, why are birds of song not also remarkable as birds of Bubbles, why do they display rainbow colours 499 plumage 1328 Birds, what are the velocities of their flights 1329 Birds, what is tho cause of their Bubbles, why are they round ... 825 Bubbles, why are they elongated when being blown 823 Bubbles, why do they close, and migrations 1330 Black, why should parts of kettles and saucepans be allowed to re- become perfect spheres when shaken from the pipe 827 Bubbles, wh3 r do they change main 201 their colours in the sunshine ... 828 Blood, in what proportions are the Bubbles, why do they burst ... 329 gases found in it 39 LESSON XL LESSOM X. Burning or supporting combus- Blood, what is venous 41 tion, what is the difference ... 45 Blood, what is arterial 42 Burning-glasses, why do they Blood, what is the constitution of appear to set fire to substances 8; the 899 Butterflies, why do they lay their Blood, what quantity does the eggs upon cabbage-leaves ... 109S human body contain 920 Butterflies' eggs, why do they lie Blood, how frequently does the wkole quantity pass through the dormant in the winter 1288 Butterflies, why do they fly by day 1298 system 922 Blowing upon tea, why does it cool it 174 Calms, why do they prevail at the equator 671 Bow, why does it propel the arrow ... ... ... ... 847 Caloric, what is it 7j Bow and arrow, what line does the arrow describe , 848 Bow and arrow, what forces tend Caloric, what is the source of it... 73 Caloric, what are the effects of it 74 Caloric, why is it called a repulsive to arrest the arrow 849 Bow and arrow, why are there feathers at the ends of arrows. . . 850 Boue:j, how many are there in the Caloric, how may it be excited to develope heat 79 Calorie, is there any in ice, snow, water, marble, &c. 89 human body 923 BOL.-S, of what substances arc they composed 924 Caloric, how do we measure the quantity of in any substance ... 329 Caloric, how does it travel ... 332 Bones, what are the uses of the ... 925 Caloric, how do we know that it is Bones, why are those of the back caloric which fuses metals ... &31 hollowed out 927 Bones, why are those of the skull Calves and lambs, why have they no horns 106* arched' 930 Camel whv has its stomach a Bonw, why are those of the skull divided by small sutures ... 931 lifini-s \vhv are thev Loliow ... 934 number of distinct bags 1QQ5 Candles, why do tallow require snulliua ... 234 QUESTIONS FORMING A COMPLETE INDEX. LESSON XIII. LESSON XV. Candles, why do composite and Charcoal fires, why do they not war not require snuffing ... 265 Candle, what becomes of it after give flames 107 Charcoal, what is it 271 it is burnt 269 Charcoal, why does it act as a Capillary blood-vessels, why are they found in every part of the disinfectant 809 Chicory, what is it 1196 system 919 Chimney, why does it cease smok- Capillary attraction, what is it ... 7SO ing after the fire has been lighted Carbonic acid gas, how is it a little while 650 formed 9 Carbonicacidgas.what bccomesof it 10 Carbonic acid gas, is it heavier or Chimney, why does a long one create a better draught than a lighter than air 11 Carbonic acid gas, what are the Chimneys, why do' some smoke when windows and doors are chief sources of 16 closed 6S3 Carbonic acid gas, what is- its effect upon the human system 21 Carbonic acid gas, what becomes Chimneys that stand 'under elevated objects, why do they of that formed by combustion 59 Carbonic acid gas, what propor- tion is dangerous to life 60 Carbonic acid, what is it 798 Chimneys, why do sooty smoke ... 637 Chimneys, why do they smoke in damp and gusty weather ... 688 Carbonic acid, where does it Chimney, why does it smoke chiefly exist 799 Carbonic acid, what axe its pure when first lighted... 679 Chocolate, what is it 1194 states 800 Circulation, why are the venous Carbon, what is it 18 blood and chyle sent to the Carbon, will it produce flame lungs 887 when burnt in oxygen 106 Carbon and hydrogen, what dif- Circulation, what is the course of the arterial blood 8S8 ferences characterise the com- Circulation, why does the blood bustion of 268 impart vitality 891 LESSON XIV. LESSON XVI. Carbon, what is the purest form Circulation, how do wo know the of it 277 blood is alive 892 Card, why do the irises on each Circulation, why does the blood side blend while a card is re- circulate 893 volving 846 Circulation, how is the body Caterpillars, why do they appe*r renewed by the blood 894 in the spring 1289 Circulation, how does the blood Caterpillars, why do they eat vora- return to the lungs after it has ciously 1290 reached the extremities 8D5 Caterpillars, why do they pass into the state of the chrysalis... 1291 Caterpillars, why do they become torpid in the chrysalis 1292 Caterpillars, why do they attach Circulation, why are the veins more perceptible than the arteries 897 Circulation, whv when we prick the flesh does it bleed 893 themselves to the leaves of plants when in the chrysalis ... 1291 Circulation, what occurs during the 899 Cats, &c., why do they see in the Circulation, what becomes of the dark 981 Cats' eyes, why are the pupils of nearly closed by day 982 Cats, &c., why have they whiskers 109t5 C'attle, why if they run round in meadows may thunder be ex- pected 112'^ matter collected by the blood... 901 Circulation, how is the blood pro- pelled through the arteries ... 916 Circulation, why are the capillary vessels capable of receiving the quantity of blood sent through Ceiling, how did Mr. Sands walk 0:1 tho 664 larger vessels 917 Cinnamon, where is it produced... 12 :S Chainva*;ne, why does it effer- vesce 806 Cleanliness, why does it proaiot: health 10'J Champagne, why do bubbles rise Clothes on fire, why should per- from it in two or three columns 807 sons throw themselves down ... 252 Charcoal, why is it danger; m to byru it in room* Cloth ag, why do some artick-s fee' fold, aud other* warm .. 128 QUESTIONS FORMING A COMPLETE INDEX. LESSON XVII. LESSON XIX. Clothing, are conductors or non- Cc ffee, what is it 119J conductors the warmer ... 121 Coffee, where is it cultivated ... 1224 Clothing, whyare white and light- Cohesion, what is the attraction of 77C coloured articles cool 218 Clothing, why are dark-coloured Coke-fires, why do they not give dresses worn in winter, and light flames ... .. ... .. 101 Coke, what is it 273 in summer ... ... ... 230 Clouds, what are they 873 Clouds, why do we not see them Cold, when is a body said to bo 78 Cold, what is the cause of the sen- sation ... ... ... .. 133 ascend 875 Clouds, why are they invisible when they rise but become visible when they have ascended 376 Clouds, why do they not descend to the earth 877 Cold, does it radiate" ... ... 207 Colour, why is a substance white 46 i Colour, why is a substance black 407 Colour, why is a rose red... ... 46S Colour, why is a lily white ... 469 Clouds, at what altitudes do they Colour, why is a primrose yellow 470 flr 878 Colour, why are there so many Clouds, how many descriptions varieties of colour and tint in are there 379 nature 471 Clouds, what produces their various shapes 380 Clouds, what are their dimensions 381 Colours, remarks upon 601 Combustion, what takes place during 43 Clouds, how are they affected by Combustion, how many kinds are winds 382 there 93 Clouds, what do Cirrus foretell ... 3S9 Conductors of heat, what sub- Clouds, what do Cumulus foretell 390 Clouds, what do Stratus foretell... 391 stances are good 110 Conductors of heat, why do bad Clouds, what do Nimbus foretell 392 conductors readily ignite ... 295 Clouds, what do Cirro-cumulus Combustion, what is spontaneous 311 foretell 393 Combustibles used for lighting, Clouds, what do Cirro-stratus fore- which vitiates the air most ... 62 tell 394 Conduction of heat, what is tho 113 Clouds, what do Cumulo-stratus Convection, what is the chief effect foretell 395 of the law of 243 LESSON XVIII. LESSON XX. Clouds, why are cloudy days colder than sunny days 396 Cork, what is it 1271 Cork-tree, why does it shed its Clouds, why are cloudy nights warmer than clear nights ... 397 Cloudy days and nights, why are own bark 1278 Corns, why when they ache may rain be expected 1115 they not always wet 432 Clouds, why are they white ... 631 Corn, why does the young ear come up enfolded in two leaves 1167 Clouds, why are they sometimes Cotton, what is it 1199 yellow 633 Clouds, what developes the elec- Cough, why do we 1023 Crickets, why do they make a tricity in the 581 chirping noise 1126 Clouds, why do they sometimes Cross-bills, why do their man- move towards each other from dibles overlap each other ... 1136 opposite directions 778 Clouds, why do they gather around mountain tops 781 Cup in a pie, why does it become filled with juice 631 Cup in a pie, does it prevent the Cloves, where are they produced 1231 juice from boiling over 663 Coal, what is it 271 Coal, why do we know that it is of vegetable origin 273 Coal, what are the chemical com- Dates, what are they produced by 1221 Death-watch, why does it make a ticking noise 1301 ponents of ... ... ... ... 274 Dew, what is it 345 Coals, why do they produce yellow flame 279 Dew, what causes the decline of temperature which produces it 347 Cockles, why have they stiff mus- cular tongues 1087 Cocoa, what is it 1195 Cocoa, what tree produces it ... 1221 Coffee-pot, why has it a wooden Dew, why is there little or none, when the nights are cloudy ... 343 Dew, why does it form most abun- dantly on cloudless nights ... S4 Dew, why is there little under the bandia .. 125 branches of thick fpliage ... 39* tii QUESTIONS FOBMING A COMPLETE INDEX. LESSON XXI. LESSON. XXIII. Dew, why is there none formed on windv nights ... ... ... 852 Ducks and geese, why do they dash water over their backs on Dew why ;\ro valleys and low places chiefly subject to it ... 353 Dew what bodies receive little of it 355 the approach of rain 1105 Ducks and geese, why have they square-pointed bills 1014 Dyes, vegetable, what arc they .. 1259 Dow, what bodies receive most of it 354 Ear, why is it spread out exter- Dow, at what period of the night is it chiefly formed 356 nally 834 Ears, why do hairs grow across Dew, why is it chiefly formed at that period 357 Dew, in what parts of the world is the greatest quantity formed ... 358 Dew, in what parts of the world is the least quantity formed ... 359 Dew, why is it seldom formed at sea 360 Dew, why is it, when heavy, re- them 86 Ear-wig, why is it so called ... 988 Ears, why is wax secreted in the 987 Ears, why do singing noises occur in the... ... 988 Ears, why do people become deaf 9S9 Ears, why do people accustomed to loud noises feel no inconve- garded as a precursor of rain ... 361 nience from them 990 Dew, what is honey-dew 864 Ears of animals of prey, why do Dew, why does it lie on the ex- posed sides of screens of plants 401 Dew, why does it rest upon the they bend forward IOCS Ears of animals of llight, why do they bend backward 1064 upper surfaces of leaves 402 Earth, why is it warmer than air Dews, why are cultivated lands during sunshine 308 more subject to them than those that are uncultivated 403 Earth, why is it colder than air after sunset 399 LESSON XXII. LESSON XXIV. Dew, why dojs the gravel-walk re- ceive less dew than the grass ... 404 Earth, how can man weigh the ... 784 Earth, what is the weight of the 788 Dew, why does little of it form at Earth-worms, why have they no the base of hedges, walls, and feet 1085 trees 406 Dews, why do morning dews and mists usually come together ... 407 Dew, what effect have winds Echoes, why do some occur immediately after the sounds ... 742 Echoes, why do some occur at a considerable interval after the Dew, why does it form in round drops upon leaves 794 Diamond, what causes the bril- sound 743 Echoes, why do some change the tone and quantity of sounds ... 744 liant colours of the 501 Echoes, why are there sometimes Digestion, why does food flow several to one sound 745 more freely to the stomach dur- Echoes, are they caused only by ing ... ... 879 distant objects 746 Digestion, why does excess in eating impair ... '...' ... 830 Digestion, what changes occur tq food in the stomach 881 Echoes, what are they 741 Electricity, what is it 561 Electricity, why is it so called .. 562 Electric fluid, why is it so called 5t>0 Digestion, what causes bilious at- tacks ... ... 882 Digestion, how is the nutritious matter taken from that which is innutritions 885 Digestion, what becomes of the Electrics, what substances are .. 567 Electricity, what is positive .. 568 I'Mectni-ity, \vh;it. isn.'gative .. 569 Electricity, what is vitreous .. 570 Electricity, wh.it is resinous .. 670 Electrical phenomena, 'what pro- duces them... ... ... ... 671 nutrition when it enters into t he circulation 888 Electricity, how does its cquilU brium become disturbed ... 172 Dixh-covers, why should they Electricity, how dees it seek to bo plain in form, and have regain its equilibrium ... ... 6f8 hrijilit surfaces 203 Electricity, what substances are Dogs, geographical distribution conductors 571 of ... ... ... .1. ... 1333 Electricity, what substances are Drearn, why do we 1020 non-conductors 579 Drowsiness, why is it felt in Electricity, what substances are " crowded rooms' " r " ''. 22 insulat. ?s ... ... 671 QUESTIONS FORMING A COMPLETE INDEX. Xiii LESSON XXV. Electricity, what is the effect when a current cf electricity meets with an insulator 577 Electric sparks, what.is the cause of 578 Electricity, why does lightning at- tend it 584 Electricity, why does it affect the shapes of clouds 613 Electric storms, why are they more frequent in hot than in cold weather 624 Electric storms, why do they fre- quently accur after dry weather 625 Electric storms, why do they puri- Electricity, what is vi'ltaic"' ".'. 636 Electrical attraction, what is it ... 778 Elemeutary body, what is meant by 19 LESSON XXVII. Eyes, why do we feel inconveni- enced by sudden light 978 Eyes, why if we look upon a bright object and turn away, are we unable to see 979 Eyes, why are we able to see bet- ter after a little while ... ... 980 Eye?, why do cats, bats, owU, yt!-laUu3 973 Eyes, whence are their humours dtf-^ed ... ... ... ... 976 xiv QUESTIONS FORMING A COMPLKTE INDEX. LESSON XXIX LESSON XXXI. Fire*, why in lighting them d, we first lay in paper, wood, nt>d .'oal WS Fire, why dors a poker laid across Flame of a candle, why will not a similar puff rekindle a rush-light 261 Flame of a candle, why will a the top revive it when dull ... 302 piece of paper twisted to form Firr-places, why should they be an extinguisher put it out ... 263 near the ground 303 Flame of a candle, why does it be Fire, why does the blacksmith come dim wh-n the wick la sprinkle water upon the coals of his foree 308 loaded with carbon 2(7 Flames of a fire, why do Fome ap- 1 Ires, what is the best method of pear much whiter than others ... 280 conveying air to 684 Fish, wl.y does putrifying look lu- minous 95 Flames of a fire, why do some of them appear blue 283 Flesh, why does it heal when we Fishes, why have they fins 1053 cutit> 302 Fishes, why are their fins propor- tionately so much smaller than Flesh-eaters, why do they satisfy themselves with a rapid meal ... 1092 the wings of birds 1054 Flesh, why do the marks of deep Fishes, whv have they scales ... 1055 cuts remain 905 Fishes, why do they float in Flesh, why does that under the streams, with their heads to- nails look red 907 wards the current 105fT Flies, how can they walk on the Fishes, why have they air-bladders 1037 ceiling 663 Fishes, why do not their eyes con- Flies, why have they fine hairs tract 1129 growing on the extremities of Fishes, why have they no eye-lids ... 1132 their legs ... 1102 Fishes, why have they the power Flowers, what is the chief cause of giving their eye-balls a sudden of the differences of their tem- motion 1133 peratures 227 Fishes, why are their tails eo much Flowers, why may wet weather be larger than their fins 1137 expected when their perfume is Flame, what is it 96 trong H03 LESSON XXX. LESSON XXXII. Flame, what temperature is re- quired to produce it 101 Flowers, why, if certain close, may rain be expected 1116 Flame of a candle, why does the Flying-top, why does it rise on the lower part of the flame appear > r , 843 blue ... 246 Flying-top, why does it return to Flame of a candle, why docs the middle of the flame loo* .)a>k ... 247 the earth, when its rotations are expended 844 Flame of a candle, why does tLs Focus, what is n 81 upper part produce a bright yol- low light 248 Flame of a candle, why is there a Fogs, what are they 365 POL'S, why are certain coasts very liable to them * 368 fringe of pale light around th& Fogs, what are dry 357 flame ,249 Flame of n candle, why does it ter- minate in a point 250 Flame of a candle, why does it lengthen when anything is held Fogs, why do they frequently rise in themorningand fall in the evening 371 Fogs, why do they sometimes rest upon a locality for days together, and then disappear 372 over it 251 Food, why do we eat it 869 Flnme or spark, why does press- ing it put it out ?53 Food, why do we eat animal and vegetable ... ... 173 Flame of a candle, why does hold- Food, why do we masticate'lt .'.'.' 671 ing a candle upside down put it Food, how does it descend into the out 257 stomach 373 Flame of a canille, why is it more diffici.lt to blow out the flame of Food, why do we not feel it being transmitted through the throat 87 a candle with a cotton wick than Food, why do we feel uneasy after one with a rush wick 258 Flanm of a candle, wliy does blow- ing sharply on it put it out ... 259 eating to excess , ... 877 Food, why do we feel drowsy after eating heartily 878 Ffatne of a candle, why will a sen- ile piuT of air s jmeliri.es relight it ... 260 Food, why do some portions nour- ish us, while other portious nre QUESTIONS FORMING A COMPLETE INDEX. LESSON XXXIII. LESSON XXXV. Fo'sil. vegetable, what is it 272 Hail, what is it 449 Friction, why does it produce heat 321 Friction, why does rubbifg two furlaces together attract latent Hail, why is it supposed that the el-ctrioal state of the clouds af- fects the formation of hail 449 h.-at ... 322 Hail-storms, why do they usually Frosf, why is the air warmer occur by day 450 during 163 Hairs, why do they grow across Frost, what is white 412 Frost, what is black 413 the passages of the nostrLs HH)O, whntisa ... ... 9P3 494 Frost, why are black frosts said to Halo, what is the cause of a 495 last 414 Haloes, why are they sometimes Fruit, why do gooseberries, plums, large, and at other times email 490 &c., taste acid 1184 Haloes, why do they foretell wet Fruit, why do ripe taste sweet, weather . 497 and unripe sour _. 1185 Hands, why when we hold them Fruits, why are succulent most against the candle do we per- abundant in tropical climates ... 1207 ceive a crimson colour 908 Fruits and vegetables, why do they Hay-stacks, why do they some- ripen in succession 1284 times take fire spontaneously ... 31G Furs, why are they worn in winter 166 Head, why is it set upon the neck 9^8 Hearing, why do people engaged Galvanism, what is it 635 GHS, wbat kind lights our streets .. 56 in battle frequently lose their ... Hearing, death of a dog through 991 Gas, why does it expand in thin noise ... ... 991 air ... ... .. 833 Heart, why does it beat without Geology, what has been its influ- any effort of the will 918 ence upon botanical geography 1249 Heart, why is it placed in the chest Giraffes, why have they small of the body 932 heads 1322 Heart and lungs, why are they en- Giraffes, why have they long necks 1323 closed by ribs 933 Giraffes, why have they long and Heart, why are its motions made flexible tongues ... .. ... 1324 independent of the will ... 950 LESSON XXXIV. LESSON XXXVL1 Giraffes, why are their nostrils nar- Heat, what is it . 71 row and small, and studded with Heat, what are the properties hairs 1325 of 86 Glass upon a lamp, why does it Heat, what is animal 87 increase the brilliancy of the Heat, what is latent P8 light 266 Heat, what is a conductor of 108 Glass, why is it transparent ... 506 Glass, does transparent reflect any light 507 Heat, what is a non-conductor of ... Heat, how is it transmitted from one body to another 109 119 Glow-worm?, why have they Heat, what is the radiation of ._ 114 brushes attached to their tails ... 1127 Heat, what is the reflection of . 115 Glow-worms, why do they emit Heat, what is the absorption of ... 118 light 1128 Heat, what is the convection of . 117 Gnats, why are their larv aud pu- Heat, what is the cause of the sensa- pae found in water 1314 tion . 134 Gnat.?, why my fine weather be Heat, what becomes of that which expected if they fly in large num- the hearth-stone receives 136 bers 1110 Heat, how long does a substance Grasses, why are they so widely feel hot or cold to the touch 139 diffused throughout nature . ... 1166 Hearth-rug, and hearth-stone, their Grasshoppers, why are they com- paratively active in their pupa relative states of h'-at Heat, which are the better conduc- 142 Lies . P ... 1293 tors, fluids or solids . ... 146 C:avitation, what is the attraction H'iit, why are dense substances of 774 the best conductors 147 fiuano, why is it a good manure ... 1262 Heat, why are fluids bad conduc- Gum resins, what are they ... ... Iv>j5 tors .. 148 (in'iis. vegetable, what are they ... 1254 Heat, why are woollen fabrics bad G.muow.U-r, why does it explode 808 conductors 14 !> Butiii nert-h, whei.ce U U ob- Heat, u air a good or bad conduc- tiui-d . 1254 tor .. 15* xvi QUESTIONS FORMING A COMPLKTE INDEX. LESSON XXXVII. LESSON XXXIX. Heat, is water a good or a bad Heat of the earth, Humboldt'u conductor 151 opinion upon the internal ... 1335 Heat, how do we know that air is Heat of the earth, Hunt's opinion not n good conductor 155 upon the internal 1336 Heat, how do wo know that water Hear, why do we 983 is not a good conductor 156 Hiccough, why do we 027 Heat, why are bottles of hot water Hoar-frost, what is it 362 wrapped in flannei 158 Hoar-frost, why docs it foretell Bteat, why are hot rolls wrapped in flannel 159 rain 363 Hoar-frosts, why are they so fre- Heat, what is the highest degree quent, and black-frost so unfre- that man can bear 176 quent 415 Hogs, why have Indian large tusks degree without injury 178 turning bark towards their eyes 1068 Heat, why may we believe that Hog, why is the under-jaw of the, the internal heat of the earth shorter than the upper-jaw ... 1039 does not arise from terrestrious Hoop, why does it roll without fall- combustion 224 ing to the ground - 861 Heat, what is the radiation of ... 181 Hoop, why does it when falling Heat, what becomes of that which make several side revolutions ... 862 is radiated 186 Horses, why h*e they smaller Heat, when does a body radiate it 184 Heat, does the movement of the air stomachs proportionately than other animals 1097 attbct the radiation of 188 Horse, why has it no gall-bladder 1098 Heat, why will not the motion of Horses, why is the secretion of nir disturb the rays of 190 : their eyes thiek and glutinous ... 1134 Heat, what bodies are good radia- tors of 192 Horses and cattle, why do they stretch out their necks, and snuff Heat, what bodies are bad radia- the air on the approach of rain ... HOC tors of ... 193 Horse-chestnut, why is it unfit for Heat, why does water keep hot food 1203 longer in a bright metal jug ... 195 Hot, when is a body said to be ... 77 LESSON XXXVIII. LESSON XL. Heat, may it. be reflected 210 Hot water, why does it feel hotter Heat, are light or dark-coloured in a metal jug than in an earthen- bodies the best reflectors ... 211 ware one 126 Heat, what bodies are the best re- Hot metal, why does it feel hotter flectors of 212 than hot wool 130 Heat, why is that which is reflected Hot metal and hot wool, which less intense than the primary ... 214 would become cold first 131 Heat, can it be reflected in any Hot and cold bodies, why, when preat intensity 215 placed near each other, do their Heat, are good reflectors also good absorbers 216 temperatures approximate ... 331 Humming-tops, why do we see the Heat of the sun's rays, how is it figures painted on them before diffused 219 Heat, how do we know that it is they spin, but not while they are spinning 813 absorbed by the earth ... ... 222 Heat, do plants absorb it 225 Humrningat, what is the accepted theory Hydrogen, why will it explode ... 52 Hydrogen, where does it chjVfly exist 51 of 328 Heat, what is the point at which Hydrogen, how is it obtained from coal 57 it becomes luminous 545 Heat, what is the relative intensity of primary and reflected ... 548 HtHt to cold, why does a sudden change bring on illnes* 1013 ] Hydrogen.gas, is an escape of it dangerous to life 63 Hydrogen-gas, what proportion mixed with air will explode .. 6, Hydrogvt-gas, does it rise or fall ,. 60 QUESTIONS FORMING A COMPLETE INDEX. LESSON XLI. LESSON XLIII. ilylrogen-eas, what proportion is Kettle-holders, of what use are dangeroua if inhaled 67 they 128 IlyiJrogen-g8, what proportion mny'be recognised by its smell 68 Kettles and saucepans, why should the lids and fronts of, be kept Hydrogen-sas, mny the use of it bright 206 be considered dangerous ... 70 Kettles, why do they become en- Hydrogen-gas, what sources of it are there in our dwellings ... 69 crusted with stony deposites ... Kite, why does it rise in the air ... 703 840 Hydrogen, why will it burat into Kite-string, why does it feel hot flame when coals become heated 100 when running through the hand 841 Hydrogen, why does bi-carburet- Kite, why does running with it ted burn with a whiter flame than cause it to ascend 612 common coal-gas 281 Knowledge, why should we seek it 1 Knowledge, why does the posses- Ice, why are blocks of it wrapped in flannel in summer time ... 154 sion of it give us power Knowledge, what are the benefits 2 Ice, why does it melt 325 of I ... 3 Ice, why does it occupy more space than water 752 Latent heat, will the abstraction of Ignis fatuus, what is it 319 it reduce the bulk of bodies ... 337 Incidence, what is the line of ... 519 Latent heat, how do we know that Incidence, what is the angle of ... 521 it exists in air 339 India-rubber, where is it obtained 3254 Laugh, why do we 1026 Infants, why have they no teeth ... 1070 Insects, why have they a large Ligaments, what are they Ligaments, why are they wrapped 937 number of eyes 1083 around the joint* 938 Insects, why have they long pro- jections from their heads ... 1100 Light, what is it Leaves, why are they green 451 1181 Insects, why do they attach their Leaves, why do some turn yellow 1186 eggs to leaves 1295 Insect?, why do they multiply so Leaves, why do they fall off in the autumn 1J87 numerously 1300 Leaves, how to make skeleton ._ 1159 LESSON XLIL LESSON XLIV Insects, what is a larva 1302 Leaves, why do they turn brown Insects, what is a pupa 1303 in autumn 1183 Insects, what is a chrysalis ... 1304 Legs crossed, why do we see the Insects, what ij a nymph 1305 elevated leg move at regular in- Insects, why do they abound in tervals 918 decaying substances and in pu- Light, at what velocity does it travel 453 trid waters 1313 Light, how long does it tke to Insects, why do we see them in travel from the sun to the earth 454 tanks of rain-water 1314 Light, what are the minor sources of 45? Iron articles, why are they intense- ly cold in winter 132 Light, what is a ray of Light, what is a medium of 458 459 Iron articles, why do they usually Light, what is a beam of 460 feel cool, even when near a fire 132 Light, what is a pencil of ... 46L Ironing-box, why does the iron Light, what is the radiant point ... 462 sometimes become too large for the box to receive it 335 Light, what is the focus of Light, what is the constitution c a 463 Ironing-box, why does the iron en- ray of ... .: 464 ter it, when partially cooled ... 336 Iron, why does it rust when wetted 768 Lishr, why are its rays white Light, what are the estimated vibm- 465 Jew's-harps, why do they give mu- tions of Light, what is the refraction of ... 465 472 sical sounds 851 Jew's-harps, why will they not produce loud sounds unless they are applied to the rnouih 852 fows-liarps, why does the altera- tion of the form of the mouth al- ter the sounds 853 Light, is it refracted when it falls upon a surface in a straight line Light, is the direction in which its rays are best dependent on the drnsities of the media Light, why does a spoon look bent when placed in a basin of wtrr 473 474 477 tmigaroos and opossums, why huve thry pouches in which they oarry their young ... 1139 Light, why do we see the rays of the sun burst thrpugh tho clouds in different directions 4*0 xviii QUESTIONS FORMING A COMPLKTE INDEX. LESSON XLV. LESSON XL VII. Light, why is the apparent depth of water always deceptive ... 479 Lightning-conductors, which is the best metal for ... 610 Light, why are some substances Lightning-conductors, why have opaque tb it 511 thev sometimes been found inef- fective 609 ies reflect it in every direction ... 517 Lightning-conductors, why should Light, meditation on 517 large buildings have several ... 611 Light and heat, what are the differ- Lightning-conductors, why should ences between 540 they have several branches pen- Light and heat, are they combined in the sun's rays 541 etrating the earth 618 Lightning, through what distance Lidit nnd heat, how do we know will its light penetrate 622 that they are separate elements 542 Light and hent, in what respects Lightning, how may we calculate the distance of a storm 623 are they similar 543 Lightning, why is the flash gener- Light and heat, in what respects ally succeeded by heavy rain ... 626 are they dissimilar 544 Light, what is polarized 549 Lightning, why is a flafh generally followed by a gust of wind ... 6C7 Light, what is the velocity of arti- Lime-kilns, why do persons viewed ficial 546 through the hot air of, appear Light, nt what rate does the light distorted and tremulous 483 of the stars travel 547 Limpets, why is it difficult to strike Light, why does it tarnish silver ... 553 them from rocks 663 Light, why does it affect colours ... 554 Light, why can pictures be taken Lips, why are they red 913 Liver, what effect has it upon the by the sun's rays 555 Light, when does it scorch plants 558 Lightning, what is the cause of ... 580 circulation 901 Looking-glass, why, if you hold one at nn"imgle towards the sun, will Liuhtnintr, why does it sometimes light be thrown in an opposite bejome zig-zag 586 direction ... 208 Lightning, why is it sometimes Loss, is there any such thing in forked 587 the operations of nature 270 LESSON XLVI. LESSON XLVIII. Lightning, why is it sometimes like a lurid sheet 588 Lungs, why are they placed in the chest of the body 932 Llsf lining, when is the flash straight 587 Lightning, when does the flah ap- Magnetism, what is it 633 pear blue 591 Lightning, why is it sometimes red. at others blue, yellow, or Magnetic bodies, what are they ... 634 Magpie, why is a single one said to foretell bad weather 1118 white 592 Mahogany, what is it 1190 Lightning, does it ever pass from Mahogany and other woods, why the earth to the clouds 593 are there curious markings in ... 1273 Lightning, does it pass from the clouds to the earth 594 Man, why is he born without a covering 1034 Lightning, what is the force of ... 595 Man, why has he no external ap- Lightning, why is it dangerous to pendage to his mouth 1037 stand near a tree during a storm 56 Marbles, why do they revolve when Lightning, why is it dangerous to sit near a fire during a storm ... 598 Lightning, why is it dangerous to be near water during a storm .. 599 Lightning, are iron houses danger- propelled along the ground ... 818 Marbles, why do striped appear to have more stripes when they are rolling than when at rest 819 Marbles, why do they rebound when ous ... , 600 Lightning, why does it seize upon bell wires, &c F ... 601 Lightning, arc umbrellas with steel dropped upon the pavement ... 820 Marbles, why do they roll furthest upon smooth surfaces , 821 Marbles, how many forces contrib- frames dangerous 603 \ Ightning, are iron bedsteads dan- ute to stop their rolling 882 MnrblRf, why do the stripes upon gurous ... ... ... ... ... 604 Lightning, what is the safest situs- them disappear when they are spinning rapidly ... ... 3^ tlon duiinft n torm 606 Lightuimj-conducttirB, do they at- tract electricity 608 Marbles, why re the rings upon them most perceptible ot ihe " poles," while they ark Spinning 82* QUESTIONS FORMING A COMPLETE INDEX. xix LESSON XLIX. LESSON LI. Matches, do they ignite eponta- Nails, why do white spots occur neously 313 upon the 910 Meat, why is it sooner cooked Needle, why will it float if laid care- when a, tin screen is placed be- fully upon water 795 fore the fire 213 Nerves, what are they 951 Metal, why does it run like a fluid Nervous system, of what does it when malted 333 consist 955 Mirrors, why do we see our fea- Nerve, what is the constitution of a 956 tures therein 209 Nervous fluid, what is the ... 957 in them 512 Nerves, how many kinds are there J58 Nerves of motion, what are they ... 959 Mirrors, what has the glass of to Nerves of sensation, what are they 959 do with the reflection 514 Nerves of special sense, what are ... 9fl Mirrors, why do compound mir- Nerves of sympathy, what are the f)63 rors reflect many images of one Nights, why are they usually cold object 515 when clear ' ... 411 Mirrors, why do reflections appear Nitrogen, what is it 33 as far behind n mirror as the Nitrogen, where is it found ... 34 object reflected stands before it 518 Nitrogen, could animals live in it 37 Mirage, what is the cause of the ... 527 Nitrogen, is it taken into the blood Mists, what are they 368 from the air 40 Mists and fogs, what is the differ- Nitrogen, will it burn 44 ence between them 369 Nitrogen, what becomes of that Mists end fogs, why do they disap. which is inhaled 46 pear at sunrise 370 Nitrogen, where does it find a Mistletoe, why have its berries a thick viscid juice 1177 fresh supply of oxygen 47 Nitrous oxyde, why does it excite Mistletoe, how are its seeds con- the system 3g veyed to the bark of trees ... 1178 Non-conductors of heat, what sub- Moles, why have they hard flat feet 1074 Mole's fur, why is it glossy and stances are m Nostrils, why are they directed smooth 1075 downwards u 994 LESSON L. LESSON LII. Moles, why are they permanent ... 904 Moles, why may rain be expected Nose, why is ife placed over the mouth 995 when they throw up their hills 1117 Nutmegs, where are they produced 1233 Monsoons, what are they 672 Monsoons, what is the cause of ... 673 Ocean, how is it heated ... ... 233 Mornings, why are they usually clear when frosty 410 Oils and fats, what are vegetable ... 1204 Oils and fats, animal, why are they Mother-of-pearl, what causes the found most abundantly in cold rich tints displayed by 500 Moths, why do they fly by night ... 1297 Moths, why are their bodies gen- climates 120! Oils and fats, vegetable, wty are they found most abundantly in erally covered with thick down 12'28 hot countries 120C Moths, why do they fly against the candle-flame 1299 Opium, what is it 1258 Ostriches, why have they small Muscles, how many are there in wings . 1031 the human body 941 Muscle, what is the constitution of a 942 Ostriches, why are their feathers soft and downy 1033 Muscles, what degree of strength Otters, seafe, &c., why have they do they possess 945 web-feet 1063 Muscles, what is the stimulus which Owls, why does their screeching eets them in action 946 denote change cf weather ... 1111 Mussels, why have they tendi- nous -ords proceeding from Owls, why does their moping fore- tell death 1118 their , ells 1086< Oxen, sheep, deer, &c., why do they ruminate 1088 Natural phenomena, a world of Oxen, and other quadrupeds, why miniature 690 have they a tough elastic lig- Nails, why have we got them al; the ament in their necks 113J fingers' ends 908 Kails, why it there a circular lino of whitish colour at the root of the 909 Oxygen, why is it necessary to life S Oxygen, what Is its union with carbon calld 7 QUESTIONS FORMING A COMPLETE INDEX. LESSON LIU. LESSON I,V. Oxygen, whftt is it ... ... . ... 25 Phosphorous, why does it look lu Oxygen of the air, why does it not niinons ... 04 Ukoflro ... ... 28 Phosphorous, does it ignite sponta- Oxygen, why do wo know that it neously when placed upon a hof will not burn of itself 29 surface 3X4 Oxygen, why do we know that it is Phosphorous, why does it ignite when sprinkled with powdered Oxygen, where is it found; 31 Oxygen, why is it mixed with ni- trogen in the air 32 charcoal 315 Photographic pictures, how does light produce them 55C Oxygen of water, why does it not support fire ... ... ... ... 307 Photographic rooms, why are they glazed with blue glass 557 Oxygen, in what way does man use it 757 Pith-tumblers, why do they always pitch on one end 808 Ozone, what is it 630 Planets, how can man weigh them 785 Ozonn, why do we know that elec- Planets, how can man measure tricity produces it 631 their distances 786 Ozone, what are the properties of C32 Plants, do they absorb heat ... 225 Plants, how do we know that they Paleness, what is the cause of ... 914 absorb heat 226 Palms, what are their characteris- Plants, why do screens prevent tics ... 1221 frost from killing them . ... 400 Pnper held over a candle-flame, Plants, why, if we cut across their why does it become scorched ... 244 stems, do we see tubes arranged Paper held below a candle-flame, in parallel lines 1159 why does it scarcely become Plants, why do some droop and warm 245 turn to the earth alter sunset ... 1167 Paper, why does it more readily Plants, why are the seeds of ignite than wood 294 Pnper, why, if it is laid flat upon many enclosed in rich juice or pulp 1172 the fire, will it "char" before it Plants, why have some tough curly ignites 304 tendrils 1173 LESSON LIV. LESSON LVI. Paper on a fire, why will it ignite Plants, why have peas tendrils, and when you send a puff of air to beans none 1174 it 305 Plants, why have grasses, &.C., joints Parachutes, why do they fall grad- or knots in their stalks 1176 ually to the ground 834 Plants, what is the circulation oL Parrots, &c., why have they crook- sap in 1179 ed bills 1047 Plants, why does their sap ascend Parrots, why can they move their and descend 1180 upper as well as their lower Plants, why do they suffer from beak 1048 the smoke of cities 1188 Particles of matter, why do they Plants, why is it understood that draw near each other 776 some of them feel 1141 Particles of matter, why will they Plants, why is it understood that excited by friction 779 Plants, of what elementary sub- Pea and pin, why do they rotate upon a jet of air blown through a tobacco-pipe 845 stances are they composed ... 1143 Plants, whence do they derive their elementary substances 1144 Peg-top, why does it make less Plants, how do they obtain carbon 1145 noisi: than a humming-top ... 811 Peg-top, why does it sometimes hum, and at other times not ... 812 Pelican, why ha? it a large pouch under its bill 1093 Plants, how do they obtain oxygen 1146 Plants, their decomposition oi gases by day and by night 1147 Plants, how do they obtain hydro- gen ... ... 1147 Pepper, where is it produced ... 1229 Perspiration, why does it cool the Plants, how do they obtain nitrogen 1148 Plants, how do they apply their ele- '""'y 173 Perspire, why do we 1009 Perspiration, how is it formed ... 1010 Perspiration, what is insensible ... 1011 Perspiration, what is sensible . 1012 ments to the formation of their structures 1149 Plantp, how is their nutritive sap applied to their growth and nourishment 1159 QUESTIONS FORMING A COMPLETE 1H1JEX. ixi LESSON LV1I. LESSON LIX. Plants, why do they grow 1154 Flunts, why if we break the stem Radiation, why does scratching a bright metal surface increase its of a hyacinth do we see a glu- powers of 199 tinous fluid exude 1155 Radiation of heat, what benefits Plants, why if we split the petal of a tulip do we see cells containing different colouring matters ... 1156 arise from it ._ ^ Radiation of light, what is it Radiation, do all bodies radiate 415 503 Plants, why if we break a pea-shell 504 across do we find a transparent Rain, what is it ' 41C membrane . ... 1157 Rain, does it ever occur without Plants, why if we cut through a clouds 417 cabbage-stump do we find a tough coating enveloping a cellular sub- Rain-drops, why are they some- times large, and at other times stance 1158 small , 418 Plants, why are their seeds formed Rains, nt what seasons are they within the corollas of flowers ... 1168 most prevalent 419 Plants, why does the flower of the poppy turn down during the Rainy days, in what months of the year are they most frequent 420 early formation of seed 1169 Rainy days, why are there more Plants, why have those of the pea- from September to March 421 tribe a folding blossom 1170 Rain, in what part of the world PlanU, why are leaf-bud* enclosed in scales which fall off as the leaves open 1171 does the greatest quantity fall ... Rain, in what part of the world do the heaviest rains fall 423 423 Plant*, what is meant by " species" Rain, in what part of the world of 1209 does the least rain fall 424 Plants, what is meant by " genus" Rainy days, how many are there in of 1210 a year 435 Plants, progressive discovery of Rain, in what part of England does new species 1211 the greatest quantity fall ... 426 Plants, what are the three great Rains, why do the heaviest occur classes of ... 1212 in hot countries 427 LESSON LVIII. LESSON LX. Plants, what are the characteristics Rain, why does the greatest quan- of exogenous 1213 tity fall at the equator 498 Plants, what are the-'^^acteristics Rain, why are some parts of the of cryptogamus 1216 earth without it 429 Plants, what are the effects of di- Rain, whji does it purify the 433 Plants, what are the effects of alti- tude upon mountains 1243 Rainy localities, why are mountain- ous countries more rainy than Plants, what agencies influence flat ones 434* their geographical distribution ... 1250 Rain, why does more fall by night Plants, what are the chief facts than by day 435 connected with the distribution Rain, why do bunches of dried sea- of by man _ 1251 Plants, why are herbaceous less solid than woody 1265 weed indicate its coming Rain, why do weather-toys foretell its coming ... ~. 436 437 Plants, why are the stalks of herba- Rain, the Capuchin toy; myste- ceous generally cylindrical ... 1266 rious walk of a wooden horse ... 438 Plants, wnat are the stotnata of ... 1267 Rain, why does ladies' hair drop Plants, why are their stomata gen- erally on the underside of their out of curl as rain approaches ... Rain, why is it said to be coming, 438 leaves 1268 when the mountains are "put- Plants, why have they pith in their ting on their night-caps" 439 centres . 1269 Rainbow, what causes a 486 porter, why does bottled produce Rainbow, why does it exhibit col- large volumes of froth 801 ours ... 487 Pulse, why dc we feel it beat ... 900 Rainbows, why are there some- times two 488 Quadrupeds, geographical distri- Rainbows, why are the columns of bution of 1331 Quicksilver, why does it reflect the secondary bow, arranged in the reverse order of those of the light from mirrors ... * ... 513 primary ... . .. ... 489 ixii QUESTION FORMING A COMPLKTE INDEX. LESSON LX1. LESSON LXIII. Rainbow colours, why do piss* lustres and chandeliers exhibit See-saw, why may the little boy keep the larger one up, when once he is uo _ . ... 864 Rainbows"' why are the coiours of the secondary how fainter than those of the primary 491 Rninbow, what is a lunar 492 Shadows, what is the cause of ... 509 Shadows, why is there some light where shadows full 510 Shadows, why do they lengthen as Rainbow, why is a lunar bow faint- er than the solar ... ... ... 493 the sun goes down 52 Shuttle-cock, why does it travel Rainbow, why is one'in the morn- ing ihe shepherd's warning ... 536 Rainbow, why is one nt night the slowly through the air _. ... 838 Shuttle-cock, why do we hear a noise when we strike it with the shepherd's delight 539 Refraction of light, what is it ... 472 Refraction and reflection of light, battledore 837 Sight, why are two persons able to see each other 551 what is the difference 502 Sight, why can we see so many Reflections, why are they reversed 490 Reflection, why do black bodies re- upon the small retina 966 Sight, why are we able to see at flect any light 505 long or short distances 974 Reflection, why does a window- pane nppenr to reflect better by Sigh, why do we 1025 Silica, what is it 1260 night than by day 516 Silk, what is it 1200 Reflection, what is the line of ... 520 Reflection, what is the angle of ... 522 Skin, why does a chill of the produce inflammatory action in the lungs 1014 Repulsion, what is it 792 Sky, what is it SiO Respiration, why does the chest Sky, why is it red at sunset ... 532 expand when we breathe ... 889 Sleet, what is it 447 Respiration, how does blood com- municate with the air in the Sleep, whstisit 1019 Smell, why do we S92 lungs 890 Sinoke, what is it 102 Rest, why does it invigorate us ... 101P Smoke, why is there so little when Rice, where is it cultivated 1219 the fire is rod 105 Rosewood, what is it ... . 1191 Sinoke, what is it 289 LESSON LXII. LESSON LXIV. Saliva, why does saliva enter the Smoke, why do fresh coals in- mouth while we are eating ... 872 Sea, why is it salt 764 crease the quantity of 2S1 Smoke, why does it issue in folds Sea, whnt is the estimated amount and curls 632 of salt in the ... 765 Smoke, why does it ascend in mild Sea, what is the depth of the ... 766 and fine weather 689 Sea-gulls, why are they numerous in fine weather 1119 Snails, why can they move in an inverted position 666 Sea-gulls, why do they fly over the Snails, where do they obtain their land on the approach of stormy shells 1306 weather 1120 Sea-crow, why is its lower bill Snails, why do their shells grow ... 1307 Snails, why are their shells spiral 1308 longer than the upper 1135 Sealing-wax, why does rubbing it Snails, why have they four tenta- cula attached to their heads ... 1309 attract to it small particles of Snails, why are they able to move matter 5fi5 without feet 1310 See, why do we 963 Snails, why do we see none in the Seeds, why are they generally en- winter time 1311 veloped in hard cases 1152 Seeds, why do they throw out roots Snails, why can they live in sealed shells 1312 before they form leaves 1153 Sneeze, why do we 1024 Seeds, why does the leaf-germ come up to the light and" the Snipes and woodcocks, why have they long, tapering bills . ... 1042 root-germ penetrate the earth ... 1285 Seeds, why are they indigestible ... 1286 See-saw, why may a little boy bal- Snore, why do we 1028 Snow, why does it keep the earth warm ICO ance a larger boy 863 Snow, why is it a good non-con- 8ee-saw ; why does the littlo boy ductor of heat 169 s'.ix t3 the earth, when the larger boy kicks the ground 864 Snow, whnt is it 440 Snow, wby is it white ... _. 44> QUESTIONS FORMING A COMPLETE INDEX. LESSON LXV. LESSON LXVII. Suow, why ia it warm, though Sound, why do sea-shells tive a white gwrments are cool ... .. 442 murmuring noise when held to Snow, why is it always on the tops the ear 734 of high mountains 443 Snow-line, what is meant by the ... 445 Sound, why can people in the arc- tic regions converse when more Scow, what is red 446 than a mile apart ... ... 735 Soda-water, why docs it effer- Sounds, why do savages lay their vesce 802 heads upon the earth to catch Soils, why are clayey unfavourable to vegetation 1160 Soils, why are sandy unfavourable sounds 736 Sounds, why can church clocks be heard striking more plainly at to vegetation 1162 some times than at others ... 7J7 Soils, why are chalk unfavourable Sound, why may the scratching of to vegetation 1] 62 a pin at one end of a long pole Soils, why are mixed favourable to be heard at the opposite ex- vegetation ... ... 1163 tremity... ... ... . ... 738 Soils, why do farmers manure Sound, why is the hearing of deaf their land 1165 persons assisted by ear-trumpets 739 Soot, why should it be prevented Sounding-boards, why are they Irom accumulating at the bot- used to improve the hearing of tom and sides of sauce-pans ... 205 Soot, what is it 290 congregations 740 Sounds, why, when we are walk- Sound, what is it 716 ing under arches or tunnels, do Sounds, what causes the air to pro- our voices appear louder ... 747 duce 717 Spark, what causes it when a Sounds, how do we know that they horse's shoe strikes against a are produced by vibrations ... 718 stone ... 340 Sounds, how do we know that Specific gravity, what is it 789 without air there would be none 719 Sounds, how are the vibrations of Spiders, why have they the power of spinning webs ... 1082 sonorous bodies imparted to the air 720 Spiders.why may fine weather be ex- pected when they build their weba 1108 LESSON LXVI. LESSON LXVIII. Sounds, how rapidly do the vibra- tions of trrtvel 721 Spiders, why may wet weather be expected when they hide 1109 Sounds, do all sounds travel at the Spiders, why may wet weather be same rate 722 expected when they break off Sounds, why are bells and glasses their webs and remove them ... 1113 stopped from ringing by touch- ing them with the finger 723 Spider, why, if the webs of the gossamer fly about in autumn, Sounds, why does a cracked bell may east winds be expected ... 1124 give discordant 724 Sounds, why do we see the flash of Spiders, gossamer, why can they float through the air 1126 a gun before we hear the report 725 Sound, why does the marching of long ranks of soldiers appear to Spinal cord, what is the 952 Spinal cord, why is it placed in the back-bone . ... 953 be irregular 726 Spinal-cord, how do the branches Sounds, what are the numbers of pass out from it . 954 vibrations that produce various 727 Spontaneous combustion, what sub- Sounds, why does the length 6f stances are liable to it 317 a wire or string influence the Spontaneous combustion, has it sounds it produces 728 ever occurred in living bodies . 319 Sound, why -does the tension of a Spontaneous combustion, why does wire or string affect its vibrations 729 it occur in the case of the drunk- Sound, why are some notes low ard m ... 330 and solemn, and others high and quick 730 Spoon-bill, why has it a Ion;* ex- panded bill, lined with sharp, Sound, why can our voices be muscular points 1045 heard at a greater distance when Spoon-bill, why has it long legs ... 1046 w speak through tubes 731 Squint, why do some people ... 967 Sound, ia ir a good conductor ... 732 Starch, what is it 1203 Bounds, why can we hear them at Star-lit nights, why are they usually a greater distance on water than colder than cloudy nights ... 350 on land ._ ... _ _. 733 Stars, why do they twinkle ... 484 sxiv QUESTIONS FORMING A COMPLKTE INDKX LESSON LXIX. LESSON LXXI. Stars, why does their twinkling Tea-pot, if the earthenware one foretell bad weather 485 were set by the fire, why would Bteam, why dors it issue from the it then make the best tea ... 201 spout of a kettle 750 Tea, what is it 1193 Storms, what i* the cause of ... 676 Tea, where is it cultivated 1205 Storms., why do the most violent Tears, what is the cause of S77 occur in and near the tropics ... 677 Btraw, why is it frequently used Temperature, why do some arti- cles feel colder than others ... 138 for manure ... . ... ... 1264 Temperature, why does it feel " Sucker, 1 ' why does it raise a stone 860 warmer after a frost has set Sugar, what is it 1197 in 163 Sugar-cane, where is it cultivated... 1226 Tendons, what are they 939 Sim, what is its distance from the Tendons, why are thy used to earth 452 attach the muscles to the bones 940 Sun, what is the 455 Teneriffe, what are the botanical Sun, from what does its luminosity regions of the Peak of 1241 arise 456 Thaumatrope, why do the figures Sun anil moon, why do they appear on appear to dance 869 smaller when near the meridian, Thaw, why is it colder when a than when nrar the horizon ... 525 thaw takes place 164 Sun, why do we see it before sun- Thermometer, what is the 709 rise, and after sunset 482 Thermometer, why docs it indicate Sun, whu is he magnitude of the 787 degrees of heat 710 Suppers, v by do they cause Thermometer, why are there Reau- dreams 1021 mur's and Fahrenheit's 711 Swallows, why may wet weather Thermometer and barometer, what be expected when they fly low 1104 is the difference 712 Syringe, why does pressing in the Thermometer, in what season of handle force out a jet of water... 856 Syringe, why will not the water the year does it vary most ... 715 Thunder, what is it 614 run out, unless the handle is Thunder-peal, why is it sometimes pressed in 857 loud and continuous 616 LESSON LXX. LESSON LXXII. Syringe, why will the water leak out, but not run 858 Syringe, why cannot the handle Thunder-peal, why it sometimes broken and unequal 617 Thunder-peal, why is it sometimes be pressed in, if a finger is kept on the orifice 859 a low, grumbling noise 618 Thunder-peal, why does it some- Tannin, what is it 1257 times follow immediately after Taste, why do we 996 the flash of lightning 620 Taste, why are some substances Thunder, through what distance sweet, others sour, &c 997 will the sound travel 621 Taste, why is it most powerful af- ter substances have been a little Thunderbolt, what is a 628 Tinder-box, the history of a ... 340 while in the mouth ... ... 998 Toasting-fork, why has it a wood- Taste, why if we put out the tongue and touch it with a nub of sugar, en handle 124 Tops, why do they stand erect shall we perceive no taste ... 999 while they spin, bnt fall when Taste, why when we draw in the they stop 814 tongue do we then perceive the taste of the sugar 1000 Tops, why do they " sleep" ... 816 Tops, why do they cease to Tasto, through what nerves are spin 817 we made sensible of the con- tact of sugar with the tip of the tongue ... 1001 Touch, in what part of the body is the sense of most peifoct ... 1C<6 Toxicoloaists, what are they ... Cl Taste, why do connoisseurs of wines hold wine in their mouths Trap and ball, why is the ball pro- pelled upward, when the trig- a few seconds when judging of it 1002 ger U struck 866 Taste, why do they also pass the Trei'g, what are the estimated ngcs fumes of the wine through their of 1214 nostrils 1003 Trees, what are the northern lim- Tea-pot, why does a bright metal its of 1237 one produce better tea than a black earthenware ... ... ... 200 Trees, why are they covered with bark 1270 QUESTIONS FORMING A COMPLETE INDEX. LESSON LXXIII. LESSON LXXV. Trees, why have those with lareo Water, why has the exceptional trunks a great number of leafy law, by which it expands whea branches 1274 freezing, been ordained 343 Trees, why have poplars compara- Water, why can we seldom suc- tively few leaves 1275 ceed in the first attempt to touch Trees, why had the mammoth com- anything lying at tho bottom of 481 paratively few leaves 1276 Water, what causes it to flow from Trees, why have oaks pn abun- a pump 651 dance of leaves 1277 Water, why does it run through a Trees, why are their trunks gen- syphon . 655 erally round 1278 Twilight, what is the cause of ... 482 Water, what is it 748 Water, why doss it become solid when it freezes 751 Vacuum, what is a 649 Water, why does it boil 753 Vacuum, is it possible to obtain a Water, what proportion of the perfect 650 earth's surface is covered by it 554 Vegetables, have they any heat ... 90 Water, why does it dissolve sub- Vegetable structures, of what do stances 758 they consist 1151 Water, why does hot dissolve more Vegetables, why do farmers sow readily than cold 759 different crops in rotation ...1164 Water, why is it sometimes hard 760 Vegetables, why are the hearts of Water, why is rain-water soft ... 761 cabbages, &c., pale yellow ... 1182 Water, why is it difficult to wash Vegetable productions, why are they so widely diffused 1189 in hard 763 Waters, why are some impreg- Vegetable eaters, why do they feed nated with mineral matters ... 767 so continually 1091 Vegetation, geographical distribu- Water, why does stagnant become putrid 769 tion of _ . .. 1208 Water, is there danger attending Vegetation, what are the character- drinking it on account of animal- istics of tropical 1218 cules ... 770 Vegetation, what are the changes Water, what are the means by in on quitting the tropics . 1232 which it may be purified 771 LESSON LXX1V. LESSON LXXVI. Vegetation, what are the character-' Water, what is the pressure of ... 775 istics of, upon approaching the Water, why will a drop upon the polar zones 1234 blade of a knife leave a dark spot 777 Vegetation, what are the charac- Water, why does it roll in agitated teristics of mountain 1238 Vines, where are their favourable globules when dropped upon hot iron 796 climates ,., 1233 Water, why does oil float upon it... 797 Water, why is spring fresh and in- Walking, why does it make us vigorating 803 warmer 26 Water, why is boiled flat and in- Water, what becomes of that sipid 804 formed by combustion 58 Weather, why does a yellow sun- Water, is it a good or bad conduc- sft foretell wet 534 tor of heat 151 Weather, why does a red sunset Water, why does it extinguish fire 306 foretell fine 535 Water, why, when a blacksmith Weather, why does a red sunrise thrusts a hot iron into a tank, do foretell wet 53 we perceive a peculiar smell ... 309 Water, why does it freeze 324 Weather, why does a grey sunrise foretell dry 537 Water, why does it become steam 326 Weather, barometrical indications Water, how many degrees of lat- ent heat are hidden in its several of , 70 Whales, why have they a large de- states 327 velopment of oily matter about Water, why does it expand when their heads _. ... . ... 1068 freezing, while bodies generally contract with cold and expand Whale, why has it feathery bones extending from its jaws 1C95 with heat 341 Whf.les, why are their eyes pro- Water, why does it never freeze vided with very thick coats ... K31 to a great depth ' % 342 Wheat, why do the ears stand up Water, how much deeper is it than it appears to be .. ._ ... 480 by day and turn down by night... 1175 - Wheat, what is it ... 1198 2 icxvi QVFSTIONS FORMING A COMPLKTE INDEX. LESSON LXXVII. LESSON LXXVin. Wheat, what is the northern limit of 1235 Winds, why are south warm and Wheat, why is eilicn diffused over rainy 3S7 its stem 1261 Wind, what is it 666 Wheat-crops, why do they greatly Winds, what are the velocities of ... 667 exhaust the soil 1263 Wind.-, what are trade 66g Whirlwinds, what are they ... 678 Winds, what is the cause of trade G<59 Why do we see 963 Winds, why do trade winds blow Why do we wink 975 Why do we weep 977 from east to west 670 Winds, what determines the char- Why do we hear 983 Why do we taste 986 acter of 674 Wind-mills, why do their wings Why do we smell ... 992 turn round CSO Why do we feel 1004 Windows, why do they reflect the Why do we dream 1020 Windows, why do they not reflect Why do suppers produce drsam- the sun's rays at noon 524 Wood, why does decayed look Why do we yawn '.'.! ".! ... 1022 luminous - 95 Why do we cough 1023 Wood, burning at one end, why Why do we sneeze 1024 does it not feel hot at the other 118 Why do we sigh 1025 Wood, why is it a bad conductor Why do we laugh 1026 of heat 119 Why do we hiccough 1027 Wood that is green, why does it Why do we snore 1028 hiss and steam when burning ... 285 Why do we feel hungry 1337 Why do wo feel thirsty 1338 Wick of a cand!.-, why does it turn Wood, why does it ignite less read- ily than paper 297 Woodcocks and snipe?, why have black as it burns 225 they nerves running down to the Wick of a candle, why is there a tip of their bills 104? spark generally at the end of it ... 256 Woodpeckers, why do they "tap'' Will-o'-the-wisp, what is it 318 at old trees 1066 Winds, what is the cause of ... 234 Woollens, why are they worn in Winds, why are east usually dry ... 384 Winds, why are west usually wet... 385 Winch, why mouth must be held with the bit and bridle." PSALM xxxn. 6. WJiy is this combination necessary ? Because we are so created that the substances of our bodies are constantly undergoing change, and this resolving of solid matter into a gaseous form, is the plan appointed by our Creator to remove the matter called carbon from our systems. 7. Why do our bodies feel warm ? Because, in the union of oxygen and carbon, heat is developed. 8. What is this union of oxygen and carbon called? It is called combustion, which, in chemistry, means the decomposi- tion of substances, and the formation of new combinations, accom- panied by heat ; and sometimes by light, as well as heat. 9. What is formed by the union of oxygen and carbon ? Carbonic acid gas. 10. What becomes of this carbonic acid gas ? It is sent out of our bodies by the compressure of the lungs, and mingles with the air that surrounds us. 11. Is this carbonic acid gas heavier or lighter than the air ? Pure carbonic acid gas is the heaviest of all the gases. That which is sent out of the lungs is not pure, because the whole of the air taken into the lungs at the previous inspiration has not been deprived of its oxygen, and the nitrogen is returned. Therefore the breath sent out of the lungs may be said to consist of air, with a large proportion of carbonic acid gas. 12. What is the composition of air in its natural state ? It consists of oxygen, nitrogen, and carbonic acid gas, in the proportions of oxygen 20 volumes, nitrogen 79 volumes, and car- bonic acid gas 1 volume. It also contains a slight trace of watery vapour. 13. What is the state of the air after it has once been Ireathcd ? It has parted with about one-sixth of its oxygen, and taken up an equivalent of carbonic acid. And were the same air to be breathed 30 THE BEASCN WHY. "A prudent man forseeth the evil, and hideth hinftelf ; but the simple pass on, and are punished." PEOVEEBS XXTII. six times successively, it would have parted with all its oxygen, and could no longer sustain life. 14. Is the impure air sent out of tlie lungs lighter or heavier than common air ? At first, being rarefied by warmth, it is lighter. But, if undis- turbed, it would become heavier as it cooled, and would descend. 15. Why is it proper to have beds raised about two feet from the ground ? Because at night, the bed-room being closed, the breath of the sleeper impregnates the air of the room with carbonic acid gas, which, descending, lies in its greatest density near to the floor. 10. What are the chief sources of carbonic acid gas? The vegetable kingdom (as will be hereafter explained), the com- bustion of substances composed chiefly of carbon, the breathing of animals, and the decomposition of carfeouic compounds. 17. Is breathing a kind of combustion ? It is. In the breathing of animals, the burning of coal?, or of wood, or candles, &c., similar changes occur. The oxygen of the air combines with the carbon of the substance said to be burnt, and forms carbonic acid gas, which unfits the air for t!ie pur- poses of either breathing or of burning, until it has been renewed by admixture with the air. 18. What is carbon ? It is one of the elementary bodies, and is very abundmt through- out nature. It abounds mostly in vegetable substances, but is also contained in animal bodies, and in minerals. The form in which it is most familiar to us is that of charcoal, which is carbon almost pure. 19. What is meant by an elementary body ? An elementary body is one of those substances in whicn chemistry is unable to discover more than cue constituent. Tor instance, the chemist finds that water is composed of oxygen and hydrogen. Water is therefore a compound body. But carbon consists of carbon only, and therefore it is called a simple, or elementary body. THE BEA8O3* TVHY. 3] "Where DO wood is, there the fire goeth out : so where there is no tale- the strife ceaseth." FEOVERBS xsvi. 20. Why is it dangerous to burn charcoal in rooms ? Because, being composed of carbon that is nearly pure, its com- bustion gives off a large amount of carbonic acid gas. 21. Wliat is the effect of carbonic acid gas upon the human system ? It induces drowsiness and stupor, which, if not relieved by ventilation, would speedily cause death. 22. What is the reason that people feel drowsy in crowded rooms ? Because the large amount of carbonic acid gas given off with tho breaths of the people, makes the air poisonous and oppressive. 23. What other causes of drowsiness are there ? The candles, gas, or fires that may be burning in the rooms where people are assembled. Three candles produce as much carbonic acid gas as one human being ; and it is probable that one gas-light produces as much carbonic acid gas as two persons. 24. Have people ever been poisoned by their oion breaths ? In the reign of George the Second, the Rajah of Bengal took some English prisoners in Calcutta, and put 146 of them into a place which was called the " Black Hole." This place was only 18 feet square by 16 feet high, and ventilation was provided for only by two small grated windows. One hundred and twenty-three of the prisoners died in the night, and most of the survivors were afterwards carried off by putrid fevers. Many other instances have occurred, but this one is the most remarkable. - CHAPTER III. 25. What is oxygen ? Oxygen is one of the most widely diffused of the elementary sub- stances. It is a gaseous body. 26. Wliy do persons ivho are walking, or riding upon horse* back feel warmer than when they are sitting still ? THE HEASON WHY. " Stand in awe and sin not : commune with your own heart upon your bed and be still." PSAIM iv. Because as they breathe more rapidly, the combustion of the carbon in the blood is increased by the oxygen inhaled, and greater heat is developed. 27. Why does the fire burn more brightly when blown by a bellows ? Because it receives, with every current of air, a fresh supply of oxygen, which unites with the carbon and hydrogen of the coals, causing more rapid combustion and increased heat. 28. Why does not the oxygen of the air sometimes take fire ? Because oxygen, by itself, is incombustible. The wick of a candle, which retains the slightest spark, being immersed in oxygen, will instantly burst into a brilliant flame ; and even a piece of iron wire made red-hot, and dipped in oxygen, will burn rapidly and brilliantly. Oxygen, though non-combustible of itself, is the most powerful supporter of combustion. 29. Why do we know that oxygen will not burn of itself ? Because when we immerse a burning substance into a jar of oxygen, it immediately burns with intense brilliancy ; but directly it is withdrawn from the oxygen, the intensity of the flame diminishes, and the oxygen which remains is unaffected.. 30. Why do we know that oxygen is necessary to our existence ? Because animals placed in any kind of gas, or in any combination of gases, where oxygen does not exist, die in a very short time. 31. Where is oxygen found ? It is found in the air, mixed with nitrogen ; in water combined with hydrogen ; in the tissues of vegetables and animals ; in our blood; and in various compounds called, from*the presence of oxygen, oxides. 32. Why is the oxygen of the air mixed so largely with nitrogen } Because oxygen in any greater proportion than that in which it is found in the atmosphere, would be too excitino- to the animal THE EEASON WHY. 33 "As vinegar is to the teeth, and as smoke to the eyes, so is the sluggard to him that sent him." PEOVESBS X. system. Animals placed in pure oxygen die in great agony from fever and excitement, amounting to madness. 33. What is nitrogen ? Nitrogen is an elementary body in the form of gas. 34. Where is nitrogen found ? It is chiefly found in the air, of which it constitutes 79 out of 100 volumes. It may be mixed with oxygen in various proportions ; but in the atmosphere it is uniformly diffused. It is found in most animal matter, except fat and bone. It is not a constituent of the vegetable acids, but it is found in most of the vegetable alkalies. 35. What are acids ? Acids are a numerous class of chemical bodies. They are gene- ratty sour. Usually (though there are exceptions) they have a great affinity for water, and are easily soluble therein ; they unite readily with most alkalies, and with the various oxides. All acids are compounds of two or more substances. Acids are found in all the kingdoms of nature. 36. What are alkalies ? Alkalies are a numerous class of substances that have a great affinity for, and readily combine with, acids, forming salts. They exercise peculiar influence upon vegetable colours, turning blues green, and yellows reddish brown. But they will restore the colours of vegetable blues which have been reddened by acids ; and, on the other hand, the acids restore vegetable colours that have been altered by the alkalies. Alkalies are found in all the kingdoms of nature. 37. Could animals live in nitrogen ? No ; they would immediately die. But a mixture of oxygen and nitrogen, in equal volumes, constitutes nitrous oxide, which gives a pleasurable excitement to those who inhale it, causing them to be merry, almost to insanity ; it has, therefore, been called laughing gas. 38. Why does nitrous oxide produce this effect ? Because it introduces into the body more oxygen than can be consumed. It, therefore, leranges the nervous system, and being 2* 34 THE REASON WHY. : 'I/ord. make me know mine end, and the measure of my days, that I may know how frail I am." PSALM xxxix. a powerful stimulant, gives an unnatural activity to the nervous centres and the brain. 39. In wliat proportions are the atmospheric gases found in tlie Hood ? The mean quantity of the gases contained in the human blood has been found to be equal ^ 1-lOth of its whole volume. In venous blood, the average quantity of carbonic acid is about 1-1 8th, that of oxygen about l-85th, and that of nitrogen about l-100th of the volume of the blood. In arterial blood their quantities have been found to be carbonic acid about l-14th, oxygen about l-3Sth, and nitrogen about l-72nd. 40. Then is nitrogen talcen into the blood from the air ? Such a supposition is highly improbable. It is probably derived from nitrogenisedfood, just as carbonic acid is derived from car- Ionised food. 41. What is venous blood? Venous blood is that which is returning through the veins of the body from the organs to which it has been circulated. 42. What is arterial blood ? Arterial blood is that which is flowing, from the heart through the arteries to nourish the parts where those arteries are distri- buted. 43. What is the difference between venous and arterial Hood? Venous blood contains more carbonic acid, and less oxygen and nitrogen than arterial blood. 44. Will nitrogen burn ? It will not burn, nor will it support combustion. 45. What is the difference between " burning" and " sup- porting combustion ?" Oxygen gns will not burn of itself, but it aids the decomposition by fire of "bodies that are combustible. It is therefore called a sup- porter of jomlustion. Ikt hydrogen gas, though it burns of itself THE SEASON WHY. 85 " As coals are to burning coals, and wood to fire ; so is a contentious man to kindle strife." PJJOVEEBS xxvi. will extinguish aflame immersed in it. It is therefore said to bo a body which will burn, but will not support combustion. 46. What becomes of the nitrogen that is inhaled ivith the air ? It is thrown off with the breath, mixed with carbonic add gas, and flics away to be renewed by a fresh supply of oxygen. 47. Where does nitrogen find afresh supply of oxygen ? In the atmosphere. Nitrogen is said to possess a remarkable tendency to mix with oxygen, without having a positive chemica 1 affinity for it. That is to say, neither the oxygen nor the nitrogen undergoes any change by the union, except that of admixture. The oxygen and the nitrogen still possess their own peculiar properties. Oxygen and nitrogen are found in nearly the same proportions in all climates, and at all altitudes. 48. In combustion does any other result take place besides the union of oxygen and carbon forming carbonic acid gas? Yes. Usually hydrogen is present, which in burning unites with oxygen, and forms water. CHAPTER IV. 49. What is hydrogen ? Hydrogen is an elementary gas, and is the lightest of all known bodies. 50. Will Tiydrogen support animal life ? It will not. It proves speedily fatal to animals. 51. Will liydrogen support combustion ? Although it will burn, yielding a feeble bluish light, it will, if pure, extinguish a flame that may be immersed in it. Hydrogen wfll therefore burn, but will not support combustion. 52. Wliy will hydrogen explode, if it will not support com- lustion ? When hydrogen explodes it is always in combination with oxygen^ 86 THE REASON WHY. "As smoke is driven away, so drive them away: as wax melteth before the fire, so let the wicked perish at the presence of God." PSALH XLVI. or with the comimn air, which contains oxygen. * Two measures of hydrogen and one of oxygen form a most explosive compound. 53. Why does hydrogen explode, when mixed with oxygen, upon being brought in contact with fire ? Because of its strong affinity for oxygen, with which, upon the application of heat, it unites to form water. 54. Wliere does hydrogen chiefly exist ? In the form of water, where it exists in combination with oxygen. Eleven parts of hydrogen, and eighty-nine of oxygen, form water. 55. Is hydrogen found elsewhere ? It is never found but in a state of combination ; united with oxygen, it exists in water; with nitrogen, in ammonia; with chlorine, in hydro-chloric acid; with fluorine, in hydro-fluoric acid; and in numerous other combinations. 56. Is the gas used to illuminate our streets, hydrogen gas? It is ; but it is combined with carbon, derived from the coals from which it is made. It is therefore called carburetted hydrogen, .which means hydrogen with carbon. 57. How is hydrogen gas obtained from coals ? It is driven out of the coals by heat, in closed vessels, which pre- vent its union with oxygen. 58. Wliat becomes of the water wliich is formed by the burning of hydrogen in oxygen ? It passes into the air in the form of watery vapour. Frequently it condenses, and may be seen upon the walls and windows of rooms where many lights or fires are burning. Sometimes, also, portions of it become condensed in the globes of the glasses that are suspended over the jets of gas. A large volume of these gases forms only a very small volume of water. 59. What becomes of the carbonic acid gas which is pro- duced by combustion ? It is diffused in the air, which should be removed by adequate ventilation, THE REASON WHY. 37 I will both lay me down in peace and sleep : for thou, Lord, only, makost i dwell in safety." PSALM rv. 60. Wliat proportion of carbonic acid gas is dangerous to life? Any proportion over the natural one of 1 per cent, may bo regarded as injuriwjis. But toxicologists state that five per cent. of carbonic acid gas in the atmosphere is dangerous to life. 61. What are toxicologists ? Persons who study the nature and effects of poisons and their antidotes. 62. WTiich kind of combustible used for lighting tends most to vitiate the air ? Assuming all the lights to be of the same intensity, the degree in which the substances burnt would vitiate the atmosphere may be gathered from the number of minutes each would take to exhaust a given quantity of air. This has been found to be : rape oil, 71 minutes ; olive oil, 72 ; Eussian tallow, 75 ; town tallow, 76 ; sperm oil, 76 ; stearic acid, 77 ; wax candles, 79 ; spermaceti candles, 83 ; common coal gas, 98 ; canal coal gas, 152. Thus it is shown that rape oil is most destructive of the atmosphere, and- that coal gas is the least destructive. 63. Is an escape of hydrogen gas from a gas-pipe dangerous to life ? It is dangerous, first, by inhalation. There are no less than six deaths upon record of persons who were killed by sleeping in rooms near to which there was a leakage of gas. It is dangerous, secondly, by explosion. [In 1843, an explosion of gas occurred in Albany-street, Regent's-park, London. The gas accumulated in a shop for a very short time only. It had been escaping from a crack in the muter for about one hour and twenty minutes. The area of the room was about 1,620 cubic feet. When the gas exploded, it blew out the entire front of the premises, carried two persons tlirough a window into an adjoining yard, and forced another person on to the pavement on the opposite side of the street, where she was killed. The effect of the explosion was felt for more than a quarter of a mile on each side of the house, and most of the windows in the neighbourhood were shattered. The iron railings over the area of the house directly opposite were snapped asunder ; and a part of the roof, and the back windows of another house, were carried t<> distaucr of: from 200 to 300 yards. The pavement was tore, up for a considerablt 38 THE REASON WHT. " Lord, our L >rd, how excellent is thy name in all the earth ! who hast set thy glory above the heavens. PSALM vm. length, and the damage done to 103 houses was afterwards reported to amount to 20,000. Other serious explosions have taken place. The explosions of " coal damp," which frequently occur in mines, are of a similar character.] 64. What proportion of hydrogen gas with atmospheric air will explode ? According to the researches of Sir Humphrey Davy, seven or eight parts of air, to one of gas, produce the greatest explosive effect ; while larger proportions of gas are less dangerous. A mix- ture of equal parts of gas and air will burn, but it will not explode. The same is the case with a mixture of two of air, or three of air, and one offfas; \mifour of air and one of gas begin to be explosive, and the explosive tendency increases up to seven or eight of air and one of gas, after which the increased proportion of gas diminishes the force of the explosion. 65. What is the best method of preventing the explosion of Observe the rule, never to approach a supposed leakage with a light. Fortunately the gas, which threatens our lives, warns us of the danger by its pungent smell. The first thing to be done is to open windows and doors, and to ventilate the apartment. Then turn the gas off at the main, and wait a short time until the accu- mulated gas has been dipersed. 66. Does hydrogen gas rise or fall ivhen it escapes ? Being twelve times lighter than common air it rises, and there- fore it would be better for ventilation to open the window at the top than at the oottom. But all gases exhibit a strong tendency to diffuse themselves, and therefore they do not rise or fall in the degree that might be anticipated. 67. What proportion of hydrogen in the air is dangerous to life, if inhaled? One-fiftieth part has been found to have a serious effect upon animals. The effects it produces upon the human system are those of depression, headache, sickness, and general prostration of the vital powers. It is therefore advisable to observe precautions in the THE REASON WHY. * From the place of his habitation he lookctli upon all the inhabitants of th earth." PSALM xxxm. GS. What proportion of gas in. ilie air may be recognised ly the smell ? By persons of acute powera of smelling it may be recognised when there is one part of gas in Jive hundred parts of atmospheric air ; but it becomes very perceptible when it forms one part in a hundred and fifty. Warning is, therefore, given to us long before the point of danger arrives. 69. WTiat other sources of hydrogen are there in our dwellings ? It arises from tho decomposition of animal and vegetable sub- stances, containing sulphur and hydrogen. These give off a gas called sulphuretted hydrogen, from which the fifitid effluviam of drains and water-closets chiefly arise. We should, therefore, take every precaution to secure effective drainage, and to keep drain-traps in proper, order. 70. JlTay the use of gas for purposes of illumination he con- sidered highly dangerous ? Not if it is intelligently managed. The appliances for the regu- lation of gas are so very simple and perfect, that accidents seldom arise except from neglect. In England 6,000,000 tons of coal are usually consumed in the manufacture of gas,producing 60,000,000,000 cubic feet of gas. And yet accidents are of very uncommon occurrence. CHAPTEE V. 71. What is heat? Heat is a principle in nature which, like light and electricity, u best understood by its effects. We popularly call that heat, which raises the temperature of bodies submitted to its influence. 72. What is caloric ? Caloric is another term for heat. It is advisable, however, to use the term caloric when speaking of the cause of heat, and as the effect of the presence of caloric. 40 THE SEASON WHY. " While the earth remaineth, seed-time and harvest, and cold and heat, and summer and winter, and day and night, shall not cease." GEN. Tin. 73. What is the source of caloric ? The sun is its chief source. But caloric, in some degree, exists in every known substance. ^ 74. WJiat are the e/ects of caloric ? Heat which, in proportion to its intensity, acts variously upon all bodies, causing expansion, fusion, evaporation, decomposition, Sfc. 75. Why is caloric called a repulsive agent ? Because its chief effects are to expand, fuse, evaporate, or de- compose the substances upon which it acts. 7G. What is an attractive agent, in contradistinction to a repulsive agent ? Chemical attraction, or affinity, is an attractive agent as when bodies seek of their own natures to unite and form some new body. 77. When is a body said to be not ? When it holds so much caloric that it diffuses heat to surround- ing objects. 78. When is a body said to be cold? When it holds less caloric than surrounding objects, and absorbs heat from them. 79. How may caloric be excited to develope heat ? By any means which cause agitation, or produce an active change in the condition of bodies. Thus friction, percussion, sudden con- densation or expansion, chemical combination, and electrical dis- charges, all develope heat. 80. Why do " burning glasses" appear to set fire to com- bustible substances ? Because they gather into one point, or focus, several rays of caloric as they are travelling from the sun, and the accumulation of caloric developes that intensity of heat which constitutes./??-*?. 81. What is a focus ? In optics, it is the point or centre at which, or around which, divergent rays are brought into the closest possible union. THE EEASOJT WHY. Jet man is born to trouble, as the sparks fly upward. I would seek unto God, and unto God would I commit my cause." JOB v. 82. What is fire? It is a violent chemical action attending the combustion of tha ingredients of fuel with the oxygen of the air. 83. What are the properties of fire ? It imparts heat, which has the effect of expanding both fluids and solids. It cannot exist without the presence of combustible materials. It has a tendency to diffuse itself in every direction. It cannot exist without oxygen or atmospheric air. 84. What elements take part in the maintenance of a fire ? Hydrogen, carbon, and oxygen. Hydrogen and carbon exist in the fuel, and oxygen is supplied by the air. 85. Soio does the combustion of a fire legin ? A match made of phosphorous and sulphur (highly inflammable substances) is drawn over a piece of sand-paper ; ihe friction of the match induces the presence of caloric, which derelopes heat, and ignites the match, the burning of which is sustained by the oxygen of the air. The flame is then applied to paper or wood, and the heat of the flame is sufficient to drive out hydrogen gas, which unites with the oxygen of the air, and burns, imparting greater heat to the carbon of the coals, which assumes the form of carbonic acid gas by union with oxygen, and in a little while all the conditions of combustion are established. 86. Wliat are the properties of heat? It may exist without fire or light. It is not sensible to vision. It makes an impression upon onr feelings. It acts powerfully upon all bodies. It has 1:0 weight. It attends, or is connected with, all the operations of nature. It radiates from all bodies in straight lines, and in all directicns, It strikes most powerfully in direct lines. Its rays may be collected into a focus, just as the rays of the sun, It may be reflected from a polished surface. It is more easily conducted by some substances than by others. 42 THE EEASOS YHY. " For my days are consumed like smoke, and my bones are burned as an hearth." PSALM cir. 87. WJiat is animal heat ? Animal heat is derived from the slow combustion of carbon in the blood of animals with the oxygen of the air which the animals breathe. 88. What is latent heat ? Latent heat (or more properly latent caloric) is that which exists, in some degree, in all bodies, though it may be imperceptible to the senses. 89. Is there latent caloric in ice, snow, water, marble, 8fc ? Yes ; there is some amount of caloric in all substances. []A blacksmith may hammer a small piece of iron until it becomes red hot. With this he may light a match, and kindle the fire of his forge. The iron has become more dense by the hammering, and it cannot again bo heated to the same degree by similar means, until it has been exposed in fire, to a red heat. Is it not possible that, by hammering, the particles of iron have been driven closer together, and the latent heat driven out ? No further hammering will force the atoms nearer, and therefore no further heat can bo developed. But when the iron has again absorbed caloric, by being plunged in a fire, it is again charged with latent heat.- Indians produce sparks by rubbing together two pieces of wood. Two pieces of ice may be rubbed together until sufficient warmth is developed to melt them both. The axles of railway carriages frequently become red hot from friction.'} 90. Have vegetables heat ? Yes ; whenever oxygen combines with carbon to form carbonic acid gas, an extrication of heat takes place, however minute the amount. Such a combination occurs much more extensively during the germination of seeds and the impregnation of flowers, than at any other time. In the germination of barley heaped in rooms, previous to being converted into malt, it is well known that a considerable amount of heat is developed. 91. Has any investigation of this subject ever been care- fully made ? Yes. Lamarck, Senebier, and Do Candolle, found the flowers of the Arum Maculatum, between three and seven o'clock in the afternoon, as much as 7 deg. Eeaum. warmer than the external air. Schultz found a difference of 4 deg. to 5 deg. between the heat of the spathe of the Canadian pinnattfolium and the sur- THE BEASOtf WHY. 43 ' And there arc diversities of operations, but it is the same God which woiketti in all." COEINTHIA^S xn. rounding air, at six to seven o'clock p.m. Other observations have established differences of as much as 30 deg. between the temperature of the spathe of the Arum cordifolium, and that of the surrounding atmosphere. 92. Have plants sometimes a temperature lower than that of the surrounding air ? Yes. It has not only been found that under particular circum- stances the heat of certain parts of plants is elevated to a very re- markable degree, but that, under nearly all circumstances, they have a temperature different from that of the external air, being warmer in winter, and cooler in summer. CHAPTER VI. 93. How many kinds of combustion are there? There are three, viz., slow oxydation, when little or no light is evolved; a more rapid combination, when the heat is so great as to become luminous ; and a still more energetic action, when it bursts iniofiame. 94. Why does phosphorous look luminous ? Because it is undergoing slow combustion. 95. Why do decayed wood, and putrifying fish, look lumi- nous? Because they are undergoing slow combustion. In these cases the heat and light evolved are at no one time very considerable. But the total amount of heat, and probably of light, generated through the lengthy period of this slow oxydation, amounts to exact- ly the same as would, be evolved during the most rapid combustion nf the same substances. 96. What is flame ? It is gaseous matter burning at a very high temperature. 97. W7iy, when toe put fresh coals upon a fire, do we heat the gas escaping from the coals without taking fire ? 44 THE BEASON WHY. 'I will praise thee, O Lord, with my whole heart; I will show forth ILy marvellous work. ' PSALM IX. Because, the fire being slow, the temperature is not high enough to ignite the gas. 98. What is the gas which escapes from the coals ? Carburetted hydrogen. 99. Why, if we light a piece of paper, and lay it where tlie gas is escaping from the coals, will it burst into flame ? Because the lighted paper gives a heat sufficient to ignite the gas ; and because also hydrogen requires the contact of flame to ignite it. 100. Why, when the coals have become heated, will the hydrogen hurst into Jlame ? Because the carbon of the coals, and the oxygen of the air, have begun to combine, and have greatly increased the heat, and have produced a rapid combustion, so nearly allied to Jlame, that it ignites the hydrogen. 101. What temperature is required to produce Jlame ? That depends upon the nature of the combustible you desire t<5 burn. Finely divided phosphorous and phosphorated hydrogen will take fire at a temperature of 60 deg. or 70 deg. ; solid phos- phorous at 140 deg. ; sulphur at 500 deg. ; hydrogen and car- bonic oxide at 1,000 deg. (red heat) ; coal gas, ether, turpentine, alcohol, tallow, and wood, at about 2,000 deg. (incipient white heat). When once inflamed they will continue to burn, and will maintain a very high temperature. 102. What is smoke ? Smoke consists of small particles of carbon of hydrogen gas, and other volatile matters, which are driven off by heat and carried up the chimney. 103. Is it notaicaste of fuel to allow this matter to escape? It is, as it might all be burnt up by better management. 10 i. How may the waste he avoided? By putting on only a little coals at a time, so that the heat of the fire shall be sufficient to consume these volatile matters as they escape. THE KEASOK WHY * And the sirong shall be as tow, and the maker of it as a spark, and they shaL both burn together, and none shall quench them." ISAIAH i. 105. Wliy is there so little smoke tvhen the fire is red? Because the hydrogen and the volatile parts of the coal have already been driven oft' and consumed, and the combustion that con- tinues is principally caused by the carbon of the coals, and the oxygen of the air. 106. Will carl/on, burnt in oxygen, produce flame and smoke ? It burns brightly, but it produces neither flame nor smoke. 107. Why do not charcoal and coke fires givefiamc ? Because the hydrogen has been driven off by the processes by which charcoal and coke are made. 108. What is a conductor of heat? A conductor of heat is any substance through which heat is readily transmitted. 109. Wliat is a non-conductor of heat? A non-conductor is any substance through which heat will not pass readily. 110. Name a few good conductors. Gold, silver, copper, platinum, iron, zinc, tin, stone, and all dense solid bodies. 111. Name a few non-conductors. Fur, wool, down, wood, cotton, paper, and all substances of a spongy or porous texture. 112. IToio is heat transmitted from one lody to another ? By Conduction, Radiation, Reflection, Absorption and Convection. 113. What is the Conduction of heat ? It is the communication of heat from one body to another by con* tact. If I lay a penny piece upon the hob, it becomes hot by conduction- 114. What is the Eadiaticn of heat? The transmission of heat by a series of rays. If I hold ray hand THE BEASON WHY. " Sing praises to the Lord, which dwellcth in Zion, declare among the people hi* doings." PSALM ix. before the fire, the rays of heat fall upon it, and my hand receives the heat through, radiation. 115. What is the Reflection offieat ? The reflection of heat is the throwing back of its rays towards the direction whence they came. In a Dutch oven the rays of heat pass from the fire to the oven, and are reflected back again by the bright surface of the tin. There is, therefore, considerable economy of heat in ovens, and other cooking utensils constructed upon this plan. 11G. What is the Absorption of heat ? The absorption of heat is the taking of it up by the body to which it is transmitted or conducted. Heat was conveyed to my hand by radiation, and taken up by my hand by absorption 117. What is the Convection of heat ? The convection of heat is the transmission of it through a body or a number of bodies, or particles of bodies, by those substances which first received it ; as when hot water rises from the bottom of a kettle and imparts heat to the cold water lying above it. CHAPTER VII. 118. Why does not apiece of wood which is burning at one end, feel hot at the other end? Because wood is a bad conductor of heat. 119. Why is wood a bad conductor of heat ? Because the arrangement of the particles of which it is composed does not favour the transmission of caloric. 120. Why do some articles of clothing feel cold, and others warm ? Because some are bad conductors of heat, and do not draw off much of the warmth of our bodies; while others are better con- ductors, and taJce up a larger portion of our warmth. THE KEASON v, FIT. 47 * The fining pot is for silver, and the furnace for gold : but tho Lord trieth the hearts." PEOVEEBS xvn. 121. Which feels the warmer, the conductor or non-con- ductor ? The non-conductor, as it does not readily absorb the warmth of our bodies. 122. What substances are the best conductors of heat? Gold, silver, copper, and most substances of close and hard for- mation, &c. 123. What substances are the worst conductors of heat T Fur, eider down, feathers, raw silk, wood, lamp-black, cotton, soot, charcoal, &c. 124. Why has the toasting-forlc a wooden handle ? Because wood is not so good a conductor as metal, therefore the wood prevents the heat from being transmitted by conduction to our, hands. 125. Why 7ias the coffee-pot a wooden handle ? Because the metal of the coffee-pot would otherwise conduct the heat to the Jiand ; but wood, being a bad conductor, prevents it. 126. Why does hot water in a metal jug feel hotter than in an earthenware one ? Because metal, being a good conductor, readily delivers heat to the hand ; but earthenware, being an indifferent conductor, parts with the heat slowly. 127. Hoio can we ascertain that icood prevents the conduc- tion of heat to the hand? By passing the top of the finger along the wooden handle of the coffee-pot, until it reaches the point where the wood meets the metal. The wooden handle will be found to be cool, but the metul will feel very hot. 128. Of what use are kettle-holders? Being made of bad conductors, such as wood, paper, or woollen cloth, they will not readily conduct the heat from the kettl* to the hand. 48 THE EEASON WHY. 'Wisdom is the principal thing; therefore get \risdom: and with all thy getting get understanding." PEOVEEBS IV. 129. Will a kettle-holder, being a lad conductor, sometimes conduct heat to the hand ? Yes. But sp slowly that the hand will not feel the inconvenience of too much heat. 130. Why does hot metal feel hotter than heated wool, though they may both be of the same degree of temperature ? Because metal gives out heat more rapidly than wool, by which it is made more perceptible to our feelings. 131. Which would become cold first ike metal or the wool? The wool, because, although the metal conducts heat more rapidly, to a substance in contact with it, it does not radiate heat as well as a blade and rough substance. 132. Why do iron articles feel intensely cold in winter ? Because iron is one of the best conductors, and draws off heat from the hand very rapidly. 133. WJiat is the cause of the sensation called cold ? When we feel cold, heat is being drawn off from our bodies. 134. What is the cause of the sensation called heat ? When we feel hot, our bodies are absorbing heat from external [The condition here implied is that of health, and of ordinary circumstances. A person in a condition of fever, suffering from intense heat arising from a diseased state of the blood, could not be said to be absorbing heat. Nor could such a description apply to a person who, by a very rapid walk, has raised the temperature of his body considerably above its natural state, by the internal combustion which has already been described. A person feeling hot in bed, from excessive clothes, feels hot from the development of heat internally, which is not conducted away with sufficient rapidity to maintain the natural tempe- rature of the body.] 135. If a person, sitting before afire-place, without afire, were to set one foot upon a rug, and the other upon the stone hearth, which would feel the colder? The foot on the stone, because stone is a good conductor, and would conduct the warmth of the foot away from it. THE B'EASON WHY. 49 "The earth is the Lori's, and the fulness thereof; the world, and they that ^ dwell therein." PSALM xxrv. 136. What does the hearth-stone do with the heat tJiat it receives ? It delivers it to the surrounding air, and to any other bodies with which it may be in contact and as it parts with heat, it takes up more from any body hotter than itself. 137. When there is no fire in a room, what is the rela- tive temperature of the various things in the room ? They are all of the same temperature. 138. If all the articles in the room are of the same tem- perature, why do some feel colder than others ? Because they differ in their relative powers of conduction. Those that are the best conductors feel coldest, as they convey away the heat of the hand most rapidly. [If you lay your hand upon the woollen table cover, or upon the sleeve of your coat or mantle, it will feel neither warm nor cold, under ordinary circum- stances. But if you raise your hand from the table cover, or coat, and lay it on the marble mantel- piece, the mantel-piece will feel cold. If now you return your hand from the inantel-piece to the table cover or coat, a sensation of viarmth will become distinctly perceptible. This will afford a good conception of the relative powers of conduction of wool and marble.'} 139. Sow long does a substance feel cold or hot to the touch ? Until it has brought the part touching it to the same temperature as itself. 140. When do substances feel neither hot nor cold ? When they are of the same temperature as our bodies. 141. Why, under these circumstances, do they feel neither hot nor cold ? Because they neither take heat from, nor supply it to, the body. 142. Wliich would feel the warmer, when the fire wot lighted, the Tiearth-rug or the hearth-stone ? The hearth-stone, because it is a good conductor, and would not only fmwtu heat readily, but would fart with it as freely (thereby 3 50 THE BEASON -WHY. " Fire and hail ; snow and vapour ; stormy wind fulfilling his word." PSAiSI CX1VIII. % making its heat perceptible). But the hearth-rug, being a bad conductor, would part with its heat very slowly, aud it would there- fore be less perceptible. 143. Would the hearth-stone fed "hotter than the liearili- rug though both were of the same temperature ? It would feel "hotter than the hearth-rug, because it would part with its heat so rapidly that it would be the more perceptible. 144. But if the hearth-stone and the hearth-rug ivere both colder than the hand, ivhich would feel the colder of the two ? Then the hearth-stone would feel the colder, because, being a good conductor, it would take heat from the hand more freely than the hearth-rug, which is a bad conductor. 145. Why would the hearth-stone feel comparatively hotter in the one case, and colder in the other ? Because, "being a good conductor, it would conduct heat rapidly to the hand when hot, and take heat rapidly from the hand when cold. CHAPTER VIII. 146. Which are the letter conductors of heat, fluids or solids ? Generally speaking, solids, especially those of them that are dense in their substance. 147. Why cere dense substances the lest conductors of heat? Because the heat more readily travels from particle to particle anlil it pervades the mass. 14S, Why are fluids lad conductors of heat ? Because of the want of density in their bodies ; and because a portion of the imbibed heat always passes off from fluids by evaporation. ji THE SEASON WHT. 51 ' He casteth forth his ice like morsels : who can stand before his word."-* * PS AIM CXLVIT. 149. Why are woollen fabrics bad conductors of heat T Because there is a considerable amount of air occupying thd spaces of the texture. 150. Is air a good or a lad conductor ? Air is a lad conductor, and it chiefly transmits heat, as water does, by convection. 151. Is water a gvod or a lad conductor ? "Water is an indifferent conductor, but it is a letter conductor than air. 152. W ' hy, when we place our hands in water, which may le of the same temperature as the air, does the^ water feel some degrees colder ? Because water, leing a letter conductor than air, takes up the warmth of the hand more rapidly. 153. Why, when we taJce our hands out of water do they feel warmer ? Because the air does not abstract the heat of the hand so rapidly as the water did, and the change in the degree of rapidity with which the heat is abstracted produces a sensation of increased warmth. 154. Why do we see llocTcs of ice wrapped in thick flannel in summer time ? Because the flannel, being a non-conductor, prevents the external heat from dissolving the ice. [Flannel wrapped around a warm body keeps in its "heat; and wrapped around a cold body, prevents heat from passing into it.] 155. How do we know that air is not a good conductor of heat? Because, in still air, heat would travel to a given point much more rapidly, and in greater intensity, through even an indifferent solid conductor, than it would through the air. 156. How do we know that water is not a good conductor tfkeatf ' Afl snow in summer, and as rain in harvest ; so honour is not seemly for a fool." PEOV. xxvi. Because in a deep vessel containing 1 ice, and with heat applied at the top, some portion of the water may be made to boil before the ice, which lies a little under the surface, is melted. 157. Why would you apply the heat at the top, in this experiment ? Because in heating water it expands and rises. The boiling of water is caused by the heated water ascending from the bottom, and the colder water descending to occupy its place. If the heat were not applied at the top, it would be distributed quickly by convection, but not by conduction. 158. Why are bottl?*^ of hot water, used as feet-warmers, wrapped in flannel ? Because the flannel, being a bad conductor, allows the heat to 2)ass only gently fror* the bottle, and preserves the warmth for a much longer time. ' 159. Why are \>t rolls sent out by the lakers, wrapped up in flannel ? Because the flarmel, being a bad conductor, does not carry off rapidly the heat *f the rolls. 160. Why M it said that snow Iceeps the earth warm ? Because snc*jr is a bad conductor, and prevents the frosty air from depriving the earth of its warmth. 161. WJiy are snow huts which the Esquimaux build found to bo icarm? Because snow, "being a bad conductor, keeps in the internal heat of the dwelling, and prevents the cold outer air from taking away its warmth. 162. Why is snoiv, being composed of congealed water (and water being a better conductor than air), so good a non- conductor ? Because in the process of congealation it is frozen into crys'taline forms, which, being collected into a masa, form a woolly body, thoa THE REASON WHY. 53 "He giveth snow like wool: ho scattereth the hoar frost like ashes." PSALM CXLTII. proving the truthfulness of the Bible simile, which says, God " giveth snow like wool." CSYSTAiS OB SSOYT, A3 SEEJf TUBOUGH A MICBOSCOPB. FlCK 1. 163. Why does it frequently feel warmer after a frost hat *et in ? Because, in the act of congelation a great deal of heat is given, out, and taken up by the air, and thus the severity of the cold is in some degree moderated. 164. Why is it frequently colder when a thaw takes place ? Because, in the process of thawing, a certain amount of heat is icithdrawnfrom the air, and enters the thawed-ice. 165. What benefit results from these provisions of Nature ? They moderate both the severity of frosts, and the rapidity of thaws, which, in changeable climates, would be seriously detrimental to life, and to vegetation. 166. WJiy are furs and woollens worn in the winter ? Because, being non-conductors, they prevent the warmth of the body from being taken up by the cold air. 167. Why are the skins of animals usually covered with fur, hair, wool, or feathers? 64 THE SEASON WHY "Hesendeth out his word, and melteth them : he causeth his wind to blow; and the waters to flow." PSAI^I CXLVII. Because their coverings, being non-conductrs of heat, preserve the warmth of the bodies of the animals. 168. Sow is the greater warmth of animals provided for in the winter ? It is observed that, as winter approaches, there comes a short woolly or downy growth, which, adding to the non-conducting pro- perty of their coats, confines their animal warmth. [In small birds during winter, let the external colour of the feathers bo what it may, there will be found a kind of black down next their bodies. Black is the warmest colour, and tho purpose here is to keep in the heat, arising from the respiration of the animaL] 169. How is warmth provided for in animals that have no such coats ? They are furnished with a layer of fat, which lies underneath the skin. Fat consists chiefly of carbon, and is a non-conductor. 170. Why are summer breezes said to be cool ? Because, as they pass over the heated surface of the body, they bear away a part of its heat. 171. Why is a still summer air said to be sultry ? Because, being heated by the sun's rays, and, being a bad conductor, it does not relieve the body by carrying off its heat. 172. Why does fanning the face make it feel cooler? Because, "by inducing currents of air to pass over the face, a part of the excessive heat is taken up and carried away. 173. Why does perspiration cool the body? Because it takes up a part of the heat, and, evaporating, carr let it into the air. 174. Why does blowing upon hot tea cool it? Because it directs currents of air over the surface of the tea, and these currents take up a part of the heat and bear it away. 175. Why does air in motion feel cooler than air that is ttill? ware of air carries away a certain portion of heat THE SEASON WHY. 55 1 Though I walk in the valley of the shadow of death I will fear no evil, for thou art with me." PSAIM xxin. and being followed by another portion of air, a further amount of heat is borne away. 176. Is the atmosphere ever as hot as the hitman lody ? Not in this country. On the hottest day it is 10 or 12 deg. cooler than the temperature of our bodies. 177. What is the highest degree of artificial heat which man has been known to bear ? A man may be surrounded with air raised to the temperature of 300 deg. (the boiling point being 212), and yet not have the heat of his body raised more than two or three degrees above its natural temperature of from 97 deg. to 100 deg. 178. Why may man endure this degree of neat for a short time without injury ? Because the skin, and the vessels of fat that lie underneath it, are bad conductors of heat. And because perspiration passing from the skin and evaporating, would bear the heat away as fast as it was received. Because, also, the vital principle (life) exercises a mysterious influ- ence in the preservation of living bodies from physical influences. 179. Is the air ever hot enough, in any part of the world, to destroy life ? Yes. The hot winds of the Arabian deserts, which are called simooms, scatter death and desolation in their track, withering trees and shrubs, and burying them under waves of hot sand. When camels see the approach of a simoom they rush to the nearest tree or bush, or to some projecting rock, where they place their heads in an opposite direction to that from which the wind blows, and en- deavour to escape its terrible violence. The traveller throws him- self on the ground on the lee side of the camel, and screens his head from the fiery blast within the folds of his robe. But fre- quently both man and beast fall a prey to the terrible simoom. 180. Wliy are these hot winds so terrible in their effects ? Because, being in motion,- they search their way to every part of 66 THE EEASON WHY. ' The fear of the Lord is tho beginning of knowledge : but fools despise wisdom and instruction." PROVERBS i. the body, and passing over it leave some portion of their heat be' hind, which is again followed by additional heat from every fresh blast of wind. CHAPTEE IX. 181. What is Eadiation ? The radiation of heat is a motion of the particles, in a series of rays, diverging in every direction from a heated body. 182. What is this phenomena of Radiation understood to arise from ? From a strongly repulsive power, possessed by particles of heat, by which they are excited to recede from each other with great velocity. 183. What is the greatest source of Radiation ? The sun, which sends forth rays of both light and heat in all directions. 184. When does a body radiate Tieat ? When it is surrounded by a medium which is a bad conductor 185. When we stand before a fire, does the heat reach us ly conduction or by radiation ? By radiation. 186. What becomes of the heat that is radiated from one body to another ? It is either absorbed by those bodies, or transmitted through them and passed to other bodies by conduction, or diffused by convection, or returned by reflection. 187. Sow do we Tcnow that heat is diffused by radiation ? If we set a metal plate (or any other body, though metal is best for the experiment) before the fire, rays of heat will fall upon it. If we turn the plate at a slight angle, and place anothe/ THE EEASON WHY. 57 * The fear of tho Lord is the beginning of wisdom : a good understanding have all they that do his commandments." PSALM cxi. object in a line with it, we shall find that the plate will reflect the rays it has received by radiation, on to the object so placed ; but if we place an object between the fire and the plate, we shall find that the rays of heat will be intercepted, and that the latter can no longer reflect heat. 188. Does the agitation of the air interfere witli the direc- tion of rays of heat ? It has been found that the agitation of the air does not affect the direction of rays of heat. 189. Why, then, if a current of air passes through a space across which heat is radiating, does the air become warmer ? Because it takes up some portion of the heat, but it does not alter the direction of the rays. [This is clearly illustrated by reference to rays of light which are seen under many circumstances. But they are never bent, moved, nor in any way affected by the wind.] 190. Why will not a current of air disturb the rays of heat, just as if would a spider's web, or threads of silk ? Because heat is an imponderable agent, that is, something which cannot Be acted upon by the ordinary physical agencies. It has no weight, presents no substantial body, and is, in these latter respects, similar to light and electricity. 191. What other sources of radiation of heat are there besides the sun and the fire ? The earth, and all minor bodies, are, in some degree, radiatort of heat. 192. What substances are the best radiators ? All rough and dark coloured substances and surfaces are the best radiators of heat, 193. What substances are the worst radiators of heat ? All smooth, bright, and light coloured surfaces are bad radiatort if heat. [Dr. Stark, of Edinburgh, has proved, by a series of experiments, the influence which the colours of bodies have upon the velocity of radiation. He surrounded 58 THE SEASON -WHY. 'Say unto wisdom, Thou art my sister ; and call understanding thy kins- woman." PEOVEEBS vn. the bulb of a thermometer successively with equal weights of black, red, and white wool, and placed it in a glass tube, which was heated to the temperature of ISO deg. by immersion in hot water. The tube was then cooled down to 50 deg. by -immersion in cold water ; the black cooled in 21 minutes, the red in 26 minutes, and the white iu 27 minutes.] 194. If you wished to keep water hot for a long time, should you put it into a bright metal jug, or into a dark earthenware one? You should put it into a bright metal jug, because, being a lad radiator, it would not part readily with the heat of the water. 195. Why would not the dark earthenware jug keep the water hot as long as the bright metal one ? Because the particles of earthenware being rough, and of dark colour, they radiate heat freely, and the water would thereby be quickly cooled. CHAPTER X. 196. But if (as stated in the Lessons upon Conduction) metal is a better conductor of heat than stone or earthenware, why does not the metal jug conduct away the heat of the water sooner than the earthenware jug ? It would do so, if it were in contact with another conductor ; but, being surrounded by air, which is a bad conductor, the heat must pass off by radiation, and as bright metal surfaces are bad radiators, the metal jug would retain the heat of the water longer than the earthenware one. 197. Supposing a red-hot cannon ball to be suspended by a chain from the ceiling of a room, how would its heat escape? Almost entirely by radiation. But if you were to rest upon the ball a cold bar of iron, a part of the heat would be drawn off by conduction. Warm air would rise from around the ball, and, moving upwards, would distribute some of the heat by convection THE EEASON WHY. 59 ' 1 wttl teach you by the hand of God ; that which is with the Almighty will I not conceal." JOB xxvii. And some of its rays, falling upon a mirror, or any other bright surface, might be diffused by reflection. 198. Do some substances absorb heat? Yes ; those substances which are the lest radiators are also the best absorbers of heat. 199. Why does scratching a bright metal surface increase its power of radiation ? Because every irregularity of the surface acts as a point of radiation, or an outlet by which the heat escapes. 200. Why does a bright metal tea-pot produce better tea than a brown or black earthenware one ? . Because bright metal radiates but little heat, therefore the water is kept hot much longer, and the strength of the tea it extracted by the heat, 201. But if the earthenware tea-pot were set by the fire, why would it then make the best tea ? Because the dark earthenware tea-pot is a good absorber of heat, and the heat it would absorb from the fire would more than counterbalance the loss by radiation. 202. How would the bright metal tea-pot answer if set upon the hob by the fire-? The bright metal tea-pot would probably absorb less heat than it would radiate. Therefore it would not answer so well, being set upon the hob, as the earthenware tea-pot. 203. Why should dish covers be plain in form, and have bright surfaces ? Because, being bright and smooth,- they will not allow heat to escape by radiation. 201 Why should the -bottoms and back parts of kettles and saucepans be allowed to remain black ? Because a thin coating of soot acts as a good adsorber of heat, tad overcomes the non-absorbing auality of the bright 60 TE EEASON WHY. 'And the foolish said unto the wise, Give us of your oil, for our mmps are gone out. 205. But why should soot be prevented from accumulating inflates at the bottom and sides of kettles and saucepans T Because, although soot is a good absorber of heat, it is a very bad conductor ; an accumulation of it, therefore, would cause a waste of fuel, by retarding the effects of heat. 206. Why should the lids and fronts of Icettles and sauce- pans be kept bright ? Because bright metal will not radiate heat ; therefore, the heat which is taken up readily through the absorbing and conducting power of the bottom of the vessel, is kept in and economised by the non-radiating property of the bright top and front. 207. I)oes cold radiate as well as heat ? It was once thought that cold radiated as well as heat. But a mass of ice can only be said to radiate cold, by its radiating heat in less abundance than that which is emitted from other bodies turrounding it. It is, therefore, incorrect to speak of the radiation of cold. CHAPTER XL 208. Why, if you hold a piece of looking-glass at an angle towards the sun, will light fall upon an object opposite to the looking-glass ? Because the rays of the sun are reflected by the looking-glass. 209. Why, when we stand before a mirror, do we see our features therein ? Because the rays of light that fall upon us are reflected upon the bright surface of the mirror. 210. Why, if a plate of bright metal were held sideways before afire, would heat fall upon an object opposite to the plate? THE EEASON WHY. ' But the wise answered saying, Not so ; lest there be not enough for us and you : but go ye rather to them that sell, and buy for yourselves." MATT. xxv. Because rays of heat may be reflected in the same manner as th rays of light. 211. Why would not the same effect arise if the plate wero of a black or dark substance ? Because black and dark substances are not good reflectors of heat. 212. What are the best reflectors of heat? Smooth, light-coloured, and highly polished surfaces, especially those of metal. 213. Why does meat become cooked more thoroughly and quickly when a tin screen is placed before the fire ? Because the bright tin reflects the rays of heat bade again to the meat. 214. "Why is reflected heat less intense than the primary heat? Because it is impossible to collect all the rays, and also because a portion of the caloric, imparting heat to the rays, is absorbed by the air, and by the various other bodies with which the rays come in contact. 215. Can heat be reflected in any great degree of intensity? Yes : to such a degree that inflammable matters may be ignited by it. If a cannon ball be made red hot, and then be placed in an iron stand between two bright reflectors, inflammable materials, placed in a proper position to catch the reflected rays, will ignite froin the heat. There is a curious and an exceptional fact with reference to reflected heat, for which we confess that we are unable to give " The Reason Why." It Is found that snow, which lies near the trunks of trees or the base of upright stones, melts before that which is at a distance from them, though the sun may shine equally upon both. If a blackened card is placed upon ice or snow under the sun's rays, the frozen body underneath it will be thawed before that which surrounds it. But if we reflect the sun's rays from a metal surface, the result is directly contrary the exposed snow is the first to melt, leaving the card standing as upon a pyramid. Snow melts under heat which is reflected from tho trees or stones while it withstands the effect of Vhe direct solar rays. lu passing through a cemetery this winter (1857). when the mow lay deep, w THE EEASOX WHY. * The light of the righteous rejoiceth, but the lamp of the wicked shall be put out." PEOVEEBS xm. were struck with the circumstance that the snow in front of the head-stones facing the sun was completely dissolved, and, in nearly every instance, the space on which the snow had melted assumed a coffin-like shape. This forced itself so much upon our attention that we remained some time to endeavour to analyse the phenomena ; and it was not until we remembered the curious effect of reflected heat that we could account for it. It is obvious that the rays falling from the upper part of the head-stone on to the foot of the grave would be less powerful than those that radiated from the centre of the stone to the centre of the grave. Hence it was that the heat dissolved at the foot of the grave only a narrow piece of snow, which widened towards the centre, and narrowed again as it approached the foot of the head-stone, where the lines of radiation would naturally decrease. Such a phenomena would prove sufficient to raise superstition in untutored minds. 216. Are good reflectors of heat also good absorbers ? No ; for reflectors at once send back the heat which they receive, while absorbers retain it. It is obvious, therefore, that reflector* cannot be good absorbers. 217. Sow do fire-screens contribute to Tceep rooms cool ? Because they turn away from the persona in the room rays of heat which would otherwise make the warmth excessive. 218. Why are white and liglit articles of clothing cool ? Because they reflect the rays of heat. [Whiter as a colour, is also a bad absorber and conductor.'] 219. Why is the air often found excessively hot in chalk districts ? Because the soil reflects upon objects near to it the heat of the solar rays. 220. Sow does the heat of the sun's rays ultimately become diffused ? It is first absorbed by the earth. Generally speaking 1 , the earth absorbs heat by day, and radiates it by night. In this way an equilibrium of temperature is maintained, which we should not otherwise have the advantage of. 221. Does not the air derive its heat directly from the suvts.rays ? Only partially. It is estimated that the air absorbs only one- third, of the caloric of the sun's rays that is to say, that R ray of THE EEASOK WHY. 63 "As for the earth, out of it cometh hread ; and under it is turned up as it wer fire." JOB xxvm. solar heat, entering our atmosphere at its most attenuated limit (a height supposed to be about fifty miles), would, in passing through the atmosphere to the earth, part with only one-third of its calorific clement. 222. Wliat lecomes of the remaining two-thirds of the solar heat ? They are absorbed, chiefly by the earth, the great medium of calorific absorption; but some portions are taken up by living things, both animal and vegetable. When the rays of heat strike upon the earth's surface, they are passed from particle to particle into the interior of the earth's crust. Other portions are distributed through the air and water by convection, and a third portion is thrown back into space by ridiation. These latter phenomena will be duly explained as we proceed. 223. How do we know that heat is absorbed, and conducted into the internal earth ? It is found that there is a given depth beneath the surface of the globe at which an equal temperature prevails. The depth" increases as we travel south or north from the equator, and corresponds with the shape of the earth's surface, sinking under the valleys, and rising under the hills. 224. Why may we not understand that this internal heat of the earth arises, as has been supposed by many philosophers, from internal combustion ? Because recent investigations have thrown considerable and satisfactory light upon the subject. It has been ascertained that the internal temperature of the earth increases to a certain depth, one degree in every fifty feet. But that below that depth tho temperature begins to decline, and continues to do so with, ever/ increase of depth. 225. Do plants absorb heat? Yes. They both absorb and radiate heat, under varying circum- tances. The majestic tree, the meek flower, the unpretending grass, all perform a part in the grand alchemy of nature. 54 THE BEASON- VHT. ' Consider the lilies of the field, how they grow ; they toil not, neither do thej spin. 'When we gaze upon a rose it is not its beauty alone that should impress us : every moment of that flower's life is devoted to the fulfilment of its part in the grand scheme of the universe. It decorates the rays of solar light, and sends the red rays only to our eyes. It absort-j or radiates heat, according to the temperature of the aerial mantle that wraps alike the flower and the man. It distils the gaseous vapours, and restores to man the vital air on which he lives. It takes into its own substance, and incorporates with its own frame, the car- bon and the hydrogen of which man has no immediate need. It drinks the dew-drop or the rain-drop, and gives forth its sweet odour as a thanksgiving. And when it dies, it preaches eloquently to beauty, pointing to the end that is to come ! CHAPTER XII. 226. Sow do we know that plants operate upon the solar and atmospheric heat ? A delicate thermometer, placed among the leaves and petals of flowers, will at once establish the fact, not only that flowers and plants have a temperature differing from that of the external air, but that the temperature varies in different plants according to the hypothetical, or supposed requirements, of their existences and conditions. 227. What is the chief cause of variation in the tempera- ture of flowers ? It is generally supposed that their temperature is affected by their colours. 228. WJiy is it supposed that the colour of a flower influ- ences its temperature 'f Because it is found by experiment that the colours of bodies bear on important relation to their properties respecting heat, and hold some analogy to the relation of colours to light. [If when the ground is covered with snow, pieces of woollen cloth, of equal size tnd thickness, and differing only in colour, are laid upon the surface of the enow, near to each other, it will be found that the relation of colour to temperature will be as follows: In a few hours the black cloth will have dissolved so much of the snow beneath it, as to sink deep below the surface the blue will have proved nearly as warm as the black; the brown, will have dissolved less of the snow ; the red less than the brown ; and the white the least THE EEASOI? WHY. 65 And yet I say unto you, that even Solomon, in al) his glory, was not arrayed like one of these." MATT. vi. or no",e at all. Similar experiments may be tried with reference to the conden- sation yf dew, &c. And it will be uniformly found that the colour of a bodj materially affects its powers of absorption and of 'radiation'] 229. Wliy do we Icnoio that these effects ars not the result of light? Because they would occur, in just the same order, in the ahsenco of light. 230. Why are dark coloured- dresses usually worn in winter, and light in summer ? Because black absorbs heat, and therefore becomes warm ; while ight colours do not absorb heat in the same degree, and therefore a they remain cool. 231. Why do iron articles, even when near fire, usually pel cool ? Because they are bad absorbers, and do not take up heat freely, unless they are in contact with a hot body. 232. Sow is heat diffused through the atmosphere ? By convection. The warmth radiating from the surface of the earth warms the air in contact with it ; the air expands, and becom- ing lighter, flies upwards, bearing with it the caloric which it holds, and diffusing it in its course. 233. Sow do the waters of the ocean become heated? Chiefly by convection. Nearly all the heat which the sun sheds upon the ocean is borne away from its surface by evaporation, or is radiated back into the atmosphere. But the ocean gathers its heat by convection from the earth. It girdles the shores of tropical lands where, being warmed to a high degree of temperature, it sets across the Atlantic from the Gulf of Mexico, and exercises an important influence upon the temperature of our latitude. 234. What is the cause of winds ? Currents of air, and winds, are the result of convection. The air, heated by the high temperature of the tropics, ascends, while the colder air of the temperate and the frigid zones blows towards tkt equator to supply its place. 66 THE KEASOX WHY. ' Give unto the Lord the glory due unto his name ; worship the Lord in the beauty of holiness."- PSALM xxix. 235. What is the cause of sea Ireezes ? Sea breezes are also the result of -convection. The land, under the heat of the day's sunshine, becomes of a high temperature, and the expanded air on its surface files away towards the ocean. As the sun goes down, the- earth cools again, and the &\r flies back to find its equilibrium. Many countries hy the sea are subjected to these periodical breezes, known as either " land" or " sea breezes," according to their direction. About eight o'clock in the morning an aerial current begins to flow from the sea towards the land, and continues until about three o'clock in the day ; then the current takes a reverse direction, flowing from the land to the sea. This it continues to do throughout the night, until the time of sun-rise, when a temporary calm 236. Why does a soap lulUe ascend in the air ? Because, being filled with warm air, it is lighter than the surrounding medium, and therefore ascends. 237. Why does the bubble fall after it has been in the air some time ? Because the air contained in it has become cool, and, as it contains carbonic acid gas, it is heavier than the air. 238. What became of the warmth at Jlrst contained in the bubble ? It has been distributed in the air through which the bubble passed. 239. What does this simple illustration of the distribution of warmth explain? It explains the law of convection, or heat distribution, over the surface of the globe. 240. Why does air ascend the chimney ? Because, being heated, it becomes lighter than the surrounding 1 medium, and therefore flies upwards, through the outlet provided for it. 241. Why does air fly from, the doors and windows toward* the fire-place 2 THE SEASON WHY. 67 * How much better is it to get wisdom than gold ? and to get understanding rattier to be chosen than silver." PEOVEHBS xvi. Because, as the warm air flies away, cold air rushes in to occupy its place. 242. What does this example of the motion of the air in our rooms explain ? It explains the movement of volumes of air by convection, and illustrates the origin of breezes and winds. 243. What is the chief effect of this law of convection ? Under its influence air and water are the great equalisers of solar heat, rendering the earth agreeable to living things, and suited to the laws of their existence. Owing, also, to this law of convection, the constituents of the air are equalised. The breath of life, supplied by the purer oxygen of the " sunny south," is diffused in salubrious gales over the wintry climes of the north. And the waters, evaporated from the bosom of the central Atlantic Ocean and the Pacific, are borne across vast continents, and poured down in fertilising showers upon distant lands. To the educated mind, nothing is too simple to merit attention. To the ignorant, few things are sufficiently attractive to excite curiosity. Knowledge enables us to estimate the varied phenomena that are hourly arising around us, and to see, even in the most trifling effects, illustrations of those great causes and consequences that govern with mighty power the material world. Man, sitting by his fire-side, is enabled to witness the operation of some of nature's grandest laws : light and heat are around him ; conduction, radiation, reflection, absorption, and convection of heat are all going on before him ; little winds are sweeping by his footstool, and warm currents, with miniature clouds folded in their arms, are passing upward before his view. Chemical changes are going on ; the solid rock of coal disappears, flying away as an invisible gas. The little " hills are melted," and hard stones have been converted into* " fervent heat." Although some of these changes are imperceptible to the eye, they are manifest to the educated mind; and the pleasures of philosophical observation are as sweet as a poet's dreams. CHAPTER XIII. 244. Why will a piece of paper, held three or four inches tver thejlame of a candle, become scorched? 68 THE EEA8ON WHY. f Neither do meu light a candle, and put it under a bushel, but on a candle- stick ; and it giveth light unto all that are in the house." MATT. v. Because the hot air and gas produced by the burning of the candle ascends rapidly. 245. Wliy will a piece of paper hel& about an inch below the flame of a candle scarcely become warmed? Because the heat ascends ; and only a little of it falls upon the paper, and that by radiation. 240. Why does the lower part of the flame of a candle (D) burn of a blue colour ? Because the hydrogen of the tallow, having a stronger affinity for the oxy- gen of the air than carbon has, ignites first. Pure hydrogen burns with a bluish flame. 247. Why does the middle of the flame (c) look dark ? Because it is occupied with gaseous vapours, derived from the tallow, which have not yet ignited. 248. Wliy does the upper part of the flame (v) produce a bright yellow light? Because it is in this part of the flame that the hydrogen of the candle, and the oxygen of the air, combine, there is just sufficient carbon mixed with the hydrogen to improve its illuminating power. 249. Why is there a fringe of pale light (A) around the upper part of the flame ? Because some of the carbon escnpes in a state of incandesence, and as soon as it reaches the air it combines with oxygen, and so forms carbonic acid gas. If any dark body, such as the bladi of a knife, be held between the ey and THE REASON WHY. 69 ' How oft is the candle of the wicked put out ? and how oft cometh their destruction upon them ?" JOB xxi. the flaine of the candle, so as to shut off the light of the more luminous part* the pale fringe around the flame will be found distinctly perceptible. Incandesence means heated to whiteness. 250. Why does the flame terminate in a point ? Because cold air rushes towards the flame in every direction, and is carried upward. At the point where, the flame terminates the cold currents have so reduced the temperature that combustion can no longer be sustained. 251. WJiy, if you hold anything immediately over the flame, will the flame lengthen ? Because, by preventing the rapid escape of the heated air, you maintain a temperature which increases the combustion at the point of the flame. 252. Why should persons whose clothes talcejire, throw themselves down ? Because flame spreads most rapidly in an upward, direction. 253. WJiy should persons whose clothes are on fire roll slowly about when they are down ? Because they thereby press out the fire. 254. Why does pressing aflame or a spark put it out ? Because it prevents the contact of the flame or spark with the oxygen of the air. Extinguishers put out tha flame of candles in the same manner. A person dies from " suffocation" through the absence of oxygen ; and it is literally practicable to " suffocate " afire. 255. Why does the wick turn black as it turns ? Because it consists principally of carlon. 256. Wliy, when the point of the wick turns out and meets the air, does it exhibit a bright spark f Because the carbon of the wick comes into immediate contact with the oxygen of the air. 257. Why does holding a candle "upside down'" p*t it out? 70 THE REASON WHY. Lord, what is man that thou takest knowledge of him! or the son of man, that thou makest account of him." PSALMS CXLIV. Because the melted grease runs down too rapidly, and at too low a temperature to undergo combustion. It therefore reduces tka Jieat, and extinguishes the flame. 258. Why is it more difficult to blow out the flame of a candle with a cotton ivick than one with a rush wick ? Because the cotton wick imbibes more of the combustible materials, and holds in its loose texture the inijammable gases in a state ready for combustion. 259. Why does llowing sharply at a candle flame put it out? Because the breath drives away the vapour of the grease which, becoming gaseous, supports the flame. And because too rapid a flow of cold air reduces the temperature below the point at which combustion can be maintained. 260. Why will a gentle puff of breath, if given speedily after the flame is extinguished, re-kindle it? Because the oxygen of the air combines with the carton and hydro- gen that are still escaping from the heated wick, and re-lights it. 261. Why will not a similar puff re-kindle the flame of a rushlight? Because its wick retains but little heat, and holds a comparatively small amount of combustible matter in a volatile state. 262. Why is a flre, when it is very low, sometimes put out by blowing it? Because the too rapid flow of cold air reduces the temperature of the burning mass. 263. Why will a piece of paper twisted like an extinguisher put out a candle? Because, before the flame of the candle can ignite the paper, the oxygen contained within it it consumed, and the flane i* suffocated. THE SEASON WHY. 71 ' When his candle shined upon my head, and when by his light I walked through darkness." JOB xxix. 264. Why do tallow candles require snuffing ? Because the oxygen of the air cannot reach the wick through the body of flame therefore the unconsumed carbon accumulates upon the wick. 265. Why do composite and wax candles not require snuffing ? Because their wicks are made by a series of plaits, by which they are bent to meet the oxygen of the air, and consumed. 266. Why does setting a glass upon a lamp increase its brilliancy, though it shortens the -flame ? Because it conducts an increase of air to the flame, and the greater supply of oxygen causes the escaping vapour of oil to be all rapidly consumed. 267. Why does a candle burn dimly when the wick has become loaded with carbon ? Because the carbon radiates the heat, and disperses it, and reduces the heat of the flame below that temperature which is essential to its luminosity. 268. What differences characterise the combustion of carbon and of hydrogen ? The combusti of their primeva. life : their scaly stoms and bending branches, with their delicate apparatus of foliage, are all spread forth before him, little impaired by the lapse of countless ages, and bearing faithful records of extinct systems of vegetation which began and terminated in times of which these relics are the infallible historians." 274. What are the chemical components of coal? They consist of carbon, hydrogen, oxygen, and nitrogen. The proportions of these elements vary in different kinds of coal. Carbon is the chief component ; and the proportions may be stated to be, generally, carbon, 90 per cent. ; hydrogen, from 3 to 6 per cent. ; the other elements enter into the compound in such small proportions, that, for all ordinary purposes, it is sufficient to say that coal consists of carbon and hydrogen, but chiefly of carbon. 275. What is charcoal ? Charcoal consists almost entirely of carbon. It is made from wood by the application of heat, without the admission of air. The hydrogen and oxygen of the wood are expelled, and that which remains is charcoal, or carbon in one of its purest states. 276. WTiat is animal charcoal ? Animal charcoal, like vegetable charcoal, consists of carbon in a state approaching purity. It is made from the bones of animals, heated in iron cylinders. It is commonly called ivory black. 277. What is the purest form of carbon known ? The purest form of carbon is the diamond, which may be said to be absolutely pure. Hence we derive another of the beautiful lessons of science a lessou which teaches us to despise nothing tliat God has given. The soot which blackens the face of a chimney-sweep, and the diamond that glistens in the crown of the monarch, consist of the same element in merely a different atomic condition. \Vhat a lesson of humility this teaches to Pride ! The haughty beauty as she walks the ball-room, inwardly proud of the radiance of her gems as they rise and fall upon her breast, little thinks or knows that every breath that is expired around her wafts away the like element of which her treasures are composed. That even in our own flesh and bones the same abounding substance lies hid; and that the buried tree of the primitive world, and the little flower of to-day, are both the instruments of giving this singular element to mail ! 278. What is coles ? Coke is coal, divested of its hydrogen and other volatile parts, by 4 THE HKASON WHY. "Oh that men would praise the I^ord for his goodness, and for his wonderful works to the children of men." PSALM cvn. a similar process to that by which charcoal is produced. It forms the residue after hydrogen gas has been made from coals. It consists almost entirely of carbon. 279. Why do burning coals produce yellow flame ? Because the hydrogen which they contain is combined with some proportion of carbon, which imparts a bright yellow colour to tho flames. 280. Why do some of the flames of a flre appear much whiter than others ? Because the quality of coals, and the conditions under which they are burnt, are liable to variation. Some coals yield a heavy hydrogen, called bi-carburetted hydrogen, which burns with a much brighter flame than carburetted hydrogen. 281. Why does bi-carburetted hydrogen burn with a tvhiter flame than the common coal gas ? Because it is combined with a larger proportion of carbon, to which it .owes its increased luminosity. 282. Why do some of tlie flames of a flre appear blue ? Because the hydrogen which is escaping where those flames occur is pure hydrogen, destitute of carbon. 283. Why does the flre sometimes appear red, and without flame? Because the volatile gases have been driven off and consumed, and combustion is continued by the carbon of the coals and the oxygen of the air. 284. Wkat effect has the burning of afire upon the compo- sition of the air ? It is found that in burning lOlb. of coal the oxygen contained ia 1,551 cubic feet of air is altogether absorbed. It is therefore neces* sary to keep the atmosphere of a room, in which a coal fire a burning, fresh and pure, to supply 155 cubic feet of fresh air fol every pound of coal that is consumed. THB EEASON -WHY. 75 1 Lord how manifold are thy works, in wisdom hast thk made them ill: th earth is full of thy riches." PSALM CIT. 285. Why does wood which is "green" hiss and steam when it is burnt ? Because it contains a large amount of water, which must be evaporated before combustion can proceed. 286. What is the effect of this evaporation? A great deal of heat is unprofi tably expended in driving off the water of the fuel. 287. Why does poking a fire cause it to turn more brightly ? Because it opens avenues through which the air may enter to supply oxygen. 288. WJiy do " blowers" improve the draft of air through afire ? Because, by obstructing the passage of the current of air over the fire, they cause additional air to pass through it, and therefore a greater amount of oxygen is carried to the coals. 289. What is smoke ? Unconsumed particles of coal, rendered volatile by heat, and driven off. 290. What is soot? Carbon in minute particles, driven off with other volatile matters and deposited on the walls of chimnies. 291. Why do fresh coals increase the quantity of smoke ? Because they contain volatile matters which are easily driven off; and because, also, they reduce momentarily the heat, so that those matters that first escape cannot be consumed. 292. Why do charcoal and coke fires burn clearly and without flame ? Because the hydrogen has Deen previously driven off from those substances. 293. Why is it difficult to light charcoal and coke fires ? 76 THE SEASON WHY. 1 He hath made his wonderful works to be remembered : the Lord is precious and full of compassion." PSALSI CXL. Because they contain no hydrogen to produce flame, and assist combustion. A new plan of kindling fires has lately been recommended. Coals are to bo laid in the bottom of the fire-place to a considerable depth*, then the paper and wood are to be laid on, and then a little coals and cinders over them. Tin's plan of " laying in " the fire is precisely the reverse of that which has been pursued for many years. The theory is, that when the coals in the bottom are ignited, a more even combustion is kept up, whilst the smoke and gas which would otherwise escape, and become as so much waste fuel, is burnt up, and produces heat. Wo have heard the plan strongly recommended by persons who nave tried it, and who testify to the great economy ef fuel to which it conduces. CHAPTER XV. 294. Why does paper ignite more readily than wood ? Because its texture is less dense than that of wood ; its particles are therefore more readily heated and decomposed. 295. But if articles of loose texture are lad conductors of heat, ivhy do they so easily ignite ? The fact that they are bad conductors assists their ignition. The heat which would pass from particle to particle of the dense substance of iron, and be conducted away, accumulates in the interspaces of paper, and ignites it. 296. Why does wood ignite less readily than paper ? Because its substance is denser than that of paper ; it therefore requires a higher degree of heat to inflame its substance. 297. Why does wood, ivhen ignited, burn longer than paper ? Because, being a denser substance, it submits a larger number of particles, within a given space, to the action of the heat, and the formation of gases. 298. Why do we, in lighting afire .first lay in vaper, then wood, and lastly coals f THE BEASON WHY. 77 ' It ia a got d thing to give thanks unto the Lord, and to sing praises tmto thy name, O Most High." PSALM xcn. Because the paper is more easily ignited than wood, and wood than coals ; therefore the paper assists the ignition of the wood, and the wood assists the ignition of the coals. 299. Why will not wood ignite by the flame of a match ? It will do so, unless there is a great disproportion between the size of the wood and the flame of a match. A thin piece of wood will ignite, but a square block will not, because the heat of the flame is insufficient to raise the temperature of a large surface to the point that will drive out its gases, 300. Why do we place the paper under the wood, and the wood'under the coals ? Because heat and flame, when surrounded by air, have a strong tendency to spread themselves upwards. 301. Would it be possible to light the coals ly putting the paper and the wood upon the top ? It would be possible ; but the loss of heat would be so great, that a much larger quantity of paper and wood would be required. 302. Why does a poker laid across the top of a dull fire revive it ? Because the poker radiates the heat it receives from the fire downward upon the fuel. Because, also, it divides the ascending air, and thereby creates currentt. The amount of good which the poker does to the fire is very slight indeed. Generally, the housewife stirs the fire first, and blows or brushes away the ashes that prevent the influx of air. She then places the poker upon the top, and the popular mind supposes that the poker " draws " the fire. The custom of placing a poker over the fire is of very remote antiquity. It was once believed that forming a cross, by placing the poker over the bars, protected the fire from the hostility of malignant witches ! 303. Why should fire-places be fixed as low as possible in rooms ? Because heat ascends, and when the fire-places are high the lower parts of the room are inadequately warmed. 78 THE SEASON WHY. "Unto thee, O God, do we give thanks : for that thy name is near thy wondroui works declare." PSALM LXXV. Also, as currents of air fly towards the fire, elevated fire-places cause drafts about the persons of the inmates to a much greater extent than they would if they were lower down. 304. Why, if a piece of paper be laid with its flat surface upon the fire, will it " char," but not ignite t Because, as in the case of the proper candle-extinguisher, the carbonic acid gas accumulating beneath it prevents its igniting. 305. Why, if you direct a current of air towards the paper, will it burst into a blaze ? Because the carbonic acid gas is displaced by a current of air Containing oxygen. 306. Why does water extinguish fire f Because it saturates the fuel, and prevents the gases thereof from combining with the oxygen of the air. 307. As water contains oxygen, why does not the oxygen of the water support the fire ? Because the affinity between the hydrogen and oxygen of the water is so strong that fire cannot separate them. "Water may be decomposed by heat, as will be hereafter explained. But the heat of an ordinary fire is insufficient. There is, however, some reason for believing that, in cases of very large fires, such as the accidental burning of houses, &c., when the supply of water thrown upon the fire is very deficient, the water does become decomposed, and add to the fury of the flames. 308. Why does the blacksmith sprinkle water upon the coals of his forge? The blacksmith uses small coals because the small pieces thereof are more easily ignited than large lumps would be, and they convey heat better by completely surrounding the articles put into the fire. He sprinkles water on the coal dust to hold its particles together by cohesion, until the heat forms it into a cake. A strong blast of hot hair drives the vapour of the water away, and leaves a porous mass to the action of the fire. 309. Why, when the blacksmith thrusts a heated iron into a tankard of water, do we recognise a peculiar smell f THE SEASON WHY. 79 "Oh the depth of the riches both of the wisdom and knowledge of God! how unsearchable are his judgments, and his ways past finding out." ROM. xi. Because the intense heat disengages a small volume of the gases cf which water is formed. 310. Which gas do we (in this instance) recognise ly iho smell? The hydrogen gas. Oxygen gas possesses no odour. 311. What is Spontaneous Combustion ? Spontaneous combustion is that which occurs in various bodies when they become highly heated by chemical changes. 312. Why is heat developed during chemical changes ? Because, as all bodies contain latent caloric, the disturbance of the atoms of which those bodies are composed, during the new combinations that constitute chemical changes, frequently sets the caloric free, and an accumulation of caloric produces spontaneous combustion. 313. Does a match ignite spontaneously when drawn over a rough surface ? No. Because in this case the combustion arises from heat applied, "by friction. 314. Does phosphorous ignite spontaneously when held in a warm hand ? Phosphorous will ignite when held in a warm hand, but it does not then produce spontaneous combustion, because it ignites through the agency of applied, heat. 315. But if a piece of dry phosphorous le sprinkled with powdered charcoal it will ignite, loithout the application of heat. Why is this ? Because the carbon (charcoal) absorbs oxygen from the air, and conveys it to the phosphorous. Here are chemical changes which develope heat, and produce spontaneous combustion. 316. Why do hay-stacTcs sometimes take fire ? Because the hay, having become damp, decays, and passes on to a state of fermentation, in which chemical changes occur, during 80 THE REASON WHY. "Who hath woe? who hath sorrow ? who hath contentions ? who hath babbling? who hath words without cause? who hath redness of the eyes ? They that tarry long at the wine." Piiov. xxm. which heat is evolved. Hay, taking fire under these circumstances, would exhibit spontaneous combustion. 317. What substances are liable to produce spontaneous combustion ? All substances which contain sugar, starch, and other compo- nents liable to fermentation. All bodies that evolve, under low degrees of temperature, inflammable gases. And all organic bodies undergoing decay. Grain, cotton, hemp, flax, coals, oily and greasy substances. 318. Wliat ~is the Ignis Fatuus (sometimes called " Will- o'-the-wisp," " Corpse Candles," and " JacTc-0 1 - Lantern") ? It is a flame produced by spontaneous combustion, caused by the decay of animal or vegetable bodies, which evolve phosphoretted hydrogen gas, under circumstances attended by a low degree of heat, sufficient to ignite the gases. It is mostly seen over marshy places, and burial-grounds. Many a " Ghost Story" has owed its origin to these singular but hannlesi appearances. People, ignorant of the cause, have been terrified at the effect. To the fancy of an affrighted mortal, the simple flame of the Ignis Fatuus has assumed the form of a departed friend, and even found a supernatural voice. If, excited by a momentary daring, the beholder moved towards the light upon which he gazed, it fled from him. If he turned from it and walked away, it followed him, step by step. The darkness of a lonely road, or the sacred solitude of a burial-place, have been sufficient accessories to authenticate the appearance of a spirit. And yet how simple the phenomenon ? Matters so volatile as those which produce the Ignis Fatuus would naturally be driven back by the motion in the air caused by an advancing body ; and, on the other hand, a body moving from them would create a current in which the Ignis Fatuus would follow. Poisonous gases, escaping from decaying bodies, pass into the air and take fire. They are thereby converted into harmless com- pounds. Thus we see that the " ghost" which terrifies the mind of the ignorant, becomes a "guardian angel" to the educated. 319. Has spontaneous combustion ever occurred in living lodies ? It has occurred in numerous instances to persons habituated to the excessive use of spirits. 320. Why should spontaneous combustion occur in the casa of the drunkard f THE EEASOK WHY. 81 " Drought and heat consume the snow waters ; so doth the grave those which have sinned." JOB xx.iv. Because spirituous drinks contain a large proportion of alcohol, one of the constituents of which is hydrogen. The vital energies of the drunkard, being destroyed by excess, chemical agencies obtain an ascendancy, and it is supposed that the hydrogen of the alcohol combines with the phosphorous of the body to form phosphoretted hydrogen, which ignites spontaneously, and literally consumes the living temple. Cases of spontaneous combustion are of rare occurrence. But they are sufficiently well authenticated by high medical authority, in many parts of the world, to present an awful warning to the inveterate drunkard. Tlie cases of which we have read the particulars present details of the most appalling description. How signally the Almighty displeasure at intemperance is expressed, when the very drink which imparts the mad pleasure of intoxication ia made the direct instrument by which the drunkard is destroyed 1 CHAPTER XVI. 321. Why does friction produce heat? Because all bodies contain latent heat, that is, heat that lies hid in their substance, and the rubbings of two bodies against each other draws the latent heat to the excited surfaces. 322. Why does the rubbing of two surfaces together attract latent heat to those surfaces ? Because it is a law of nature that heat shall always attend motion ; and it is generally found that the intensity of heat bears a specific relation to the velocity of motion. 323. What are the sources of heat ? The rays of the sun, the currents of electricity, the action ot chemicals, and the motion of substances. 324. Why does water freeze ? Because its latent heat is partly drawn off* by the surrounding air. 325. Why does ice melt ? Because the heat, onee latent in the water, bat drawn off by the air, has returned to it, and restored the water to its former condition. 4* 82 THE SEASON WHY. * So teach us to number our days, that we may apply our hearts unto wisdom.' PSALM xc. 326. Why does water become steam ? Because a larger amount of heat has entered into it than can remain latent in water. The water therefore expands and rises in the form of vapour, or water attenuated by heat. 327. How many degrees of heat are latent, or hidden, in the different states of water ? In thawing ice, 140 deg. of caloric become latent; and in converting the water into steam, 1,000 deg. more of caloric aw be taken up. Therefore, ice requires to take up 1,140 deg. of latent caloric before it becomes steam. 328. What is the most modern theory of heat ? It is this that caloric, which produces heat, is an extremely subtile fluid, of so refined a nature that it possesses no weight, yet is capable of diffusing itself among the particles of the most solid bodies, It is also believed that all bodies are subject to the action of two opposing forces : one, the mutual attraction of their particles ; the other, the repulsive force of caloric and that bodies exist in the ceriform, fluid, or solid state, according to the* predominance of either the one or the other of these opposing forces. 329. Sow do we measure the quantity of caloric in any substance ? It is impossible to determine the amount of caloric which any body contains. Our sensations would obviously be deceptive, since, if we dipped the right hand in snow, and held the left hand before the fire, and then immersed both hands in cold water, the water would feel warm to the right hand and cold to the left hand. But, as caloric uniformly expands substances that are under its influence, one of the bodies most sensitive to calorific effects has been selected to be the indicator of the amount of caloric. This substance is quicksilver; and the scale of measurement, and the apparatus for exhibiting the rise or fall of the quicksilver, consti- tute the thermometer. 330. If it is impossible to measure the amount of caloric in any substance, hoio can it le said that ic* absorbs 140 deg. i* becoming water ? THE EEASON WHY. 93 Great Is the Lord, and (greatly to be praised in the city of our God, inths mountain of his holiness." PSALM XI/FIII. Those figures simply record the amount of caloric indicated by the thermometer. The instrument will show with sufficient accu- racy the relative amount of caloric in various bodies, or in the samo bodies under different circumstances, but it can never determine the precise amount of caloric in any one body. 331. Why, if a hot and a cold body tvere placed near to each other, would the cold one become warmer, and the hot one cooler ? Because free caloric (that is, caloric that is not latent,) always exhibits a tendency to establish an equilibrium. If twenty bodies, of different temperatures, were placed in the same atmosphere, they would all soon arrive at the same temperature. The caloric would leave the bodies of those of the highest, and find its way to those of the lowest temperature. 332. Hew does caloric travel ? It travels in parallel rays in all directions with a velocity approximating to that of light ; and it passes through various bodies with a rapidity proportionate to their power of conduction. 333. WTiy does melted metal run like a stream of fluid? Because caloric has passed into its substance, and, repelling its particles, has separated them to that degree which produces fluidity. 334. Sow do we Jcnow that it is caloric passing into the substance of the metal which produces this effect? Because, as soon as a bar of metal begins to be heated, it expands and lengthens. It continues to do so, until the heat arrives at that point which causes the metal to melt. 335. Why does the iron of an ironing-box sometimes become loo large for the box to receive it ? Because caloric has passed into the substance of the iron, and repelled its particles, "by which it has become expanded. 336. Why does the iron enter the box when it has become partially cooled? 84 THE SEASON WHY. "Cast thy burden upon the Lord, and he shall sustain thee; he shall neve? suffer the righteous to be moved." PSAXM LV. Because a portion of the caloric has left the iron, the particles of wWch have drawn closer together, and contracted the mass. This effect is frequently observed by females in domestic life, who, when they are ironing, or using the Italian irons, find that the heated metal has been too much expanded to enter the box or tube. They find it necessary to wait until the cooling of the iron has had the effect of reducing its dimensions. The expansion of bodies by heat is one of the grandest and most important laws of nature. We are indebted to it for some of the most beautiful, as well as the most awful, phenomena. And science has gained some of its mightiest conquests through its aid. Yet frequently, though quite unthought of, in the hands of the humble laundress, will be found a most striking illustration of this wonderful force of caloric. . 337. Are there any instances in which the abstraction of latent heat will reduce the bulk of bodies ? Yes, there are several. But the most familiar one is that which is exhibited by mixing a pint of the oil of vitriol with a pint of water. A. considerable amount of heat will be evolved ; and it will be found that the two pints of fluid will not afterwards fill a quart measure. 338. Js there any latent heat in air ? Yes : a considerable amount. In a pint measure of air, though in no way evident to our perceptions, there lurks sufficient caloric to raise a piece of metal several inches square to glowing redness. 339. How do we know that caloric exists in the air ? It has been positively demonstrated by the invention of a small condensing syringe, by which, through the rapid compression of a small volume of air, a spark is emitted which ignites a piece 01 prepared tinder. 340. What is the cause of the spark when a horse's shoe strikes against a stone ? The latent heat of the iron or the stone is set free by the violent percussion. The same effect takes place when j/?i strikes against steel, as in the old method of obtaining a light with the aid of the tinder-box. What; an eloquent lecture might be delivered upon the old-fashioned tinder- box, illustrated by the one experiment of " striking a light." In that box lie, eold at*l motionless, the Flint and Steel, rude in form and crude in substance. And yet, within the breast of each, there lies a spark of that grand THE REASON WHY. "The waters are laid as with a stone, and the face of the deep is frozen." JOB xxxvin.' which influences every atom of the universe ; a spark which could invoke tfc fierce agents of destruction to wrap their blasting flames around a stately forest, or a crowded city, and sweep it from the face of the world ; or which might kindle the genial blaze upon the homely hearth, and shed a radiant glow upon a group of smiling faces ; a spark such as that which rises with the curling smoke from the village blackmith's forge or that which leaps with terrific wrath from the troubled breast of a Vesuvius. And then the tinder the cotton the carbon : What a tale might be told of the cotton- field where it grew, of the black slave who plucked it, of the white toiler who spun it into a garment, and of the village beauty who wore it until, faded and despised, it was cast amongst a heap of old rags, and finally found its way to the tinder- box. Then the Tinder might tell of its hopes ; how, though now a blackened mass, soiling everything that touched it, it would soon be wedded to one of the great ministers of nature, and fly away on transparent wings, until, resting uoon some Alpine tree, it would make its home among the green leaves, and for a while live in freshness atid beauty, looking down upon the peaceful vale. Then the Steel might tell its story, how for centuries it lay in the deep caverns of the earth, until man, with his unquiet spirit, dug down to the dark depths and dragged it forth, saying, " No longer be at peace." Then would come tales of the fiery furnace, what Fire had done for Steel, and what Steel had done for Fire. And then the Flint might tell of the time when the weather-bound mariners, lighting their fires upon the Syrian shore, melted silicious stones into gems of glass, and thus led the way to the discovery of the transparent pane that gives a crystal inlet to the light of our homes ; of the mirror in whose face the lady contemplates her charms ; of the microscope and the telescope by which the invisible are brought to sight, and the distant drawn near ; of the prism by which Newton analysed the rays of light ; and of the photographic camera iu which the sun prints with his own rays the pictures of his own adorning. And then both Flint and Steel might relate their adventures in the battle-field, whither they had gone together ; and of fights they had seen in which man struck down his fellow-man, and like a fiend had revelled in his brother's blood. Thus, even from the cold hearts of flint and steel, man might learn a lesson which should make him blush at the " glory of war ;" and the proud, who despise the teachings of small things, might learu to appreciate the truths that are linked to the story of a " tinder-box." LESSON XVII. 841. Since all bodies expand by heat and contract by cold, why does water, when it reaches the freezing point, expand? Because, in freezing, water undergoes crystallization, in which its particles assume a new arrangement occupying greater space. 342. Why does water never freeze to a great depth f Because the covering of ice which formed upon the surface of 86 THE SEASON WHY. " For he saith to the snow, Be thou on the earth ; likewise to the small rain, and to the great rain of his strength." JOB xxxvir. the water prevents the cold air from continuing to draw off the caloric of the water. 343. Why has this exceptional law of the expansion oj water, when freezing, been ordained? Because, but for this, deep waters might be frozen through theii whole depth. This would destroy the myriads of fish and other living things that inhabit the water. Parts of the earth, now clad in verdure, would be lost in eternal winter ; and even in the most temperate zones it would take months to effect a thaw ; and thawing would be attended with such floods and subterranean commotions as are terrible to contemplate. 344. Why are bed-room windows sometimes covered with crystalline forms on winter mornings T Because the vapour of the breaths of the inmates has condensed upon the window-panes, and formed water. The water has frozen with the cold, and exhibits the beautiful crystalline forms into which its particles are arranged. [Here we have another domestic illustration of the great laws of nature. It is the same law which locks the artic regions in ice and decorates our window- panes. This beautiful phenomenon is usually witnessed by us on frosty mornings when we rise from our beds. It has a story which the observer of nature may read in its sparkling eyes. It tells that, although without the air is biting cold, God has wrapped a mantle around the face of nature to keep it from injury ; and that the earth and the waters, though looking chilled and dead, have still the warmth of life preserved in their bosoms.] 345. What is dew? Dew is watery vapour diffused in the air, condensed by coming in contact with bodies colder than the atmosphere. 346. Why does the air become charged with watery vapour ? Because, during the day, under the influence of the sun's rays, vapours are exhaled from all the moist and watery surfaces of the earth. These vapours are held in suspension in the atmosphere until, by a change in the temperature of the earth, and of bodies on the surface of the earth, they are condensed, and deposited in translucid drops. 347. What causes the decline of temperature that favour* the deposition of deys ? THE BEASON WHY. 87 ' The Lord is my shepherd, I shall not want. He maketh me to lie down in green pastures." PSALM xxm. The earth, which during the day received heat from the solar rayg, radiates the heat back into the air, and therefore becomes itself colder. All the various objects upon the face of the earth also radiate heat in a greater or lesser degree. And dew will be found to be deposited upon the surfaces of such bodies in proportion to the fall of their temperature through radiation. 348. Why is there little or no dew when the nights are cloudy ? Because clouds act as secondary radiators ; and when the earth radiates its heat towards the clouds, the clouds again radiate it back to the earth. Tig. 3. ILLUSTRATING THE FOEMATION OB DEW. If plates of glass be laid over grass-beds, as in the engraving Tig. 3, no dew will be deposited on the grass underneath the glass plates, although all around the grass will be completely wetted. The explanation is that the glasses, being radiators of heat, act in the same manner as the clouds, returning the heat to the bodies underneath them, and preventing the formation of dew thereon. 349. Why does dew form most abundantly on cloudless nights ? Because the heat which is radiated by the earth does not return to it. The temperature of the earth, and the air immediately upon its surface, is therefore lowered, and dew is formed. It has been observed that sheep that have lain on the grass during the formation of dew have their backs completely saturated with it, but that under- neath the line where their bodies turn to the earth, their coats will be dry. In the sameSnanner glass globes suspended in the air, on dew forming nights, will be found loaded with globules of dew upon the top, but there will be o# ppearaac(> of moisture underneath. 88 THE EEASON WHY. ' Dost thou know the balancings of the clouds, the wondrous works of him which is perfect in knowledge." JOB xxxvu. 350. Why arc star-lit nights usually colder than cloudy nights ? Because heat is radiated from the earth, and passes away into the utmost regions of the atmosphere. 351. Why is there little dew under branches of thick foliage ? Because the foliage acts as a screen, which prevents the radiated heat of the earth from passing away. 352. Why is there no dew formed on windy nights ? Because, as winds generally consist of dry air, they absorb and bear away the atmospheric moisture. 353. Why are valleys and low places chiefly subject to dew? Because the elevated lands around them prevent the disturbance of the air in which the moisture is held. 354. What bodies are most likely to be covered with, dew ? All bodies that are good radiators of heat, such as wool, swans- down, grass, leaves of plants, wood, &c. 355. What bodies are likely to receive little dew ? All bad radiators of heat, such as polished metal surfaces, smooth stones, and polished surfaces generally. Dew will be found to lie more abundantly upon rough and woolly leaves than upon smooth ones. 356. At what period of the night is the largest amount of dew usually formed ? It is generally supposed that dew is formed most copiously in the mornings and evenings. But such is not the case. It is deposited at all hours of the night, but most plentifully after midnight. 357. Why is dew formed most plentifully after midnight ? Because, as radiation has been going on for some time, the temperature of the earth, and of various bodies upon it, ha* been considerably reduced. THE EEAS02T WHY. Out of whoea womb came the ice ? and the hoary frost of heaven, who hath gendered it ?" JOB xxxvm. 358. In what parts of the world is the maximum of dew famed ? In warm lands near the sea, or in the vicinity of rivers or lakes, as the localities of the Red Sea, the Persian Gulf the coast of Coromandel, in Alexandria, and Chili. 359. In what parts of the world is the minimum of dew formed? It is quite absent in arid regions, in the interior of continents, such as Central Brazil, the Sahara, and Nubia. 360. Why is dew seldom formed at sea ? Because of the defective radiating quality of the surface of mater. 361. Why is a heavy dew regarded as the precursor of rain ? Because a heavy formation of dew indicates that the air is saturated with moisture. 362. What is hoar-frost ? Hoar-frost is frozen dew. 363. Why is hoar-frost said to foretell rain ? Because it shows that the air is saturated with moisture, and the temperature of the air being low, the vapours are likely to condense, and produce showers. 364. Wliat is honey-dew ? Honey-dew is the name applied to a sweet and sticky moisture occasionally deposited upon the leaves of plants. It is, however, an error to call it dew, as it is procured by a class of insects termed aphides. 365. What are fogs? Fogs are clouds formed near the earth's surface ; but London fogs are distinguished from clouds by the fact that they embrace in their vaporous folds the smoke and volatile matters imparted to the air by the operations of man. This is also the case with fogi generally that arise near large towns. 90 THE EEASON WHY. 'Hath the rain a father? or who hath begotten the drops of dew?" JOB xxxviii. 366. Why are certain coasts liable to almost perpetual fogs? Because of local or geographical agencies which contribute to theii production. The coasts of California are almost constantly wrapped in fog ; and, almost as constantly, the western coast of the American continent, as far south as Peru. Newfoundland, Nova Scotia, and Hudson's Bay, are all subject to dense and frequent fogs arising from the condensation of vapour from the water flowing from the hot Gulf- stream, coming in contact with the colder air. 367. What are dry fogs ? Dry fogs are characterised by a dull opaque appearance of the atmosphere. They are most common in certain parts of North America, though they sometimes occur in Germany and in England. They are generally referred to the electrical state of the atmosphere, but the theory of them is still a matter of doubt. 368. Wliat is a mist ? The term mist is generally applied to vapours that rise over marshy places, or the surfaces of water, and. roll or move over the land. 369. Wliat is the difference between a mist and a fog ? Fogs, as they are known to us, generally arise over the land, and are usually mingled with the smoke of large towns. Mists generally arise over water, or wet surfaces. 370. Why do mists and fogs disappear at sunrise ? Because the condensed vapours are again expanded and dis- persed by the heat of the sun's rays. 371. Why do fogs frequently rise in the morning and fall again in the evening. Because, warmed by the sun's rays, they become more rarefied, and fly away at an altitude where they appear to be altogether dispelled ; but at night, when the earth cools by radiation, the vapours near the earth again condense, and settle in the for m of fa- 372. Why do fogs sometimes rest v/pon a given locality for several days together, and then disappear ? THE HEASOK WHY. 91 ' He bindeth up the waters in his thick clouds ; and the cloud is not rent under them." JOB xxvi. They are probably kept near to the surface of the earth by a superstratum of cold air. A cold air lying above, or a cold air lying below, might equally contribute to keep a fog near the surface of a particular part of the earth, until a flow of wind, or a fall of rain, altered the atmospheric condition. There are many interesting facts connected with the history of dew. It has attracted the attention of natural philosophers in all ages. But its true theory was never understood until recently. The ancients imagined that dews were shed from the stars; and the alchemists and physicians of the middle ages believed that the dew distilled by night possessed penetrating and wonder- working powers. The ladies of those times sought to preserve their beauty by washing in dew, which they regarded as a " celestial wash." They collected it by placing upon the grass heaps of wool, upon the threads of which the magio drops clustered. CHAPTER XVIII. 373. What are clouds ? Clouds are volumes of vapour, usually elevated to a considerable height. Fig. 4. CIEBO-CUMULCS, OE SOXDEB CLOCD. 374. Whence do clouds arise ? From the evaporation of water at the earth's surface. 375. Wliy do we not see them ascend? We do, sometimes, in the form of what we call misti, but generally the vapours that rise and contribute to the formation of clouds are so thin that they are invisible. THE SEASON WHY. * With clouds he covereth the light, and commandeth it not to shine by the cloud that cometh betwixt." JOB xxxvi. 37G. Why, if they are invisible when they rise, do they become visible when they have ascended ? Because the vapours become cooled in passing through the air, and form a denser body. 377. Why, when they are condensed, do they not follow the course of gravitation, and descend ? Because the vapours form into minute vesicles, which we may call vapour bubbles, and these, being warmed by the sun, are specifically lighter than the air. Because, also, the lower parts of clouds do partially descend, but again becoming more rarefied by meeting with a warmer atmo- sphere, they again ascend, and are thus poised upon the air. Because, also, there is always a degree of atmospheric motion upward, caused by the convection of heat from the earth's sur- face. And, although there must also be downward movements of the air to supply the place of that which has ascended, still the heat of the ascending air, combined with its upward movement, expands and floats the vapour of the clouds. 378. At what height do clouds usually fly ? They fly aD every degree of altitude; but clouds of specific character are said to fly at given altitudes, or to occupy certain ranges of altitude. We will give their probable altitudes when speaking of the specific clouds. Fig. 5. CIEEUS, OB CT7EL CLOUD. 379. How many descriptions of clouds are there? There are seven. THE SEASON WHY. 93 ' Who giveth rain upon the earth, and sendeth waters upon the fields." JOB v. 1. The Cirrus (Fig. 5), estimated range of altitude from *0,000 to 24,000 feet. 2. The Cumulus (Fig. 7), from 3,000 to 10,000 feet. 3. The Stratus, an extended continuous level sheet of cloud, increasing from beneath. They fly very low. 4. The Nimbus (Fig. 10), 1,500 to 5,000 feet. 5. The Cirro-cumulus (Fig. 4), from 3,000 to 20,000 feet. 6. The Cirro-stratus (Fig. 6), from 5,000 to 10,000 feet. 7. The Cumulo-stratus (Fig. 9), from 3,000 to 10,000 feet. Fig. 6. CIBEO-STBATUS, OE WANE CLOUD. The estimated heights given must be looked upon as very conjectural although they have been derived from the best existing authorities. It is sufficient to know that the range of the altitude of the various clouds is from that of the Nimbus, or thunder cloud, 1,500 feet, to that of the Cirrus, 24,000 feet, the others being intermediate. The first three of the clouds above enumerated constitute what are called the primary forms. The remaining four are called secondary forms, because they arise, as their names generally indicate, out of combinations of the primary forms. Although, from the frequent mingling of clouds, it is not always practicable to identify them by the adopted classification, still, as there is generally a prevalence of one type of cloud over another, the observer would be able to. distinguish a " Cirrus sky," or Cirro-cumulus sky," &c. Upon some occasions the typical characters of the clouds are beautifully defined ; and the contemplation of their forms, and the laws of their formation, affords infinite pleasure to the observer. The advantages of scientific .knowledge are such, that whether you look downwards to the earth, or upwards to the sky rou have still the writing of God to read. 380. What produces the various shapes of clouds f 1. The state of the atmosphere. 2. The electrical condition of the clouds. 3. The movements of the atmosphere. 4. The season qf the year. 94 THE EEASOK WHY. "Behold, he withholdeth the waters, and they dry up; also he sendeth them out, and they overturn the earth." JOB xii. 381. What are the dimensions of clouds ? A single cloud has been estimated to have as many as twenty square miles of surface, and to be above a mile in thickness, while others are no larger than a house, or a man's hand. Fig. 7. CUMULTJS, OE PILE CLOUD. 382. Sow are clouds affected by winds ? If cold winds blow upon the clouds, the cold condenses the vapour, turning the clouds into rain. But if warm dry winds blow upon the clouds, they rarefy the vapour to a greater degree, and temporarily disperse the clouds. 383. Sow do winds affect the shapes of clouds ? When winds are mild, and gentle, the clouds break into small patches, and rise to a considerable height. But when the winds are cold and blustering, the clouds fly low, and roll along in heavy masses. 384. Why are east winds usually dry ? Because in coming towards England they pass over vast continents of land, and comparatively little ocean. Hence they are r ot loaded with vapours. 385. Why do west winds generally Iring rain? Because they come across the Atlantic, and are heavily charged with vapour. 386. Why are north winds generally cold and dry ? Because they come from the arctic ocean, over vast areas of tea *xd tnow. BEASOK "Terrors arc turned upon me: they pursue my soul as the wind; and mj welfare passeth away as a cloud." JOB xxx. 387. Why are south winds tvarm and rainy ? Because they come 'from the southern regions, heated by the hot earth and sands, and as they cross the sea they absorb a large amount of vapour. Fig. 9. CUMCLO-STRATUS, OR TWAIN CLOUD. 388. Why are clouds said to indicate ike changes of the weather ? Because, as it is the state of the clouds that, to a great extent, determines the state of the weather, the formation of the cloudi must predicate approaching changes. 389. What do cirrus clouds foretell ? Cirrus clouds foretell fine weather, when they fly high, and are thin and light. They foretell light rain when, after a long continuance of fine weather, they form fleecy lines stretched across the sky. They foretell a gale ofivind when, for some successive days, they gather in the same quarter of the heavens, as if denoting the point from whicli to expect the coming gale. (Fig. 5). 390. What do cumulus clouds foretell ? Cumulus clouds, when they are well defined, and advance wit li the wind, foretell fine weather. 96 THE EEASON WHT. ' When lie made a decree for the rain, and a way for the lightning and thn thunder." JOB xxvm. When they are thin and dull, and float against the wind, or in opposition to the lower currents, theyforelell rain. When they increase in size, and become dull and grey at sunxtt. they predict a thunder-storm. (Fig. 7.) 331. Wliat do stratus clouds foretell ? Stratus clouds foretell damp and cheerless weather. 392. What do nimbus clouds foretell ? Nimbus clouds foretell rain, storm, and thunder. (Fig. 10.) 393. Wliat do cirro-cumulus clouds foretell ? Cirro-cumulus clouds, in summer, foretell increasing heat attended by mild rain, and a south wind ; but in whiter they com- monly precede the breaking up of a frost, and the setting in of foggy and wet weather. (Fig. 4.1 304. WJiat do cirro-stratus clouds foretell ? Cirro-stratus clouds foretell rain or snow, according to the season of the year. These clouds extend in long horizontal streaks, thinning away at their base, and in parts becoming wavy or patchy. When they are thus defined in the heavens they are a certain indication of lad weather. (Fig. 6.) 395. What do cumulo-stratus clouds foretell ? Cumulo-stratus clouds usually foretell a change of weather from rain to fine, or from fine to rain. (Fig. 9.) Fig. 10. NIMBUS, OB SIOEIT CLOTH). THE SEASON WHY. 97 " Behold, I will put a fleece of wool in the floor ; and if the dew be on the fleece only, and it be dry upon all the earth beside, then shall I know that thou wilt save Israel. * * * CHAPTER XIX. 390. Why are cloudy days colder than sunny days ? Because the clouds intercept the solar rays in their course towards the earth. 397. Why are cloudy nights warmer than cloudless nights ? Because the clouds radiate back to the earth the heat which the earth evolves ? Because, also, the clouds radiate to the earth the heat they have derived from the solar rays during a cloudy day. 398. Why is the earth warmer than the air during sun- shine ? Because the earth freely absorbs the heat of the solar rays ; but the air derives comparatively little heat from the same source. 399. Why does the earth become colder than the air after sunset ? Because the earth parts with its heat freely by radiation ; but the air does not. 400. Why do glasses, mats, or screens, prevent the frost from Jcilling plants ? Because they prevent the radiation of heat from the plants, and also from the earth beneath them. 401. Why are the screens frequently covered with dew on their exposed sides ? Because they radiate heat from bo th their surfaces. A piece of giass, laid horizontally over the earth, would radiate heat both npivards and downwards. But on its lower surface it would receive the radiated heat of the earth, while from its upper surface it would throw off its own heat and become cool. Therefore dew would be deposited upon the upper, but not on the under surface. 402. Why does dew rest upon the upper surfaces of leaves ? 5 98 THE SEASON WHY. 'And it was so: for he rose up early on the morrow, and thrust the fleece together, and wringed the dew out of the fleece, a be wl fu'.l of water. Because the under surfaces receive the radiated warmth of tha earth. 403. Why cere cultivated lands subject to heavier dew* tlian those that are uncultivated ? Because cultivation breaks up the hard surface of the earth, and thus its radiating power is increased. 404. Why is the gravel walk through, a lawn comparatively dry while the grass of the lawn is wet with dew ? Because gravel is a bad radiator, but grass is a good radiator. 405. What benefit results from this arrangement ? In cultivated lands, where moisture is required, it is induced by the very necessity which demands it ; while in rocky and barren places, where it would be of no good, dew does not form. 406. Why does 'little dew form at the base of hedges and walls, and around the trunks of trees? Because those bodies in some degree counteract the radiation of heat from the earth ; and they also radiate heat from their own substances. 407. Why do heavy morning deivs and mists usually come together ? Because they both have their origin in the humidity of the atmosphere. The temperature of the earth having fallen, dew has been deposited ; but, at the same time, the condensation of the vapour in the air has formed a screen over the surface of the earth, which has checked the further radiation of heat, and, consequently, the further formation of dew. The sun rises, therefore, upon an atmosphere charged with visible vapour at the earth's surface, and his first sloping rays, having little power to warm the atmosphere, the mist continues visible for some time. 08. What effect have winds upon the formation of dew ? Winds, generally, and especially when rapid, prevent the forma- tion of dew. But those winds that are moist, and contribute to the formation of clouds, indirectly aid the formation of dew through tht KHE BEASON WHY. 99 " And Gideon said unto God, * * * " Let it now be dry only upon the fleece, and upon all the ground let there be dew. formation of clouds, and also by the moisture they impart to the air. 409. Why does the humidity of the atmosphere sometimes form clouds, and at others form fogs, mists, dews, fyc. ? The result depends upon the varying temperature, motion, and direction of the atmosphere. A warm light atmosphere, of a few day's duration, will elevate the vapours to the region where they are formed into clouds. A chill air, lying upon the surface of the warmer earth, will occasion mists or fogs. A cold earth, acting upon the vapours contained in a warmer atmosphere, will condense them and occasion dews. 410. Why are frosty mornings usually clear ? Because, in the cold ntmosphere which preceded the frost, there was but little evaporation ; and now that the frost has set in, the vapours that existed have become frozen in the form of hoar-frost. 411. Why are clear nights usually cold? Because the " screen" afforded by the clouds does not exist ; therefore the heat of the earth escapes, while the vapours of the air are abstracted from it by condensation into dew, thereby imparting great clearness to the nights. 412. WJiy are hoar-frosts, or, as they are termed, " white frosts," so frequent, and " Hack frosts" so unusual ? Because white, or hoar-frosts, result from the coldness of the earth, which, from its great radiating power, is always varying. But black-frosts result from the coldness of the air, which is liable to less variation of temperature than the earth. 413. What is a Hack-frost ? A black frost results from the coldness of the atmosphere, which is at the time overshadowed by a dull cloud, giving a dark- ness to everything, and a leaden appearance to the frozen surface of water. 414. Why are black-frosts said to latt ? tOO THE EEA8ON WHY. "And God did so that night : for it was dry upon the fleece only, and there WM dew on all the ground." JUDGES vi. Because as they result from the temperature of the air, which is less likely to vary than that of the earth, there is a probability that the coldness thereof will last for some time. 415. What benefits result from the radiation of heat, Sfc. ? But for the radiation of heat, we should be subjected to the most unequal temperatures. The setting of the sun would be like the going out of a mighty fire. The earth would become suddenly cold, and its inhabitants would have to bury themselves in warm covering, to wait the return of day. By the radiation of heat, an equilibrium of temperature is provided for, without which we should require a new order of existence. The amount of heat which our earth receives from the sun, and the economy of that heat by the laws of radiation, reflection, absorption,, and convection, arc exactly proportionate to the necessities of our planet, and the living things that inhabit it. It is held by philosophers that any change in the orbit of our earth, which would either increase or decrease the amount of heat falling upon it, would, of necessity, bo followed by the annihilation of all the existing races. The planets Mercury and Venus, which are distant respectively 37 millions of miles, and 68 millions of miles, from the great source of solar heat, possess a temperature which would melt our solid rocks; while Uranus (1,800 millions of miles), and Neptune (whose distance from the sun has not been determined), must receive so small an amount of heat, that water, such as ours, would become as solid as the hardest rock, and our atmosphere would be resolved into a liquid ! Yet, poised in the mysterious balance of opposing forces, our orb flies unerringly on its course, at the rate of 65,003 miles an hour ; preserving, in its wonderful flight, that precise relation to the sun, which takes from his life-inspiring rays the exact degree of heat, which, being shared by every atom of matter, and every form of organic existence, is just the amount needed to constitute the heat' life of the world ! CHAPTER XX. 416. What is rain? Kain is the vapour of the clouds which, being condensed by a fall of temperature, forms drop? of water that descend to the earth. It is the return to the earth in the form of water, of the moisture absorbed by the air in the form of vapour. 417. Does rain ever occur without clouds ? It sometimes, but rarely happens, that a sudden transition from THE BEA.SON- WHY. 101 " Canst thou lift up thy voice to the clouds, that abundance of waters maj cover thee ?" JOB xxxvm. warmth to cold will precipitate the moisture of the air, without the formation of visible clouds 418. Why are drops of rain sometimes large and at other times small ? Because the drops, in falling, meet and unite, and also gather moisture in their descent. The greater the height from which a rain drop has descended, the larger it is, provided that its whole course lay through a rainy atmosphere. The size of the drops is also influenced by the amount of moisture in the atmosphere, the degree of cold, and the rapidity of the change of temperature, by which the drops are produced. 419. In what seasons of the year are rains most prevalent T Throughout Central Europe rains are most prevalent in summer, but in Southern Europe the preponderance is on the side of winter rains. 420. In what months of the year does it rain most frequently in this country ? It rains more frequently from September to March, than from March to September ; but the heaviest rains occur from March to September. 421. Why are there more rainy days from September to March ? Because the temperature of the air is more frequently lowered to that degree which precipitates its vapours. Months in the order of their comparative wetness , 1. October. 2. February. 3. July. 4. September. 5. January. 6. December. Months in the order of their comparative dryness : 1. March. 2. January. 8. May. 4 August. 5. April. 6. Xovember. 422. In what part of the world does the greatest quantity of rain fall ? The greatest quantity of rain falls near the equator, and thi amount decreases towards the poles. 102 THE EEASON WHY. 'Who can number the clouds in -wisdom? or who can stay the bottles of heaven." JOB xxxviu. 423. In what part of the world do the heaviest rains occur ? The heaviest rains occur in the tropics, during the hot season. The drops of rain in the tropical regions are so large, and the force with which they descend so great, that their splash upon the skin causes a smarting sedation. 424. In what parts of the ivorld do the least rains occur ? There are some parts of the earth which are rainless, such as Egypt, the desert of Sahara, the table lauds of Persia and Mont- golia, the rocky flat of Arabia Petrae, &c. 425. Sow many rainy days are there in a year ? The frequency of rainy days is greatest in countries near the sea, and their number decreases the further we journey from the sea- border towards the inland. In England it rains on an average 152 to 155 days in the year. 426. In what part of England does the greatest amount of rainfall ? In the town of KeswicJc, in Cumberland, where 63 inches of rain fall in a year ; Kendal, in Westmoreland, 58 inches ; Liverpool, 34 inches ; Dublin, 25 inches ; Lincoln, 24 inches ; London, 21 inches. 427. Why do the heaviest rains occur at the tropics ? Because the hot air absorbs a large amount of vapour, and rises into the higher regions of the atmosphere, where the vapours are suddenly condensed into heavy rains, by cold currents from the poles. 428. Why does the greatest quantity of rain fall at the equator ? Because the hot air absorbs a large amount of vapour, and as the atmosphere is usually calm, there is an absence of currents, by which the saturated air would be removed. In this, which is called " the Region of Calms," rain falls almost daily. 429. Why are some parts of the earth rainless? THE BEASON WHY. 103 * Thou, O God, didst send a plentiful rain, whereby thou didst confirm tliino inheritance, when it was weary." PSAXM LXVIII. Because, being situated in tropical or torrid latitudes, and at a distance from the ocean, the atmosphere above them is always in a dry state. 430. Wlien is air said to le saturated with vapour f When it cannot take up a larger quantity than that which it already holds. When common salt is dissolved in water, until the water can take up no more, the water is then said to be saturated with salt. 431. Wliat proportion of water is air capable of sustaining in the form of vapour ? The amount of water held in suspension by the air averages the following proportion : one thousand cubic feet of air contain as much vapour as, were it condensed to water, would yield about two fifths of a pint. But one thousand cubic feet of air are capable of holding half -a- pint of water; and this may be regarded as the point of saturation. Thus, in a room ten feet square and ten feet high, the air, at the point of saturation, would hold in the form of vapour, half-a-pint of -water. It must not be forgotten, however, that the point of saturation necessarily varies with the temperature of the air. 432. Why are cloudy days and nights not always wet ? Because the air has not reached the state of saturation. 433. WJiy does rain purify the air ? Because it produces motion in the particles of the air, by which they are intermixed. And it precipitates noxious vapours, and cleanses the face of the earth from unhealthy accumulations. 434. Why are mountainous localities more rainy than fiat ones? Because the mountains attract the clouds; and because the clouds that are flying low are borne against the sides of the mountains and directed upwards, where they meet with cold currents of air, 435. Why does more rain fall ly night than by day f 104 THE SEASON WHY. As the hart panteth after the water brooks, so panteth my soul after thee O God." PSAI-M XLII. Because by night the temperature of the air, heated during the day, falls to that degree which condenses its vapours into rain. 436. Why do bundles of dried, sea-weed indicate the probability of coming rain ? Because they readily imbibe moisture, and when they become soft and damp they show that the air is approaching the point of saturation. 437. Why does the weather-toy, called the "weather-cock" foretell the probability of rain ? Because it is made with a piece of cat-gut which swells with moisture, and as it swells, shrinks. The cat-gut is so applied that when it shrinks, it turns a rod which sends the man out of the house, and when it dries it sends the woman out. Therefore, when the man appears, it is a sign of wet, and when the woman appears it is a sign of dry weather. There is another toy, called the Capuchin, which is made upon the same principle. The figure lifts a hood over its head when wet is approaching, and takes it off when the weather is becoming dry. In this case, a piece of cat-gut is also employed. Various weather-toys may be made upon this principle among others, a little umbrella, which will open on the approach of wet, and close on the return of fine weather. A gentleman once made a wooden horse, which he declared should of itself walk across a room, without machinery of any kind. The assertion was discredited; but the horse was placed in a room close to the wall on one side. The room was locked, and otherwise fastened, so that no one could interfere with the experiment. After a time the door was opened, and it was found that the horse had actually crossed the floor, and stood on the opposite side. The horse was made from wood of a peculiar kind, liable to great expansion in wet weather, and cut in a manner to produce the greatest elongation. The fore hoofs were so made that where they were set they wouli remain, so that the contracting parts should draw up from behind. It is easj to understand how, in this way, the wooden horse crossed the apartment. 438. WJiy does ladies' hair drop out of curl upon the approach of damp weather ? Because the hair absorbs moisture, which causes its spirals to relax and unfold. 439. Why is it said in mountainous countries that rain it THE EE1SON WHY. 105 ' Hast thou entered into the treasures of the snow ; or hast thou seen tho treasures of the hail." JOB xxxvin. coming, because the mountains are "putting their night-caps on?" Because the clouds descend when they are heavy with vapour, and being attracted to the mountain tops they are said to " cap the mountains." CHAPTER XXI. 440. What is snow ? Snow is congealed vapour, which would have formed rain ; but, through the coldness of the air, has been frozen in its descent into cry staline forms. (Fig. 1.) 441. Why is snow white ? Because it reflects all the component rays of light. 442. Why is snow said to be warm, while white garments are worn for coolness ? Snow is warm by virtue of its light and woolly texture. But it is also warm on account of its whiteness ; for, had it been black, it would have absorbed the heat of the sun, which would have thawed the snow. Instead of which, it reflects heat ; and the reflected heat falls upon bodies above the snow, while the warmth of the earth is preserved beneath it. Wldte clothing is cool, because it reflects from the body of the wearer the heat of the sun. White snow is warm, because it reflects the sun's heat upon bodies. There are few persons but have felt the effect of the sun's rays reflecfedby the white snow on a clear wintry day. And, as regards the warmth of snow towards the earth, by preventing the radiation of heat, it has been found that a thermometer buried four inches deep in snow has shown a temperature of nine degrees higher than at the surface. 443. Why are lofty mountains always covered with, snow f Because the upper regions of the atmosphere are intensely cold. 444. Why are the upper regions of the atmosphere intensely cold? Because the atmosphere retains but little of the heat of the titn't 5* 106 THE SEASON WHY. . " He causeth the vapours to ascend from the ends of the earth : he makcth lightnings for the rain -. he bringeth the wind out of his treasuries." Ps. xxxv rays as they pass to the earth. Because at high altitudes the air is greatly rarefied. And because the radiation of heat from tlio earth does not materially affect such high regions. 445. What is meant l>y the snow line? The snow line is the estimated altitude in all countries where snow would be formed. Even at the equator, at an altitude of 15,000 to 16,000 feet from the level of the sea, snow is found upon the mountain summits, where it perpetually lies. As we proceed north or south from the equator the snow line lessens in altitude. Had we in England a mountain 6,000 feet high, it would be per- petually crowned with snow. 446. Why do we hear of red snow ? Red snow is the name given to the snow in the arctic regions upon which a minute vegetable (probably the Protoccus nivalis) grows, imparting to the snow a red colour. Eecent microscopic investigations have shown it to consist of a minute vegetable cell, which secretes a red colouring matter. Snow is found to be of greater import nee to man than is generally supposed. But, although in this country we are enabled to recognise the hand of Provi- dence in the gift, there are latitudes wherein the blessing thus conferred is more deeply felt. In such countries as Canada, Sweden, and Russia, the falling of snow is looked for with, glad anticipations, quite equalling those which herald the " harvest-home" of England, or the " vintage" of France. No sooner is the ground covered with snow, than crankj old vehicles that had been jolting over rough roads, and sticking fast in deep ruts of mud, are wheeled aside, and swift sledges take their place. Towns distant from each other find an easy mode of communication ; the markets are enlivened, and trade thrives. Snow supplies a kind of railroad, covering the entire face of the country, and sledges glide over it, almost with the speed of the locomotive. 447. What is sleet? Sleet is snow which, in falling, has met with a warmer current of air than that in which it congealed. It therefore partially melts and forms a kind of wet snow. 448. What is hail? Hail is also the frozen moisture of the clouds. It is probably formed by rain drops in their descent to the earth, meeting with an exceedingly cold current of ait by which they become suddenly .frozen into hard masses. THE EEASON "WHY. 10? ' If the clouds be full of rain, they shall empty themselves upon the earth." ECCLES. xi. It is also supposed that the electrical state of the air and of tho clouds influences the formation of hail. 449. Wliy is it supposed that the electrical state of the air and the clouds affects the formation of hail ? Because hail is more common in the summer than at other eeasons, and is frequently attended by storms of thunder and lightning. 450. Why do hail-storms most frequently occur ly day ? Because the clouds, being charged with vapour to saturation, favour the formation of hail by sudden electrical or atmospheric changes. In the gradual cooling of night, the clouds would expend themselves in rain. Astonishing facts respecting hail-storms are upon record. In 1719 there fell at Kremo, hailstones weighing six pounds. In 1828 there was a fall of ice at Horsley, in Staffordshire, some of the pieces of which were three inches long, by one inch broad ; c.nd other solid pieces were about three inches in circumference. Hail storms are most frequent in June and July, and least frequent in April and October. Hail clouds float much lower in the sky than other clouds ; their edges are marked by frequent heavy folds ; and their lower edges are streaked with white, the other portions being massive and black. (Fig. 10.) CHAPTER XXII. 451. What is light? Light, according to Newton, is the effect of luminous particles which dart from the surfaces of bodies in all directions. According to this theory, the solar light which we receive would depart from the sun and travel to the earth. According to Huyghens, light is caused by an infinitely elastio ether, diffused through all space. This ether, existing everywhere, is excited into waves, or vibrations, by the luminous body. The theory of light is so undetermined that neither the views of Newton, nor those of Huyghens, can be said to be exclusively adopted. "Writers upon natural philosophy seize hold of either or both of those theories, as they present themselves more or less favourably in the explanation of natural phenomena. In " The Season Why," as we have to speak of the effects of light rather than of its cause, we sb.all ay ?id, as faff as possible, the doubtful points. But lot aa 108 THE BEASON WHY. " And God said, Let there be light : and there was light. one be discouraged by the fact that the theory of light, as, indeed, of all the imponderable agents, is imperfectly understood. Rather Jet us rejoice that there are vast fields of discovery yet to be explored j and that light, the most glorious and inspiring element in nature, invites us from the sun, the moon, and the stars, and from the face of every green leaf and variegated flower, to search out the wonders of its nature, and further to exemplify the goodness and wisdom of God. 452. Wliat is the distance of the sun from the earth ? Ninety five millions of miles. 453. At lohat rate of velocity does light travel? At the rate of 192,000 miles in a second, through our atmo sphere; and 192,500 miles in a second through a vacuum. 454. Sow long does light take to travel from the sun to the earth ? Eight minutes and thirteen seconds. 455. What is the constitution of the sun ? It is a spherical body, 1,384,472 times larger than the earth. 456. From what does the luminosity of the sun arise f From a luminous atmosphere, or, as M. Arago named it, photo- sphere, which completely surrounds the body of the sun, and which is probably burning with great intensity. 457. What are the minor sources of light ? Light may be produced by chemical action, by electricity, and by phosphor esence, in the latter of which various agencies unite. 458. What is a ray of light ? A ray of light is the smallest portion of light which we can recognise. 459. What is a medium ? A medium is a body which affords i passage for the rays of light. 460. What is a learn of light ? A beam of light is a group of parallel ravt. 461. What is a pencil of light? THE SEASON WHY. 109 " And God saw the light, that it was good : and God divided the light from the darkness." GEN. r. A pencil of light is a body of rays which come from or move towards apeint. 462. What is the radiant point ? The radiant point is that from which diverging rays of light are emitted. 463. What is the focus 'f The focus is the point to which converging rays are directed. Diverging, starting from a point, and separating. Converging, drawing together towards a point. 464. What is the constitution of a ray of light ? A ray of white light, as we receive it from the sun, is composed of a number of elementary rays, which, with the aid of a triangular piece of glass, called a prism, may be separated, and will produce under refraction the following colours : 1. An extreme red ray a mixture of red and blue, the red predomin ating. 2. Bed. 3. Orange red passing into and combining with yellow. 4. Yellow the most luminous of all the rays. 5. Crreen yellow passing into and combining with the blue. 6. Blue. 7. Indigo a dark and intense blue. 8. Violet blue mingled with red. 9. Lavender grey a neutral tint. 10. Eays called fluorescent, which are either of a pure silvery blue, or a delicate green. 465. Why is a ray of light, which contains these elementary rays, white ?- Because the colour of light is governed by the rapidity of the vibrations of the ether-waves. When a ray of light is refracted by, or transmitted through a body, its vibrations are frequently disturbed and altered, and thus a different impression is made upon the eye. Light which gives 37,640 vibrations in an inch, or 468,000,000,000,000 in a second of time, produces that sensation 110 THE SEASON WHY. ' The light of the body is the e.ye : if therefore thine eye be single, thy whole body sh;u: be full of light." MATT, v upon the eye which makes the object that directs the vibrations appear red. Yellow light requires 44,000 vibrations in a'n inch, and 535,000,000,000,000 in a second of time. And the other colours enumerated (see 404) all require different velocities of vibration to produce the colours by which they are distinguished. Accepting the theory of vibrations, and applying it to the elucidation of the phenomena of light it is unnecessary, we think, to believe that a ray of white light contains rays in. a state of colour. It is said that if we divide a circular surface into parts, and paint the various colours in the order and propor- tions in which they occur in the refracted ray, and then spin the circle with great velocity, the colours will blend and appear white. But such is not the case ; the result is in some degree an illusion, arising out of the sudden removal of the impression made upon the eye by the colours -, and if a piocc of white paper be held by the side of the coloured circle in motion, the latter will be found to be grey. When it is remembered that in colouring a white surface with thin colours, the whitfe materially qualifies the colours, it must be admitted that the experiment fails to support the assertion that the colours of the spectrum produce white. But there can be no difficulty in understanding that a ray of light undergoing refraction, becomes divided into minor rays, which differing in their degrees of refrangibility, vary also in the velocity of their vibrations, and produce the several sensations of colour. 466. Why is a substance white? Because it reflects the light that falls upon it without altering its vibrations. 467. Why is a substance Hack ? Because it absorbs the light and puts an end to the vibrations. 468. Why is the rose red ? Because it imparts to the light that falls upon it that change in its vibratory condition, which produces on our eyes the sensation of redness. 469. Why is the lily while ? Because it reflects the light without altering its vibrations. 470. Why is the primrose yellow f Because, though it receives white light, it alters its vibrations to 4i,000 in an inch, and 535,000,000,000,000 in a second, and this is the velocity of vibration which produces upon the eye a sensation of yellow. THE BEASON WHY. HI * But if thine eye be evil, thy whole body shall be full of darkness. If therefore the light that is in thee be darkness, how great is that darkness."- MATT. v. 471. Why are there so many varieties of colour- and tint in the various objects in nature ? Because every surface has a peculiar constitution, or atomic condition, by which the light falling upon it is influenced. In tropical climates, where the brightness of the sun is the most intense, there the colours of natural objects are the richest ; the foliage is of the darkest green ; the flowers and fruits present the brightest hues; and the plumage of the buajs* is of the most gaudy description. In the temgerate climates these features are more subdued, still bearing relation to the degree of light. And at a certain depth of the ocean, where light penetrates only in a slight degree, the objects that abound are nearly colourless. It has been held by many philosophers (and the theory is so far conclusive that it cannot be dispensed -with) that there is an analogy between the vibra- tory causes of sound, and the vibratory causes of colour. Any one who has seen an yEolian harp, and listened to the wild notes of its music, will be aware that the wires of the harp are swept by accidental currents of air ; that when those currents have been strong, the notes of the harp have been raised to the highest pitch, and as the intensity of the currents has fallen, the musical sounds have deepened and softened, until, with melodious sighing, they have died away. No finger has touched the strings ; no musical genius has presided at the harp to wake its inspiring sounds ; but the vibration imparted to the air, as it swept the wires, has alone produced the chromatic sounds that have charmed the listener. If, then, the varied vibrations of the air are capable of imparting dissimilar sensations of sounds to the ear, is it not only possible, but probable, that the different vibrations of light may impart the various sensa- tions of colours to the eye 1 CHAPTER XXIII. 472. What is the refraction of light ? "When rays of light fall obliquely upon the surface of any transparent medium, they are slightly diverted from their course. This alteration of the course of the rays is called refraction, and the degree of refraction is influenced by the difference between the densities of the mediums through which light it transmitted. 112 THE EEASON WHY. " Let your light so shine before men, that they may see your good works, and glorify your father which is in heaven." MATT. v. 473. If a ray of light falls in a straight line upon a trans- parent surface, is it then refracted ? In that case the ray pursues its course there is no refraction. 474. Is the direction in which the rays are bent, or re- fracted, influenced by the relative densities of the media? A ray of light falling slantingly upon a window, in passing through it is-lfi^htly brought to the perpendicular ; and if it then falls upon the surface of water, it is still further brought to the perpendicular in passing through the water. 475. Is light refracted in passing from a dense medium to a thinner one ? It is ; but the direction of the refraction is just the opposite to the instance just given ; a ray of light passing through water into air, does not take a more perpendicular course, but becomes more oblique. Fig. 11. 476. Why, if a rod or a spoon be set in an empty basin, will it appear straight, or of its usual shape ? Because the rays of light that are reflected from it all pass through the same medium, the air. 477. Why if water be poured into the basin will the rod of spoon appear bent ? Because the rays of light that pass through the water are reflected in a different degree to those that pass through tha air THE REASON WHY. 113 " Evening, and morning, and at noon, will I pray, and cry aloud ; and lie shall hear my voice." PSALM LT. Place in the bottom of an empty basin (Fig. 11.) a shilling ; then stand in such a position at the point B that the line of sight, over the edge of the basin, just excludes the shilling from view. Then request some one to pour water into the basin, until it is filled to G (Fig. 12.), keeping your eye fixed upon tha spot. The shilling will gradually appear, and will soon come entirely in view. Not only will the shilling be brought in view, but also portions of tha basin before concealed. This is owing to the rays of light passing from tho bottom through the water in a direction more perpendicular than they would have done through the air ; but on leaving the water they become more obUque,a,nd. hence they convey the image of the shilling over the edge of the basin, which otherwise would have obstructed the view. Fig. 12. 478. Wliy is it that in cloudy and showery days we see the sun's rays bursting through, the clouds in different directions ? Because, in passing through clouds of different densities the rays are bent out of their course. 479. Why is the apparent depth, of water always decep- tive ? Because the light reflected from the ohjects at the bottom is refracted, as it leaves the water. 480. How much deeper is water than it appears to le ? About one-third. A person bathing, and being unable to swim, should calculate before jumping into the water, that if it looks two feet deep, it is quite three feet. 481. Why can we seldom at the first attempt touch anything lying at the bottom of the water with a stick? Because we do not allow for the different refractive powers of water and of air THE BEASON WHY. ' I do set mj- bow in the cloud and it shall be for a token of a covenant between me and the earth." 482. Wliy do we see the sun sun-set ? before sun-rise, and offer Because of the refractive effects of the atmosphere. Rays of light, passing obliquely from the sun through the air to the earth, are refracted three or four times by the varying density of the medium. Each refraction bends the rays towards the perpendicular ; and hence we see the sun before it rises and after it sets, Fig. 18. DIAGRAM EXHIBITING THE BEFEACTION OP THE SUN'S EATS IN PASSING THEOUGH THE ATMOSPHEEB. 483. Why do figures, viewed through tlie hot air proceeding from furnaces, and from lime-kilns, appear distorted and tremulous ? Because the ever varying density of the air which is flying away in hot currents, and succeeded by cold, constantly changes the refractive power of the medium through which the figures are viewed. 484. Why do the stars twinkle ? Because their light reaches us through variously heated and moving currents of air. In this case the earth is the Jciln, and the stars the object that is viewed through the refractive medium. 485. Why does much twinJcling of the stars foretell lad weather ? Because it denotes that there are various aerial currents of different temperatures and densities, producing atmospheric disturbance. THE BEASON WHY. 115 ** And it shall come to pass, when I bring a cloud over the earth, that the bow shall be seen in the cloud." GENESIS IX. 486. WTiat causes the rainloiv ? The refraction of the sun's rays by the falling rain. 487. Why does the rainbow exhibit various colours ? The colours belong to the elementary rays of light ; and these rays having different degrees of refrangibility, some of them are bent more than ethers ; they are therefore separated into distinct rays of different colours. 488. Why are there sometimes two rainbows ? Because the rays of refracted light, reflected upon other drops of rain, are again refracted, and then reflected again, forming a secondary bow. 489. Why are the colours of the secondary bow arrayed in the reverse order of the primary bow ? Because the secondary bow is a reflection of the primary bow, and, like all reflections, is reversed. 490. Wliy are reflections reversed ? Because those rays which first reach the reflecting surface are the first returned. If you hold your open hand towards the looking-glass, the light passing from the point of your finger will reach the reflector and be returned before the rays that pass from the back parts of the hand. Hence the image of the hand will present the reflection of the finger point towards the point of the finger. 491. Why are the colours of the - secondary rainbow fainter than those of the primary ? Because they are derived from the refraction and reflection of rays which have already been refracted and reflected, and thereby their intensity has been diminished. 492. What is a lunar rainbow f A lunar rainbow is caused by the light of the moon, in the same manner as tts solar rainbow is caused by the light of the sun 116 THE SEASON WHY. " I am come a light into the world, that whosoever believeth in me should not abide in darkness." JOHN xm. 493. Why is the lunar rainbow fainter than a solar rainbow ? Because the light of tJie moon is the reflected light oj the sun, and is therefore less intense. 494. What is a halo ? A. halo is a luminous ring, which forms between the eye of the observer and a luminous body. Haloes may appear around the disc of the sun, moon, or stars. But in this country the lunar haloes are the most remarkable and frequent. 495. What is the cause of the luminous ring ? The refraction of light as it passes through an intervening cloud, or a stratum of moist and cold air. 496. Why are haloes sometimes large and at other times small ? Because they are sometimes formed very high in the atmosphere, at other times very low. Being high, and farther removed from the spectator, and nearer the source of light, they appear smaller ; while the nearer they are, the larger they appear. 497. Why do haloes foretell wet weather ? Because they show that there is a great amount of atmospheric moisture, which will probably form rain, 498. Why do glass lustres and chandeliers exhibit' " rainbow colours" ? Because they refract the rays of light in the same manner as the rain drops. 499. Why does a soap bubble show the prismatic colours ? Because, like a large rain drop, it refracts the rays of light, and shows the elementary rays. 500. What causes the rich tints displayed ly " mother-of- pearl?" The refraction of the light that falls upon the surface of thg pearl. THB BEASOIf WHY. 117 * Light is sown for the righteous, and gladness for the apright in heart." PSALiI XCVJI. 501. What causes the brilliant colours of the diamond ? The refraction of the rays of light by the various facets of the diamond. The refraction of light, and the production of prismatic colours, surrounds us with most interesting phenomena. The laundress, whose active labours raise over the wash-tub a soapy froth, performs inadvertently one of the most delicate operations of chemistry the chemistry of the imponderable agents and the result of her manipulations manifests itself in the delicate colours that dance like a fairy light over the glassy films that follow the motion of her arms. The laughing child, throwing a bubble from the bowl of a tobacco pipe into the ah-, performs the same experiment, and produces a result such as that which filled the philosophic Newton with unbounded joy. The foam of the sea shore, the plumage of birds, the various films that float upon the surface of waters, the delicate tints of flowers, and the rich hues of luscious fruits, all combine to remind us, that every ray of light comes like an angelic artist sent from heaven, hearing upon his palette the most celestial tints, with which to beautify the earth, and rfiow the illimitable glory of God. CHAPTER XXIV. 502. What is the difference between the refraction and the reflection of light? Refraction is the deviation of rays of light from their course through the interference of a different medium ; reflection is the return of rays of light which, having fallen upon a surface, are repelled by it. 503. What is the radiation of light? The radiation of light is its emission in rays from the surface of a luminous body. 604. Do all ladies radiate light ? All bodies radiate light ; but those that are not in themselves primary sources of light, are said to reflect it. 505. Do black bodies reflect any light T Black bodies absorb the light that falls upon them. Bat ihejr reflect a very small degree of light. 506 Why is glass transparent f 118 THE SEASON WHY. "As in water face answereth to face, so the heart of man to man. PEOVEKBS xxvi. T . Because its atoms are so arranged that they allow the vibrations of light to continue through their substance. 507. Does glass obstruct the passage of any portion of light f Glass reflects (sends back) a very small portion of light. This may be observed by holding a piece of paper, or a hand, a few inches from a window, when a faint reflection of it will be visible. Probably the small amount of light reflected by transparent glass, which gives a passage to the greater part of the rays, may serve to illustrate the small amount of light reflected from black surfaces, which absorbs the greater portion of light. Instead of a piece of white paper, hold a piece of black cloth two or three inches from the window-pane, and you will have two reflections so weak that the image of the cloth will be almost lost. The first reflection is that of the very small amount of light from the black surface on to the glass, and the second reflection is that of the inconceivably small amount returned by the glass, and by which the faint image of the black cloth is produced. But put the black cloth outside of the window-pane, and then hold an object before them, and you will find that the two weak reflectors, acting together, produce an improved image, or reflection. 508. Why, if a book is held between a candle-light and the wall, does a shadow fall upon the wall ? Because the rays of light are intercepted by the book. 509. Why do the rays pass over the edges of the look in a direct line with the flame of the candle? Because light always travels in straight lines. 510. Wliy is there some amount of light even where shadows fall ? Because, as all objects reflect light, some of them throw their light into the field of the shadow. 511. Why are some substances opaque to light ? Because the arrangement of their particles will not admit of the vibrations of the luminous ether passing through them. Opaque impervious to rays of light. 512. Why do we see our faces reflected in THE EEASON WHY. 'The day is thine, the night also is thine: thou hast prepared the light and the sun." PSAIM LXXTV. Because the rays of light from our faces are reflected by tho surface of the quicksilver at the back of the glass. 513. Why does tlie quicksilver reflect the rays of light ? Because, being densely opaque to light, and presenting also a bright surface, it is a good reflector, and it throws back the whole of the rays. 514. What has the glass to do with the reflection ? The glass has nothing to do with the reflection, except that it affords a field upon which the reflecting surface of the quicksilver is spread ; and it keeps the air and dirt from dulling the quicksilver . The parts of a mirror from which the quicksilver is nibbed away give no reflection that could assist the reflecting power of the quicksilver. That the surface of the glass does not reflect the image, is shown by the fact, that if you put the point of any object against the glass, the thickness between the poiiit and the place where the reflection of it begins, will shoto the exact thickness of the glass. 515. Why does a compound mirror (a multiplying mirror) exhibit a large number of images of one object. Because all objects reflect rays of light in every direction, and therefore the different mirrors, being at various angles, receive each a reflection of the same object. 516. Wliy does a ivindow-pane appear to be a better reflec- tor by candle-light than by day-light ? The reflecting power of glass is precisely the same by night as by day, and is always very feeble. But it appears to be greater by night, because the surrounding darkness increases the apparent strength of the reflection. 517. How do we know that objects reflect light in every direction? Because if we prick a hole in a card with a pin, and then look through that small hole upon a landscape, we can see some miles of country, and some thousands of objects j every part of every object throughout the whole scene, must have sent rays of light to the small hole pricked in the card. 120 THE BEASON WHY. ' Such knowledge is too wonderful for me ; it is high, I cannot attain unto it."- PSAiM CXXXIX. At one extremity of the landscape, viewed through the hole in the card, there may be a forest of trees ; in the distance there may be hills bathed in golden light, and overhung with glittering clouds; in the mid-distance there maybe a river winding its course along, as though it loved the earth through which it ran, and wished, by wandering to and fro, to refresh the thirsty soil ; in the foreground may be a church, covered by a million ivy leaves ; and grouping towards the sacred edifice may be hundreds of intending worshippers, old and young, rich and poor ; flowers may adorn the path-ways, and butterflies spangle the air with their beauties : yet every one of those objects the forest, the hills, the clouds, the river, the church, the ivy, the people, the flowers, the butterflies must have sent rays of light, which found their way through the little hole in the card, and entered to paint the picture upon the curtain of the eye. This is one of the most striking instances that can be afforded of the wonderful properties of l$ght, and of the infinitude of those luminous rays that attend the majestic rising of the sun. Not only does light fly from the grand " ruler of the day " with a velocity which is a million and a half times greater than the speed of a cannon-ball, but it darts from every reflecting surface with a like velocity, and reaches the tender structure of the eye so gently that, as it falls upon the little curtain of nerves which is there spread to receive it, it imparts the most pleasing sensations, and tells its story of the outer world with a minuteness of detail, and a holiness of truth. Philosophers once sought to weigh the sunbeam ; they constructed a most delicate balance, and suddenly let in upon it a beam of light ; the lever of the balance was so delicately hung that tho fluttering of a fly would have disturbed it. Everything prepared, the grave men took thdr places, and with keen eyes watched the result. Tho sunbeam that was to decide the experiment had left the sun eight minutes prior to pass the ordeal. It had flown through ninety-flve millions of miles of space in that short measure of time, and it shot upon the balance with unabated velocity : but the lever moved not, and the philosophers were mute. CHAPTER XXV. 518. Why, wlien we move before a mirror, does the image draw near to the reflecting surface as we draiv near to it, and retire when we retire ? Because the lines and angles of reflection are always equal to the lines and angles of incidence. 519. What is tlie line of incidence ? If a person stands in a direct line before a mirror, the line through which the light travels from him to the mirror is the lint of incidence. Incidence falling on. THE SEASON WHY. 121 Blessed be the Lord, who daily loadeth us with benefits, e?en the God of our salvation." PSALM LXVIII. 520. What is the line of reflection ? The line of reflection is tl^e line in which the rays of light are returned from the image formed in the glass to the eye of the observer. Reflection a turning back. 521. What is the angle of incidence? The angle of incidence is the angle which rays of light, falling on a reflecting surface, make with a line perpendicular to that surface. ABC \ iietlecting Surface. Jfig. 14. EXPLAINING THE LINES AND ANGLES OP HTCIDENCB AITD OF EEELECTION. 522. What is the angle of reflection ? The angle of reflection is the angle which is formed by the returning rays of light, and a line perpendicular to the reflecting surfaje. It is always equivalent to the angle of incidence. TaU a marble and roll it across the floor, so that it shall strike the wainscot rbliqi.aly. Let A in the diagram represent the point from which the marble is wnt. The marble will not return to the hand, nor will it travel to the line B. but w Jl bound off, or be reflected, to C. Now B is an imaginary line, perpen- dicult r to the reflecting surface; and it will be found that the path described by the marble in rolling to the surface and rebounding frov it, form, with the line B, two angles that are equal. These represent the angles of incidence and of refaction, and explain why the reflection of a person standing at A before a mirrc-r, would be seen by another person standing at C. This simple law in optics explains a great many interesting phenomena, and therefore it should be ckm-ly imprewed upon the memory. 6 122 THE BEASOff WHY. And God made two great lights ; the greater light to rule the day, and the lesser light to rule the night : he made the stars also." GEN. I. 523. Why do windows reflect the sun in the evening ? Because the eye of the observer is in the line of the rejleciu n. 524. Why do windows not reflect the sun at noon ? They do, but our eyes are not then in the line of the reflection, * Position of Sun at evening. Line of Reflection at evening. \ Ig. 15. SHOWING THE LINES OP INCIDENCE AND BEFIECTIOW OF THE SUN'S RATS AT NOON AND AT EVENING. It Ls obvious from the foregoing diagram that the evening rays of reflection rail upon the eyes of spectators, while the reflections at noon are so perpendicular that they are lost. 525. Why do the sun and moon appear smaller ivhen near the meridian, than when near the horizon ? Because, when near the horizon, they are brought inta comparison with the sizes of terrestrial objects ; but when neal the meridian they occupy the centre of a vast field of sky, and as there are no objects of comparison surrounding them, they appear smaller. This ia one " Reason Why," assumed by some observers. But there is also mother reason to be found in the fact that, when the sun or nioon is near th horinori, w Vievr it through a greater depth of atmosphere than we do when a* THE SEASON "WHY. 123 ' There is no darkness nor shadow of death, where the workers of iniquity may hide themselves." JOB xxxiv. the meridian. (See Fig. 13.) A straight line passed upward thrurh t be air would not be so long as that which passes to S. Consequently, as the air ia generally impregnated with moisture, at the time when tuest> ei'acis are observed, the rays of light are caused to diverge more, and the dkc J the -un or moon appears magnified. Probably both of these reasons contribute to the effect. This latter reason also explains why the disc of the sun or moon may some- times appear oval in shape, the lower stratum of air being more loaded with moisture than that through which we view the upper part of tlie disc. 526.- Why do our shadows lengthen as the sun goes down ? Because light travels only in straight lines, and as the sun descends, the direction of his rays becomes more oblique, thereby causing longer shadows. 527. What is the cause of the optical illusions frequently observed in nature ? ^ There are various kinds of natural optical illusions : The mirage, in which "landscapes are seen reflected in burning sands. The fata morgana, in which two or three reflection of objects occur at the same time. The cerial spectra, or serial reflections, &c. Fig. 16. IHrBTRAIIKG THE APPEABATfCE OP PHANTOM SHIPS. The optical illusions above enumerated owe their origin to vanom 124 THE IlEASOS WHY. ' Jn the morning ye say, it will be foul weather to-day, for the sky is red lowering." MATT. xvi. atmospheric conditions, in which refractions and reflections are mul tiplied by the different densities of atmospheric layers. They chiefly occur in hot countries, where, from the varying effects of licat, the conditions of atmospheric refraction and reflection frequently prevail in their highest degree. 528. Why do toe have twilight mornings and evenings ? Because the coming and the departing rays of the sun are refracted and reflected by the upper portions of the atmosphere. (See Fig. 13.) 529. How long before the sun appears above the horizon does the reflection of his light reach us? The time varies with the refracting and reflecting power of the atmosphere, from twenty minutes to sixty minutes. But the sun's position is usually eighteen degrees below the horizon when twilight- begins or ends. 530. Why i* the sTcy Hue ? The white light of the sun falls upon the earth without change ; It is then reflected back by the earth, and as it passes through the atmosphere portions of it are again returned to us, and this double reflection produces a polarised condition of light which imparts to vision the sensation of a delicate Hue. (See 549.) 531. Why do the clouds appear white ? Because they reflect back to us the solar beam unchanged. 532. Why does the slcy appear red at sunset ? Because the light vapours of the air, which are condensed as the sun sets, refract the rays of light, and produce red rays. The refraction which produces red requires only a moderate degree of density. 533. Why do the clouds sometimes appear yellow f Because there is a larger amount of vapour in the air, produces a different degree of refraction, resulting in yellow. 534. Why does a yellow sunset foretell wet weather? THE EBASON WHY. 125 " When it is evening ye say it will be fair weather, for the sky is red." MATT. xvi. Because it shows that the air is heavy with vapours. The refraction that produces yellow requires a greater degree of density. 535. W hy does a red sunset foretell fine weather? Because the redness shows that the vapours in the air toward* the West, or wet quarter, are light, as is evidenced by the degree of refraction of the sun's rays. 536. Why does a red sunrise foretell wet? Because it shows that towards the East, or dry quarter, the air is charged with vapour, and therefore probably at other points the air has reached saturation. 537. Why does a grey sunrise foretell a dry day ? Because it shows that the vapours in the air are not very dense. 538. Why is " a rainbow in the morning the shepherd's warning?" Because it shows that in the West, or wet quarter, the air is saturated to the ram point. 539. WJiy is " a rainbow at night the shepherd's delight ?" Because it shows that the rain is falling in the East, and as that is a dry quarter, it will soon be over. Kainbows are always seen in opposition to the sun. CHAPTER XXVI. 540. Wliat is the difference between light and heat ? The most obvious distinction is, that light acts upon vision, and heat upon sensation, or feeling. Another distinction is, that heat expands all bodies,and alters their atomic condition ; while light, though usually attended by heat, does not display the same expansive force, but produces varioui effects which are p&yuliar ti itself. 126 THE BEASON'WHY. " Te are the light of the world. A city that is set on a hill cannot be hid." MATTHEW v. 541. Are light and lieat combined, in the solar ray ? Yes. A ray of light, as well as containing elementary rays thai produce colours under refraction, contains also chemical rays, and heat rays. 542. How do we know that light and heat are separate, elements ? Because we have heat rays, as from dark hot iron, from various chemical actions, and from friction, which are unattended by the development of light. And we have light, or luminosity, such as that of phosphor esence, which is unaccompanied by any appreciable degree of heat. But, besides this confirmation, further proof is afforded by the fact, that in passing rays of solar light through media that are transparent to heat, but not to light, the heat rays may be separated from the luminous rays, and vice versa. Black glass, and black mica, which are nearly opaque to light, are transparent to heat to the extent of ninety degrees out of a hundred. While pale green glass, coloured by oxide of copper, and covered with a coating of water, or a thin coating of alum, will be perfectly transparent to light, but will be almost quite opaque to heat. These remarks- apply, in a greater or less degree, to various other substances. 543. In what respects are light and heat similar? Both heat and light have been referred to minute vibratory motions which occur, under exciting causes, in a very subtile elastic medium. They are both united in the sun's rays. They are both subject to laws of absorption, radiation, reflection, and refraction. They are both essential to life, whether animal or vegetable. Both may be developed in their greatest intensity by electricity. They are both imponderable. 544. In what respects are light and heat dissimilar f Heat frequently exists without light. Light is usually attended with heat. Light ma." be instantly extinguished, but THE EEASON "WHY. 127 1 When I consider thy heavens, the work of thy fln&ers, the moon and the stars which thou hast ordained : Heat can only be more gradually reduced, by diffusion. The solar rays deliver heat to the earth by day, and the heat remains with the earth when the light has departed. Heat diffuses itself in all directions. Light travels only in straight lines. The colours that absorb and radiate both light and heat do not act in the same degree upon them both. Black, which does not radiate Kght, is a good radiator of heat, &c., &c. The oxy-hydrogen light emits a most intense heat, but glass which will transmit the rays of light, will afford no passage to the rays of the heat. Heat is latent in all bodies, but no satisfactory proof has been found that light is latent in substances. These are only a few of the analogies and distinctions that exist between the two mysterious agents, light and heat. But they are sufficient to supply the starting points of investigation. The importance of the heat that attends the solar rays may be illustrated by the experiments performed a few years ago, by Mr. Baker, of Fleet-street, London, who made a large burning lens, three feet and a half in diameter, and employed another lens to reduce the rays of the first to a focus of half an inch in diameter. The heat produced was so great that iron plates, gold, and stones were iiistantly melted ; and sulphur, pitch, and resinous bodies, were melted under water. 545. What is tlie point of Jieat at which bodies become luminous ? The point of heat at which the eye begins to discover luminosity has been estimated at 1,000 deg. 546. What is the velocity of artificial light ? The light of a fire, or of a candle, or gas, travels with the same velocity as the light of the sun, a velocity which would convey light eight times round the world while a person could count " one." 547. At what rate of velocity does the light of the stars travel ? At the same velocity as all other light. And yet there are stars so distant that, although the light of the sun reaches the earth in eight minutes and a half, it requires hundreds of yeart to bring their light tc us. 128 THE BKASOX WHY. 'What is man, that thouart mindful of him? and the son of man that thou visitesthim?" PSALSI vm. 548. What is the relative intensity of primary and reflected light ? The intensity of a reflection depends upon the power of the reflecting surface. But, taking the sun and moon as the great examples of primary and reflected light, the intensity of the sun's light is 801,072 times greater than that of the moon. 549. What is polarized light ? Polarized light is light which has been subjected to compound refraction, and which, after polarization, exhibits a new series of phenomena, differing materially from those that pertain to the primary conditions of light. 550. What are the chief deductions from the phenomena observed under the polarization of light ? The polarization of light appears to conflrm in a high degree the vibratory theory of light ; and to show that the vibrations of light have two planes or directions of motion. The mast of a ship, for instance, has two motions : it progresses vertically as the ship is impelled forward, and it rolls laterally through the motion of the billows. Something like this occurs in the vibrations of light, only the vertical vibration is the condition of one ray, and the lateral vibration is the condition of another ray, and the vibrations of these two rays intersect each other in the solar ray. When these vibrations occur together,, the ray has certain properties and powers. But by polarization the rays may be separated, and the result is two distinct rays, having different vibrations. It then appears that various bodies are transparent to these polarized rays only in certain directions. And this fact is supposed to show that bodies are made up of their atoms arranged in certain planes, through or between which the lateral or the vertical waves of light, together or singly, can or cannot pass ; and that the transparency or the opacity of a body is determined by the relation of its atomic planes to the planes of the vibrations of light. Ordinary light, passing through transparent media, produces no very remarkable effect in its course ; but polarized light appear* t* THE EEASON WHY. "A man that is called Jesus made clay, and anointed mine eyes, and said unto me, Go to the pool of Siloarn, and wash : and I went and washed, and I received sight." JOHN ix. illuminate every atom of the permeated substance, and by surround- ing it with a prismatic clothing, to afford an illustration of its molecular arrangement. 551. Why are two persons able to see eacJi other ? Because rays of light flow from their bodies to each other's eyes, and convey an impression of their respective conditions. In some popular works that have come under our notice, we find that the student is told that "we cannot absolutely see each other we only see the rays of light reflected from each otlier." The statement is erroneous as expressed. "We do not see the rays of light, for if we did so, the effect of vision would be destroyed, and all bodies would appear to bo in a state of incandesence, or of phosphor esence. Rays of light, which are in themselves invisible, radiate from the objects we look upon, enter the pupil of the eye, and impress the seat of vision in a manner which conveys to the mind a knowledge of the form, colour, and relative size and position of the figure we look upon. If this is not seeing the object what is? It would be just as reasonable to say, that we cannot hear a person speak that we only hear the vibrations of the air. But as the vibrations are imparted to the air by the organs of voice of the speaker, as he sets the air in motion, and makes the air his messenger to us, we cer- tainly hear him, and can dispense with any logical myths that confound the understanding, and contribute to no good result. 552. What is actinism ? Actinism is the chemical property of light. * Actinism ray power. 553. Why does silver tarnish when exposed to light ? Because of the actinic, or chemical power of the rays of the sun. 554. Why do some colours fade, and others darken, when exposed to the sun ? Because of the chemical power of the sun's rays. 555. Why can pictures lie taken l>y the sun's rays ? Because of the actinic powers that accompany the solar light. 556. What is the particular chemical effect of light exhibited in the production of photographic pictures ? Simply the darkening of preparations of silver, by the actinic rays. 557. Why are photographic studios usually glazed witlt Hue glass f 130 THE BEASOJT "WHY. The hay appeareth, and the tender grass showeth itself, and herbs of the mountain are fathered." PBOV. rxvii. Because blue glass obstructs many of the luminous rays, but it IB perfectly transparent to actinism. 558. WTiy do plants become scorched tinder the unclouded tun? Because the heat rays are in excess. The clouds shut off the corching light ; but, like the blue glass of the photographer's studio, they transmit actinism. 559. What effect has actinism upon vegetation ? It quickens the germination of seeds ; and assists in the forma- tion of the colouring matter of leaves. Seeds and cuttings, which are required to germinate quickly, will do so under the effect of blue glass (which is equivalent to saying, the effect of an increased proportion of actinism), in half the time they would otherwise require. 560. In what season of the year is the actinic poicer oj tight the greatest ? In the tpring, when the germination of plants demands its vitalising aid. In summer, when the maturing process advances, light and heat increase, and actinism relatively declines. In the autumn, when the ripening period arrives, light and actinism give way to a greater ratio of heat. \Ve shall have frequently, in the progress of our lessons, to refer to light hi its connection with the chemistry of nature, and with organic life. But let us now invite the student to pause, and for a moment contemplate the wonders of a sunbeam. How great is its Telocity how vast its power how varied it.s parts yet how ethereal ! First, let us contemplate it as a simple beam in which light and heat are associated. How deep the darkness of the night, and* how that darkness clings to the recesses of the earth. But the day beams, and darkness flies before it, until every atom that meets the face of day is lit up with radiance. That which before lay buried in the shade of night is itself now a radiator of the luminous fluid. Mark the genial warmth that comes as the lister of light ; then stand by the side of the experimentalist and watch the point on which he directs the shining focus, and in an instant see iron melt and stones run like water, under the fervent heat ! Now look upward to the heavens, where the falling drops of rain have formed a natural prism in tho rainbow, and shown that the beam of pure whiteness, refracted into various rays, plows with all the tints that adorn the garden of nature. These are the i*i!-rle efforts of light. But follow it into the crust of the ea-rth, where it is, b.t another y wrr, which is ne'her light nor heat, quickening the seed into life,- waick it w the germ springs up, and the plant puts forth ito tend* THE BEASON WHT. 131 But as it is written, Eye hath not seen, nor ear heard, neither nave entered into the heart of man, the things which God hath prepared for them that love him." CORINTH. BOOK I., II. parts, touching them from day to day with deeper dyes, until the floral picture is complete. Follow it unto the sea, where it gives prismatic tints to the anemone, and imparts the richest colours to the various algae. Think of the millions of pictures that it paints daily upon the eyes of living things. Con- template the people of a vast city when, attracted by some floating toy in the air, a million eyes look up to watch its progress. The sun paints a million images of the same object, and each observer has a perfect picture. It makes common to all mankind the beauties of nature, and paints as richly for the peasant as for the king. The Siamese twins were united by a living cord which joined their systems, and gave unity and sympathy to their sensa- tions. In the great flood of light that daily bathes the world, we have a bond of union, giving the like pleasures and inspirations to millions of people at the same instant. And that which floods the world with beauty, should no lest be a-bond of unity and love. CHAPTER XXVII. 561. What is electricity f Electricity is a property of force which resides in all matter, and which constantly seeks to establish an equilibrium. 562. WTiy is it called electricity ? Because it first revealed itself to human observation through a substance called, in the Greek language, electrum. This substance is known to us as amber. 563. In tchat way did electrum induce attention to this property of force in matter ? Thales, a Greek philosopher, observed that, by briskly rubbing electrum, it acquired the property of attracting light particles o/ matter, which moved towards the amber, and attached themselves to its surface, evidently under the influence of a/orce excited in tha amber. 564. What is amber ? It is a resinous substance, hard, bitter, tasteless, and glossy. It has been variously supposed to be a vegetable gum, a fossile, and an animal product. It is probably formed by a species of ant that inhabit pine ftrests. The bodies of ants are freauently found in its substanc* 132 THE EEASON -WHY. "He made darkness his secret place : his pavilion round about him were dark waters and thick clouds of the skies. 565. Why does the rubbing of a stick of sealing-wax cause it to attract small particles of matter ? Because it excites in the sealing-wax that force which was first observed in the amber. Sealing-wax, therefore, is called an electric (amber-like) body. 566. Why do we hear of the electric fluid? Simply because the term fluid is the most convenient that can be found to express our ideas when speaking of the phenomena of electric force. But of the nature of electricity, except through its observed effects, nothing is known. 567. What substances are electric ? All substances in nature, from the metals to the gases. But they differ very widely in their electrical qualities. 568. What is positive electricity? Electricity, when it exists, or is excited, in any body, to an amount which is in excess of the amount natural to that body, is called positive (called also vitreous). 569. What is negative electricity ? Electricity, when it exists, or is excited, in any body, in an amount which is less than is the amount natural to that body, is called negative (called also resinous). 570. Why is "positive" electricity called also rs of the tower. A similar disaster occurred to St. Bride's church, Fleet-street, London, about 100 years ago. The lightning first struck upon the metal vane of the steeple, and then ran down the rod and attacked the iron cramps, smashing the large stones that lay between them. The church was nearly destroyed. By the same wonderful force, ships have been disabled, trees split asunder, houses thrown down, and animal a struck dead. 596. Why is it dangerous to stand near a tree during an electric storm ? Because the tree is a letter conductor than air, and electricity would probably strike the tree, and then pass to the person stand- ing near. 597. If trees are good conductors, why do they not convey the electricity to the ground? Trees are only indifferent conductors, and the electricity would quit the tree to pass through any better conductor. 598. Why is it dangerous to sit near a Jire during an electric storm T Because the chimney, being a tall object, and smoke a good conductor, would probably attract the electricity, and convey it to the body of a person sitting near the fire. 599. Why is it dangerous to be near water during an electric storm ? Because water is a good conductor, and the vapour arising from it might attract the electricity. Man, being elevated over the water, might form the first point attacked by the electricity. GOO. Are iron houses dangerous during an electric storm ? Jfo ; they are very safe, because their entire surface is a good 138 THE EEA90N WHY. ' To him that rideth upon the heavens of heavens, which were of old ; lo, he dot; end out his voice, and that a mi^nty voice." PSALM ixvin. conductor, and would convey the electricity harmlessly to the earth. G01. Why does electricity seize upon bell wires and iron fastenings ? Because copper wires are the vety lest conductors of electricity ; and iron articles are also good conductors. 602. Supposing electricity to attack a bell, wire, where would the point of danger exist ? At the extremities of the wire, where the conducting power of the wire would cease, and the electricity would seek to find another conductor. 603. Are umbrellas, with steel frames, dangerous in an electric storm ? They are dangerous in some degree, because they might convey electricity to the hand, and then transfer it to the body. But, generally speaking, when it rains, the rain itself, being a good conductor, relieves the disturbance of electricity by conveying it to the ground. 604. Are iron bedsteads dangerous in electric storms ? No, they are safe, because the iron frame, completely surround- ing the body, and having a great capacity for conduction, would keep the electricity away from the body. 605. Why is it safe to be in bed during an electric storm ? Because feathers, hair, wool, cotton, &c., especially when dry, are good insulators or non-conductors. 606. What is the safest situation to be in during an electric storm ? In the centre of a room, isolate i t as far as possible from sur- rounding objects ; sitting on a chair, and avoiding handling any of the conducting substances. The windows and doors should be closed, to prevent drafts of air. 607. In the open air, what is the safest situation f ** TH3 SEASON WHT. 139 ' God thundereth marvellously with his voice : great things doeth he, which < cannot comprehend." JOB xxxvi. To keep aloof, as far as possible, from elevated structures ; and regard the rain, though it might saturate our clothes, as a protec- tion against the lightning stroke, for wet clothes would supply so good a conductor, that a large amount of electricity would pass over man's body, through wet garments, and he would be quite unconscious of it. During a violent electric storm in the Shetland Islands, a fishing boat was attacked by the electric fluid, which tore the mast to shivers. A fisherman was sitting by the side of the mast at the time, but he felt no shock. Upon taking out his watch, however, he found that the electric current had actually fused his watch into a mass. In this case, it is more than probable that the man was saved through the saturation of his clothes with rain. 608. Do lightning conductors " attract" electricity ? Not unless the electric current lies in their vicinity. 609. Why have liglitning conductors sometimes been found ineffective ? Because they have been unskilfully constructed ; have been too small in their dimensions, and have not been properly laid to convey the electricity harmlessly away. 610. W hat is the lest metal for a lightning conductor ? Copper, the conducting power of which is Jive times greater than that of iron. 611. Why should a large building have several conductors ? Because the influence of a conductor over the electricity of the surrounding air does cot extend to more than a radius of double the height of the conductor above the building : for instance, a conductor rising ten feet high above the building would influence the electricity twenty feet all round the conductor. 612. Why should conductors have at their lose several Iranches penetrating the earth ? To facilitate the discharge of the accumulated, electricity into the earth. 613. Why does electricity affect the shapes of clouds? Because electricity does not penetrate the masses of todies, but fleets generally Heir surfaces. Hence electricity exists in th* 140 THE SEASON WHY. ' All ye inhabitants of the world, and dwellers on the earth, see ye, when b* lifteth up an ensign on the mountains ; and when he bloweth a trumpet, hear ye." ISAIAH xvm. turf aces of clouds, and in its efforts to find an equilibrium it causes the clouds to roll in heavy masses, having dark outlines. Th fact that electricity resides in, and is conducted by, the surfaces of bodies, Is well established, and should receive due attention in the protective measures adopted to secure life and property against the effects of lightning. A practical suggestion that arises out of this fact is, (hat tttbes of copper would form far more efficient conductors than bars of the same metal. A copper tube, of half an inch diameter, would conduct nearly double the amount of electricity which could be conveyed away by a bar of copper of the same diameter. The upper extremity of the tube should be open obliquely, that the electric current might be induced to pass over both the inner and outer surface*. CHAPTER XXIX. 614. W hat is thunder T Thunder is the noise which succeeds the rush of the electrical fluid through the air. 615. Why does noise follow the commotion caused ly elec- tricity ? Because, by the violence of the electric force, vast fields of air are divided ; great volumes of air are rarefied ; and vapours are condensed, and thrown down as rain. Thunder is therefore caused by the vibrations of the air, as it collapses, and seeks to restore its own equilibrium. 616. Why is the thunder-peal sometimes loud and con* tinuous ? Because the electrical discharge take place near the hearer, aud therefore the vibrations of the air are heard in their full power. 617. Why is the thunder-peal sometimes broken and unequal ? Because the electrical discharge takes place at a considerable distance, and the vibrations are affected in their course by mountains and vallej/3. Because, also, the forked arms of the THE REASON WHY. 14] 'Lo, these we parts of his ways ; but how little a portion Is heard of him? but the thunder of his power who can understand ?" JOB xxv. lightning strike out in different directions, causing the sounds of thunder to reach us from varying distances. 618. Why lias the thunder-peal sometimes a low grumbling noise ? Because the electrical discharges, though violent, take place far away, and the vibrations of the air become subdued. 619. Why does the thunder-peal sometimes follow imme- diately after the flash of 'lightning ? Because the discharge of electricity takes place near the hearer. 620. Why does the thunder-peal sometimes occur several seconds after tliejlash ? Because the discharge takes place far away, and llglit travels with a much greater velocity than sound. 621. Through what distance will the sound of thunder travel? Some twenty or thirty miles, according to the direction of the tvind^ and the violence of the peal. 622. Through what distance will the light of lightning travel ? The light of lightning, and its reflections, will penetrate through a distance of from a hundred andffty to two hundred miles. 623. How may we calculate the distance at which the electric discharge takes place ? Sound travels at the rate of a quarter of a mile in a second. If, therefore, the peal of thunder is heird four seconds after the flash of lightning, the discharge took place about a mile off. The pulse of an adult person beats about once in a second; therefore, guided by the pulse, any person may calculate the probable distance of tht eCorm : 2 beats, | a mile. 3 beats, f of a mile. 4 beats, 1 mile. 142 THE SEASON TTHT. * Tlio clouds poured out water ; the skies sent out a sound ; thine arrows alsu went abroad. 5 beats, 1 miles. G beats, 1| miles. 7 beats, If miles. 8 beats, 2 miles, &c. Attention should be paid to the direction and speed of the wind, and some modifications of the calculation be made accordingly. Persons between 20 and 40 years of age should count Jive beats of the pulse to a mile; under 20, six beats. 624. Why are electric storms more frequent in Jiot than in cold loeather ? Because of the greater evaporation, as the effect of heat ; and also of the effect of heat upon the particles of all bodies. 625. WTiy do electric storms frequently occur after a duration of dry weather ? Because dry air, being a bad conductor, prevents the opposite electricities from finding their equilibrium. 626. Why is a flash of lightning generally succeeded ly heavy rain ? Because the electrical discharge destroys the vescicles of* the vapours. If a number of small soap-bubbles floating in the air were suddenly broken by a violent commotion of the atmosphere, the thin films of the bubbles would form drops of water, and fall like rain. 627. Why is an electrical discharge usually followed by a oust of wind? Because the equilibrium of the atmosphere is disturbed by the heat and velocity of lightning, and the condensation of vapour. Air, therefore, rushes towards those parts where a degree of vacuity or rarefaction has been produced. 628. Wliat is a thunderbolt ? The name thunderbolt is applied to an electrical discharge, when the lightning appears to be developed with the greatest intensity around a nucleus, or centre, as though it contained a burning body. But there is, in reality, no such thing as a thunderbolt. THE EEASOKT WHY. 143 " The voice of the Lord is upon the waters : the God of glory thundereth ; the Lord is upon many waters." PSALM xxix. 629. Why do electric storms purify the air? Because they restore the equilibrium of electricity which is essential to the salubrity of the atmosphere ; they intermix the gases of the atmosphere, by agitation; ihej precipitate the vapours of the atmosphere, and with the precipitation of vapours, noxious exhalations are taken to the earth, where they become absorbed ; they also contribute largely to the formation of ozone, which imports to the air corrective and restorative properties. 630. What is ozone ? Ozone is an atmospheric element recently discovered, and respect- ing which differences of opinion prevail. It is generally supposed to be oxygen in a state of great strength, constituting a variety of form or condition. 631. Why do we know that electricity contributes to the formation of ozone ? Because careful observations have established the fact that the proportion of ozone in the atmosphere is relative to the amount of electricity. 632. What are the properties of ozone ? It displays an extraordinary power in the neutralisation of putre- factions, rapidly and thoroughly counteracting noxious exhalations ; it is the most powerful of all disinfectants. Schonbien, the discoverer of ozone, inclines to the opinion that it is a new chemical element. Whatever it may be, there can be no doubt that it plays an important part in the economy of nature. Its absence has been marked by pestilential ravages, as in the cholera visitations ; and to its excess are attributed epidemics, such as influenza. It was found, during the last visitation of cholera, that the fumigation of houses with sulphur had a remarkable efficacy in preventing the spread of the contagion. The combustion of sulphur ozonised the atmosphere ; the same result occurs through the emission of phosphoric vapours; ozone is also developed by the electricity evolved by the electrical machine, and in the greater electrical phenomena of nature. The smell imparted to the air during an electric storm is identical with that which occurs in the vicinity of an electrical apparatus it is & fresh and sulphurous odour. The opinion is gaining ground that the respiration of animals and the combustion of matter are sources of ozone, and that plants produce it when under the influence of the direct rays of the sun. It is also believed to be produced by water, when the sun's rays fall upon it. The most recent opinion respecting ozono is, that it is electrized oxygen. The subject is of vast importance, and opens another field of discovery to the pioneers of scientific truth. 144 THE EEASON WHY. ' The voice of thy thunder was in the heaven i the lightnings lightened th world, the earth trembled and shook." PSALM LXVII. 633. What is magnetism ? Magnetism is the electricity of the earth, and is characterised by the circulation of currents of electricity passing through tha earth's surface. 634. Wliat are magnetic lodics ? Magnetic bodies are those that exhibit phenomena which show that they are under the influence of terrestrial electricity, and which indicate the direction of the poles, or extreme points, of magnetic force. 635. What is Galvanism ? Galvanism is the action of electricity upon animal bodies, and i? BO called from the name of its first discoverer, Galvani. 636. Wliat it Voltaic electricity ? Voltaic electricity is the electricity that is developed during chemical changes, and is so called after Volta, who enlarged upon the theory of Galvani. 637. What are the differences between mechanical, or fractional electricity, Voltaic electricity, Galvanism, and magnetism ? Frictional electricity is electricity suddenly liberated under the effects of the motion, or the mechanical disturbance of bodies. Voltaic electricity is a steady flow of an electric current, arising from the gradual changes of chemical phenomena. Galvanism and Voltaism are almost identical, since the latter is founded upon, and is a development of, the former. But the term Galvanism is frequently used when speaking of the develop- ment of electricity in animal bodies. Magnetism is the electricity of the earth, and is understood tc imply the fixed electricity ofterrestial bodies. Man knows not what electricity is ; yet, by an attentive observance of its effects, he avails himself of the power existing in an unknown source, and produces marvellous results. When the Grecian philosopher, Thalcs, sat rubbing a piece of amber, and watching the attraction of small particles of matter to its surface, ho little knew of the mighty power that was then whispering lo him its offer to serve mankind. And when Franklin, with the THE REASON WHY. 145 " A ml I heard as it were the voice of a great multitude, and as the voice of many waters, and as the voice of mighty thunderings, saying Alleluia : for the Lord God omnipotent reigneth." REV. xix. aid of a boy's plaything, drew down an electric current from the clouds, and caught a spark upon the knuckles of his hand, even he little conjectured that the time was so near when that strange element, which sent its messenger to him along the string of a kite, would become one of man's most submissive servants. So many great results have sprung from the careful observation of the simplest phenomena, that we should never pass over inattentively the most trifling thing that offers itself to our examination. Nature, in her revelations, never seeks to startle mankind. The formation of a rock, and the elaboration of a truth, are alike the work of ages. It was the simple blackening of silver by the sun's rays which led to the discovery of the chemical agency of light. It was the falling of an apple which pointed Newton to the discovery of the laws of gravitation. It was the force of steam, observed as it issued from beneath the lid of a kettle, that led to the invention of the steam-engine. And it is said of Jacquard, that he invented the loom which so materially aided the commerce of nations, while watching the motions of his wife's fingers, as she plied her knitting. As great discoveries spring from such small beginnings, who among us may not be the herald of some great truth the lounder of some world-wide benefaction ? That the area of discovery has not perceptibly narrowed its limits, is evident from the fact that the g-eatest elements in nature are still mysteries to man. And though it may not "be within the power of a finite being to unravel the chain of wonders that enfold the works of an infinite God, still it is evident, from the progress which discovery has made, and from the good which discovery has done, that God does invite and encourage the human mind to contemplate the workings of Divine power, and to pursue its manifestations in every element, and in every direction. The wonderful force of electricity astonishes us all the more when we view it in contrast with that equally wonderful element, light. We have seen that light travels with a velocity of 192,000 miles in a second, but that it falls upon a delicate balance so gently, that it produces no perceptible effect. As far as we know the nature of electricity, it is even more etliereal than light; yet, while the ether of light falls harmlessly and imperceptibly even with the momentum of a flight of ninety-five millions of miles, the ether of electricity, bursting from a cloud only five hundred yards distant, will split massive stones, level tall towers with the dust, strike majestic trees to the ground, and instantly extinguish the life of man ! Why does the one ether come divested of all mechanical force, while that which seems to be even more ethereal than it, is capable of exerting the mightiest force over material things ? Does it not appear that the Creator of the universe has established these paradoxes of power to testify his Omnipotence to show to man that with Him all things are possible ; and that, in the grand cosmicism of the universe, every attribute of Omnipotence has been fulfilled ? Let us now consider man's relation to this Omnipotence. He sees that electricity smites the tall edifice, and observes that in doing so it displays a choice of a certain substance through which it passes harmlessly, and that its violence is manifested only when its path is interrupted. Man, taking advan- tage of this preference of electricity for a particular conductor, stretches out an arm of that substance, and points it upwards to the clouds; electricity 146 THE EEASON WHY. "And the, seventh angel poured out his vial into the air; and there came great voice out of the temple of heaven, from the throne, saying, It is done." REV. xvi. accepts the invitation, and passes harmlessly to the earth. But this not all: man learns by observation that electricity resides in all matter ; that it may ha collected or dispersed; that it travels along a good conductor at the rate of he.lf-a-million of miles tn a second of time ; he constructs a battery, a kind of scientific fortress, in which he encamps the great warrior of nature ; and then, laying down a conducting wire, he liberates the mighty force: but its flight must be on the path which man has defined, and its journey must cease at tho terminus which man has decreed, where, by a simple contrivance of his ingenuity (the movements of a magnetic needle), the electric current is made to delivci whatever message of importance he desires to convey. Thus, the element which iu an instant might deprive man of life, is subdued by him, and made the obedient messenger of his will CHAPTER XXX. 638. What is the atmosphere ? The atmosphere is the transparent and elastic body of mixed gases and vapours which envelopes our globe, and which derives its name from Greek words, signifying sphere of vapour. 639. To what height does the atmospher extend? It is estimated to extend to from forty to ffty miles above the surface of the earth. 640. Why is it supposed that the atmosphere does not extend beyond that heiyht ? Because it is found, by experiment and observation, that the air becomes less dense in proportion to its altitude from the earth's surface. The gradual decrease of atmospheric density observed in ascending a mountain, or in a balloon, supplies sufficient data to enable us to calculate the height at which the atmosphere would probably altogether cease. At an altitude of 18,000 feet the air is indicated by the barometer to be only half as dense as at the surface of the eari'.i. And as the densities of the atmo'- siihere decrease in a geometrical progression, the density will be reduced to one- fourth at the height of 36,000 feet ; and to one-eiglith at 54,000 feet. The effects of the decreasing density of the atmosphere are, that the intensity of light and sound are diminished, and tJie temperature is lowered. Persons who Ime reached a very high elevation, state that the sky above them began to assume the appearance of darkness ; and there can be no doubt that, if it were possibla to reach an altitude of some fifty to sixty miles, there would be perfect blot*' THE BEASOff WHT. ' For he looketh to the ends of the earth, and seeth under the whole heaven; To make the weight for the winds." JOB xxvm. ness, although the sun's rays might be pouring through the darkened space, to illuminate the atmosphere. Upon the summit of Mont Blanc, the report of a pistol at a short distance can scarcely be heard. When Gay Lussac reached the height of 23,000 feet, he breathed with great pain and difficulty, and felt dis- tressing sensations in his ears, as though they were about to burst. Upon the high table-lands of Peru, the lips of Dr. Ischudi cracked and burst ; and blood Uowed from his eyelids. 641. What is the amount of atmospheric pressure at the earth's surface ? The pressure of the atmosphere at the earth's surface is fifteen 'pounds to every square inch of surface. That is to say, that the column of air, extending fifty miles over a square inch of the earth, presses upon that square inch with a weight equal to fifteen 642. Is that the weight of dry or moist air? That is the weight of air at what is called the point of saturation, when it is fully charged with watery vapour. 643. WJiat is the proportion of watery vapour in the atmosphere ? The proportion constantly varies. Evaporation is not a result of accident ; it seems an established law that the air shall constantly absorb vapour until it has reached the maximum that it can hold. Experiments have been tried, in which dry air has been pressed upon the surface of water with great force, but no degree of pressure could prevent the formation of vapour. (See 431.) 644. What is the total amount of atmospheric pressure on the earth's surface ? The total amount of atmospheric pressure on the earth's surface, at 151bs. to the square inch, amounts to 12,042,604,800 ,000,000,0001bs. This pressure is equal to that of a globe of lead of sixty miles in diameter. 645. What is the pressure of the atmosphere upon the human body? Estimating the surface of man's body to be equal to fifteen square feet, he sustains an atmospheric pressure of 32,4001bs., or nearly fourteen tons and at-half. The mare variation of weight, 148 THE BEASON TVHT. * I therefore so run, not as uncertainly ; so fight I, not as one that beateth th air." COHIXTH. ix. arising out of the changes in the state of the atmosphere, may amount to as much as a ton and a-Jialf. 646. Wlnj does not man feel this pressure ? Because the diffusion of air which, surrounding him in every direction, and acting upon the internal as well as the external surfaces of his body, and probably surrounding every atom of his frame, establishes an equilibrium, in which every degree of pressure counteracts and sustains itself. 647. What is the weight of air relative to that of water ? A cubic foot of air weighs only 523 grains, a little more than an. ounce ; a cubic foot of water weighs one thousand ounces. 648. Wliat is the greatest height in the atmosphere which any human being has ever reached? M. Gay Lussac, in the year 180-i, ascended to the height of 23,000 feet. 649. What is a vacuum ? A vacuum is a space devoid of matter. The term is generally applied to those instances in which air is drawn from within an air-tight vessel. 650. Is it possible to form a perfect vacuum ? It is probably impossible to do so, even with the most powerful instruments some portion of air would remain, but in so thin a a form that it would be imperceptible. 651. Why does the depression of a pump-handle cause the water to flow ? Because the putting down of the handle lifts up the piston with its valve closed, thereby tending to produce a vacuum ; but th pressure of the air upon the water not contained in the pump, forces more water up into the part where a vacuum would otherwise be formed. Then, when the handle is raised, and the piston forced downwards, the valve opens, and the water rushes through. There is a second valve, below the piston, which closes with the THE REASON WHY. 143 " The wind bloweth where it listeth, and thou hearest the sound thereof, but canst not tell whence it cometh, and whither it goeth : so is every one that is born of the Spirit." JOHIT II., in. downward movement, to prevent the water from rushing back' again. 652. Hoiv high will atmospheric pressure raise water in the bore of a pump ? It will raise water to an elevation of thirty feet above its level. 653. W hy will it raise water to an elevation of thirty- feet? Because a column of water ef thirty feet high, nearly balances the weight of a column of air of equal surface, extending to tJit whole height of the atmosphere. When, therefore, water is elevated to the height of thirty feet, the power of the pump is enfeebled, as the air and the water balance each other. 654. How is water raised to a greater elevation when it is required ? By mechanical contrivances, by which the water is forced to a greater elevation. 655. Why does water run through the "bent tube called a typhon ? Because the atmospheric pressure upon the water on the outside of the syphon forces it into the tube as fast as the syphon empties itself through its longer arm. 656. Why does water run through the longer arm of the syphon ? Because the weight of the water in the longer arm of the syphon is greater than that in the shorter ; therefore it runs out by its own gravity. And, as in running out, it creates a tendency towards a vacuum, the pressure of the outer air comes into operation, and forces the water through the tube. 657. Why does water issue from the earth in springs? Some springs are caused by natural syphon* formed in the fissures of rocks, which, communicating with bodies of water, are continually filled by atmospheric pressure, and therefore convey streams of water to the point where they are set free. 150 THE SEASON WHT. ' Ascribe ye strength unto God : his excellency is over Israel, and his strength is in the clouds." PSALM ivm. 658. WJiy, if a wine glass is filled with water, and a card laid upon it, and the whale inverted, will the water remain in the glass ? Because the pressure of the atmosphere upon the surface of tho card counteracts the weight of the water. 659. What has the card to do with the experiment ? It forms a base upon which the water may rest, while the glass is being inverted ; and it prevents the air from acting upon tho fluidity of the water, and forcing it out of the glass, 660. WJiy will not leer run out of the tap of a cask until a spile has leen driven in at the top ? Because the pressure of the air upon the opening of the tap counteracts the weight of the beer. But when the spile is driven in, the air enters at the top, and counteracts itt own pressure at the bottom. 661. Why does a cup in a pie becomes/tiled with juice ? Because the heat expands the air, and drives nearly all of it out of the cup. When the pie is taken out of the oven, and begins to cool, air cannot get into the cup again, because its edges are surrounded by juice. A partial vacuum, therefore, exists within the cup, and the pressure of the external air forces the juice into it. 662. Does the cup prevent the juice from boiling over ? No. So long as the heat exists, the cup remains empty ; and as it occupies space, the air is driven out of it, into the pie, it rather tends to force the juice over the sides of the dish. It is only when cooling that the juice enters the cup. 663. Why can flies walk on the ceiling ? Because their feet are so formed that they can form a vacuum, under them ; their bodies are therefore sustained in opposition to gravitation by atmospheric pressure. 664. Sow did Mr. Sands perform the feat of walking across the ceiling ? By having large discs of wet leather attached to his feet, so that THE BEASON WHY. 15] * And God made a wind to pass over the earth." G ENESIS Tin when they were placed upon a smooth surface, the air was excluded, and when he allowed his weight to act upon one of the discs, it formed a hollow cup and a vacuum. By forming a vacuum of only twelve square inches he gained a pressure of ISOlbs. ; this being more than his weight he could accomplish the feat with no other difficulty than that of remaining in an, inverted position. The air was admitted underneath the discs by valves, which were closed by springs, which being pressed by the heels of the performer, let in the air, and set the feet free. 665. Why is it difficult to strike limpets from rocks ? Because they have the means of forming a vacuum under their shells, and are pressed on to the rocks by the weight of the atmo- sphere. 666. WTiy can snails move over plants in an inverted position ? Because they form a vacuum with the smooth and moist surfaces of their bodies, and are supported by atmospheric pressure. CHAPTER XXXI. 666. What is wind? Wind is air in motion. (See 234.) 667. What are the velocities of winds ? A breeze travels ten feet in a second ; a light gale, sixteen feet in a second ; a stiff gale, twenty-four feet in a second ; a violent squall, thirty-five feet in a second ; storm wind, from forty-three to fifty -four in a second ; hurricane of the temperate zone, sixty feet in* a second; hurricane of the torrid zone, one hundred and twenty to three hundred feet in a second. When wind flies at one mile an hour, it is scarcely perceptible. When its velocity is one hundred miles an hour, it tears up trees, and devastates its track. 668. What are trcde winds f 152 THE BEASON WHY. They shall be as the morning cloud, and as the early dew that passeth wy. as the chaff that is driven with the whirlwind out of the floor, and as the smoke out of the chimney." HOSEA xm. Trade winds are vast currents of air, which sweep round tht globe over a belt of some 12,000 miles in width. 609. What is the cause oftraJe winds f The air over the tropical regions becomes heated and ascends ; it, then diverges in tvnp high currents, one towards the north, and the' other towards the south pole, where, being cooled, it again descends, and returns towards the equator to replace the air as it ascends therefrom. There is, therefore, a constant revolution of vast cur- rents of air between the tropics and the poles, producing north and south winds. 670. WTiy do the trade winds How from east to icest. though, in their origin, their direction is from north to south and from south to north ? Because, as the north and south winds blow towards the equator, they are affected by the revolution of the earth from west to east. As the two winds from the poles approach the equator, they are gradually diverted from their northerly and southerly course, to ail easterly direction, by the revolution of the earth. 671. Wliy is there a prevalence of calms at the equator ? Because, as the north and the south winds move towards Ihe equator, they drive before them volumes of atmosphere, which, meeting in opposite directions, resist and counterpoise each other, and abide in a state of stillness between the north and south- easterly winds, one on the north and the other on the south of the equator. 672. What are monsoons ? Monsoons are periodical winds which blow at a given period of the year from one quarter of the compass, and in another period of the year from the opposite quarter of the compass. 673. What is the cause of monsoons ? Monsoons are caused by changes in the position of the snn. When the sun is in the southern hemisphere, it produces a north- east wind, and when it is in the northern hemisphere, a north-west wind The north-east monsoon blows from November to Marob. THE EEASOK WHY. 153 1 He stoui blow upon them and they shall wither, and the whirlwind shall take them away as stubble." ISAIAH XL. and the south-west monsoon from the end of April to the middle of October. The region of moonsoons lies a little to the north of the northern border of the trade wind, and they blow with the greatest force, and with most regularity, between the eastern coast of Africa and Hindustan. 674. What determines the character of icinds ? The character of winds is influenced by the condition of the surfaces o^er which they How. Winds blowing over dry and arid plains and deserts are dry and hot. Winds blowing across snow- capped mountains and regions of ice are cold. Winds that cross oceans are wet ; and those that cross extensive continents are dry. 675. What icinds are most prevalent in England ? In England out of a thousand days, north winds prevail in 82 ; north-east, 111 ; east, 99 ; south-east, 81 ; south, 111 ; south-west, 225 ; west, 171 ; north-west, 120. 676. What is the cause of 'storms ? Storms result from violent commotions of the atmosphere, and are chiefly the result of extreme changes of temperature. The magnetic state of the earth, and the electrical state of the atmosphere, also materially influence the phenomena of storms. By some persons the theory is entertained that storms result from various winds rushing into a centre in which the atmosphere has become extremely condensed. According to this theory, a storm is a mighty whirlwind. A most violent hurricane occurred in 1780, which destroyed Lord Rodney's fleet, and a vast number of merchant ships. It is said to have killed 9,000 persons in Martinique alone, and 6,000 in St. Lucia. The town of St. Pierre in Martinique was totally destroyed ; and only fourteen houses in the town of Kingston, in St. Vincent, were left uninjured. 677. WJiy do the most violent storms occur in and near the tropics ? Because there the temperature is very high, and the cold currents of air rushing towards the equator from the poles, causes great atmospheric disturbance 678. What are whirlwinds ? 7* . 154 THE SEASON "WHY. ' Out of the south cometh the whirlwind ; and cold out of the north." JOB xxxvu. Whirlwinds are produced by violent and contrary currents meeting and striking upo.r. each other, producing 1 a circular motion. They generally occur after long calms, attended by much heat. Whirlwinds occurring at sea, or over the surface of water, some- times put the water in motion, and as the wind rises upwards it lifts with it a whirling mass of water, producing a water tpout. Fig. 19. A WATEB BPOUT. 679. Why does the chimney smoke when the fire is first lighted? Because the air in the chimney is of the same temperature as that in the room, and therefore will not ascend. 680. Wliy does the smoking (into the room) cease, after the fire has leen lighted a little while ? Because the air in the chimney, being warmed by the firo beneath, becomes lighter and ascends rapidly. 681. Why does a long chimney create a greater draught than a short one ? Because the short chimney contains less air than the long one ; there is, consequently, less difference of weight between the warm THE SEASON WHY. 155 ' And, lo, the smoke of the country went up as the smoke of a furnace." GKS. xix. air of the short chimney and the external air ; it therefore has not so great an ascensive power. 682. Why does smoke issue in folds and curls ? Because it is pressed upon by the cold air which always rushes towards a rarer atmosphere. It thus illustrates the development of storms. 683. Why do some chimneys smoke when the doors and windows are closed? Because the draught of air is not sufficient to supply the wants of the fire, and enable it to create an upward current. 684. What is the lest method of conveying air to fires? Tubes built in the walls, communicating with the outer air, and terminating underneath the grates. 685. Why is this the lest method of ventilation ? Because doors and windows may then be made air-tight, and draughts across rooms be prevented. 686. Why do chimneys that stand under elevated objects, such as hills, trees, and high buildings, smoke ? Because the wind, striking against the elevated object, flies back, and a part of it rushes downward. 687. Why do sooty chimneys smoke ? Because the accumulation of the soot diminishes the size of the fiue, and lessens the ascensive power of the draught, by reducing the quantity of warm air. It also obstructs the motion of the air, by the roughness of its surface, 688. Why do chimneys smoke in damp and gusty weather ? Because the ascending air is suddenly chilled by gusjs of damp and cold air, and driven do^n the chimney. 156 THE REASON WHY. ' Remember that thou magnify his work, which men behold. Every man may see it; mail may behold it afar off." JOB xxxvi. 689. Why docs smoke ascend in a straight line in mild and fine weather? Because the air is still, and being dry and warm it does not chill the smoke, nor drive it out of its course. 600. Why do tlie wings of wind-mills turn round? Because the wind, striking at an angle upon the wings, forces them aside ; and as there are four wings all upon the same angle, and fixed upon the same centre, the oblique pressure of the wind causes the centre to rotate. There is a world of miniature phenomena which has never been fully recog- nised, in which we may see the mightier works of nature pleasingly and truth- fully illustrated. When the wind blows into the corner of a street, and whirling around, catches straw, dust, and feathers in its arms, and then wheels away, flinging the troubled atoms in all directions, it is a miniature of the mightier whirlwind, which wrecks ships, uproots trees, and levels houses with the earth. "When a cloud of dust, on a hot summer's day, rises and flies along the thirsty road, making the passenger close his eyelids, and dusting the leaves of wayside vegetation, it is a miniature of the terrible simoom, which blows from the desert sands, scatteriug death and devastation in its track. When steam issues from the tea-urn, and becomes condensed in minute drops upon the window-pane, the miniature is of the earth's heat, evaporating tho waters, and the cold air of night condensing the vapours into dew. When grass and corn bend before the wind, and are beaten down by its force ; when the pond forgets its calm, and rises in troubled waves, casting the flotilla of natural boats that move upon its surface, in rude disorder upon its windward shore, the little storm is but a miniature of those great hurricanes which wrecked a fleet in the Black Sea, and levelled the encampments of a mighty army. When the snow that has gathered upon the house-top, warming beneath tho smiles of the sun, slips from its bed, and drops in accumulated heaps from the roof, it is a miniature of those terrible avalanches which in the Pyrenees bury villages in their icy pall, and doom man and beast to death. When the rivulet hurries on its course, and meeting with obstructions, leaps over them in mimic wrath, overturning some little raft upon which, perchance, n weary fly has alighted, it is a miniature of those rapids on whose banks the hippopotamus and the alligator yet live ; and where, though rarely, man may be seen directing his raft over the troubled current, amid the rush of debris from forests unexplored. And wherein a basin of the rivulet, two opposing currents meot, and form a iLttlo vortex inVj which insect life and vegetable fragments poming within th* THE REASON WHY. 157 " Can any understand the spreadings of the clouds, or the iioise of his tabernacle f " JOB xxxvi. sphere of its influence are drawn, it is a miniature of the roaring wlrirlpjol or the wilder maelstrom of the Norwegian seas. Nature rehearses all her parts in mild whispers ; and for every picture that she paints, she places a first study upon the canvas. Man need not go into the heart of her terrors to understand their laws. Many an unknown Humboldt, sitting by the river's side, may rejoice in the " aspects of nature," and share the bliss of knowledge with the great philosopher. CHAPTER XXXII. 691. What is a barometer ? A barometer is an instrument which indicates the pressure of the atmosphere, and which takes its name from two Greek words signifying measurer of weight. 692. Why does a barometer indicate the pressure of the atmosphere ? Because it consists of a tube containing quicksilver, closed at one end and open at the other, so that the pressure of the air upon the open end balances the weight of the column of mercury (quick- silver), and when the pressure of the air upon the open surface of the mercury increases or decreases, the mercury rises or falls in response thereto. 693. Why is a barometer called also a " weather-glass ?" Because changes in the weather are generally preceded by altera- tions in the atmospheric pressure. .But we cannot perceive those changes as they gradually occur ; the alteration in the height of the column of mercury, therefore, enables us to know that atmospheric changes are taking place, and, by observation, we are enabled to determine certain rules by which the state of the weather may be foretold with considerable probability. 694. Why are barometers constructed with circular dials, and an index to denote changes ? Beeauso that is a convsnient mechanical arrangement, by which 158 Fair weather cometh out of the north : with God is terrible majesty." JOB xxxvu. the alterations of the relative pressures of the air and the mercury are more dearly denoted vijw by an inspection of the mercury FiR. 20. BAEOMETEE. Fig. 21. TUBE OF BAEOMETEB, WHEEL, AND PULLEr. 695. Why does tlie hand of the weather dial change if* position when the column of mercury rises or falls ? Because a weight, which floats upon the open surface of the mercury, is attached to a string, having a nearly equal weight at the other extremity; the string is laid over a revolving pivot to which the hand 'is fixed, and the friction of the string turns th land, at the mercury rises or falls. THE EEASON WHY. 159 " Thou visitcst 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." PSAXM nr. GOG. WTiy docs tapping the face of the barometer sometimes cause the hand to move ? Because the weight on the surface of the mercury frequently leans against the sides of the tube, and does not move freely. And, also, the mercury clings to the sides of the tube by capillary attraction ; therefore, tapping on the face of the barometer sets the weight free, and overcomes the attraction which impedes the rise or fall of the uercury. Fig. 21 illustrates the mechanism at the back of the barometer. A is a glass tube ; between A and E there exists a vacuum, caused by the weight of the mercury pressing downwards. This space being a vacuum, makes the barometrical column more sensitive, as there is no internal force to resist or modify the effects of the external pressure. E represents the height of the column of mercury ; C the open end of the tube ; F the weight resting on the surface of the mercury ; P the pivot over which the string passes, and upon which the hand turns : W the weight which forms the pulley with the weight F. G97. W7iich is the heavier, dry or vaporised air ? Dry air is heavier than air impregnated with vapours. 698. Why is dry air heavier than moist air ? Because of the extreme tenuity of watery vapours, the density of which is less than that of atmospheric air. 699. Why does the fall of the barometer denote the approach of rain ? Because it shows that as the air cannot support the full weight of the column of mercury, the atmosphere must be thin with watery vapours. The fall of the mercury in the long arm of the tube would cause the weight F to be pressed upwards. This would release the string to which the weight "W is attached ; it would, therefore, fall, and turn the hand down to Rain, or Much Eain. 700. Why does the rise of the barometer denote the approach cffine weather ? Because the external air becoming dense, and free from highly elastic vapours, presses with increased force upon the mercury upon which the weight F floats ; that weight, therefore, sinks in the short tube as the mercury rises in the long one, and in sinking turns the hand to Change, Fair, &c. 160 THE EEASON WHY. ' He caused an east wind to blow in the heaven ; and by his power he brought in the south wind." PSALM ixxvm. 701. Why does the barometer enable us to calculate the "height of mountains ? Because, as the barometer is carried up a mountain, there is a less depth, of atmosphere above to press upon the mercury ; it therefore falls, and by comparing various observations, it has been found practicable to calculate the height of mountains by the fall of the mercury in a barometer. 702. To what extent of variation is the weight of the atmosphere liable ? It may vary as much as a pound and a half to the square inch at the level of the sea. 703. When does the barometer stand highest ? When there is a duration of frost, or when north-easterly winds prevail. 704. Why does the barometer stand highest at these times? Because the atmosphere is exceedingly dry and dense, and fully balances the toeight of the column of mercury. 705. When does the barometer stand lowest ? When a thaw follows a long frost ; or when south-west wind* prevail. 706. Why does the barometer stand lowest at those times ? Because much moisture exists in the air, by which it is rendered less dense and heavy. 707. What effect has heat upon the barometer ? It causes the mercury to fall, by evaporating moisture into the air. 708. What effect has cold upon the barometer ? It causes the mercury to rise, by checking evaporation, and increasing the density of the air. In noting barometrical indications, more attention should be paid to tho tendency of tho mercury at the time of the observation, than to the actual ttate of the column, whether it stands high or low. The following rules of tarometio -coding are given as generally accurate, but liable to exceptions :- THE REASON WHY. * For so the Lord said unto me, I will take my rest, and I will consider in my dwelling place like a clear heat upon herbs, and like a cloud of dew in the heat of harvest." ISAIAH xvm. Fair weather indicated by the rise of the mercury. Foul weather by the fall of the mercury. Thvnder, indicated by the fall of tho mercury in sultry weather. Cold, indicated by the rise of the mercury in spring, autumn, and winter. Heat, by the fall of the mercury in summer and autumn. Frost, indicated by the rise of the mercury in winter. Tiiaw, by the fall of the mercury during a frost. Continued bad weather, when the fall of the mercury has been gradual through several fine days. Continued fine weather, when the rise of the mercury has been gradual through several foul days. Sad weather of short duration, when it sets in quickly. Fine weather of short duration, when it s*ts in quickly. Changeable weatlter, when an extreme change has suddenly set in. Wind, indicated by a rapid rise or fall unattended by a*change of temperature. The mercury rising, and the air becoming cooler, promises fine weather ; but the mercury rising, and the air becoming warmer, the weather will be changeable. If the top of the column of mercury appears convex, or curved upwards, it is an additional proof that the mercury is rising. Expect fine weather. If the top of the column is concave, or curved downwards, it is an additional proof that the mercury is falling. Expect bad weather. CHAPTER XXXIII 709. What is the thermometer ? The thermometer is an instrument in which mercury is employed to indicate degrees of heat. Its name is derived from two Greek words, meaning heat measurer. 710. Why does mercury indicate degrees of heat? Because it expands readily with Jieat, and contracts with cold ; and as it passes freely through small tubes, it is the most convenient medium for indicating changes of temperature. 71 1. Why are there Eeaumur's Thermometers and Fahren- heit's Thermometers ? Because their inventors, after whom they are named, adopted a different system of notation, or thermometrical marks ; and as their thermometers have been adopted by various countries and authors, it is now difiicu tj dispense with either of them. 163 THE BEASON WHY, " When ye see a cloud rise out of the west straightway ye say, There cotneth shower ; and so it is. And when ye see the south wind blow, ye say there will be heat ; and it cometh to pass." LUKE xin. THERMOMETER. Reaumur. Fahrenheit. Pig. 22. THE THERMOMETERS OP BEACMUR AND FAHRENHEIT ? COMPARED, feratwref We have combined the two (see Fig. 22.) The diagram will, we have no doubt, prove exceedingly useful to scientific readers and experimentalists. There is also another system of notation, adopted by the French, called the centigrade, but it is not much referred to in Great Britain. In the centigrade thermometer zero is the freezing point, and 100 the boiling point. Fahrenheit's scale is generally preferred. Reaumur's is mostly used in Germany. Of Fahrenheit's scale 32 is the freezing point, 55 is moderate heat, 76 summer heat in Great Britain, 93 is blood heat, and 212 is the boiling point. Mr. Wedgwood has invented a thermometer for testing high temperatures, each degree of which answers to 130 degrees of Fahren- heit. According to his scale cast iron melts at 2,786 deg. ; fine gold at 2,016 deg. ; fine silver 1,873 deg. ; brass melts at 1,809 deg. ; red heat is visible by day at 980 deg. ; lead melts 612 deg. ; bismuth melts 476 deg. ; tin melts 442 deg. ; and there is a curious fac'j with regard to the three metals, lead, bismuth, and tin, that if they are mixed in the proportions of 5, 8, and 3 parts respectively, the mixture (after previous fusion) will melt at a heat below that of boiling water. 712. What is the difference between the thermometer and the barometer f In the thermometer the column of mercury is much smaller than in the barometer, and is sealed from the air ; while in the barometer the column of mercury is open at one end to atmospheric influence. 713. Wliy does the mercury in the thermometer, being sealed un. indicate the external tern- THE BEASTS WHY. 163 Blessed is the people that know the joyful sound : they shall walk, O Lord, in the light of thy countenance." PSALM LXXXIX. Because the heat passes through the glass, in which the mercury is enclosed, and expanding or contracting the metal within the bulb, causes the small column above it to rise or fall. 714. When does the thermometer vary most in its indi- cation of natural temperature ? It varies more in the winter than in the summer season. 715. Why does it vary more in the winter than in the summer ? Because the temperature of our climate differs more from the temperature of the torrid zones in the winter than it does in the summer, and the inequalities of temperature cause frequent changes in the degree of prevailing heat. The same remarks (714, 715,) apply to the barometer. CHAPTER XXXIV. 716. What is sound ? Sound is an impression produced upon the ear by vibrations of the air. 717. What causes the air to vibrate and produce sounds ? The atoms of elastic bodies being caused to vibrate by the appli- cation of some kind of force, the vibrations of those atoms are imparted to the air, and sound is produced. 718. Sow do we know that sounds are produced by the vibrations of the air, induced by the vibrations of the atoms oj bodies ? If we take a tuning fork, and hold it to the ear, we hear 720 sound. If we move it rapidly through the air, or if we blow upon it, it pro- duces no sound ; but if we strike it, a sound immediately occurs ; the vibration of the fork may be seen, and felt by the hand that holds it ; and as those vibrations cease, the sound dies away. 719. Ifoio do we know that without air th$*e ivould be no tound f 164 THE SEASON WHY. " And even things without life giving sound, whether pipe or harp, except they give a distinction in the sounds, how shall it be known what is piped or harped." COKINTH, xiv. Because if a tuning fork were to be struck in a vacuum (as under the receiver of an air pump) no sound would be heard, although the vibrations of the fork could be distinctly seen. 720. How are the vibrations of sonorous bodies imparted to the air ? When a bell is struck, the force of the blow gives an instant agitation to all its particles. The air around the bell is driven back by the impulse of the force, and thus a vibration of compression is imparted to the air ; but the air returns to the bell, by its own natural elasticity, thus producing a vibration of expansion when it is again struck, and thus successive vibrations of compression and expansion are transmitted through the air. 721. Sow rapidly are these vibrations transmitted through the air ? They travel at a rate of rather more than a quarter of a mile in a second, or twelve miles and three-fourths in a minute. 722. Do all sounds travel at the same rate ? f All sounds, whether strong or weak, high or low, musical or discordant, travel with, the same velocity. 723. Why are bells and glasses stopped from ringing by touching them with the finger ? Because the contact of the finger stops the vibration of the atoms of the metal and glass, which therefore cease to impart vibrations to the air, 724. Why does a cracked bell give discordant sounds ? Because the connection between the atoms of the bell being broTcen, their vibrations are not uniform : some of the atoms vibrate more intensely than the others ; the vibrations imparted to tbe air are therefore jarring and discordant. 725. Why, when we see a gun fired at a distance, do we see the flash and smoke, before we hear the report ? Because light, which enables ns to see, travels at the velocity ol THE EEASON WHY. 165 ' My heart maketh a noise in me : I cannot hold my peace, because thou hast heard, O my soul, the sound of the trumpet, the alarm of war." JEB. iv. 192,000 miles in a second; while sound,}*? which we hear, travels only at the rate of a quarter of a mile in a second. 726. Why does the tread of soldiers, when marching in long ranJcs, appear to be irregular ? Because the sounds proceeding from different distances, reach our ears in varying periods of time. 727. What are the numbers of vibrations in a second that produce the various musical sounds ? C or Do, 480 vibrations in a second ; B or Si, 450 vibrations ; A or La, 400 vibrations ; G or Sol, 360 vibrations ; F or Fa, 320 vibrations ; E or Mi, 300 vibrations ; D or Re, 270 vibrations ; C or Do, 240 vibrations. It is thus seen that the more rapid the vibrations, the Uglier the note, and vice versa. 728. Why does the length of a wire or string determine the sound that it produces ? Because the shorter the string the more rapid are its vibrations when struck. 729. Why does the tension of a wire or string affect its vibrations ? Because when the string or wire is tight, a touch communicates vibrations to all its particles ; but when it is loose the vibrations are imperfectly communicated. 730. Why are some notes low and solemn, and others high and quick ? Because the vibrations of musical strings vary from 32 vibrations in a second, which produces a soft and deep bass, to 15,000 vibrations in a second, which produces the sharpest treble note. 731. Why can our voices be heard at a greater distance when we speak through tubes ? Because the vibrations are confined to the air within the tube, and are not interfered with by other vibrations or movements in the air ; the tube itself is also a good conductor of sound. 166 THE SEASON WHY. " And I will cause the noise of thy songs to cease ; and the sound of thy harps shall no more be heard." EZEKIEL xxvi. 732. Is air a good conductor of sound ? Air is a good conductor, but water is a letter conductor than air ; wood, metals, the earth, &c., are also good conductors. 733. Why can we Jiear sounds at a greater distance on water than on land ? For various reasons : because the smooth surface of water is a good conductor; because there are fewer noises, or counter vibrations, to interfere with the transmission of sound ; and because there are no elevated objects to impede the progress of the vibrations. 734. Why do sea-shells give a murmuring noise when held to the ear ? Because what may be called expended, vibrations always exist in air where various sounds are occurring. These tremblings of the air are received upon the thin covering of the shell, and thus being collected into a focus, are transmitted to the ear, 735. Why can people in the arctic regions converse ivhen more than a mile apart ? Because there the air, being cold and dense, is a very good conductor; and tae smooth swface of the ice also favours the transmission of sound. 736. Why do savages lay their heads upon the earth to hear the sounds of wild leasts, fyc. ? Because the earth is a good conductor of sound. For this reason, also, persons working under ground in mines, can hear each other digging at considerable distances. 737. Why can church clocks be heard striking much more clearly at some times than at others ? Because the density of dry air improves the sound-conducting power of the atmosphere. The transmission of sounds is also assisted by the direction of the winds. 738. Why may the scratching of a pin at one extremity of THE REASON WHY. 167 " The morning is cornc unto thee, O thou that dwellest in the land : the time ii come, the day of trouble is near, and not the sounding again of the mountains." EZEKIEL viz. a long pole be heard by applying *the ear to the opposite extremity ? Because wood is a good conductor of sound, and its atoms arc susceptible of considerable vibration. It is, therefore, chosen in numerous instances for the construction of musical instruments. Deaf persons have been known to derive pleasure from music by placing their hands upon the wood-work of musical instruments while being played upon. 739. Why is the hearing of deaf persons assisted by ear- Because ear-trumpets collect the vibrations of the air into a focus, and make the sounds produced thereby more intense. 740. Why are sounding-boards used to improve the hearing of congregations ? Because, being suspended over, and a little behind, the speaker, they collect the vibrations of the air, and reflect them towards the congregation. 741. What are echoes ? Echoes are sounds reflected by the objects on which they strike. 742. Why do some echoes occur immediately after a sound ? Because the reflecting surface is very near ; therefore the sound returns immediately. 743. Why do some echoes occur a considerable time after a sound ? Because they are at a considerable distance, and the sound takes time to travel to it, and an equal time to return. 744. Why do some echoes change the tone and quality of sound ? Because the reflecting surface, having vibratory qualities of its own, mingles its own vibrations with that of the sound. 745. Why are there sometimes several echoe* to one sound f THE EEA.SON WHY. And God said, Let the waters under the heaven be gathered together unto ona place, and let the dry land appear : and it was so." GEX. i. Because there are various reflecting surfaces, at different distances, each of which returns an echo. 746. Are sounds reflected only by distant objects ? Sounds are doubtless reflected by walls and ceilings around us. But we do not perceive the echoes, because they are so near that they occur at the same moment with the sound. In lofty buildings, however, there is frequently a double sound, making the utterance of a speaker indistinct. This arises from the echo follow- ing very closely upon the sound. 747. Why, when we are walking under an arch-way or a tunnel, do our voices appear louder ? Because the sounds of our voices are immediately reflected. And as a gas reflector increases the intensity of lirjJit, so a sound reflector will increase the apparent strength of our voices. There are many places where remarkable echoes occur. On the banks of the Rhine, at Lurlcy, if the weather be favourable, the report of a rifle, or the sound of a trumpet, will be repeated at different periods, and with various degrees of strength, from crag to crap, on opposite sides of the river alternately. A similar effect is heard in the neighbourhood of some of the Lochs in Scotland. There is a place at Woodstock, in Gloucestershire, which is said to echo a sound fifty times. Near Rosneath, a few miles from Glasgow, there is a spot where, if a person plays abar of music upon a bugle, the notes will be repeated by an echo, but a third lower; after a short pause, another echo is heard, again in a lower tone ; then follows another pause, and a third repetition follows in a still lower key. The effect is very enchanting. The whispering galleries of St. Paul's, of the cathedral church of Gloucester, and of the Observatory of Paris, owe their curious effects to those laws of the reflection of sound, by which echoes are pro- duced ; but in these cases the effect is assisted by the elliptical form of the edifice, each person bemg in the focus of an ellipse. CHAPTER XXXV, 748. What is water? Water is a fluid composed of two volumes of hydrogen to one of oxygen, or eight parts by weight of oxygen to one of hydrogen, It is nearly colourless and transparent. 749. Why, if a saucer of water be exposed to the air, mil it gradually disappear ? THE EEASON WHY. " .rliolil there ariueth a little cloud from the sea, of the bigness of a man's baud. And it came to pass in the meantime, that the heaven was black with clouds and wind, and there was a great rain." 1 KINGS XTIII. Because water is highly expansive, and rises in thin vapour, vhen in contact with warm and dry air. 750. Why does steam issue from the spout of a kettle ? Because the heat of the fire passes into the water, and drives its atoms apart, making those of them that rise quickly to the surface lighter than the air, upon which they consequently rise. 751. Why does water become solid when it freezes ? Because the latent heat of the water passes away from be- tween its atoms into the air ; the atoms, therefore, draw closer together. 752. Why, if the atoms of water draw closer together when freezing, does ice expand, and occupy greater space than water ? Because, when the atoms of water are congealing, they do not form a compact mass, hut arrange themselves in groups of crystal points, which occupy greater space. Water contracts when freezing until it sinks to 40 deg., and then it expands as ice is formed. 32 deg. is said to be the freezing point, but it should be called the frozen point. 753. WJiy does water loil ? Because heat, entering into the lower portions of the water, expands it ; the heated portions are then specifically lighter than those that are cooler ; the hot water therefore rises upward, and forces the cooler water down. 754. What proportion of the earth's surface is covered with water ? There are about one hundred and forty seven millions of square miles of water, to forty -nine and a half millions of square miles of land. t 755. What is the amount of water pressure ? The pressure of the sea, at the depth of 1,100 yards, is equal to 15,000 Ibs. to the square inch. 8 170 THE EEASON WHY, "But the land, whither ye go to possess it, is a land of hillf and valleys, and driuketh water of the rain of htxven." DEUT. n. 756. What element is the most abundant in nature ? Oxygen, which forms so large a part of water. Of animal substances, oxygen forms three-fourths ; of vegetable substances it forms four-Jifths ; of mineral substances it forms one-half ' ; it forms eight-ninths of the waters and one-fifth of the atmosphere ; and aggregating the whole creation, from one- half to two-thirds consists of oxygen. 757. In what ways does man use oxygen ? Man eats, drinks, breathes, and burns it, in various proportions and combinations. It is estimated that the human race consume in those various ways l,000,000,0001bs. daily; that the lower animals consume double that amount; and that, in the varied works of nature, no less than 8,000,000,000lbs. of oxygen are used daily. 758. Why does water dissolve various substances ? Because the atoms of water are very minute ; they therefore permeate the pores, or spaces, between the atoms of those bodies, and overcoming their attraction Jor each other, cause them to separate. 759. Why does hot water dissolve substances more readily than cold ? Because the heat assists to repel the particles of the substance undergoing solution, and gives the water a freer passage between the atom. 760. Why is pump water sometimes hard ? Because, in passing through the earth, it has become impregnated with mineral matters, usually the sulphate and carbonate of lime. 761. Why is rain water soft ? because it is derived from vapours which, in ascending to the clouds, could not bear up the mineral waters with them. It therefore became purified or distilled. 762. Why do kettles become encrusted tvith stony do- posits ? Because that portion of the water which is driven off in steam THB SEASON WHY. 171 ' He gathereth the waters of the sea together as an heap ; he layeth up the depth in storehouses." PSALM xxxiu. leaves the mineral matters behind; they therefore form a crust around the sides of the kettle. It is said that if a child's marble be placed in a kettle, it will attract the earthy particles, and prevent the encrusting of the sides of the vessel. 763. Why is it difficult to wasli in hard water ? Because the soap unites with the mineral matters in the water, and being neutralised thereby, cannot dissolve the dirt which we desire to cleanse away. 764. Why is the sea salt ? Because salt is a mineral which prevails largely in the earth, and which, being very soluble in water, is taken up by the ocean. Lakes and rivers, also, even those that are considered fresh, hold in solution some degree of saline matters, which they contribute to the ocean. As, in the evaporations from the sea, the salt remains in it, while the vapours fall as rain, and again wash the earth and carry some of its mineral properties to the ocean, the greater saltness of the sea, as compared with rivers, is accounted for. By some persons the opinion is entertained that the sea has been gradually getting salter ever since the creation of the world. This, they say, arises from the evaporation of water free from salt, and the returns of the water to the sea, taking with it salt from the land. 765. What is the estimated amount of salt in the sea ? . The amount of common salt in the various oceans is estimated at 3,051,342 cubic geographical miles, or about five times more than the mass of the mountains of the Alps. 766. What is the depth of the sea ? The extreme depth has not, probably, been ascertained. But Sir James Boss took soundings about 900 miles west of St. Helena, whence he found the sea to be nearly six miles in depth. Now, if we take the height of the highest mountain to be five miles, the distance from that extreme rise of the earth, to the known depth of the sea, will be no less than eleven miles. 767. Why are the wafers of some springs impregnated with mineral matters ? 172 THE J.EASON WHT. " Who hath measured the waters in the hollow of his hand, and meted out heaven with the span, and comprehended the dust ol the earth in a measure and weighed the mountains in scales, aud the hills in a balance ?" ISAIAH XL. Because the water passes through beds of soda, lime, magnesia, carbonic acid, oxides of iron, sulphate of iron, &c., &c., and takes up in some slight degree the particles of those minerals, according to the proportions in which they abound. 768. W hy does iron rust rapidly ivhen icetted ? Because the water contains a large proportion of oxygen, some of which combines with the iron and forms an oxide of iron, which is rust. 769. Why does stagnant water become putrid ? Because the large amount of oxygen which it contains accelerates the decomposition of dead animal and, vegetable substances that accumulate in it. 770. Is there danger in drinJcing water on account of the living animalcules which it contains ? No danger arises from the living creatures in water ; but putrefactive matters may produce serious diseases. 771. What is the best method of guarding against im- purities ? By obtaining water from the purest sources, and by filtering it before drinking, by which nearly all extraneous matters would be separated from it. CHAPTER XXXVI. 772. What is attraction ? Attraction is the tendency of bodies to draw near to each other. It is called attraction, from two Latin words signifying drawing towards. 773. How many Jcinds of attraction are there ? There are five principal kinds of attraction : 1. The attraction of gravitation. 2. The attraction of cohesion. 8. The attraction of chemical affinity. THE BEASON WHY. 173 Behold, the nations are as a drop of a bucket, and are counted as the small dust of the balance : behold, he taketh up the isles as a. very little thing." ISAIAH Xi. 4. The attraction of electricity. 5. And capillary attraction. 774. Why do all lodies heavier than the air fall to the earth ? Because they are influenced by the attraction of gravitation, by which all bodies are drawn towards the centre of the earth. 775. Why do lodies lighter than the air ascend? Because the air, being a denser body, obeys the law of attraction and in doing so displaces lighter bodies that interfere with its gravitation. 776. Why do fragments of tea, and bubbles floating upon the surface of tea, draw towards each other, and attach themselves to the sides of the cup. Because they are influenced by the attraction of cohesion. Cohesion. The act of sticking together. 777. Why will a drop of water upon the Hade of a knife leave a dark spot ? Because the iron of the knife attracts the oxy gen of the water, \>j chemical affinity ; and the two substances form a thin coating of oxide of iron. Affinity. Attraction between dissimilar particles through which they form new compounds. 778. Why do clouds sometimes move towards each other from opposite directions ? and 779. Why do light particles of matter attach themselves to sealing wax, excited by friction ? Because they are moved by the attraction of electricity. 780. Why will a towel, the corner of which is dipped ifi water, become wet far above the ivater ? Because the water is conveyed up through the towel, by capillary attraction. The atoms of the water are attracted by the threads of the towel, and drawn up into the small spaces between the threads. Capillary. Resembling a hair, small in diameter. |74 THE EEASON WHY. " He stretcheth out the north over the empty place, and hangeth the earth upon nothing." JOB xxvi. 781. Why do small lalies floating upon water move towards larger ones ? Because the attractive power of a large body is greater than that of a small one. As each atom of matter has inherent power of attraction, it follows that a large aggregation of particles must attract in proportion to the number of those particles. 782. WTiy do clouds gather around mountain tops ? Because they are attracted by Hie mountains. 783. Why would a piece of lead tied to a string, and let down from a church steeple, incline a little from the perpendicular towards the church ? Because the masses of stone of which the church is built would attract the lead. 784. Sow can man weigh the earth ? By observing what is called the deflection of small bodies when brought within given distances of larger bodies, the degree of attraction exercised by the large body upon the smaller one becomes known. This attraction of the large body exercised over the smaller body is an opposing influence, acting against the earth's attraction of the small body, which is drawn out of its course : it constitutes a natural balance between the influence of the earth and another body, acting in opposition to it. Founded upon these, and some other data, man can weigh the earth, and give a morally certain result ! Deflection. The act of turning aside. 785. Sow can man weigh, the planets ? The planets exercise as certain an influence upon each other as do two pieces of wood floating upon a basin of water. As the planetary bodies fly through their prescribed orbits, and approach nearer to, or travel further from, each other, they are observed to deviate from that course which they must have pursued but for the increase or the decrease of some influence of attraction. By making observations at various times, and by comparing a number of results, it is possible to weigh any planetary body, however vatt, or however distant. THE SEASON WHY. *Ts not God iu the height of the heaven? and behold the height of the stars, how high they are ?" JOB xn. 78G. Sow can man measure the distances of the planets ? By making observations at different seasons of the year, when the earth is in opposite positions in her orbit ; and ty recording, by instruments constructed with the greatest nicety, the angle of sight, at which the planetary body is viewed ; by noticing 1 , also, the various eclipses, and estimating how long the first light after an eclipse has ceased reaches the earth, it is possible to estimate the distances of heavenly bodies, no matter how far in the depths of the universe those orbs may be. 787. What are the opinions founded upon estimates respecting the magnitude of the sun ? The diameter of the sun is 770,800 geographical miles, or 112 times greater than the diameter of the earth ; its volume is 1,407,124 times that of the earth, and 600 times greater than all the planets together ; its mass is 359,551 times greater than the earth ; and 738 times greater than that of all the planets. A single spot seen upon its surface has been estimated to extend over 77,000 miles in diameter, and a cluster of spots have been estimated to include an area of 3,780,000 miles. 788. What is the weight of the earth? The earth has a circumference of 25,000 miles, and is estimated to weigh 1,256,195,670,000,000,000,000,000 tons. 789. What is the specific gravity of a lody ? It is its weight estimated relatively to the weights of other bodies. 790. What determines the force with which lodies fall to the earth ? Generally speaking, their specific gravity, which is proportionate to the density, or compactness of the atoms of which they arc composed. 791. Why does a feather fall to the earth more gradually than a shilling ? Because the specific gravity of the feather and of the shilling in 176 THE SEASON WHY. 'Where wast thouwhen I laid the foundations of the earth? declare, if hast understanding. relative to that of the air, the medium through which the feather and the shilling pass. If there were no air, a shilling and a feather dropped at the same time from a height of forty miles, would reack the earth at the same moment. CHAPTER XXXVII. 792. What is repulsion ? Kepulsion is that property in matter by which it repels or recedes from, those bodies for which it has no attraction or affinity. 793. Why does dew form into round drops upon the leaves of plants ? Because it repels the air, and the substances of the leaves upon which it rests. Because, also, its own particles cohere. 794. Why do drops of water roll over dusty surfaces ? Because they repel the particles of dust ; and also because their own particles have a stronger attraction for each other than for the particles of dust. 795. Why does a needle float when carefully laid upon the siirface of water ? Because the needle and the water mutually repel each other. 796. Why does water, when dropped upon hot iron, move about in agitated globules ? Because the caloric repels the particles of the water. 797. Why does oil float upon the surface of water ? Because, besides being specially lighter than water, the particles of the oil and the water mutually repel each other. 798. What is carbonic acid? Carbonic acid is a mixture of carbon and oxygen, in tba proportion of 3 Ibs. of carbon to 8 Ibs. of oxygen. 799. Where does carbonic acid cliiefty exist t THE EEASON WHY. ^77 ' Who liath laid the measures thereof, if thou knowest V or who hath stretched the line upon it? It exists in various natural bodies in which carbon and oxygen are combined ; it is evolved by the decomposition of numerous bodies called carbonates, in which carbon is united with a particular base, such as the carbonate of lime, the carbonate of iron, the carbonate of copper, &c. It is_ also evolved by the processes of fermentation, by the breathing of animals, the combustion of fuel, and the functions of plants. Carbonic acid also exists in various ^caters. Carbonic acid is found most largely in solid combinations with other bodies : it forms 44-100lhs of all limestones and marbles, and it exists in smaller quantity, combined with other earths, and with metallic oxides. 800. What are the states in which iaaksgiviag into the air ; the broad blue heayeus for a time look down and THE SEASON WHY. Jgl " How mighty are his wonders ! his kingdom is an everlasting kingdom, and his dominion is from ge K.ration to generation." DANIEL ir. imile upon the bltssed work ; and then the clouds again gather in a golden train, and one by one fill the high arches of the atmosphere, until the earth once more grows thirsty, a.nd the flower supplicates for drink. "With reference to Light, its wonders, and the curious but imperfect theories respecting it, we have little to add, except with regard to its physiological action upon the eyes of man and of animals, which will be given in another place. But of its sister, Darkness for it would not do now to call darkness the antagonist of light, since it will be seen that they 'work harmoniously for good we have to say, that recent discoveries indicate that darkness is as necessary to the health of nature as light. Not only is it necessary to compose man and animals to sleep, to give rest to the over-wrought nerves of the industrious but light is the quickening power of vegetation, and although plants grow by night, they grow, as man does, when stretched upon his bed, but some of their func- tions, which are actively excited in the presence of light, are at rest in dark- ness. Nor is this all : there is not an atom npon the face of the earth which is not affected by the rays of the sun, their light, their heat, their actinism. Colours change : some are bleached, others are darkened. All bodies are expanded. The hardest rock sustains an effect from the sun's rays ; and an unceasing sun, shining upon the hardest granite, would in time produce such a disturbance of its atomic condition, that adamant would crumble away to dust. The going down of the sun, therefore, marks the period when not only does the bird fly to her resting-place, and man turn to his couch ; but when every atom of a vast hemisphere subsides into a state of quietude, and when homo- geneous particles of matter return to their mutual rest. In a few succeeding lessons, we Intend to point out some of the scientific truths that are illustrated in the use of toys. We think we shall be able to show to our young readers, that even the hours of play may be made the periods of delightful instruction ; and that there is no "reason why" the acquire- ment of knowledge should not sweetly accord with the occasional pursuit of those pastimes by which health of body and vigour of mind are induced. But before we commence the discharge of that pleasant duty, let us say a few words respecting Carbon, that important agent in the world's history. It is, doubtless, perplexing to the minds of many persons, to understand how the diamond can be pure carbon ; how charcoal can be carbon a little less pure than the diamond ; and how coal and sugar can also be carbon, less pure than the charcoal. The statement that in the diamond carbon exists in a different atomic condition, is almost as instructive to the inquiring mind, as to say. " It is so, because it is." Diamonds are expensive things, and so difficult to experiment upon, even if they were not expensive, that the doors of inquiry seem locked. To turn diamonds into charcoal, or into carbonic acid gas, is a very costly formula of experiment. Charcoal fires, thus sustained, would soon burn a man out of his louse; and soda water, impregnated with carbonic acid gas, produced from diamonds, would be a very expensive beverage. If -ve could only turn charcoal into diamonds, and carbonic acid gas into brilliants, that would be quit* another affair. A new Eldorado would be discovered, and there would be s many experimenters that, when they all succeeded, they would find that diamonds had lost their va2ue. However, a* a fact for the encouragement o< those who would liks to bt early in the race, we may state that the atoms o THE BEASON WHY. * He delivereth and rescueth, and he worketh signs and wonders in heaven and in earth." DANIEL vn. charcoal which are repulsed from the charcoal points, during the electric agita- tion which produces the electric light, acquire a hardness and a sharpnesi almost equal to that of the diamond only there is still the awkward obstacle in t he way, that they Juippen to be black. We must see, therefore, whether there is anything in nature that we can experiment upon, theoretically or practically, to give us a clearer conception of this difficult matter. There is a large dew-drop resting upon a luxuriant cabbage leaf one of those great leaves that have flourished in defiance of the snail, and now spreads out like tb gigantic frond of the Victoria Rcginit. That dew-drop is one of the beautifU diamonds which Nature sprinkles about on cloudless nights, as if to show the stars, in answer to their twinkling, that wo have something that will glisten and twinkle too. The dew-drop is a very good imitation of a diamond, and to the lover of God's works, quite as precious as the stone set in gold. It does not consist of carbon it probably may have a mite of carbonic acid in its embrace but that is not necessary to our purpose : all we want to know is, the different atomic conditions of which bodies are susceptible, and the very dissimilar appearances they exhibit under the variations of atomic states. It doesn't glisten so much as the diamond, because it is round it we could cut it into a number of facets, it would refract light almost as perfectly as the diamond. It is not solid but we can freeze it, and we shall at once exhibit two different atomic conditions, that will represent nearly enough, the diamond, and the liquid carbonic acid. Then, if we evaporate the dew-drop, we shall produce a volume of vapour nearly two thousand times as large as the dew-drop. The steam will be white ; but we have only to imagine it black, and then we get an analogy of the differences of the atomic conditions that prevail in the diamond, carbonic acid, and charcoal, tinder, lamp-black, or any light form of carbon. Of course we have been illustrating atomic conditions only, and not chemical composition. There are a few other facts connected with carbon that merit consideration. Carbonic acid gas, entering the lungs, is a deadly poison; but entering the stomach, which lies close under the lungs, and is over-lapped by them, it is a refreshing beverage. Although charcoal, when burnt, gives off the most poisonous gas, it seems to be very jealous of other gaseous poisons ; for if it be powdered, and set about in pans where there is a poisonous atmosphere, it will seize hold of poisonous gases, and, by absorbing, imprison them. Even in a drop of toast and water, the charred bread seizes hold of whatever impurities exist in the water ; and water passed through beds of charcoal, becomes filtered, and made beautifully pure, being compelled to give up to the charcoal whatever is obnoxious. If a piece of meat that has already commenced putrifying, be sprinkled with charcoal, it will not only object to the meat putrifying any further, but it will sweeten that which Jias already undergone putrefaction. Although, in the form of gas, it will poison the blood, and cause spocdy stupefaction and death ; if it be powdered, and stitched into a piece of silk, and worn before the mouth as a respirator, it will say to all poisonous gases that come to the mouth with the air, " I have taken this post to defend the lung?, and I arrest you, on a charge of murderous intention." Such are the rarious facts connected with carbon ; and they forcibly indicate that those wlw auilurstand Nature's w orks, are lively to receive her best protection, THE EEASON TVIIY. 183 The father of the righteous shall greatly rejoice ; and he that bcgetteth a wle child shall have joy of him." PEOVEBBS xxm. CHAPTER XXXVIIL 810. Why does a humming-top make a humming noise? Because the hollow wood of the top vibrates, and the edges of the hole in its sides strike against the air as it spins; the air is thereby set in vibration. 811. Why does a peg-top hum less than a humming- top? Because, being a solid body of wood, and having no hole in its sides, its particles are not so easily thrown into vibration; consequently it does not so readily impart vibrations to the air. 812. Why does a peg-top sometimes hum, and at other times not ? Because, if it is spun with great force, and its peg is struck sharply against the pavement, the wood is set in vibration, and the surface of the top, repelling the air by its rapid motion, causes vibratory waves. But if it be spun with insufficient force, the wood is not set in vibration. Fig. 23. HUMMING-TOP BEFOBE Fig. 24 HUMMIVG-TOP SPINNING. SPINNING. 813. Why do we see the figures painted upon the humming- top, before it spins, but not ivhile it is spinning ? Because the rapid whirling of the top brings the images of its different parts so quickly in succession upon the rttina of the eye. 184 TDE SEASON WHY. 'Train up a child in the way ho should go; and when he is old, he will not depart from it." PEOVERBS xxu. that they deface each other, and impart an impression of coloured rings, instead of definite objects. 814. Why does a top stand erect when it spins, but fall when it stops ? Because the top is tinder the influence of, and is balanced between opposing forces. The rapid rotation of the top gives to all its particles a tendency to fly from the centre. If the atoms of the wood were not held together by the attraction pf cohesion, they would fly away in a circle outward from the io^,just as drops of water fly off from a mop, while it is "being twirled. If you take a spoonful of sand, salt, or dust, and drop it upon the top, it will be scattered in a circle, just as the atoms of the top would be, if they were free to separate, but not with the same force, because the atoms of the salt, &c., not being in an active state of rotation, would only be influenced by momentary contact with the rotating body. This tendency of the particles of a rotating body to fly outward from the centre, is called the centrifugal force. Centrifugal. From two Latin words meaning receding from the centre. The other force influencing the top is the attraction of gravita- tion: the attraction which, were the top not spinning, would draw it towards the earth. The " spill " projecting from the bottom of the top stands in the line in which the top is drawn towards the earth and keeps it from obeying the law of gravitation. Therefore the rotatory motion given to the top, by the rapid unwinding of the string, and the tendency of its atoms to fly outward, balance the top upon the line in which it is drawn to the earth, and which is occupied by the spill, which prevents it falling to the ground. 815. Why does a top first reel around upon the spill, then become upright, and "sleep," and then reel again, and fall ? Because, in being thrown from the hand, the top is delivered a little out of the perpendicular, but the spill is rounded off at the point, and when the top is rotating rapidly, the gravita- tive force which attracts the top to the ground continually acting upon it, draws the weic/M tiff. 18. PEG-TOP " BEEIJNG." THE BEASON TVHY 185 1 Even a child is known by his doings, whether his work be pure, and whether it be right." PEOVEEBS xx. of the top on to the extreme centre of the round point. When the rotation subsides, and the centrifugal force is weakened, then the top is no longer balanced upon the extreme point of the spill, but falls upon it sides, until the force of gravita- tion is exerted beyond the line of the spill, upon the body of the top, and then it falls to the ground. 816. Why does a top " sleep ?" Because a* that period of its spinning, which is called " sleeping," me centrifugal and the gravitative forces acting upon the top, are nearly balanced; and the top, obeying chiefly the rotatory force, appears to be in a state of comparative rest. 817. Wliy does the top cease to spin ? Because the friction of the air against its sides, and the friction of the spill against the ground, act in opposition to the rotatory force, which is a temporary impulse applied by external means the hand of the person who spins it and as soon as this applied force is expended, the top yields to the law of gravitation, which is a permanent and, ever-prevailing force. 818. Why does a marlle revolve, as it is propelled along the ground? Because, in propelling the marble, the thumb impels the upper turf ace forward, and the finger draws the under surface back- card. This gives a tendency to the upper and lower hemispheres of the marble to separate, which they would do, but for the cohesion of the atoms of the marble. The upper part of the marble, therefore, rolls forward, drawing after it the under part, which acquires a forward motion by the force with which it is drawn upward, and in this way the opposite portions of the marble act upon each other in the successive revolutions. When the marble strikes upon the earth, a new influence is exerted upon it, which is the friction of the earth upon the surface that comes in contact with it ; but the upper part of the marble, being free, overcomes the friction acting upon the Ltwer part, and thus the marble continues to progress, until the applied fore* ichizh projected it is expended. THE EEASON WHY. ' Better is a poor and a wise child, than an old and foolish king who will no more be admonished." ECCLESIASTES IV. 819. Why does a striped marble appear to have a greater number of stripes when rolling, than when at rest ? Because the stripes are presented in rapid succession to the eye ; and as the eye receives fresh impressions of stripes before the previous impressions have passed away, the stripes appear multiplied. Fig. 26.-MABBLE AT BEST Fig. 27. MAEBLE BOLLING. 820. Why does a marble rebound when dropped upon the pavement ? Because the force of its fall to the earth compresses ihe atoms of which the marble is composed ; and the atoms then exert the force of elasticity to restore themselves to their former condition ; and by the exercise of this force the marble is repelled, or thrown upward from the pavement. Although a marble may be made of very hard stone, yet that stone may be elastic, and possess, though in a much less degree, the same kind of elasticity which causes the India-rubber ball to rebound from the earth. 821. Why does a marble, assuming it to be impelled with equal force, roll further on ice than on pavement, and further on pavement than on a pebble walk? Because the friction is greater upon pavement than upon ice, and greater upon a pebble walk than upon pavement. 822. JLow many forces contribute to stay t\e progress of rolling marble ? THE REASON WHY. 187 * Ho thill turn the heart of the fathers towards the children, and the heart of the children to their fathers." MALACUI iv. The friction of the air, the friction of the earth, and tue attraction of gravitation, which tends to bring all bodies to a state of rest. 823. Why do the Stripes upon a marble disappear -when it is spun with great velocity ? Because, as in the case of the humming-top, the different parts of the surface are brought so rapidly in succession to the fight, that they deface or con- fuse the impressions upon the ^" retina. 824. Why are rings most perceptible at the opposite Fig.28.- 1I A fi BLESPI N .MX G BAPII>LT. j o Because the point, or pole, upon which the marble spins, and that which corresponds to it, on the upper surface, travel lest rapidly than the central portions, which being of a larger circumference, pass through a greater amount of space, in the same period of time. The stripes at the poles of the marble, are, therefore visible, while those at its equator are imperceptible, (See 522.) CHAPTERXXXIX. 825. Why are soap-bubbles round ? Because they are equally pressed upon all parts of their rurfact by the atmosphere. 826. Why are bubbles elongated when being llown ? Becaxise the unequal pressure of the current of breath by which (hey are being filled, alters the relative pressure upon the outer surfaces. 827. Why does the bubble close, and become a perfect tphere, ichen shaken from the pipe? 188 THE SEASON WHY. ' Children's children are the crown of old men ; and the glory of children their fathers." PBOVERBS xvii. Because the attraction of cohesion draws the particles of soap together, directly the bubble is set free from the bowl. Pig. 29. BLOWING SOAP BUBBLES. 828. Wliy do lullles, lloivn in the sunshine, change their colours ? Because the films of the bubbles constantly change in thickness, through the atoms from the upper part descending towards the bottom, and therefore the varying thickness of film refracts, in different degrees, the rays of light. 829. Why do lullles burst ? Because the atoms that compose their films fall towards the earth by gravitation; the upper portion of the bubbles then becomes -very thin, and as the denser air of the atmosphere presses towards the warm breath within the bubble, it bursts the film. See 236. 237, etc., 501, etc. 830. Why do balloons ascend in air ? Because the air or gas which they contain is specifically lighter than the atmosphere; the atmosphere, therefore, forces itself underneath the balloon, by its own tendency towards the earth, and the balloon is thereby raised upwards. A balloon is but a larger kind of bubble, made of stronger materials. 831. Why does an air-balloon become inflated when ih* spirit set upon the sponge is lit ? THE BEASON WHY. 189 1 A wise son heareth his father's instruction." PEOVEEBS xin. Because the lieat of the flame, and the burning of the spirit, A, create a volume of rare/ied, or thin air, which inflates the balloon, and makes it specifically lighter than the surrounding medium. 832. Why do balloons some- times burst when they ascend very high ? Because, as they get into the thinner air, which exists at high altitudes, the gas within them ex- pands, and the coating of the balloon is burcit asunder. Fig. 30. AIB-BAJLLOOX. 833. Why does the gas of balloons expand in thin air ? Because the air exerts a less amount of pressure upon the air or gas contained in the balloons. 834. Why do parachutes fall very gradually to the ground ? Because the air, coming n con- tact with, the under surface of the expanded head of the parachute resists its downward progress. 835. Why does a shuttlecock travel slowly through the air? Because the air acts upon the feathers of the shuttlecock, in the same manner as it does upon the parachute it strikes against their expanded surface, and resists their progress through the air. 836. Why does the shuttle- Fig. 31. PAPES PAKACHUTE. cock spin in the air ? 190 THE EA.SOy 1VHY. ' Come ye children, hearken unto me, I will teach you the fear of the Lord." PSALM xxxv. Because the surfaces of the feathers fall upon the air obliquely, or slantingly, and therefore, as the shuttlecock descends, it turns in the air. Flit. 32. BATTLEDOEB AHD SHUTTLECOCK- 837. Why do we hear a noise when we strike the shuttle- cock with the lattledore ? Because the percussion of the shuttlecock upon the parchment of the battledore causes it to vibrate, and the vibrations are imparted to the air. 838. Why is the sound a dull and short one ? Because the vibrations of the parchment are not very rapid, therefore there is little intensity in the vibrations of the air. 839. Why does the exercise, afforded by playing battle- dore and shuttlecock, make us feel warm ? Because it makes us breathe more freely, and causes the blood to flow faster ; we, therefore, inhale more oxygen, which produces heat by combining with the carbon of our blood. 840. Why does a Jcite rise in the air ? A kite rises in the air by the force of the wind, which sMIcct obliquely upon its under surface. The string is attached to the " belly-band " in such a manner that it is nearer the top than the bottom of the band : this causes the bottom of the kite, when its surface is met by ',he wind, to recede in the direction of the wind THE REASON WHY. ]9] * Be ye therefore followers of God, as dear children ; and walk in love, as Christ also hath loved us." EPHESIAXS v the top is accordingly thrown forward, and the kite is made to lie obliquely upon the current of air moving against it. The kite then being drawn by the string in one direction, and pressed by the air in another direction, moves in a line which describes a medium between the two forces acting upon it. 841. Why does the kite-string feel hot wlien running through the hand ? Fig. 33. DIAGEAM: EXPLAINING THE FLIGHT OP A KITE. Because the rapid friction sets free the latent heat of the string, attracts the heat of the hand to the spot where the friction occurs, and sets free the latent heat of the air, which follows the string through the hand, and is compressed by the friction. 842. Why does running with the kite cause it to rise higher ? Because it increases the force with which the wind strikes upon the surface of the kite. If a person were to run with a kite at the rate of jive miles an hour, through a still air, the effect would be equal to a wind flying at the rate of Jive miles an hour against a kite held by a stationary string. 843. Why does the flying-top rise in the air ? Because its wings meet the air obliquely, just as the surface of the kite does. And the twirling of the top, causing the obliqoB 192 THE BEASOIT WHY. " Children obey your parents in the Lord : for this is right. surfaces of its wings to strike the air, produces the equivalent effect of a wind from the earth blowing the top upwards. 844. Why does the flying-top return to the earth when its rotations are expended ? Because the reaction produced by its wings striking upon the air, is insufficient to counteract the attraction of gravitation. Pig. 34 FLYING-TOP. Fig. 35.-PEA AND PIPE. 845. Why does a pea, into which a pin has teen stuck, dance in suspension upon a jet of air llown through a pipe ? Because the jet of air, being slightly compressed under the convex form of the pea, by the weight of the pin, forms a concave cup of air, in which the pea rests. In the case put, it is supposed that the pin is passed through the pea until its head comes in contact with it. The pin is dropped into the hole of the pipe, and the breath is then applied, the pipe being held upright. The pea will rise in the air, and l;e suspended upon the jet, while the point of the pin will rotate around the stem of the pipe. There are otlier methods of fixing the pin which alter the result, and require a different explanation to that given above. LESSON XL. 846. Why does a mouse, painted upon one side of a card, and a trap upon the othtr, represent to the t ;t t- a THE BEASOX WHY. 193 1 Honour thy father and thy mother * * That it may be well with thee. and thou mayest be long on the earth." EPHESIANS vi. mouse in a trap when the card is rapidly twirled upon a string ? Because the image of the mouse is brought to the retina of the eye before the image of the -trap has passed away. The two impressions, therefore, unite upon the retina, and produce the image of a mouse in a trap. Fig. 3^. CAED -WITH MOCSE-TEAP. Pig. 37. BBTZR8B OP CAED WITH MOUSE. 847. Why will a low stretched out of its natural position, propel an arrow through, the air ? Because its substance, being highly elastic, the particles thereof seek to restore themselves to their former state, as soon as the resisting power is withdrawn. The force derived from this elas- ticity, is communicated to the arrow by the string against which it is placed. 848. Why is the arrow propelled forward ? Because the elasticity of the bow, acting equally upon its two ends, to which the string is fastened, produce a line of force in a diagonal direction. It thus illustrates the law, that when a body is acted upon by two forces at the same time, whose directions ar inclined to each other, it will not follow either of them, but will describe a line between the two. 849. What forces tend to arrest the flight of the arrow? The friction of the air, and the attraction of gravitation. 194 THE SEASON "WHY. * My son, give, I pray thec, glory to the Lord God of Israel, and make confession unto him." JOSHUA vn. 850. Why are feathers usually fastened to the ends of arrows ? Because the greater friction of air acting upou them, opposes the progress of that part of the arrow in a greater degree than it does the other portion. The effect is, to keep the point of the arroio forward, and in a straight line with its opposite extremity. If the arrow were shot the reverse way from the bow, it would turn round, in the course of its flight, in consequence of the friction of the air, offering greater resistance to the progress of the feathered end. Fig. 88. BOW AND AEEOW. Fig. S^-JEVS HAHP. 851. Why does a Jew's harp give musical sounds ? Because the vibrations of the metal tongue are communicated to the ear. 852. Why will not the Jew's harp produce loud sounds unless it is applied to the mouth ? Because the vibrations are not very intense, but when it is blown upon by the breath, the air is pressed upon it, and the vibrations are thereby rendered more powerful. 853. Why does the alteration of the arrangement of the mouth, affect the formation of the sounds ? Because it sends the air to the tongue of the harp in a greater of Utter degree of compression. THE REASON WHY. 195 1 Hear, ye children, the instruction of a father, and attend to know under- standing.." PBOVEKBS IV. 854. Why does the pressure applied to the handle of an air pistol propel the cork? .Because, between the cork A and the air-tight piston c, there is a closed chamber of air B. When the handle D, which moves the piston c, is rapidly pushed in, it compresses the air until it is so much condensed, that it forces out the cork A. Fig. 40. AIR PISTOL, OR " POP-GUN." 855. Why must the handle le drawn out, before the corJc is placed in ? Because otherwise a partial vacuum would be formed between A and c, and there would not be sufficient air to force out the cork by the return of the piston c D. 856. Why does water rise in a syringe when the handle is drawn out ? Because the pressure of the air on the water outside of the syringe, forces it into the space vacated by the drawing up of the handle, and where, otherwise, a vacuum would be formed. Fig 41. SYRINGE, WITH JET OP WATEB. 857. Why does not the water run out when the syringe is raised ? Because the pressure of the air upon the small orifice resists the weight of the water. 858. Why does the water leak out, lut not run ? Because water has a tendency always iomove to the lowest point, 196 TUB KEiSON WHY. ' Remember new thy creator in the days of thy youth." ECCLESIASTES n. but as the air does not enter freely the water cannot escape. It therefore drops, as small portions of the air enter. 859. Why cannot the handle be pressed in, if the Jinger IB applied to the orifice ? Because water is not compressible, like air ; it must therefore escape before the handle can be pressed in. Air may be forced into a much smaller compass than is natural to it ; but it is impossible to compress water in -any great degree. Fis?. 42. "SCCKEE." Fig. 43. HOOP. 860. Why does a " sucker''' raise a stone ? Because underneath the sucker a vacuum is formed and the external air, pressing on all sides against the vacuum, lifts the stone. The term " sucker " is founded upon the mistaken notion that the leather " sucks," or " draws" the stone. That such is not the case is evident : if, when the stone is suspended, a pin's point be passed under the leather, so as to open a small passage for the air, the stone will drop instantly. 861. Why does a hoop roll, without Jailing to the ground ? Because the centrifugal force gives it a motion which is called the tangent to a circle that is, a tendency in all its parts to fly off in a ttraight line. When a piece of clay adhering to the hoop flies off, it leaves the hoop in a line which is straight with the part of THE BEA8ON WHY. 'Children obey jour parents in all things: for this is well-pleasing unto the Lord." COLOMBIANS in. the surface from which it was propelled ; this line is the tangent t& the circle of the hoop ; and the tendency of all the parts of the hoop to fly off in this manner, counteracts the attraction of the earth, so long as the hoop is kept in motion. 862. Why does the hoop, in falling, make several side revolutions ? Because its onward movement, not being quite expended, in- fluences the centre of gravity of the hoop, and changes its line of direction. The hoop is also elastic, and when its sides strike the earth, they spring up again, and continue turning until the opposing forces are overcome by the attraction of gravitation. 863. Why will a little boy balance a large boy on a see-saio ? Because the " see-saw" may be placed so that its ends are at unequal distances from the centre. This gives the little boy the power of leverage, by which is meant the increase of power, or weight, by mechanical means. Fig. 44. BOYS AND " SEE-SAW." 864. Why does the little boy sink to the ground when the larger boy slightly kicks the earth ? Because the larger boy, by kicking against the earth, opposes by mechanical force the attraction of gravitation acting upon him, and he becomes temporarily less attracted to the earth than the little boy. 865. Why can the little boy, if he choose, keep the big boy up, when once he is up ? 198 THE B BASON WHY. 'Little children, let no man deceive you: he that doeth righteousness is righteous, even as he is righteous." 1 JOHN in. Because, as the big boy is then on an inclined plane with the fulcrum, or centre upon which the see-saw moves, the arm of the lever, upon which the big boy sits, is relatively shortened, and he has then less mechanical power. Also, a portion of the weight of the larger boy is transmitted along the lever to the arm upon which the little boy sits. C 866. Why is the ball propelled upward, in the game of trap and ball, when the trigger is struck ? Because, when the trigger is struck at A, it is forced down- wards, turning upon the fulcrum B, the opposite end, forming the spoon, is thereby forced up- Pig. 45. TEAP AND BAH. wards, describing a small arc, or curved line; but directly the ball is set free from the spoon, it rises b a right line with the direction it was taking, at the moment it was set free. Fig. 46. BAT AND BALL. 867. What principles of natural philosophy are illustrated ly the results of bat and loll? Percussion, when the bat strikes the ball ; rotatory motion, when the ball is sent whirling away ; momentum, which it acquires by velocity ; elasticity, when it rebounds from an object against which THE SEASON "WOT. 199 " A wise son makes a glad father : but a foolish son ia the heaviness of his mother." PEOTEEBS x. it strikes; reflected motion, when it is turned by a body upon which it impinges ; friction, as it rolls along the ground ; the communication of force, when it sets another body in motion against which it strikes ; gravitation, when it falls to the earth ; and inertia, when it lies in a state of rest. 8G8. Why do pith-tumblers always pitch upon one end? Because the lead B is specifically heavier than the pith to which it is attached; it therefore always falls undermost ; and as the lead is rounded off, just like the spill of a top, after the head has oscillated a little, and expended the force of the momentum of its fall, it will settle upon its centre of gravity, or the point through which it is attracted to the earth. 809. Why do the figures upon the " Thau- matrope" appear to dance, when they are B made to revolve before a mirror ? Because the eye, in looking through the holes in Fig. 47. the card, towards the reflections in the mirror, 'ITU- TUMBLES. rece i veg a rapid succession of impressions. As the figures upon the card are represented in a graduated series of positions the first one standing upright, the second with his knees a little bent, the third a little more bent, as in the act of springing, and so on, the figure being in each case tJie same, but the position slightly altered, imparts an impression to the mind, through the eye, that one figure is passing through a series of motions. Thaumatrope.Trom two Greek words, meaning wonder and to turn. We have said enough, we hope, to show that even the play-hours of children may be made instructive to them ; and that the simplest toys may be used to illustrate some of the grandest laws of nature. Nor may this kind of instruction be confined to children alone. Grown-up people, whether participators in the sports of youth, or simple observers of their games, may gain instruction for themselves, and be the better teachers of their children, by taking an interest in their enjoyments, and giving to their minds, through the attractiveness of pastime, a taste for observing and estimating the varied phenomena which present themselves. Moreover, we think that parental government acquires a greater power wue* 200 THE KEASON WHY. ' Jesus said, Suffer little children, and forbid them not, to come unto i of such is the kingdom of heaven." MATTHEW xix. 5; for it leans towards the natural desires of childhood, and wins those desires into a proper direction. Love existing between parent and child is the best tie to home, and the strongest incentive to duty. There is also something in the gentleness of childish nature which may influence for good the sterner mould of man, too often warped and clouded by the cares of life. Fig. 48. THAUMATEOPE, OE " WOBTDEE-TTTEIf EE." In Kay's " Life of Sir John Malcolm," we find an admirable and apt passage. Sir John says : " I have been employed these last few hours with John Elliot, and other boys, in trying how long we could keep up two cricket-balls. Lord Minto caught us. He says he must send me on a commission to some very young monarch, for that I shall never have the gravity of an ambassador for a prince turned of twelve. He, however, added the well-known and admirable story of Henry IV. of France, who, when caught on all fours carrying one of his children, by the Spanish envoy, looked up and said, ' Is your excellency married?' 'lam, and have a family,' was the reply. '"Woll. then,' said the monarch, 'I am satisfied, and shall take he galloped, with his son another turn round the room,' and off his back flogging and spurring him. 1 have sometimes thought of breaking myself of what are termed boyish habits; but reflection has satisfied me that it would be very foolish, anil that I should csleom it a blessing that I can find amusement in everything, from tossinsr a cricket-ball, to negotiating a treaty with the Emperor of China. Men who will give themselves entirely to business, and despise (which is the term) trifles, ara ver.f able, in their general conception of the. great outlines cf a pian, but they feel a want of knowledge, which is only to be gained by mixing with all classes in the world, when they come to those lesser points upon which its successful' xecution may depend. ' THE REASON WHY. 201 ' Whether therefore ye eat, or drink, or whatsoever ye do, do all to the glory of God." CORINTH, x. CHAPTER XLI. *869. Why do we eat food? Because the atoms of which our bodies are composed are con- tinually changing. Those atoms that have fulfilled the purposes of nature are removed from the system, and, therefore, new matter must be introduced to supply their place. 870. Why do we eat animal and vegetable food ? Because their substances are composed of oxygen,' hydrogen, carbon, and nitrogen the four chemical elements of w?iich the human system is formed. They are, therefore, capable of nourish- ing the body, after undergoing digestion. 871. Why do ice masticate our food? Because mastication is the first process towards the digestion of food. Before animal or vegetable substances can nourish us, their condition must be entirely changed, their organic states must be dissolved, and they must become simple matter, in a homoge- neous mass, consisting of the four chemical elements necessary to nutrition, and they must again be restored to an organic condition. 872. Why does saliva enter the mouth when we are eating ? Because, in addition to the mechanical grinding of the food by the action of the teeth, it is necessary that it should undergo certain chemical modifications to adapt it to our use. There are placed, therefore, in various parts of the body, glands, which secrete peculiar fluids, that have a chemical influence upon the food. The first of these glands are the salivary glands of the mouth, which pour out a clear watery fluid upon the food we eat, and which fluid has been found to possess a property which contributes to the digestion of food. The moisture afforded by the salivary secretion is also necessary to enable us to swallow the food. 873. Why does the salivary juice enter the mouth just at tke moment that ice are eating ? 9* THE EEASOX "WHY. ' And the Lord said unto him, Who hath made man's mouth P or who maketh the dumb, or the seeing, or the blind ? have not I the Lord f " EXODUS rv. Because the glands, which are buried in the muscles of the mouth, and which in their form are much like bunches of currants, are always full of salivary secretion. There are nerves which aru distributed from the brain to these glands, and when other nei"ves which belong to the senses of taste, of sight, or of feeling, are excited by the presence of food, a stimulus is imparted to the salivary glands, through the nerves that surround them, their ceHs collapse, and the juice which they contain is poured out through their stems, or ducts, into the mouth. 874. Hoto do we know that impressions imparted to one set of nerves, may be imparted to another set, so as to put any particular organ in action. Because very frequently the mere sight of rich fruit, or a3id sub- stances, will cause the saliva to flow freely. In this case it is evident that the salivary glands could not see or know that such substances were present. An impression must, therefore, be made upon the brain, through the organ of vision, and the desire to taste the substances being awakened, a nervous stimulus is imparted to the glands of the mouth, and they at once commence their action, as if food were present. 875. Why does food descend into the stomach ? Because, after the teeth, the tongue, and the muscles of the mouth generally, have rolled the food into a soft bolus, it is con- veyed to the back of the mouth, where it is set upon the opening of the throat (oesophagus). It does not then descend through the throat by its own gravity, because the throat is generally in a com- pressed or collapsed state, like an empty tube ; and we know that persons can eat or drink when with their heads downwards. The (Esophagus is formed of a number of muscular threads, or rings, and each little thread is like a hand ready to grasp at the morsel that is coming. As soon as the bolus is presented at the top of the throat, these little muscular hands lay hold of it. and transmit it downwa d, passing it from one to another, until it is conveyed through the long passage, to the door of the stomach, which it enters. THE EEASON WHY. 203 ' Remove far from me poverty and lies ; give me neither poverty nor riches ; feed me with food convenient for me." PEG VERBS xxx. Fig. 49. SECTION OP THE STOMACH, Ac. A. The inner coat of the stomach. (The stomach is here represented cut through its length, so that we can see its inside.) B. The lower extremity of the throat, or oesophagus, through which food enters the stomach. C. The passage out of the stomach, called the pylons, where a muscular con- traction prevents the escape of undigested food. Di The duodenum, and the ducts through which the bile and pancreatic juices enter and mingle with our food. 876. Why do we not feel the food leing transmitted through the throat ? Because the nerves of the body differ in their powers : some are nerves of feeling, some of motion, and others are nerves of the senses. The nerves of feeling are most abundantly distributed to those parts where feeling is most useful and necessary to us. But the faculty of feeling our food undergoing digestion would be no service to us whatever ; therefore the nerves of motion are plen- tifully distributed to the throat and stomach, but very few of the nerves of feeling just as many as will tell us when we eat anything too hot, or too cold, or that the stomach is out of order. 877. Why do we feel uneasy after eating to excess? Because the stomach is distended, and presses upon the other organs by which it is surrounded- 204 THE SEASON WHY. 'Wliosatisfteththy mouth with good things; so that thy youth is renewed like the eagles." PSA_LM cm. 878. Why do we feel drowsy after eating heartily ? Because, while the stomach is in action, a great proportion of the Hood of the body is drawn towards it, and as the blood is withdrawn from the other parts of the body, they fall into a state of languor. 879. Why does Hood flow more freely to the stomach during digestion ? Because the energy of an organ is increased by ilieflow of Hood, which supplies the material of which our organs are composed, and in which the vital essence, supporting life, resides. 880. Why does excess in eating Iring on indigestion ? Because the power of the stomach to digest food is governed by the amount of food required by the system. It seems to be an instinct of the stomach to hold back food which is in excess, and by indications of pain and disturbance to warn its master that excess las been committed. 881. Why is food digested in the stomach ? Because it enters the stomach in the form of a paste, produced by the action of the mouth ; and directly food enters, the gastric juice, which is formed by glands embedded in the coats of the stomach, trickles down its sides. This is a more powerful solvent than the salivary juice it is like the same kind of fluid, only much stronger, and it soon turns the food from a rough and crude paste into a greyish cream (chyme), The heat of the stomach assists the operation, and the muscular threads of the coats move the cream along, in the same manner that the muscles of the esophagus brought do\vn the food. The cream is passed towards the door which leads outward from the stomach (pylorus) ; but if, in the midst of the cream, there are nny undissolved particles of food, it closes upon them, and thej return again to the stomach to be further changed. 882. Why does indigestion Iring on lilious attacfa ? THE SEASON WHY. 205 " "When thou hast eaten and art full, then thoti shalt bless the Lord thy God for the good laud which he hath given thee." DEUT. viu. Because the liver secretes a fluid to assist in the digestion of food. The liver is a gland a similar organ to the glands of the mouth and it forms bile in the same manner that they form the salivary juice. Only the liver is a much larger gland, and a much greater quantity of blood passes through it. The liver pours its secretion into the biliary duct (Fig. 49) to mix with the grey cream as it passes onward, and to further dissolve it. But when the stomach is excited by food which it cannot dissolve, and when the owner of the stomach, disregarding its remonstrances, will persist in over-eating, or in eating things that disagree with the system, then the liver and the stomach sympathise, and the muscular threads, or hands, that prevail all through the alimentary organs, instead of moving omcard, move backward, and throw some bile into the stomach to assist to dissolve and remove the excessive or improper food. CHAPTER XLII. 883. Why does some portion of the food we eat nourish the system, while other portions are useless? Because most food contains some particles that are indigestible, or that, if digested, are innutritions, and not necessary for the system. The liver is the organ by whose secretion the useful is separated from the useless ; for when the bile enters through the duct (Fig. 49) and mixes with the grey cream coming from the stomach, it remains no longer a grey cream, but turns into a mass coloured by bile, having upon its surface little globules ofmilTc, small, but very white. Those minute globules of milk (chyle) are the nutritious particles derived from the food; the other portion, coloured with bile, is the useless residue, or rather the bulk from which the nutrition has been extracted. 884. Why does the milky, or nutritious matter, separate from the innutritious, upon admixture with, bile ? Because the bile contains an oily matter which repels the waterj milk of nutrition. 206 THE KEASOX WHY. ' God hath made of one blood all nations of men for to dwell on all the face at the earth." ACTS xvn. The pancreatic juice also enters through the same duet with the bile. But its precise use is not understood. It is a fluid much like the salivary secretion Of the glands of the mouth. A B. Jugular veins which return blood from the head to the heart. C. The superior vena cava, or trunk vein, which pours the blood returned from the upper part of the system into the heart. There is a similar large vessel which meets this one and brings back blood from the lower part of the body, and they both pour the blood into the right side of the heart. D E. The branches of the venous system which bring back the blood from the arms. F F. The great aorta, the blood vessel which conveys arterial blood from the heart, and gives off branches that supply every part of the body. G. Another large vein which re- turns the blood from the muscles of the chest, &c. H H. The thoracic duct, which re- ceives the newly dissolved food from the small absorbents, that collect it from the intestines. It conveys this nutrition (called chyle) upward along the back; until it reaches where the duct turns into the junction of two veins, and pours its contents into the veins bringing blood back to the heart. The nu- trition, therefore, is at this moment Fig. 50. GBEAT VESSELS op THE mixed with the venous blood, and CIECULATIOK, AND THE DTTCT ig sent to t h e lungs to be OiygCU- WHICH CONVEYS NUTEITIVE . , MATIEE TO THE BLOOD. 885. How is tlie nutrition taJcen away from the Ulious residue ? The muscular threads (or hands, as we figuratively call them) continue to pusL forward the digested matter through a long tube, THE SEASON WHY. 207 ' But now hath God set the members in the body, every one as it pleased him." 1 COEINTHIAJTS XII. called the alimentary canal, or bowels. This canal is some thirtj feet in length, and is folded in various layers across the abdomen, and tied to the edge of a sort of apron, which is gathered up and fastened to the back- bone. All along this alimentary canal those muscular hands are pushing the digested mass along. But upon the coat or surface of the canal there are millions of little vessels called lacteals, which look out for the minute globules of milk as they pass, and absorb them, which means that they pick them up, and carry them away. Thrre is an immense number of these little vessels, all busily at work picking up food for the system. Then there is a large vessel, called the thoracic duct, which comes down and communicates with those little vessels (it is a sort of overseer, having a large number of workmen,) and collects the produce of their toil, and carries it upwards to the part where it passes/row the organs of digestion into the vessels of circulation. 886. What becomes of tlie nutrition, when it has entered the vessels of the circulation ? It is sent through a large vein into the heart, entering that organ on the right side, from which the heart propels it into the lungs, mixed with venous blood ; and the venous, or blue blood, is sent into the lungs, taking with it the milk, the formation of which we have traced. 887. Why are the venous llood and the chyle sent to the lungs ? Because the venous blood, in its circulation through the body, has parted with its oxygen, and taken up carbon, and it requires to get rid of the carbon, and take up more oxygen. The chyle, also, now combined with the blood, requires oxygen, and having obtained it, is converted into bright red blood, and the bine blood of the veins, having got rid of its carbon, which formed the carbonic acid of the breath, has again become bright red blood. We must therefore, in pursuing our description, cease to speak of blue, or venous blood, and of white milk, or chyle, for the two have now combined, and, with the oxygen of the air, have formed arterial Ueod. JOS THE BEA50H WHY. ' My flesh and my heart fainteth ; but God is the strength of my heart, and iny portion for ever." PSAI.M LXXIII. 888. What lecomes of the arterial blood thus formed? It is sent back from the lungs to the right side of the heart, from which it is sent into the great trunk of the aorta, and from thence it passes into smaller blood-vessels, until it finds its way to every part of the system. Fig. 61. THE OBGASrS OB KESPIEATIOIf. A. Thahtart. BB. C. The aorta, and on either side of the aorta the vessels which convey the venous blood to the lungs to be oxygenized, and the corresponding vessels which return it to the heart, after it has undergone that operation. (For aorta see Fig. 50.) D. The trachea, or large air passage, through which the air passes into the spongy texture of the lungs, when we breathe. E E. Arteries and veins, being the trunks of the vessels that supply tho head, &c. 889. Why does the chest expand when we breathe ? Because the lungs consist of millions of hollow tubes, and cells, which, having been emptied by throwing off carbonic acid gas and nitrogen, become compressed, and the atmospheric aw THE SEASON WHY. 209 " Al ! the while my breath is in me, and the spirit of God is in my nostrils, My lips shall not speak wickedness, n^r my tongue utter deceit." JOB xxvu. flowing into these millions of spaces, and filling the lungs, just aa water fills and swells a sponge, causes them to expand, and occupy greater room. 890. How does the blood communicate with the air in the lungs ? Through the sides of very minute vessels, of which, perhaps, a fine hair gives us the best conception. But these vessels are twisted and wound round each other in such a curious manner, that they form millions of cells, and by being twisted and wound, a much greater surface of air and blood are brought to act upon each other, than could otherwise be accomplished. 891. Why does the Hood which is thus formed, impart vitality to the parts to which it is sent ? Because the blood is itself vitalised is, in fact, alive, and capable of diffusing life and vitality to the organisation of which it forms a part. This is a very wonderful fact, but no less true than wonderful, that dead matter which, but a little while ago, was being ground by the teeth, softened by the saliva, and solved by the gastric juice and bile, has now acquired life. Nobody can tell the precise stage or moment when it began to live. But somewhere between the stomach and the lungs, melted by the gastric juice, softened by the secretion of the pancreas, separated by the bile of the liver, macerated by the muscular fibres of the bowels, taken up by the absorbents, warmed by the heat of the body, and aerated in the lungs, it has by one, or by all of these processes combined, been changed from the dead to the living state, and now forms part of the vital fluid of the system. CHAPTER XLIII. 892. Why do we "know that the blood has become endowed with vital powers ? Becav.se, in the course of its formation, it has not only undergone change of cond?.tioa and colour ; but, if examined now by the micro- scope, it will bo found to consist of millions of minute cells, or discs, 210 THE BEASON WHY. "But they that wait upon the Lord shall renew their strength; they shall mount up with wings as eagles ; th^ shall run and not be weary ; and they shall walk and not faint." ISAIAH XL. which float in a watery fluid. The paste produced by mastication con- sisted of a crude admixture of the atoms of food ; the cream (chyme) formed from this in the stomach, presents to the microscope a heterogeneous mass of matter, exhibiting no appearance whatever of a new organic arrangement ; the milk (chyle) which is formed in the intestines is ftund to contain a great number of very small molecules, which probably consist of some fatty matter; as the chyle progresses towards the thoracic duct (Fig. 50), it app3ars to contain more of these, and slight indications present themselves of the approach towards a new organic condition. But wherever vitalisation begins, no human power can say with confidence. Yet there can be no doubt that the blood is both organised and vitalised, and that it consists of corpuscles, or little cells, enclosing matters essential to life. 893. Why does the blood circulate ? Because all the bones, muscles, blood-vessels, nerves, glands, cartilages, &c., of which the body is composed, are constantly under- going a change of substance. It is a condition of their life, health, and strength, that they shall be " renewed," and the blood is the great source of the materials by which the living temple is kept in repair. 894. How is the body renewed by the blood ? Every drop of blood is made up of a large number of corpuscles, each of which contains some of the elements essential to the wants of the system. Let us, to simplify the subject, consider the blood vessels of the body to be so many canals, on the banks of which a number of inhabitants live, and require constant sustenance. The corpuscles of the blood are the boats which are laden with that sustenance, and when the heart beats, it is a signal for them to start on their journey. Away they go through the arch of the great acrta, and some of the earliest branches which it sends off convey blood to the arms. We will now for a moment dismiss the word artery, and keep up the figure of a system of canals, with a number of towns upon their banks. "Well, away go a fleet of boats fhrough the aorta canal, until they reach a point whic!i approaches Shoulder-town ; some of the THB REASON -WHY. 21. Though hand join in hand, the wicked shall not be unpunished ; but the seec of the righteous shall bade irered." PEOVEEBS xxi. boats pass into the axillary canal and Shoulder-town is supplied ; the other boats proceed along the humeral canal until they ap- proach Elbow-town, when another division of the boats pass into other branch canals and supply the wants of the neighbourhood ; the others have passed into the ulnar canals and the radial canals until they have approached Wrist-town and Hand-town, which are respectively supplied ; and then the two canals have formed a junc- tion across the palm and supplied Palm-town, where they have given off branches and boats to supply the four Finger-towns, and Thumb-town. Between A and B the brachial canal, which gives off branches to supply Elbow-town, Ac., and then divides into two main courses, di- verging to the opposite sides of the arm, and sending a smaller canal down the centre. D D. The point where the ulnar canal and the radial canal, after having passed and supplied Wrist- town, form a junction, running through Palm-town, and in their course giving off branches to supply the four Finger-towns and Thumb- town. For further explanations of the engraving, see 57. 895. How does the blood return to the lungs, after it has reached the extremities ? The veins constitute a sys- tem of vessels corresponding to the arteries. We may say that the arteries form tke down canal, and the veins the up canal. The arteries, com- mencing in the great trunk ol the aorta, branch off into larjre and then into -smaller tubes, until they form capillary or Fie. 52. - ILLUSTRATION OP TUB hair-like vessels, penetrating SYSTEM 0V CANALS THAT 8UPPI.T THB FORE-ABU WITH B*ooD. 212 THE SEASON WHY. " As for man his days are as grass ; as a flower of the field so he flourishcth." PSALM cm. The capillary extremities of the arteries, unite with the capillary extremities of the veins, and the blood passes from the one set of vessels into the other. As the arteries become smaller from the point where they receive the blood, so the veins grow larger the venous capillaries, pour their contents into small vessels, and these again into larger ones, until the great venous trunks are reached, and the blood is passed again into the heart as at first described. (Fig. 50.) 896. Why do we see Hue marks upon our arms and lands? Because large veins lie underneath the skin, through which the blood of the fingers and hand is conveyed back to the heart. 897. Why are the veins more perceptible tJian the arteries ? Because the arteries are burie4 deeper in the flesh, for protection. It would be more dangerous to life to sever by accident an artery than a vein. A person might bleed longer from a vein than from an artery, without endangering life ; because the arteries supply the life sustaining blood. The Almighty, therefore, has buried the arteries for safety. 898. Why when we prick the flesh, with a needle does it Heed? Because the capillary arteries and veins are so fine, and are so thickly distributed all over the body, that not even the point of a needle can enter the flesh without penetrating the coats of several of these small vessels. 899. What occurrs during the circulation of the blood ? Not only do the various parts to which the boats are sent take from them whatever they require, but the boats collect all those matters for which those parts have no further use. The bones, the nerves, the muscles, &c., all renew themselves as the boats pass along; and all give something to the boats to bring back. One of the chief exchanges is that of oxygen foi THE EEASON -WHY. 213 "Let every thing that hath breath praise the Lord. Praise ;-e the Lord." PSALM' ct. carbon, by which a gentle heat is diffused throughout the sys- tem. It is for this purpose that fresh air is so constantly necessary. But other exchanges take place. The blood, in addition to oxygen and carbon, contains hydrogen and nitrogen. But it contains its four elements in various forms of combination, producing the following materials for the use of the body : of 1,000 parts of blood, a lout 779 are wafer ; 141 are red globules ; 69 are albumen ; 3 are fibrin; 2 are fatty matter; 6 are various salts. Albumen and fibrin are a kind of flesh imperfectly formed, and probably are chiefly used in repairing the muscles. The red corpuscles contain the oxygen which goes to combine with the superabundant carbon, and develope heat; the fatty matters probably repair the fatty tissues, and glands that are of a fatty nature ; and the various salts contribute to the bones, and to tho chemical properties of those secretions which are formed by the glands, &c., while the great proportion of water is employed in cleansing, softening, and cooling the whole, or the living edifice, and it is the medium through which all the nutrition of the body is distributed. 900. Why do we feel the pulse leat ? Because every time that the heart contracts it send a fresh supply of blood to the blood-vessels, and the motion thus imparted creates a general pulsation throughout the system : but it is more distinctly perceived at the pulse, because there a rather large artery lies near to the surface. 901. What becomes of the matter collected by the blood in the course of its circulation ? We have already explained that carbon is thrown off from the lungs in the form of carbonic acid gas. But there are many other matters to be separated from the venous blood, and its purification is assisted by the action of the liver, which is supplied with a large vein, called the portal vein, which conveys into the substance of the liver, a large proportion of the venous blood, from which that organ draws off those matters which form the bile, and other matters which are transmitted with the bile to the bowels. The live* and 214 THE REASON WHY. " Thy hands have made me and fashioned me : give me understanding, that I may learn thy commandments." PSALM cxix. the lungs, therefore, are the great purifiers of the venous blood. But there are also smaller organs that assist in the same work. Fig. 63. SHOWING THE DISTRIBUTION OF BLOOD THROUGH BRANCHES OB THE AORTA. A. The aorta. B. Branches given off for the aorta to supply one portion of the intestines. C. Branches given off by the aorta to supply other portions of the intestines. A. complete communication maybe traced between these vessels from the origin of one to that of the other. D. The pancreas, or sweetbread, a large gland that forms the pancreatic juice, Which it pours in through the duct. See Fig. 50. E E E. The large intestines, forming tho termination of the alimentary ranal CHAPTER XLIV. 902. Why when we cut our flesh does it foal ? THE REASON WHY. 215 " And God said, Let us make man in our own image, after our likeness ; and let them nave dominion over the fish of the sea, and over the fowl of the air, and over the cattle, and over all the earth, and over every creeping thing." GEN. i. Because the blood coagulates over the cut, and throws out a kind of lymph, which forms an incipient flesh, and excludes the air while the blood-vessels are engaged in repairing the part. 903. Why, since all the substance of the body undergoes change, do we preserve the same features throughout our lives ? Because our substance changes in the minutest atoms ; and each separate atom has a life of itself, the maintenance of which pre- serves the unity and permanence of the whole. 904. Why do moles upon the skin continue permanent, while bruises and wounds disappear ? Because moles are themselves organised formations, and repair themselves just as any other part of the body does. But bruises and wounds are the result of accidental disturbances, which in course of time become removed. 905. Why do the marks of deep cuts sometimes remain? If the cut is so deep and serious as to destroy the system of vessels which supply and repair the part, then it is evident that they cannot work so perfectly as when in their sound condition. Their functions are, therefore, interfered with, and instead of having flesh uniform with the other parts of the system, there results a tear, or a wound imperfectly repaired. 906. Why ivhen we hold our hands against a candle- light do we perceive a beautiful crimson colour ? Because the fluids aud vessels of the body are in some degree transparent, and the thin textures of the sides of the fingers allows the light to pass, and shows the beautiful crimson colour of the blood. If the web of a frog's foot be brought in the field of a good microscope, and set against a strong light, the blood may be seen in circulation, with the most wonderful effect. Each vessel, and every globule of blood, can bo seen most distinctly, and the junction of the arteries and veins can be clearly traced. Tho little boats of nutrition may be seen chasing each other in rapid succession, and when the animal exerts itself to escape, the flow of the blood increases ; and not unfrequently, under these circumstances of agitation, ha\c we seen two or three blood discs struggling together to enter a vessel that was too ! WHT. "Thus saith the Lord God unto these bones, lie-hold I will cause breath to enter into you, and ye shall live: and complicated 'structure of the eyes, and ^supply points of attachment, and grooves, by which the muscles are enabled to turn the eyes freely, and thereby extend the field of vision. 930. WTiy are the bones of the skull arched? Because in that form they acquire greater strength, and heneu the utmost degree of safety is combined with extreme lightness of material. Fig. 54 VIEW OF THE BONES OP TUB THOEAX, OK CHEST, SHOTTING THB PEOTECTIOS AFFOEDED TO THE ORGANS OF CIRCULATION AND BESPIEA- TlOlf. A. The sternum, or breast-bone. B B. The ribs, which rise a little from behind, and fall as they come for- ward, by which they acquire a greater flexibility. CO. The cartilaginous points of the short ribs, by which their exransive and compressive powers are much increased. D E. Part of the vertebral column, or back-bone. 931. Why are the tones of the skull divided ly sutures (seams), with points wliichfit into each other like small teeth ? Because, by that arrangement, concussions of the skull, which might be fatal to the brain, are deadened, and injuries from accident greatly modified. I HE SEASON WHY. 221 "And I will lay the sinews upon you, and will bring up flesh upon you, and cover you with skin, and put breath in you, and ye shall live ; and ye shall know that I am the Lord." EZEKIEL xxivn. 932. Why are the hsart, lungs, fyc., placed within the chest ? Because the functions of those organs require considerable space, while their importance in the system of life, renders it essential that they should be securely protected from tho probabilities of accident. 933. Why are the heart and lungs enclosed for protection in a series of ribs, and not in a close case, like the brain ? Because, by the inflation and contraction of the lungs, their capacity is constantly changing. When man takes a moderate inspiration, he inhales about thirty cubic inches of air, and the lungs increase in size one-eighteenth of their whole capacity. Consequently, were they enclosed in a frame of fixed dimensions, it must needs be, to that extent at least, larger than is necessary, when the frame is made to dilate and contract with the capacity of the lungs. So perfect is the Almighty contrivance, that not only are the ribs made to protect the lungs, but, by their elasticity, and the contrac- tions and dilations of the muscles which lie between them, they assist the lungs in their labours, and work with them in perfect harmony. 934. Why are the bones of the arms, legs, fyc., made hollow ? Because lightness is thereby combined with strength. There is a provision by which, in the extremities of bones, where an enlarged surface is required, lightness is still com- bined with the necessary degree of strength. The bones are made up of & cellular forma- tion; and this generally occurs in parts which are much called into action, in the various movements of the body. A. Lower part of the bone of the thigh. B. Head of the bone of the leg. C. The knee cap, showing its relation to the other THE CELLCLAB STEPC- bones, and the manner in which it is enclosed by the TUBE OP BONE, BT tendons seen at Fig. 58. WHICH LIGHTNESS AND D A pad of f at) lessening the friction of the bones. TAWED. AM B ~ and modifying the shocks produced by jumping, *c. 222 THE EEASOK WHY. * Again he said unto me, Prophesy upon these bones, and say unto them, O jrt dry bones, hear the word of the Lord." EZEKIEL xxxvu. 935. Why are the bones of the arms and legs formed in long shafts ? Because a considerable leverage is gained, by which, the advan- tages of quickness of motion, and increase of mechanical power, are secured. 936. Why are the bones of the hands and feet numerous and small ? Because the motions of the hands and feet are very varied and complicated. There are no less than twenty-eight banes in one hand and wrist; and about as many in a foot and ankle. To these are fastened a great number of ligaments and muscles, by which their varied compound movements are controlled. But for the complexity of the mechanism of our hands and feet, our motions would be extremely awkward, and many of the valuable mechanical inventions which now benefit mankind, could never have been introduced. The bones of the hands and feet are in number equal to one-half of the whole of the bones of the body. CHAPTER XLVI. 937. What are ligaments ? Ligaments consist of bands and cords of a tough, fibrous, and 'tmooth substance, by which the bones are bound together and held in their places, allowing them freedom to move, and supplying smooth surfaces over which they glide. 938. W hy are the joints bound with ligaments ? Because the bones would otherwise be constantly liable to flip from their places. THE REASON WHY. 223 ' That which *.o born of the flesh is flesh ; and that which is born of the Spirit is spirit." JOHN in. 939. What are tendons ? Tendons are long cords, of a substance similar in its nature to cartilage, by which the muscles are attached to the lone*. Fig. 56. SHOWINO A BALL AND SOCKET JOINT, AND THE MANNER IH WHICH LIGAMENTS ABB EMPLOYED TO HOLD BONES IN THEIK POSITIONS. A. The ball, or head of the thigh bone. B. The socket, showing the ligament iu the socket, which holds the head of the bone in its place, but allows it free motion. C. Ligaments tied from bone to bone, giving firmness to the parts. 940. Why are tendons used to attach the muscles to the tones ? Because, by this arrangement, the large muscles by which the extremities are moved, may be placed at some distance from the bones upon which they act, and thus the extremities, instead of being large and clumsy, are small and neat. 941. How many muscles are there in the human body ? There are about four hundred, and forty-six muscles that have been dissected and described, and the actions of which are perfectly understood. But there is probably a much larger number of muscles, and of compound actions of muscles, than the skill of man has been able to recognise. 224 THE EEASON WHY. ' AU flesh is not the same flesh : but there is one kind of flesh of men, another flesh of beasts, another of fishes, and another of birds." COBJN THIANS xvi. 942. What is the consti- tution of a muscle ? Every muscle is made up of a number of parallel fleshy fibres, or threads, which are bound together by a smooth and soft tissue, forming 1 a sheath or case to the muscle, and enabling it to glide freely over the surfaces upon which it moves. A. Lowef extremity of the muscle which draws the fore-arm towards the upper-arm, bends tho elbow, raises the hand to the head, and is powerfully exerted in pulling, lift- ing, &c. C. A muscle which gives off four long tendons, which pass under tho ligaments of the wrist, one to each finger, and by which the fingers are bent upon the palm of the hand, as in grasping, &c. F. Tendon of a muscle which draws the little finger and the thumb towards each other. The ligaments may be seen enfold- the finger-joints, and also crossing the wrist, underneath the tendons. Fig. 57. H-LTTSTEATION OP THH BBLATION OF MUSCLES, TENDONS, AND BONES. The muscles are compressed into tendinous cords at their ends, by which they are united to the bones. They are arranged in pairs, having reciprocal actions each muscle having a companion muscle by which the part which it moves is restored to its original position, when the influence of the first muscle is withdrawn, and the stimulus given to bring back the part. 943. Why can we raise our fingers ? Because muscles which. He on the fore-arm, and have thei THH EEASON WHY. 225 1 Tliou hast clothed me with skin and flesh, and hast fenced me with bones and sinews." JOB xi. tendons fastened at the ends of the fingers, contract, and by becoming shorter, draw the fingers upward, and towards the 944. Why can we throw lack the fingers after they have teen raised? Because the muscles at the back of the arm, whose tendons are attacked to the back of the fingers, contract and restore them to their former positioa. 945. What degree of strength do the muscles possess ? The degree of strength of a muscle depends upon the healthy condition of the muscle, the amount of stimulus which it receives at the time of exertion, and the manner in which its powers are applied. The great muscle of the calf of the leg has been found, when removed from a dead body, to be capable of sustaining a weight equal to seven times the weight of the entire body But the contractile power of the living muscles is very great: the thigh bone has frequently been broken by muscular contractions in fits of epilepsy. And in cases where there has been a dislocation of the thigh, the head ofthe thigh-bone being thrown out of its socket, (Fig. 56) it has been found necessary to employ strong ropes, attached to a wheel turned by several hands, in order to overcome the contraction of the excited muscles, and to enable the operator to restore the bane to its place. 946. What is the stimulus which sets the muscles in action ? The muscles are excited to action by the nerves, which they receive from the spinal cord. 047. Why does it require the influence of the ^oitt to set the arms in motion ? Because the muscles which form their mechanism are voluntary muscles that is, they are subject to the will of man, and j 226 THE REASON WHY. " And he took him by the right iiand, and lifted him up ; and immediately hii feet and ancle bones received strength." ACTS in. enced by impulses directed to them through the nervous system by the mind, which is the governing power. 948. Why does the heart beat without any effort of the will? Because the muscles of the heart are involutary muscles that is, they are independent of the will, and receive a continuous nervous stimulus which is not under the controul of the mind. Fig. 58 MUSCLES AND VES- SELS OP THE LEG AND FOOT. A. A large ligament, which covers the kneo pan, or inoveable bone of the knee, by which the ends of the bones of the thigh and leg are kept from slipping over each other. B. A muscle which passes underneath the cartilages of the ankle, and gives off four ten- dons, which are distributed to the toes, and by which they are extended in elongating the foot, walking, &c. C. Part of the muscle which forms the fleshy bulb of the calf of the leg, and which terminates in the large tendon attached to the heel, called the tendon of Achilles. D. One of the ligaments which bind the tendons and the bones of the ankle. E. Arteries proceeding from the large vessel descending the leg, by which the toes are sup- plied. 949. Why are the muscles of the arms, <$fc., made subject to the con' troul of the icill ? Because, as they supply the mechanism through which we adapt ourselves to our varying wants and circumstances, it was necessary that they should be placed under the controul of the mental poweCj and be moved only in accordance with wans necessities. THE SEASON WHY. 227 * If thou sayest, Behold, we knew it not ; doth not he that pondereth the heart consider it ? and he that keepeth thy soul, doth not he know it ? and shall not he render to every man according to his works ? " PEOVEEBS xxiv. 950. Wliy are the motions of the heart, fyc., made independent of the -will ? Because, as the necessity for the heart's motion is fixed and unalterable, the constant motion of the heart could be best secured by giving it a fixed nervous influence, by which it might be unfailingly prompted to fulfil its functions. If the movements of man's heart were subject to his will, he would be constantly required to regard the operations of that organ ; and so large an amount of mental care and physical exertion would have to be employed hi that direction, that man's sole work would be to keep himself alive. Hence we see the goodness of the Creator in giving life to man, and in keeping the vital impulses under his divine care. CHAPTER XLVII. 951. What are nerves ? The nerves are branches of the brain and the spinal cord ; they are distributed in great numbers to all the active and sensitive parts of the body. 952. What is the spinal cord ? The spinal cord is a long and large cord of nervous matter, which extends from the brain through a continuous tube formed by corresponding hollows in the bones of the back. It serves as a nervous trunk for the distribution of nerves, just as the aorta dis- tributes branches of blood-vessels. 953. Why is the spinal cord placed in the grooves formed ty the back-lone ? Ueing a very vital part of the system, and from the delicacy of its structure liable to injuries, it is set in the back-bone for protection; and so great is its security that it is only by force of au unusual kind tha 4 ; it can bo injured. 228 THE REASON WHY. ' A sound heart ia the life of the flesh : but envy is the rottenness of the bones." PROVERBS xiv. 954. Sow can branches proceed from it, if it is so securely encased in bone ? Because in the bones, on each side of of the spinal cord, there are smaller grooves for the transmission of the nervous branches. 955. Of what does tlie nervous sys- tem consist ? Of the brain, the spinal cord, and the branches which are called nerves. A. B. Veins of the fore-arm. B. Cnnal formed in the muscle, through which a trunk-vein emerges. C. Canal formed in the muscle, through which a large nerve emerges. D. Canal through which a vein enters to communicate with the deep muscles of the arm. 956. What is tie constitution of a nerve ? It consists of a thin membrane, or sheath, surrounding a greyish oily matter, which forms the nervous marrow. In the centre of this marrow is usually found a small fibre, which is supposed to be the essential part of the nerve ; and most nerves consist of a number of these sheaths enclosing fibres running in parallel directions. 957. What is the nervous fluid? The term nervous fluid is used to express our ideas of the mode by which the brain and spinal cord influence the remote parts : just as we say the electric fluid, without knowing that such a fluid exists. It is the most convenient form of expression. 958. Sow many classes of nerves are there f There are : 1. The nerves of motion. 2, The nerves of sensation. 59. SHOWING THB DISTRIBUTION OF NERVES AND VEINS, AND ILLUS- TRATING THE MANNER IN WHICH THEY PASS THROUGH THE FLESH TO REACH THE PARTS TO WHICH THEIR FUNCTIONS BELONG. THE BEASOK WHY. 229 1 Having many things to write unto you, I would not write with paper and ink ; but I trust to come unto you, aud speak face to face, that our joy may be full." n JOHN. 3. The nerves of special sense. 4. The nerves of sympathy. 959. Wliat are the nerves of motion? The nerves of motion are tho9> which, in obedience to the will, ttimulate the muscles to act, and apportion the amount of stimulation they convey to the degree of exertion required. Pig. 60. MUSCLES OP THE HEAD AND FACE, WITH STEHVE3 DISTRIBUTED THEEETO. A A A. The facial nerve emerging from underneath the ear, and distributing branches to the cheeks, temple, forehead, &c. This nerve excites the muscles of the face, and is chiefly instrumental iu producing the expressions of the countenance under the changing emotions of the mind. B 15 B. MMsles by which various motions are imparted to the head, face, tnuth, &c., under the stimulus of the nerves. 960. W hat are the nerves of sensation ? Tlia nerves of sensation are those which impart a consciousness to the brain that its commands to the nerves of motion have been obeyed, and how for they h?ve beeu, fulfilled. 230 THE BEASON WHY. " Oh that men would praise the Lord for his goodness, and for his wonderful works to the children of men." PSALM cvn. Let us perform a simple experiment, which will more clearly illustrate the phenomena of motion and of sensation, which we are now describing, than * great deal of writing upon the subject. You hold in your hand thisi book : close it, and set it upon the table ; lay your hands passively upon your lap, and then will your hand, to take up the book, which is the same as to say, com- mand your hand to take up the book. What occurs ?^ The hand, immediately obeying your desire, stretches forward to the book, and takes hold of it. How do you know that you have hold of it ? You see that yon have : but were your eyes closed, you would be equally aware that the hand had reached the book, and fulfilled your wishes. It is by the nerves of sensation that you are made aware that the hand has fulfilled yoxir instructions. Consider what took place in the simple action. In the first instance, a desire arose in your mind to take up the book. The brain is the organ of the mind ; and having branches either proceeding from itself, or from the spinal cord, to every part of the body branches that traverse like telegraphic wires throughout every part of the system, it transmitted instructions along the nerves that proceed to the muscles of the arm and hand, directing them to take up the book. This was done instantly ; and as soon as it was done you became conscious that your will had been obeyed because the nerves sent back a sen- sation to the brain acquainting it that the book had been taken up, and that at the moment of the dispatch it was in the firm hold of the hand. In all the varied motions of the body this double action of the nerves takes place. It is obvious that without an outward impulse from the brain, upon which the desire of the mind first made an impression, no motion of the mus- cles of the arm and the hand could have taken place ; and it is also obvious that without an inward impulse from the nerves to the brain, you would not have known that the muscles had fulfilled your instructions. The hand might have dropped by the side of the bock, or have gone too far, or not far enough, and you would not have been waare of the result, but for an inward communication through the nervs. We are not now speaking of the nerves which endow us with the sense of feeling ; because they are regarded as separate and distinct from those nerves that produce in us consciousness of muscular response. When we walk, rise, or sit, we are made conscious, without any special feeling being exerted, that the muscles have placed the limb, or the body, in the desired position, that it is set down safely and firmly, and that we may repose upon it securely without further attention. We refer the impressions made by the book upon the nerves of the hand, and which enable us to tell whether it feels hot or cold, whether its surface is rough or smooth, and so on, to the special sense of feeling. The consciousness of muscular action is a separate and distinct function ; and it is generally believed that the same nerves that convey the command of the will outward, bringing back the intimation that the will has been obeyed, but that different fibres of the nerves convey the outward and the inward impulses. A single nerve may therefore be ,'ikened to a double wire connected with the electric telegraph: one transmittii 'g despatches in one direction, and the other iu the opposite direction. 961. What are the nerves of special sense ? The nerves of specisJ. sensj an those thrcugrh which we hear,se0t feel, smell, and taste. THE BEASON WHY. 231 ' For the Lord seeth not as man seeth ; for man looketh on the outward appear- ance, but the Lord looketh on the heart." SAMUEL xvi. 962, What are the nerves of sympathy ? The nerves of sympathy, or the system of sympathetic nerves, are those which are distributed to the internal organs, and which are independent of the will. They regulate the motions of the heart, the lungs, the stomach, &c., and stimulate the organs of secretion, so that those organs work in harmony with. each, other. As the internal organs are all more or less dependent upon each other r and unite their functions for similar ends, it is obvious that there should prevail among them a mutual consciousness of their state. Otherwise, when the stomach had formed chyme, the liver might have no bile ready to fulfil its office ; the absorbents might be in a state of rest at the moment when nutrition was set before them ; and the heart might beat slowly, while the lungs were in active exertion to obtain additional blood to support an active exercise. The sympathetic system of nerves therefore regulates and harmonises these internal functions. CHAPTER XLVIII. 963. Why do we see objects ? Because the light which is reflected from them enters OUT eyes and produces images of their forms upon a membrane of nerves called the retina, just as images are produced upon a mirror. 964. Why does this enable us to see ? Because the membrane which receives the images of objects is connected with the optic nerve which transmits to the brain impres- sions made by the reflections of light, just as other nerves convey the effects of feeling, hearing, tasting, &c. 9G5. Why are ice enabled to move our eyes ? Because various muscles are so placed in relation to the eye- ball, that their contraction draws the eye in the direction required. We are thus enabled to adjust the direction of the eye to the position of the objects we desire to see, in other words to set the mirror in tuck a j osili E. Nerves of tlu palate, showing the manner in which they arc passed through the bones of the roof of the mouth. 993. Why do hairs grow across the passages of the nostrils ? Because they form a defence against the admission of dust and Insects, which would otherwise frequently irritate U - e nc*voua structure of the nose. 99i. Why are the nostrils directed downwards? Because, as odows and effluvia ascend, the nose IB directed THE BEJLSON WHY. 241 " Can that which is unsavoury he eaten without salt ? or is there any taste in the white of an egg ?" JOB T r. towards them, and thereby receives the readiest intimation of tho?e bodies floating in the air which may be pleasurable to the sense, or offensive to the smell, and injurious to life. 995. Why is the nose placed over and near the moutTi f Because, as one of the chief duties ot that organ is to exercise a watchfulness over the purity of the substances we eat and drink, it is placed in that position which enables it to discharge that duty with the greatest readiness. CHAPTER L. 990. Why do we taste ? Because the tongue is endowed with gustatory nerves, having the function of taste as their special sense, just as the optic, the auditory, and the olfactory nerves, have their special duties in the eyes, ears, and nose. 997. Why do some substances taste sweet, others sour, others salt, fyc. ? It is believed that the impressions of taste arise from the various forms of the atoms of matter presented to the nerves of the tongue. 998. Why do we taste substances most satisfactorily after they have remained a little while in the mouth ? Because the nerves of taste are most abundantly distributed to the under surface of the tongue ; and when solid substances have been in the mouth a little while, they impregnate the saliva of the mouth with their particles and come in contact in a fluid solution tcith the gustatory nerves. 999. Why if we put a nub of sugar to the tip of the tongue has it no taste ? Because the gustatory nerves are not distributed to thai part of th( tongue. 342 THE SEASON -WHY. "Wine is a mocker, strong drink is raging; and whosoever is deceived thereby i not wise." PKOVEEBS xx. 1000. Why, when we draw the tongue in, do we recognise the sweetness of the sugar ? Because the dissolved particles of sugar are "brought in contact with the nerves of taste. 1001. TJirough what nerves are we made sensible of the contact of sugar with the tip of the tongue ? Through the nerves of feeling, which are abundantly distributed to the tongue to guide it in its controul over the mastication of food. 1002. Why do conniseurs of wines close their mouths and distend their chins for a few seconds, when tasting wines ? Because they thereby bring the wine in contact with the under surface of the tongue, in which the gustatory nerves chiefly reside. 1003. Why do they also pass the fumes of the wines through their nostrils? Because flavour, in its fullest sense, comprehends not only the taste, but the odour of a substance ; and, therefore, persons of experience attend to both requisites. The various conditions of taste are defined to be : 1. Where sensations of touch are alone produced, as by glass, ice, pebbles, &c. 2. Where, in addition to being felt upon the tongue, the the substance excites sensation in the olfactory nerves, as by lead, tin, copper, &c. 3. Where, besides being felt, there are peculiar sensations of taste, expressive of the properties of bodies, as salt, sugar, tartaric acid, Ac. 4. Where, besides being felt and tasted, there is an odour characteristic of the substance, and essential to the full develope- meut of its flavours, as in cloves, lemon-peel, carriway-seed, and aromatic substances generally. 1004. Why do we feel? Because there are distributed to various parts of the body fine nervous filaments, which have for their special duty the trans- mission to the brain of impressions made upon them by contact with subfctaoces. " Th3 -works of the Lord are great, sought out of all them that have pleasure therein." PSALM cxi. 1005. In what parts of the lody does the sense of touch more especially reside ? In the points of the fingers and in the tongue. By laying a piece of paper upon a table, and upon the paper a piece of cloth, on the piece of cloth a bit of silk, and on the bit of silk a piece of leather, so that the edge of each would be exposed to the extent of half-an-inch, it would be possible by the touch to tell when the finger passed successively over the leather, silk, cloth, or paper, and arrived on the table. Those impressions of touch must have been communicated, with their extremely nice disiinctions, to the sensitive nerves that lie underneath the skin, and must have been transmitted all the way through the arm to the brain, although the touch itself was so light as scarcely to be appreciable with regard to the force applied. A hair lying on the tongue will be plainly perceptible to the touch of the tongue ; and the surface of a broken tooth will often causes the tongue great annoyance, by the acute perception it imparts of the roughness of its surface. The toes are also highly sensitive, though their powers of touch are seldom fully developed. Persons who have lost their arms, how- ever, have brought their feet to be almost as sensitive as fingers. Blind persons increase, by constant exercise, their powers of touch to such a degree that they are able to read freely by passing their fingers over embossed printing ; and they have been known to distinguish colours by differences in their grain, quite unappreciable by other persons. 1006. Why is feeling impaired when the hands are cold ? Because, as the blood flows slowly to the nerves, they are less capable of that perception of touch which is their special sense. The skin contracts upon the nervous filaments, and impairs the contact between them and the bodies which they touch. 1007. Why do the fingers prick and sting when they again become warm ? Because, as the warmth expands the cuticle, and the blood begins to flow more freely through the vessels, the nerves are mad* conscious of the movements of the blood, and continue to be BO until the circulation is equally restored to all the parte. 244 THE REASON "WITT. 1 la the sweat of thy face shalt thou eat bread, till thou return to the ground i for out of it thou wast taken : for dust thou art, and uuto dust shall thou return." GENESIS in. 1008. Why do persons whose legs and arms have been amputated fancy they feel the toes or fingers of the amputated limb ? Because the nervous trunk which formerly conveyed impressions from those extremities remains in the part of the limb attached to the body. The mind has been accustomed to refer the impulses received through that nervous trunk to the extremity where the tensations arose. And now that the nerve has been cut, the painful sensation caused thereby is referred to the extremity which the nerve supplied, and the sufferers for a time appear to continue to feel the part which they have lost. CHAPTER LL 1009. Why do we perspire ? Because the skm is filled with very minute pores, which act as outlets for a portion of the water of the blood, that serves to moisten and cool the surface of the body, and to carry away some of the matter no longer needed in the system. 1010. Sow is the perspiration formed ? By very small glands, which lie embedded in the skin. It is estimated that there are about 2,700,000 perspiratory glands distributed over the surface of the body, and that these glands find outlets for their secretion through no less than seven millions of pores. 1011. What is insensible perspiration ? Insensible perspiration is that transmission of watery particles through the skin which is constantly going on, but whicli takes place so gently that it cannot be perceived. It is, however, very important in its results, as no less than from twenty to thirty- three ounces of water may pass imperceptibly throryh the skin in twenty-four hours. 1012. What is sensible perspiration f THE BEASOJT WHY. 24i 'AndElisha sent a message unto him, saying, Go and wash in Jordan times, and thy flesh shall come again to thee, and thou shalt be clean." ii KINGS v. Sensible perspiration is that moisture which exudes upon the skin in drops larye enough to be perceptible, when the body is heated by exercise or other means. 1013. Why does a sudden change from heat to cold bring on illness ? Because the effect of eold arrestt the action of the vessels of the gkin, and suddenly throws upon the internal organs the excretory labour which the skin should have sustained. 1014. Why does a chill upon the sldn frequently produce inflammation of the lungs ? Because the lungs and the skin together discharge the chief pro- portion of the watery fluid of the body. When the skin's action is checked, the lungs have to throw off a much greater amount of fluid. The lungs, therefore, become over worked, and inflam- matory action sets in. 1015. Why does cleanliness promote health ? Because every atom of dirt which lodges upon the surface of the Body serves to clog and check the working of those minute pores, by which much of the fluid of the body is changed and purified. In the internal parts of the system, the Creator has made ample provision for cleanliness. Every organ is so constituted that it cleanses and lubricates itself. Every surface of the inner body is perfectly clean, and as soft as silk Nature leaves to man the care of those surfaces which are under his immediate observation and controul ; and he who, from idleness, or indifference to nature's laws, is guilty of personal neglect, opposes the evident intentions of the Creator, and must sooner or later pay the penalty of disobedience. 101G. Why does exercise promote health ? Because it assists all the Junctions upon which life depend. It quickens the circulation, and thereby nourishes every part of the body, causing the bones to become firm, and the muscles to become full and healthy. It promotes breathing, by which oxygen is taken into the system, and carban thrown off, and thereby it produces a higher degree of organic Ufa and strength than would otherwise exist. It 246 THE REASON WHY. " Love not sleep lest tliou come to poverty : open thine eyes, and thou shalt b satisfied with bread." PHOV. xx. promotes perspiration, by which, through the millions of pores of the skin, much of the fluid of the body is changed and purified. And it induces that genial and diffused warmth, which is one of tho chief conditions of a high degree of vitality. 1017. Why do we feel fatigue ? Because those organs which stimulate the mechanism of the Dody to act, themselves require rest and repair. When the brain and nerves arrive at that state, they make their condition known to the system generally, by indications which we denominate fatigue. 1018. Why, after rest, do we return invigorated to our labours ? Because the nervous system has accumulated, during the hours of rest, a fresh amount of that vital force which we call the nervous fluid, aud by which the various organs of the body are excited to perfora the duties assigned to them. 1019. What is sleep ? Sleep is understood to be that state of the body in which the relation of the brain to some parts of the body is temporarily suspended. There are some parts of the body that never sleep : such are the heart, the lungs, the organs of circulation, and those parts of the nervous system that direct their operations. But when sleep overtakes the system, it seems as if the relations of those parts under the controul of the will were temporarily suspended ; as if, for instance, those nerves which move the arms, the legs, the eyes, the tongue, &c., were all at once unfastened, just as the strings of an instrument are relaxed by the turning of a key, or the throwing down of a bridge over which they were stretched. "What is meant by the temporary suspension of the relation of the brain to some parts of the body, may be thus explained. Notice a man when ho sits dosing in a chair : at first his head is held up, the brain controlling the muscles of the neck, and keeping the head erect. But drowsiness comes on, the brain begins to withdraw its influence, and the muscles of the neck becoming as it were "unstrung," the head drops down upon the breast. But the sleep is unsound, and disturbed by surrounding noises. The brain is therefore fre- quently excited to return its influence to tho muscles, and draw up the head of THE BBASON- WHY. 247 1 Yet a little sleep, & little slumber, a little folding of the hands to sleep : So shall thy poverty cx>me as one that travelleth ; and thy want s an armed man." PKOVEHBS xxv. the sleeper. He gives a sudden start, every muscle is tightened in an instant, up goes the head, the eyes open, the ears listen, until a feeling of security and composure returns ; the sleep again deepens, the nervous connection is again witlidrawn, and then down drops the head as before. 1020. Why do we dream ? Dreams appear to arise from the excitement of the brain during those hours when its connection with the other parts of the living organism is suspended. For instance : a man dreams that he is pursued by a furious animal, and the mind passes through all the excitement of flying from danger; but tho connection between the moving power, and the machinery of motion being suspended, no motion takes place. The same impressions upon the brain, when the nerves were " strung" to the muscles, would have caused a rapid flight, and a vigorous effort to escape from the apprehended danger. 1021. Why do suppers, when indigestible substances are eaten, produce dreaming ? Probably because, as the digestive organs are oppressed, and those parts of the nervous system which stimulate the organs of digestion are excited by excessive action, those portions of the brain which are not immediately employed by the digestive process are disturbed by that sympathy which is observed to pievail between the relative parts and functions of the body. 1022. Why do we yawn ? Because, as we become weary, the nervous impulses which direct the respiratory movements are enfeebled. It has been said that those movements are involuntary, and that the parts engaged in producing them are not subject to fatigue. But the operation of breathing is, to some extent, voluntary, though when we cease to direct it voluntarily, it is involuntarily continued by organs which know no fatigue. "When, therefore, we feel weary still controuling our breathing in our efforts to move or to speak there frequently arrives a periud when, for a few seconds, the respiratory process is suspended. It seeins to be the point at which the voluntary nerves of respiration arc about to deliver their office over to the involuntary nerves ; bo> * 48 THE SEASON WHY. " Aad it shall be, when they say unto thee, Wherefore sighest thou? that thou shalt answer, For the tidings, because it comethj and every heart shall melt, and all hands shall be feeble." EZEKIEL xxi. the pause in the respiration has caused a momentary deficiency of breath, and the involuntary nerves of respiration, coming suddenly lo the aid of the lungs, cause a spasmodic action of the parts involved, and a yawn, attended by a deep inspiration to compensate for the cessation of breathing, are the result. 1023. Why do we cough ? Because the respiratory organs are excited by the presence of E07ne body foreign or unnatural to them. A cough is an effort on the purt of the air tubes to free themselves from some source of irritation. And so important are the organs of breathing to the welfare of the body, that the muscles of the chest, back, and abdomen, unite in the endeavour to get rid of the exciting substance. 1024. Why do toe sneeze ? Because particles of matter enter the nostrils and excite the nerves of feeling and of smell. In sneezing, as in coughing, the effort is to free the parts affected from the intrusion of some matters of an objectionable nature. And in this case, as in the former one, there is a very general sympathy of other organs with the part affected, and an energetic effort to get rid of the evil. 1025. Why do we sigh ? Tha action of sighing arises from very similar causes to those of yawning. But in sighing, the nervous depression is caused by grief; while in yawning, it is the result of fatigue. In sighing, the effect is generally caused by an expiration in yawning by an inspiration. The mind, wearied and weakened by sorrow, omits for a few seconds to continue the respiratory process ; and then suddenly there comes an involuntary expiration of the breath, causing a faint sound as it passes the organs of the voice. 1020. W hy do we laugh ? Laughing is caused by the very opposite influences that produce sighing. The nervous system is highly excited by some external cause. The impression is so intense, and the mind so fixed upon it, that the respiratory process is irresrular, and uncontrolled. Person* THE REASON WHY. 249 1 Except ye utter by tho tongue words easy to be understood, how shall it be known, what is spoken? for ye shall speak into the air." CORINTH, xiv. excited to a fit of laughter generally hold their breath until they can hold it no longer, and then suddenly there is a quick expiration causing eccentric sounds, the mind being too intently fixed upon the cause of excrement, either to moderate the sounds, or to controul the breathing. 1027. Why do we hiccough ? Hiccough is caused by a spasmodic twitching of the diaphragm, & thin muscular membrane which divides the chest from the abdomen. It generally arises from sympathy with the stomach ; nnd it is highly probable that the muscular twitches and jerks are so many efforts on the part of the diaphragm to atsist tJie stomach to get rid of some undigested matter. 1028. Why do we snore ? Snoring is caused by air sweeping through the passages that lead from the mouth through the nostrils, and which, in our waking moments, are capable of certain muscular modifications to adapt them to our breathing. But as in sleeping the nervous controul over them is withdrawn, they are left to the action of the air which, in sweeping by them, sets them in vibration. "We have endeavoured, by the employment of the simplest language, and by reference to some of the most familiar phenomena of nature, to impart to the reader a clear conception of those sublime laws which controul our being, and afford evidence of the goodness and power of that Almighty God to whom we are indebted for the life that we enjoy, and the varied and beautiful existences which, to the rightly constituted mind, make the earth a vast aggregation of interesting objects. We will now, before we pass on to the final section of our work, review some of the more important facts that have been communicated, and devote a few pages to meditations upon the formation of the human body that wonderful temple of which each of us is a tenant. We have described man's organisation. What is that organisation for 1 It is to make use of tlie elements upon which man exists. The lungs make use of the air; the eye makes use of the light; the stomach, and the system generally, make use of water ; every part of the body uses heat ; and all parts of the sys- tem demand food. The hand feeds as constantly as the mouth. The mouth is the receptacle of food, by which the body is to be fed ; the stomach is the kite-hen in which food is prepared for the use of the body ; arid the blood-vessels are the canals through which the food is sent to those members of the body that are in need of it. When we speak Df man's "organs" or "members," we speak of those parts of the living machinery by which the elements are used up, or employed, for man's benefit. And this view of the subject, bearing in mind that the body is held together as the temple of a living Spirit, superior to mere flesh and blood, gives us a higher and clearer perception of the distinction ir 250 THE BEASON WHY. 1 Not unto us, O Lord, not unto us, but unto thy name give glory, for thy mercy, and for thy truth's sake." -PSALM: cxv. between the body and the soul than that which we might otherwise entertain. The body is a machine, working for the spirit, which is its owner. While the machine works, the spirit directs and \*fluences its actions. But when the machine stops, the spirit resigns its pow*r overaruined temple, quits it, and flies to a region where, as a spirit, it becomes subject to a new order of existence consistent with its severance from earthly things and laws, and there it enters upon its eternal destiny, according to the judgments and appointments of God. It is no longer dependent upon a relation between spiritual and material laws. Suppose that the air which man breathes, instead of returning from his lungs clear and imperceptible to sight, were tinged with colour; we should sec, that every time a man breathed, the air would rush in a stream into his mouth, and then return again ; and the air which returned would, being warm, be lighter than the outer air, and would rise upward over the man's head, who: e, cooling and mingling with the outer air, it would descend again. We do, in fact, see this action evidenced; when in wintertime the cold condenses the vapour of the breath, we see the little cloud constantly rising before the breather's face, and dispersing in the surrounding air. Is it not a wonderful thing that that clear and elastic substance, which you cannot feel, though it touches every part of your body, and which you cannot see, is composed of two distinct bodies, having very different properties ; and that the two bodies can easily be separated from each other? Air is of the first importance to life. Hence it is provided for us every- where. We require air every second, water every few hours, and food at inter- vals considerably apart. Air is therefore provided for us everywhere. Whether we stand or sit ; whether we dwell in a valley or upon a mountain j whether we go into the cellar under our house, or into the garret at the top of it, air is there provided for us. God, who made ii a law that man should breathe to live, also sent him air bundantly, that he might comply with that law. And all that is required from man in this respect is, that he will not shut out God's bounty, but receive it freely. As we have employed the idea that if the air were coloured we should have the opportunity of marking the process of breathing, let us enlarge upon this, arid suppose that every time the air were returned from the lungs it became of a darker colour, the darkness denoting increasing impurity. If we placed a man in a room full of pure air, we should see the air enter his lungs, and sent back slightly tinged; but this would disperse itself with the other air of the room and scarcely be perceptible. As the man continued to breathe, however, each moasuro of air returning from the lungs would serve to pollute that abiding in the room, until at last the whole mass would become cloudy and discoloured, and we should see such a change as occurs when water is turned from a pure and clear stato into a muddy condition. The air docs become polluted with each respiration, and although it is colourless, it is as impure as if with every breath given off from the lungs it becamu of a dark colour in proportion to its impurity. Thus wo see how important it is that we should provide ourselves with pure air , and tnat, in seeking warmth and comfort in our houses, we should provide an adequate supply of fresh atmosphere because it is more vital to life than either water or food. Indeed, so cons-.ant is our requirement of xz, that if we had to fetch it, fat THE REASON WHY. 251 'There is a natural body, and there is a spiritual body." i COEIITTHIAKS XT. purposes of breathing, or simply to raise it to our mouths, as vi do water when we drink, it would be tiie sole occupation of our lives we could do nothing else. For this reason, God has sent the air to us, and not required us to go to the air. And the great error of man is, that in too many instances, he shuts off the supply from himself, and brings on disease and pain by inlialing a poisonous compound, instead of air of a healthful kind, which bears an adaptation to the wants of life. Whilst the rooms of our house are filled with air, it is otherwise with water, which we require in less degree than air. If we have not the artificial means by which water is brought to our houses, through th , pipes of a water company, there is a spring or a pump in the garden ; or in the absence of these, a good sound cask, standing at the end of our house, forming a* receptacle to the water-pipes that surround it, provides us with a supply of water distilled from the clouds. If we were to drink a good draught of water once a day, that would be sufficient for all the purposes of life, as far as regards the alimentary uses of water. Man is, therefore, allowed to go to the stream for his drink, and is required to raise it to his lips at those moments when he uses it. Although, in breathing, man separates the oxygen, of the air from the nitrogen, thereof, he does not separate the oxygen of the water from the hydrogen Water, in fact, undergoes no change in the body, excepting that of admixture with the substances of the body. And its uses are, to moisten, to cool, to cleanse, and also to nourish the parts with which it comes in contact. But it afford.-, no nourishment of itself; it mixes with the blood, of which it forms a material part, and is the means of conveying the nourishment of the blood to every part of the system. After it lias filled this office, and taken up impurities that required to be removed, it is cast out of the system again, without undergoing any chemical change. Man's body is to his Soul, in many respects, what a house is to its occupant. But how superior is the dwelling which God erected, to that which man has built. Reader, come out of yourself, and in imagination realise the abstraction of the Soul from the body. Make an effort of thought, and do not relinquish that effort, until you fancy that you see your image seated on a chair before you. And now proceed to ask yourself certain questions respecting your bodily tenement questions which, perchance, have never occurred to you before ; but which will impress themselves the more forcibly upon you, in proportion as you realise for a moment the idea of jour Soul examining the body which it inhabits. There sits before you a form of exquisite proportions, with reference to the mode of life it has to pursue the wauts of the Soul for which it has to care, and which it has to guard, under the direction of that Soul, its owner and master. Over the brows that mark the intellectual front of that fine form, there fall the auburn locks of youth, or the grey hair of venerable age. Each of those hairs is curiously organised. If you take a branch of a tree, and cui it across, you will find curious markings caused by vessels of various tructure, all necessary to the existence of the plant. In the centre will bo found cither a hollow tube, or a space occupied by a soft substance called pith. Each hair of your head is as curiously formed as the branch of a tree, and in a manner not dissimilar, though its parts are so minute that the unaided eye cannot discern them. Every hair has a. root, just as a tree ha, and through this root it receives its nourishment. As tlw ve*jfi 252 THE BEASON WHY. " The very hairs of your head are all numbered." MATTHEW n. which feed a plant are always proportionate to the size of the plant itse'f, how fine must be those vessels which form the roots of the hair, being in proportion to the size of the hair, which is in itself so small that the eye cannot see its structure? Tho hair is, in fact, an animal plant, growing upon the body in much the same mariner that plants grow upon the surface of tho earth. But how does this hair grow? Not alone by the addition of matter at its roots, pushing up and enlongating its stem : nourishment passes up through its whole length, and is deposited upon its end, just as the nourishment of a tree is deposited upon its extreme branches. If, after having your hair cut, you were to examine its ends by the microscope, you would discover the abrupt termination left by the scissors. But allow the hair to grow, ahd then examine it, and you will discover that it grows from its point which, in comparison with its former state, is perfect and fine. The reason why th'! beard is so hard is, that the ends of the hair are continually being lhaved off. The hair of the beard, if allowed to grow, would become almost as toft as the hair of the head. But why is man's head thus covered with hair? For precisely the same reason that a house is thtched-to keep the inmates warm. We might add, also, to give beauty to the edifice. But as beauty is a conventional quality and if men were without it they would consider themselves quite as handsome as they do now we will not enlarge upon the argument. Our bald-headed friends, too, might have reason to complain of such a partial hypothesis. Tho brain is the great organ upon which the health, the welfare, and the happiness of the system depends. The skull, therefore, may be regarded as analagous to the " strong box," the iron chest in which tho merchant keeps his treasure. There is no point at which the brain can be touched to its injnry, without first doing violence to the skull. Even the spinal cord runs down the back through a tunnel or tube, formed in a number of strong bones, so closely and firmly jointed together, that they are commonly termed " tho back-bone." Look at the eyebrows. "What purpose do they fulfil ? Precisely that of a shed, or arch placed over a window to shelter it from ra : n. But for the eye- brows the perspiration would frequently run from the brow into the eyes, and obscure the sight ; a man walking in a shower of rain would scarcely be able to sec ; and a mariner in a storm would find a doublo difficulty in braving the tempest. Now we come to the eye, which is the window of the Soul's abode. And what a window ! how curiously constructed 1 how wisely guarded ! In the eyelashes, as well as the eyebrows, we see the hair fulfilling a useful purpose, differng from any already described. The eyelashes serve to keep cold winds, dust, and too bright sun, from injuring or entering the windows of the body. When we walk against tho cash wind, we bring the tips of our eyelashes together, and iu that way exclude the cold air from the surface of the eye ; and in the samo manner we exclude the dust and modify the light. The eyelashes, therefore, are like so many sentries, constantly moving to and fro, protec ing a most important organ from injury. The eyelids are the shutters by which the \VMJ<.I \v--i are opened and closed. But they al-o cleanse the eye, kecring it bright and moist. There are, moreover, in the lids of each eye or window, little glands, or springs, by which a clear fluid is formed and supplied for cleansing the eye The eye is placed in a socket of the skull, in which it has free motiou, turning rifffctorleft, up or down, to serve the purpose of ti* THE REASON WHY. 253 "Thou art of purer eyes than to behold evil, and canst not look on iniquity." HABAKKUK i. inhabitant of tho dwelling. Of the structure of the eye itself we will not say much, for the engravings will afford a clearer understanding than a lengthy written description. But we would have you examine the formation of the iris of the living eye, the ring which surrounds the pupil. Hold a light to it, and you w:ll find that the iris will contract and diminish the pupil; withdraw t-ho light, and the iris will relax, and the pupil expand, thus regulating the amount of light. The images of external objects are formed upon the retina of the eye, a thin membrane, spread out upon the extremity of a large nerve, which proceeds immediately to the brain, and forms the tek-graphic cord by which information is given to the niind, of everything visible going on within the range of sight. Now, think for a few moments upon the wonderful structure of those windows of the body. Can you fancy, in the walls of your house, a window which protects itself, cleanses itself, and turns in any direction at the mere will of the tenant ; and when that tenant is oppressed by excess of light, draws its own curtain, and gives him ease ; and when he falls asleep, closes its own shutters, and protects itself from the cold and dust of night, and the instant he awakes in the morning, opens, cleanses itself with a fluid which it has prepared during the night, and kept in readiness ; and repeats this routine of duty day after day for half a century, without becoming impaired ? Such, nevertheless, is the wonderful structure of the window of the body the eye. In some scientific works that have recently been published, curious investiga- tions have been made known. It has been shown that the eye is impressed momentarily, as a photographic 1 plate is impressed by the rays of the sun. But the photography of the eye has this extraordinary quality that one image passes away, and another takes its place immediately, without confusion or indistinctness. But the most wonderful assertion of all is, that under the excitement of memory these photographic images are restored ; and that when ) " in our mind's eye," we see the image of some dear departed friend, the retina really revives an image which once fell upon its sensitive surface, and which image has been stored up for many years in the sacred portfolio of its affections ! Another extraordinary assertion is one which comes supported by a degree of authencity that entitles it to consideration. It is said that the eye of a dead man retains an impression of the last picture that fell upon the faithful retina. Dr. Sandford, of America, examined the eye of a man named Beardley, who had been murdered at Auburn, and he published in the Boston Atlas the following statement : " At first we suggested the saturation of the eye in a weak solution of atrophine, which evidently produced an enlarged state of the pupil. On observing this, we touched the end of the optic nerve with the extract, when tho cyo instantly became protuberant. We now applied a powerful lens, and discovered in the pupil, the rude, wrn-away figure of a man, with a li.ht coat, beside whom was a round stone, standing or suspended in the air, with a small hand e, stuck in the earth. The remainder was debris, evidently lost fro> the destruction of the optic, and its separation from the mother brain. Had we performed the operation when the eye was entire in the socket, with all its powerful connection with the brain, there is not the least doubt but that we should have detected the last idea and impression made ou the mind and eyt. of the unfortunate ff.an. The picture would evidently be entire ; and perhaps we hould have hod tha joutour. or better sfcill, the exact figure of the murder**- 254 TITE REASON TVIIY. Be not rash with thy mouth, am 1 , let not thine heart bo hasty to utter anything before God : for God is iu heaven, and thou upon earth ; therefore let thy words be few." ECCLESIASTES v. The last impression on the brain before death is always more terrible from fear than any other cause, and figures impressed on the pupil more distinct, which w attribute to the largeness of the optic nerve, and its free communication with the brain." "Whether the supposition, which seems to be supported by the experiment above detailed, be correct or not, it is in no sense more wonderful than the facts which are already known respecting this curious and perfect organ. The nose is given us for two purposes to enable us to respire and to smell. As odours arise from the surface of the earth, the cup or funnel of the nose is turned down to meet them. In the nostrils hair again serves a useful purpose. It not only warms the air which enters the nostrils, but it springs out from all sides, and forms an intersecting net, closing the nostrils against dust, and the intrusion of small insects. If by any means, as when taking a sharp sniff, foreign matters enter the nostrils, the nose is armed with a set of nerves which communicate the fact to certain muscles, und the organs of respiration unite with those muscles to expel the intruding substances. In this action, the diaphragm, or the muscle which divides the abdomen from the chest, is pressed down, the lungs are filled with air, the passage by which that *ir would otherwise escape through the mouth, is closed up, and then, all at once, with considerable force, the air is pressed through the nostrils, to free them from the annoying substance. So great is the force with which this action takes place, that the passage into the mouth is generally pushed open occasioning the person in whom the action takes place, to cry " "tsha !" and thus is formed what is termed a sneeze. As with the eye, so with the nose- innumerable nerves are distributed over the lining membrane, and these nerves are connected with larger nerves passing to the brain, through which everything relating to the sense of smell is communicated. The nose acts like a custom-house officer to the system. It is highly sensitive to the odour of most poisonous substances. It readily detects hemlock, henbane, monk's hood, and the plants containing prussic acid. It recognises the foeted smell of drains, and warns us not to breathe the polluted air. The nose is so sensitive, that air containing a 200,000th part of bromine vapour will instantly be detected by it. It will recognise the 1,300,000th part of a grain of otto of roses, or the 13,000,000th part of a grain of musk ! It tells us in the mornings that our bed-rooms are impure ; it catches the first fragrance of the morning air, and conveys to us the invitation of the flowers to go forth into the fields, and inhale their sweet breath. To be "led by the nose," has hitherto been used as a phrase of reproach. But to have a good nose, and to follow its guidance, is one of the safest and shortest ways to the enjoyment of health. The mouth answers the fourfold purpose of the organ of taste, of sound, of mastication, and of breathing. In all of these operations, except in breathing, the various parts of the mouth are engaged. In eating we use the lips, the tongue, and the teeth. The teeth serve the purpose of grinding the food, the tongue turns it during the process of grinding, and delivers it up to the throat for the purposes of the stomach, when sufficiently masticated. The lips serve tc confine the food in the mouth, and assist in swallowing it, and there are glands underneath the tongue, and in the sides of the mouth, which pour in a fluid to moisten the food. And so watchful are those glands of 1 heir duty, that the mer Imagination frcque ttl? causes tl.cm to act. Their fluid is required to modity THE EEASOy \VHY. 255 'I Off unto you, Swear not at all; neither by heaven, for it is God's throne ; Nor by the earth ; for it is his footstool." MATTHEW V. the intensity of different flavours and condiments in which man, with his love ol eating, will indulge. Thus, when we eat anything very acid, as a lemon, or any- thing very irritating, as Cayenne pepper, the effect thereof upon the sensitive nerves of the tongue is greatly modified by a free flow of saliva into the mouth. And if wo merely fancy the taste of any such things, those glands are so watch ful, that they will immediately pour out their fluid to mitigate the supposed effect. In speaking, we use the lips, the teeth, the tongue; and the chest supplies air, which, being controlled in its emission, by a delicate apparatus at the mouth of the wind-pipe, causes the various sounds which we ha7e arranged into speech, and by which, under certain laws, we are enabled to understand each other's wants, paiticipate in each other's emotions, express our loves, our hopes, our fears, and glean those facts, the accumulation of which constitutes know- ledge, enhances the happiness of man, and elevates him, in its ultimate results above the lower creatures to which the blessing of speech is denied. The curious structure of the tongue, and the organs of speech, would fill a very interesting volume. The tongue is unfortunately much abused, not only by those who utter foul words, and convert the blessing of speech, which should improve and refine, into a source of wicked and profane language ; but it constantly remonstrates against the abuse of food, and the use of tilings which are not only unnecessary for the good of our bodies, but prejudicial to their health. When the body is sufficiently fed, the tongue ceases its relish, and derives no more satisfaction from eating: but man contrives a variety of inven- tions to whip the tongue up to an unnatural performance of its duty, and thus we not only over-eat, but eat things that have no more business in our stomachs, than have the stones that we walk upon. Can we wonder, then, that disease is so prevalent, and that death calls fur many of us so soon. That wonderful essence, the Soul of man, rises above all finite knowledge. Its wonders and powers will never, probably, be understood until when, in a future state of existence, the grandest of all mysteries shall be explained. When we talk of the brain, we speak of that which it is easy to comprehend as the organ, or the seat of the mind ; when we speak of the mind, we have greater difficulty in comprehending the meaning of the term we employ ; but when we speak of the Soul, we have reached a point which defies our under- standing, because our knowledge is limited. The brain may be injured by a blow ; the mind may be pained by a disagreeable sight, or offended by a harsh word ; but the Soul can only be influenced secondarily through the mind, which is primarily affected by the organs of the material senses. Thus the hap- piness or the misery of the Soul dej>cnds to a very great extent upon the proper fulfilment of the duties of the senses, which are the servants of tho Soul, over which the mind presides, as the stewaidwho mediates between the employer and the employed. The Ear, which is taught to delight in sweet sounds, and in pure language, is a better servant of the master Soul, than one which delights not iu music, and which listens, with approbation or indifference, to the oaths of the profane. The Eye which rejoices in the beauties of nature, and in scenes of domestic happiness and love, is a more faithful servant than one that delights in wit- neising scenes of revelry, dissipation, and strife. The Nose which esteems the iweet odour of flowers, or the life-giving freshness of the pure ah*, is more dutiful to his master than one that rejects not the polluted atmosphere a* 256 THE BEASOS WHY. "Out of the same mouth proeeedeth blessing and cursing. My brethren, these things ought not so to be." JJLMES III. neglected dwellings. The Month which thirsts for morbid gratification of taste, is more worthless than one which is contented with wholesome viands, and ruled by the proper instincts of its duty. "Who that can understand the wonderful structure of the tongue, and the complicated mechanism cf the organs of speech and of hearing, could be found to take pleasure in the utter- ance of oaths, and of words of vulgar meaning? Were those beautiful cords that like threads of silk are woven into the muscular texture of the mouth, and along which the essence of life travels with the quickness of thought, to do the bidding of the will were they given for no higher use than to sin against the God who gave thn, and upon whose mercy their existence every moment depends? The actions of the senses must necessarily affect the mind, which is the head steward of the Soul ; and the Soul becomes rich in goodness, or poor in sin, in proportion as the stewardship, held by his many servants, is rightly or wrong- fully fulfilled. As in an establishment where the servants are not properly directed and ruled, they often gain the ascendancy, and the master has no power over them, so with man, when he gives himself up to sensual indulgences. The Soul becomes the slave of the senses the master is controlled \y the sen-ants. "\Tith regard to the mechanism of motion, let us take the case of a man who is walking a crowded thoroughfare, and we shall see how active are all the servants of the Soul, under the influence of the mind. He walks along in a riven direction. But for the act of volition in the mind, not a muscle would stir. The eye is watching his footsteps. There is a stone in his path, the eye informs the mind, the mind communicates with the brain, and the nerves stimulate the muscles of the leg to lift the foot a little higher, or turn it on one side, and the stone is avoided. The eye alights on a familiar face, and the mind remembers that the eye has seen that face before. The man goes on thinking of the circumstance under which he saw that person, and partially forgets bis walk, and the direction of his steps. But the nerves of Tolition and motion unite to keep the muscles up to their work, and he walks on without having occasion to think continually, " I must continue walking." He has not to make an effort to lift his leg along between each interval of medi- tation : he walks and meditates the while. Presently a danger approaches him from behind. The eye sees it not knows no more, in fact, than if it were dead. But the ear sounds the alarm, tells the man, by the rumbling of a wheel, and the tramp of horses' feet, that he is in danger; and then the nerves, putting forth their utmost strength, whip the musclfs up to the quick performance of their duty ; the man steps out of the .ray of danger, and b saved. He draws near to a sewer, which is vomiting forth its poisonous exhalations. The eye is again unconscious it cannot see the poison lurking in the air. The ear, too, is helpless ; it cannot bear witness to the presence of that ent-my to life. But the nosedefrc s the noxious agent, and then the ere points out the direction of the sewer, and guides nis footsteps to a path where he may escape the injurious consequences. A clock strikes, the ear informs him that it is the hour of an %ppoiutment; the nerves stimulate the muscles again, and he is hastened nward. He does not know the residence of his friend, but his tongue a&ks fo- him, and his ear makes known the reply. He reaches the spot sits-rc.-ts. The action of the muscks is stayed ; the nerves are for a time time at rest. Th blood which had flown freely to feed the muscles while they were working THE BEASOy WHY. 257 " I am but a little child : I know not how to go out or come in." i KIUGS in. goes more steadily through the arteries and veins, and the lungs, which had been purifying the blood 111 its course, partake of the temporary rest. Let us rememter that there are two sets of muscles, acting in unison with epxh other, to produce the various motions ; they are known by the general terms of flexors and extensors ; the first enable jis to bend the limbs, the other to bring the limbs back to their former position. The flexors enable us to close the hand, the extensors to open it again. The flexors enable us to raise the foot from the ground the extensors set the foot down again in the place desired. Consider for a moment the nicety with which the powers of these muscles must be balanced, and the harmony which must subsist between them in their various operations. When we are closing the hand, if the extensor muscles did not gradually yield to the flexors if they gave up their hold all at once, tha hand, instead of closing with gentleness and ease, would be jerked together in a sudden and most uncomfortable manner. If, in such a case, you were to lay your hand with its back upon the table, and wish to close the hand, the fingers would fall down upon the palm suddenly, like the lid of a box. Again, consider how awkward it would be in such a case ; our walk through the streets would become a series of jumps and jerks ; when a man had raised his foot, after it had been jerked up, there it would stand fixed for a second before the opposite muscles could put on their power to draw it down again. This case is not at all suppositious : there is a derangement frequently observed in horses, iu which one set of muscles becomes injured, and we may see horses suffering from this ailment, trotting along with one of their legs jerking up much higher than the others, and set down again with difficulty, just in the manner described. It is also to be observed that very nice proportions must exist between the sizes of the muscles and the s^es of the bones. If this were not the case, our motions, instead of being firm and steady, would be all shaky and uncertain. In old persons the muscles become weak and relaxed ; hence there is a tendency in the movements of the aged to fall, as it were, together ; the head is no longer erect, the body bends, the knees totter, and the arms lean towards the body as for support. In the child a somewhat similar state of things exists. The muscles have not been properly developed, nor have they been brought sufficiently under the controul of the nervous system. The child, therefore, totters and tumbles about, and it is not until it has stumbled and tumbled some hundreds of times in its little history, that the muscles have become strong enough to fulfil their office, or have been brought sufficiently under the controul of the nervous system, to perform well the various duties required from them. In all these things, we recognise the perfection of the. divine works. We are apt, too apt, to overlook this perfection, because it prevails in everything; but by speculating upon what inconveniences we might suffer, were not things ordained as they are, we obtain most convincing evidences of divine goodness und wisdom. Having taken this view of the muscular system of the external man, let us turn our attention to the muscles of the internal organs. The muscles of whicJ* we have been speaking are called the voluntary muscles, because we have them under our own controul they are subject to the influences of our will. But there is the other set of muscles. STiat are they I W talk of the beating, or o 258 THZ BEASON WHY. " Watchman, whab of the night? The watchman said, The morning comctb, and also the uight if ye will enquire, enquire ye ; return, come." ISAIAH xxi. the pal}. Uation, of the heart. But, what is it that causes the heart to beat ? You cannot, ifyou wish it, make your heart beat more quickly or more slowly. Place your finger upon your pulse, and notice the degree of rapidity with which its pulsations follow. Now think that you should like to double the frequency of those pulsations. Say to the heart, with your inner voice, that you wish it to beat 120 times iu a minute, instead of 60. It does not obey you ; it does not appreciate your command. Now place your finger on the table, and your watch by the side of your hand, and tell your finger to beat 60 times in the minute, or 100 times, or 150 times, or 200 times, and the finger will obey you because it is moved by muscles which are subject to the will, while the heart is composed of muscles which are not subject to the will. Why should this be ? Why should man have the power to regulate his finger, and not to regulate his heart ? For the sustentatiou of our bodies it is needful that the blood should ever be in circulation. If the heart were to cease beating only for three or four minutes (perhaps less) life would be extinct. In this short time the whole framework of man, beautiful in its proportions, perfect in its parts, would pass into the state of dead matter, and would simply wait the decay that follows death. The eye would become dull and glazed, the lips would turn blue, the skin would acquire the coldness of clay love, hope, joy, would all cease. The sweetest, the fondest ties would be broken. Flowers might bloom, and yield their fragrance, but they would be neither seen nor smelt ; the sun might rise in its brightest splendour, yet the eye would not be sensitive to its rays ; the rosy-cheeked child might climb the paternal knee ; but there, stiff, cold, without joy, or pain, or emotion of any kind, unconscious as a block of marble, would sit the man whose heart for a few moments had ceased to beat. How wise, then, and how good of God, that he has not placed this vital organ under our own care ! How sudden would be our bereavements how frequent our deaths, how sleepless our nights, and how anxious our days, if we had to keep our own hearts at work, and death the penalty of neglect. And yet, before we were born, until we reach life's latest moment through days of toil, and nights of rest even in the moments of our deepest sin against the God who at the time is sustaining us, our hearts beat on, never stopping, never wearying, never asking rest. This brings us to another reflection. Our arms get weary, our legs falter from fatigue, the mind itself becomes overtaxed, and all our senses fall to sleep. The eye sees not, the ear is deaf to sound, the sentinels that surround the body, the nerves of touch, are all asleep you may place your hand upon the brow of the sleeping man, and he feels it not. Yet, unseen, unheard, without perceptible motion, or the slightest jar to mar the rest of the sleeper, the heart beats on, and on, and on. As his sleep deepens, the heart slackens its speed, that his rest may be the more sound. He has slept for eight hours, and t lie time approaches for his awakening. But is the heart weary that heart which has toiled through the long and sluggard night ? No ! The moment the waking leeper moves his arm, the heart is aware that a motion has been made, that effort and exercise are about to begin. The nerves are all arousing to action; the eyes turn in thevr sockets, the head moves upon the neck; the sleeper leaves his couch, and the legs are once more called upon to bear the weight of the body. Blood is the food of the eye, the food of the ear, of the foot, the hand, and every member of the frame. Wliile they labour they must be fed that v THE REASON WHY. 259 'Awake up, iny glory ; awake, psaltery and harp : I myself will awake early." PSALM LVII. the condition of their life, the source of their strength. The heart, therefore, BO far from seeking rest, is all fresh and vigorous for the labours of the day, and proceeds to discharge its duty so willingly, that we do not even know of the movements that are going on within us. Thus we have seen the difference between the voluntary and the involuntary muscles, and we have perceived the goodness of our Creator in not entrusting to our keeping the controul of an organ so vital to life, as the heart. But the heart is not the only organ which thus works unseen and unfelt. There are the lungs and the muscles of the chest, the stomach, and other parts occupying the abdomen, together with all those muscular filaments which enter into tho structura of the coats and valves of the blood-vessels, and which assist to propel the blood through the system. All these are at work at every moment of man's life ; and yet, so perfect is this complicated machinery, that we really do not know, except by theory, what is going on within us. During the time that the sleeper has been at rest, the stomach has been at work digesting the food which was last eaten. Then the stomach has passed the macerated food into the alimentary canal, the liver has poured out its secretion, and produced certain changes in the condition of the dissolved food : and tho lacteals, of which there may be many thousands, perhaps millions, have been busy sucking up those portions of the food which they knew to be useful to the system, whilst they have rejected all those useless and noxious matters upon which the liver, like an officer of health, had set his mark, as unfitting for the public use. This busy life has gone on uninterruptedly ; every member of that body, every worker in that wonderful factory, has been unremitting in his duty, and yet the owner, the master, has been asleep, and wakes up finding every bodily want supplied ! Notwithstanding that much has already been said of the wonders that pertain to the eye, it has not yet been considered as the seat of tears, those mute but eloquent utterers of the sorrows of the heart. Beautiful Tear! whether lingering upon the brink of the eyelid, or darting down the furrows of the care-worn cheek thou art sublime in thy simplicity great, because of thy modesty strong, from thy very weakness. Offspring of sorrow ! who will not owu thy claim to sympathy ? who can resist thy eloquence ? who can deny mercy when thou pleadest ? Every tear represents some in-dwelling sorrow preying upon the mind and destroying its peace. The tear comes forth to declare tho inward struggle, and to plead a truce against further strife. How meet that the eye should be the seat of tears where they cannot occur unobserved, but, blending with the beauty of the eye itself, must command attention and sympathy t Whenever we behold a tear, let our kindliest sympathies awake let it have a sacred claim upon all that we can do to succour and comfort under affliction. What rivers of tears have flown, excited by the cruel and perverse ways of man J War has spread its carnage and desolation, and the eyes of widows and orphans have been suffused with tears! Intemperance has blighted the homes o millions, and weeping and wailing have been incessant ! A thousand other evils which we may conquer have given birth to tears enough to constitute a flood a great tide of grief. Suppose we prize this little philosophy, and each one determine r*tver to excite a tear in another. Watching the eye as the telegraph 260 THE BEASOX WHY. "Who is as the wise man? and who knoweth the interpretation otj. ,iing a man's wisdom maketh his face to shine, and the boldness of his fa< shall be changed." ECCLESIASTES vm. of the mind within, let us observe it with anxious regard ; and whether we are moved to complaint by the existence of supposed or real wrongs, let the Indication of the coming tear be held as a sacred truce to unkindly feeling, and our efforts be devoted to the substitution of smiles for tears ! There is only one other matter to which we think it necessary to allude, before we pass to the concluding section of our work. It has been said (162), that snow which is white, keeps the earth warm ; that white as a colour is cool, and that black absorbs heat (231). These assertions may appear to be contradictory, and, taken in connection with the fact of the blackness of the skin of negroes in hot climates, may at a first glance be considered unsatisfactory. They are, however, perfectly reconcileable, and that too, without the slightest evasion of the real bearing of the asserted facts. White snow is warm on account of Us tenure, which, being woolly, forms a layer of non-conducting substance ever the surface of the earth, and keeps in its warmth ; white clothing, worn as a garment consisting of a thin material, is cool, because the white colour turns back the rays of the sun that fall upon it. Swansdown, although white, being a non-conductor, would be warm, because, though it would reflect the light and heat, it would confine and accumulate the heat of the body. The black skin of the negro is a living texture, and is not subject to the same laws that govern dead matter. The skin of the negro is largely provided with cells which secrete a fatty matter that acts as a non-conductor of the external heat, and also a much larger number of perspira- tory glands than exist in the skins of Europeans. The perspiration cools the blood, and carries off the internal heat, while the oily matter gives a shiuing surface to the skin, and reflects the heat, to which the fatty matter presents itself as a non-conducter. We see, therefore, that there are two express provi- sions for the cooling of the negroes' skin, independent of the colour. The skin of the Esquimaux who inhabits a cold country is white, though it might be supposed that a black skin would best conduce to the warmth of his body. But the Esquimaux has, underneath his skin, a thick coating of fat, by which the internal heat of the body is prevented from escaping. This resume of the subjects embodied in the form of question and answer in the previous pages, will serve to impress the more important truths upon the mind of the reader, while it has enabled us to fill up many omissions necessi- tated by the arbitrary form of catechetical composition. THE EEASON TVHY. 261 'Ask now the beasts, and they shall teach thee; and the fowls of the air, and they shall tell thee." JOB xn. CHAPTER LII. 1029. Why are there so many bodily forms in the animal creation ? Because the various creatures which God has created have different modes of life, and the forms of their bodies will be found to present a perfect adaptation to the lives allotted to them. Because, also, the beauty of creation depends upon the variety of objects of which it consists. And the greatness of the Creator's power is shown by the diversity of ends accomplisJicd by different means. 1030. Why are birds covered icith feathers ? Because they require a high degree of warmth, on account of the activity of their muscles ; but in providing that warmth it was necessary that their coats should be of the lightest material, so as not to impair their powers of flight ; and feathers combine the highest warming power, with the least amount of weight. 1031. Why have ostriches small ivings ? Because, having long legs, they do not require their wings for flight ; they are merely used to steady their bodies while running. 1032. Why are ostrich feathers soft and downy? Because, as the feathers are not employed for flight, the strength of the feather as constructed for flying is unnecessary, and the feathers therefore consist chiefly of a soft down. 1033. Why have ivater-birds feathers of a close and smooth texture ? Because such feathers keep the body of the bird warm and dry, by repelling the water from their surface. A bird could scarcely move through the water, with the downy feathers of the ostrich, because of the amount of water the down would absorb. 1034. Why is man born without a covering ? Because man is the only animal that can clothe ifseff. Aa in 262 THE BEASON WHY. 'Who teachetli us more than the beasts of the earth, ami makcth us wiser tLan the fowls of heaven?" JOB xxxv. the various pursuits of life he wanders to every part of the globe, he can adapt himself to all climates and to any season. 1035. Why do the furs of animals become thicker in th winter than in the summer ? Because the creator has thus provided for the preservation of the warmth of the animals during the cold months of winter. 1036. Why does a black down grow under the feathers of birds as winter approaches ? Because the down is a non-conductor of heat, and black the warmest colour. It is therefore best adapted to keep in their bodily warmth during the cold of winter. 1037. Why has man no external appendage to his mouth ? Because his hands serve all the purposes of gathering food, and conveying it to the mouth. Man's mouth is simply an opening ; in other animals it is a projection. 1038. Why have dogs, and other carnivorous animals, long pointed teeth, projecting above the rest ? Because as they have not hands to seize and controtil their food, the projecting teeth enable them to snap and hold the objects which they pursue for food. 1039. Why is the under jaw of the hog, shorter and smaller than the upper one ? Because the animal pierces the ground with its long snout, and then the small under jaw works freely in the furrow that has been opened, in quest of food. 1010. Why hare birds hard beaks ? Because, having no teeth, the beak enables them to seize, hold, and divide their food. 1011. Why are the beaks of birds generally long and sharp ? Because the greater number of birds live by picking up small THE BEASON "WHY. 263 * 5s the fishes that are taken in an evil net, and as the birds that are caught in the snare; so are the sous of men snared in an evil time, when it falletb, suddenly upon them." ECCLESIASTES ix. objects, such as^rorms, insects, seeds, &c. The sharp bealf, therefore, serves as a fine pincers, enabling them to take hold of tlieir food conveniently. 1042. Why have snipes and woodcocks long tapering tills ? Because they live upon worms which they find in the soft mud of streams and marshy places ; their long bills, therefore, enable them to dig down into the mud after their prey. 1043. Why have woodcocks, snipes, fyc., nerves running down to the extremities of their bills ? Because, as they dig for their prey in the soft sand and mud, they cannot see the worms upon which they live. Nerves are, therefore, distributed to the very point of their bills (where, in other birds, nerves are entirely absent) to enable them to prehend their food. Fig. 67. SPOONBILL. 1044. Why have ducks and geese square-pointed bill*? Jiecause they not only feed by dabbling in soft and muddy soil, but they consume a considerable quantity of green food, and their square bills enable them to crop off the blades of grass. 264 THE SEASON WHT. " Let the heaven and earth praise him, the seas, and everything that movetb therein." PSAI-M nix. 1045. Why has the spoon-bill a long exftonded bill, lined internally ivith sharp muscular points ? Because the bird lives by suction, dipping its broad bill in search of acquatic worms, mollusks, insects and the roots of weeds. The bill form? a natural spoon, and the muscular points enable the bird to filter the mud, and to retain the nourishment which it finds. 1016. Why has the spoon-till long legs? Because it wades in marshy places to find its food. Its legs are therefore long, for the purpose of keeping its body out of the water, and above the smaller acquatic plants, while it searches for its prey. 1017. Why have the parrots, fyc., crooked and hard bills ? Because they live upon nuts, the stones of fruit, and hard seeds. The shape of the bill, therefore, enables them to hold the nut or seed firmly, and the sharp point enables them to split or remove the husks. 1048. Why can a parrot move its upper as well as its lower bill? Because by that means it is enabled to bring the nut or seed nearer the fulcrum, or joint of the jaw. It, therefore, acquires greater power, just as with a pair of nut-crackers we obtain increased power by setting the nut near to the joint, 1049. Why have animals with long necks large throats? Animals that graze, or feed from the ground, generally have a more powerful muscular formation of the throat than those which feed in other positions, because a greater effort is required to force the food upward, that would be needed to convey it down. 1050. Why are the bones of birds hollow ? Because they are thereby rendered lighter, and do not interfere with the flight of the bird as they would do if they were solid. Greater strength is also obtained by the cylindrical form of the bone, and a larger surface afforded for the aitachrtient of powerful musclet. THE BEAsflff WHY. 265 ' And my hand hath found, as a nest, the riches of the people ; and as ouo gathereth eggs that are left, have I gathered all the earth ; and there was none that moved the wins, or opened the mouth, or peeped." ISAIAH x. 1051. Why Uto all birds lay eggs ? Because, to bear their young in any other manner, would encumber the body, and materially interfere with their powers of flight. As soon as an egg becomes large and heavy enough to be cumbersome to the bird, it is removed from the body. A shell, impervious to air, protects the germ of life within, until from two to twenty eggs Lave accumulated, and then, although laid at different intervals, their incubation commences together, and the young birds are hatched at the same time. CHAPTER LIII. 1052. Why have birds with long legs short tails ? Because the tails of birds are used to guide them through the air, by a kind of steerage. When birds with long legs take to flight, they throw their legs behind, and they then serve the same purpose as a tail. ig. 68. PEBCH. 1053. Why have fishes fins ? The fins of fishes are to them, what wings and tails are to birds, enabling them to rise in the fluid in which they live by the reaction of the motions of the fins upon its substance. 266 THE BE"ASON WHY. "Speak to the earth, and it shall teach thee; and the fishes of the sea shall declare unto thee. Who knoweth not in all these that the hand of the Lord hath wrought this." JOB XII. 1054. Why are the fins of fishes proportionately sc much tmallcr than the icings of birds? Because there is less difference between the specific gravity of the body of a fish, and the water in which it moves, than between the body of a bird, and the air on which it flies. The fish, therefore does not require such an expanded surface to elevate or guide it. 1055. Why have fishes scales? Because scales, while they afford protection to the bodies of fish, are conveniently adapted to their motions ; and as the scales present no surface to obstruct their passage throityh the water, as hair or feathers would do, they evidently form the best covering for the acquatic animal. 1056. Why do fishes float in streams (when they are not swimming) with their heads towards the stream? Because they breathe by the transmission of water over the surface of their gills, the water entering at the mouth, and passing over the gills behind. When, therefore, they lie motionless with their heads to the stream, they are in that position which naturally assists their breathing process. 1057. Why havefishes air-bladders ? Because, as the density of water varies greatly at different depths, the enlargement or contraction of the bladder regulates the relation of the specific gravity of the body of the fish to that of the water in which it moves. 1058. Why have whales a very large development of oily matter about their heads ? Because their heads are thereby rendered the lighter part of their bodies, and a very slight exertion on the part of the animal will bring its head to the surface to breathe air, which it constantly requires. 1059. Why have birds that swim upon water iceb-feet ? Because the spreading out of the toes of the bird brings the membrane between the toes into the form of a fin, or water -wing, THE SEASON WHY. 267 " And Jesus saith unto him, The foxes have holes, and the birds of the air have nests ; but the sou of man hath not where to lay his head." MATTHEW xui. by striking which against the water, the bird propels itself along. 1060. Why have birds that swim and dive short legs ? Because long legs would greatly impede their motions in the water, by becoming repeatedly entangled in the weeds, and by striking against the bottom. Waders, however, require long legs because they have to move about through the tall vegetation of marshy borders. Fig. 69. STILT-PLOVER AND DUCK. 1061. Why have the feet of the heron, cormorant, Sfc., deep rough notches upon their under surface ? Because, as those birds live by catching fish, they are enabled by the notches in their feet, to hold the slippery creatures upon which they feed, 1062. Why have otters, seals, fyc., web-feet ? Because, while the feet enable them to walk upon the land, they are equally effective in their action upon the water, and hence they are adapted to the amphibious nature of the animals to which they belong. 1063. Why do the external ears of animals of prey, such as cats, tigers, foxes, wolves, hyenas, fyc., bend forward ? Because ftiey collect the sounds that occur in the direction of Iht 268 THE SEASON " Doth the hawk fly by thy wisdom, and stretch her wings toward the south ? " Doth the eagle mount up at thy command, and make her nest on high ? pursuit, and enable the animal to track its prey with greater certainty. 1064. Why do the ears of animals of flight, such as hare*, rabbits, deer, Sfc., turn, backward ? Because they thereby catch the sounds that give them warning of the approach of danger. 1065. Why has the stomach of the camel a number of distinct bags, like so many separate stomachs ? Because water is stored up in the separate chambers of the stomach, apart from the solid aliment, so that the animal can feed, without consuming all its drink. It is thereby able to retain water to satisfy Us thirst while travelling across hot deserts, where no water could be obtained. 1066. Why do woodpeckers " tap" at old trees ? Because by boring through the decayed wood, with the sharp and hard bills with which they are provided, they get at the haunts of the insects upon which they feed. 1067. Why are woodpeckers' tongues about three times longer than their bills ? Because, if their bills were long, they would not bore the trees so efficiently ; and when the trees are bored, and the insects alarmed, they endeavour to retreat into the hollows of the wood ; but the long thin tongue of the woodpecker fixes them on its sharp horny point, and draws them into the mouth of the bird. 1068. Why have the Indian hogs large horns growing from their nostrils and turning back towards their eyes ? Because the horns serve as a defence to the eyes while the* animal forces its way through the thick underwood in which it lives. 1069. Why have calves and Umbs, and the young of lorned cattle generally, no horns while they are young ? Because the presence of horns would interfere with the twskling THIS EEASON WHY. 269 She dwelleth and abideth on the rock, upon the crag of the rock and tha strong place. "From thence she seeketh the prey, and her eyes behold afar off. Heryountf ones also suck up blood : and where the slain are, there is she." JOB xxxix. of the young animal. When, however, it is able to feed itself by browsing, then the horns begin to grow. 1070. Why have infants no teeth ? Because the presence of teeth would interfere with their suckling, while the teeth would be of no service, until the child could take food requiring mastication. 1071. Why cannot flesh-eating animals live upon vege- tables ? Because the gastric juice of a flesh-eating animal, being adapted to the duty which it has to perform, will not dissolve vegetable matter. 1072. Why have birds gizzards ? Because, having no teeth, the tough and fibrous gizzards are employed to grind the food preparatory to digestion. 1073. Why are small particles of sand, stone, tyc., found in the gizzards of birds ? Because, by the presence of those rough particles, which become embedded in the substance of the gizzard, the food of the bird is more effectively ground. When our fowls are abundantly supplied with meat, they soon fill their craw, but it does not immediately pass thence into the gizzard ; it always enters in small quantities, in proportion to the progress of trituration, in like manner, as in a mill, a receiver is fixed above the two large stones which serve for grinding the corn, which receiver, although the corn be put into it by bushels, allows the grain to dribble only in small quantities into the central hole ih the upper mill-stone. Paley. CHAPTER LIV. 1074. Why has the mole hard and flat feet, armed with sharp nails? Because the animal is thereby enabled to burrow in the earth, in search for worms. Its feet are so many shovels. 1075. Why is the mole's fur exceedingly glossy and smooth ? Because it smoothness enables it to work under ground without 270 THE BEASON WHY. ' I know all tlie fowls of the mountains, and the wild beasts are mine." the soil sticking to its coat, by which its progress would be impeded. From soils of all kinds, the little worker emerges shining and clean. What I have always most admired in the mole is its eyes. This animal occasionally visiting the surface, and wanting, for its safety and direction, to ba informed when it does so, or when it approaches it, a perception of light was necessary. I do not know that the clearness of sight depends at all upon the size of the organ. "What is gained by the largeness or prominence of the globo of the eye, is width in the field of vision. Such a capacity would be of no use to an animal which was to seek its food in the dark. The mole did not want to look about it ; nor would a large advanced eye have been easi'y defended from the annoyance to which the life of the animal must constantly expose it. How indeed was the mole, working its way under ground, to guard its eyes at all ? In order to meet this difficulty, the eyes are made scarcely larger than the head of a corking-pin ; and these minute globules are sunk so deeply in the skull, and lie so sheltered within the velvet of its covering, as that any contraction of what may be called the eye-brows, not only closes up the apertures which lead to the eyes, but presents a cushion, as it were, to any sharp or protruding substance which might push against them. This aperture, even in its ordinary state, is like a pin-hole in a piece of velvet, scarcely pervious to loose particles of ear h. -Paley. Fig. 70. -ELEPHANTS DEINKINO. 1076. Why has the elephant a short unoending neck ? Because the elephant's head is so heavy, that it could not have been supported at the end of a long neck (or lever), without a provition of immense muscular povoer. THE SEASON WHY. 271 " Be not afraid, ye beasts of the field : for the pastures of the wilderness de spring, for the tree beareth her fruit, the fig-tree and the vine do yield their strength." JOEL n. 1077. Why has the elephant a trunk ? The trunk of an elephant serves as a substitute for a neck, enabling the animal to crop the branches of trees, or to raise water from the stream. 1078. Why do the hind legs of elephants lend forward f Because the weight of the animal is so great, that when it lay down it would rise with great difficulty, if its legs bent outward, as do the legs of other animals. Being b?nt under the body, they have a greater power of pushing directly upward, when the powerful muscles of the thighs straighten them. According to Cuvier, the number of muscles, in an elephant's trunk, amounts to forty thousand, all of which are under the will, and it is to these that the proboscis of this animal owes its flexibility. It can be protruded or contracted at pleasure, raised up or turned to either side, coiled round on itself or twined around any object. With this instrument the elephant collects the herbage on which he feeds and puts it into his mouth ; with this he strips the trees of their branches, or grasps his enemy and dashes him to the ground. But this admi- rable organ is not only adapted for seizing or holding substances of magnitude ; it is also capable of plucking a single leaf, or of picking up a straw from the floor. The orifices of the canals of the extremity are encircled by a projecting margin, produced anteriorly into a finger-like process endowed with a high degree of sensibility and exceedingly flexible. It is at once a finger for grasping and a feeler: the division between the two nasal orifices or their elevated sides serves as a point against which to press ; and thus it can pick up or hold a small coin, a bit of biscuit, or any trifling thing with the greatest ease.Knight't Animal Kingdom. 1079. W hy have bats hooked claws in their wings ? Because bats are almost destitute of legs and feet ; at least those organs are included in their wings. If they alight upon the ground, they have great difficulty in again taking to the wing, as they cannot run or spring to bring their wings in action upon the air. At the angle of each wing there is placed, therefore, a bony hook, by which the bat attaches itself to the sides of rocks, caves, and buildings, laying hold of crevices, joinings, chinks, &c. ; and when it takes its flight, it unhooks itself, and its wings are at once free to strike the air. 10SO. Why does the latfly ly night? Because it lives chiefly upon moths, which are night-flying insect* 272 THE SEASON WHT. " So are the paths of all that forget God ; and the hypocrite's hope shall Whose hope shall be cut off, and whose trust shall be a spider a web." JOB vm. 1081. Why does the bat sleep during the winter ? Because, as the winter approaches, the moths and flying insects upon which it feeds, disappear. If, therefore, it did not sleep through the winter it must have starved. Fig. 71. BAT WITH HOOKED WIKQi. 1082. Why has the spider the power of spinning a web ? Because, as it lives upon flies, but is deficient of the power of flying in pursuit of them, it has been endowed with an instinct to spread a snare to entrap them, and with the most wonderful machinery to give that instinct effect. There are few things better suited to remove the disgust into which young people are betrayed on the view of some natural objects, than this of the spider. They will find that the most despised creature may become a subject of admira- tion, and be selected by the naturalist to exhibit the marvellous works of the creation. The terms given to these insects, lead us to expect interesting par- ticulars concerning them, since they have been divided into vagrants, hunters, swimmers, and water spiders, sodentary, and mason-spiders ; thus evincing a variety in their condition, activity, and mode of life ; and we cannot bo sur- prised to find them varying in the performance of their vital functions (as, for example, in their mode of breathing), as well as in their extremities and instru- ments. Of these instruments the most striking is the apparatus for spinning and weaving, by which they not only fabricate webs to entangle their prey, but form cells for their residence and concealment ; sometimes living in the ground, sometimes under water, yet breathing the atmosphere. Corresponding with their very singular organisation are their instincts. We are familiar with the watchfulness and voracity of some spiders, when their prey is indicated by the vibration of the cords of their net-work. Others have the eye and dis- position of the lynx or tiger, and after couching in concealment, leap upon their victims. Some conceal themselves under a silken hood or tube, six eyos only projecting. Some bore a hole in the earth, and liun it as luieiy as if it were done with the trowel and mortar, and then hang it with delicate curtains. A very extraordinary degree of contrivance is exhibited in the trap -door spidor. This door, from which it derives its name, has a frame and hinge on the mouth of the cell, and is so provided that the claw of the spider can lay hold of it. xcJ THE SEASON WHY. 273 44 The spider taketk hold with her hands, and Is in king's palaces." PROVEEBS xxx. whether she enters or goes out, says Mr. Kirby, the door shuts of itself. But the water-spider has a domicile more curious still : it is under water, with an opening at the lower part for her exit and entrance ; and although this cell be under water, it contains air like a diving-bell, so that the spider breathes the atmosphere. The air is renewed in the cell in a manner not easily explained. The spider comes to the surface ; a bubble of air is attracted to its body ; with this air she descends, and gets under her cell, when the air is disengaged and rises into the cell ; and thus, though under water, she lives in the air. There must be some peculiar property of the surface of this creature by which she can move in the water surrounded with an atmosphere, and live under the water breathing the air. 9 Fig. 72. WEB 0* THE GEOMETEICAL SPIDER. The chief instrument by which the spider performs these wonders is the spinning apparatus. Tte matter from which the threads are spun is the liquid contained in cells ; the ducts from these cells open upon little projecting teats, and the atmosphere has so immediate an effect upon this liquid, that upon exposure to it the secretion becomes a tough and strong thread. Twenty-four of these fine strands form together a thread of the thickness of that of the ilk-worm. We are assured that there are three different sorts of material thui produced, which are indeed required for the various purposes to which tu* 12* 274 THE EEA.SON WHY. 1 For every beast of the forest is mine, and the cattle upon a thousand hills." PSALM L. are applied as, for example, to mix up with the earth to form the cells ; to line these cells as with fine cotton ; to make light and floating threads by which they may be conveyed through the air, as well as those meshes which are so geometrically and correctly formed to entrap their prey. Not* by Lord Brougham to Paley's Natural Tlu-rtogy. 1083. Why have many insects a great number of eyes ? Because the orb of the eye is fixed ; there is therefore placed over the eye a multiple-lens, which conducts light to the eye from every direction; so that the insect can see with a fixed eye as readily as it could have done with a moveable one. As many as fourteen hundred eyes, or inlets of light, have been counted in the head of a drone-bee. The spider has eight eyes, mounted upon different parts of the head ; two in front, two in the top of the head, and two on each side. 1084. Why have birds of prey no gizzards ? Because their food does not require to be ground prior to digestion, as does the food of grain-eating birds. 1085. Why have earth worms no feet ? Because the undulatory motion of their muscles serves them for all the purposes of progression needed by their mode of life. 1086. Why have mussels strong tendinous threads proceeding from their shells ? Because as they live in places that are beaten by the surf of the sea, they moor their shells by those threads to rocks and timbers. 1087. Why have cockles stiff muscular tongues ? Because, having no threads to moor themselves, as the mussels have, they dig out with their tongues a shelter for themselves in the sand. 10S8. Why do oxen, sheep, deer, fyc., ruminate ? Becauss they have no front teeth in the upper jaw, the place of which is occupied by a hardened gum. The first process, therefore, consists simply of cropping their food, which is passed into the paunch, to be brought up again and ground by J .he back teeth when the cropping process is over. Because, in a wild state, they are constantly exposed to th THE SEASON WHY. 1 A righteous man regardeth the life of his beas t : but the tcuder roercit * the wicked are cruel." PEOVEBBS xii. attacks of carnivorous beasts, and as the mastication of the large amount of vegetable food required for their sustenance would -ke a considerable time, they are provided with stomachs, by whic4 they aro enabled to fill their paunches quickly, and then, retirit^ to a place jf safety, they bring their food up again, and chew it at leisure. 1089. Why can ruminating animals recover the food from tJieir paunches ? Because they have a voluntary power over the muscles of the throat, by which they can bring up the food at will. 1090. Why can they Tceep the unchewed food in the paunch, from the "cud" they have chewed for nourishment ? Because their stomachs are divided into three chambers : 1, the paunch, where the unchewed food is stored; 2, the reticulum, where portions of the food are received from the paunch, and moistened and rolled into a " cud," to be sent up and chewed ; and 3, the psalterium, which receives the masticated food, and con- tinues the process of digestion. In quadrupeds the deficiency of teeth is usually compensated by the faculty of rumination. The sheep, deer, and ox tribe, are without fore-teeth in the upper jaw. These ruminate. The horse and ass are furnished with teeth in the upper jaw, and do not ruminate. In the former class, the grass and hay descend into the stomachs nearly in the state in which they are cropped from the pasture, or gathered from the bundle. In the stomach, they are softened by the gastric juice, which in these animals is unusually copious. Thus softened and rendered tender, they are returned a second time to the action of the mouth, where the grinding teeth complete at their leisure the trituration which is necessary ; but which was before left imperfect. I say, the trituration which is necessary; for it appears from experiments, that the gastric fluid of sheep, for example, has no effect in digesting plants, unless they have been previously masticated ; that it only produces a slight maceration, nearly as common water would do in a like degree of heat ; but that when once vegetables are reduced to pieces by mastication, the fluid then exerts upon them its specific operation. Its first effect is to soften them, and to destroy their natural consistency ; it then goes on to dissolve them, not sparing even the toughest parts, such as the nerves of the leaves. I think it very probable, that the gratification also of tha uimal is renewed and prolonged by this faculty. Sheep, deer, and oxen, , appear to be in a state of enjoyment whilst they are chewing the cud. perhaps thai i'aey best relish their food. Paley. 276 THE BEASON -WHY. * I am like a pelican of the wilderness : I am like an owl of the desert. I watch, and am as a sparrow alone upon the house top." PSALM en. CHAPTER LV. 1091. Why do quadrupeds that are vegetable eaters feed so continually ? Because their focc contains but a small proportion of nutrition, so that it is necessary to digest a large quantity to obtain sufficient nourishment. 1092. Why do flesh eating animals satisfy themselves with a rapid meal ? Because the food which they eat is rich in nutritious matter, and more readily digestible than vegetable food; it does not therefore, require the same amount oi-grinding with the teeth. Fig. 73. PELICAN WITH DILATED POrCH. 1093 Why has the pelican a large pouch under it lill Because it subsists upon fish, generally of the smaller kind, and nges its pouch at a net for catching them ; the pouch also serves a* THK EEASON WHY. 277 * And God created great whales, and every living creature that moveth, which the waters brought forth abundantly, after their kind, and every winged fowl after his kind: and God saw that it was good." GENESIS i. a paunch, in which the fish are stored, until the bird ceases from the exertion of fishing, and takea its meal at leisure. In their wild state they hover and wheel over the surface of the water, watching t In shoals of fish beneath, and suddenly sweeping down, bury them- selves in the foaming waves; rising immediately from the water by their own buoyancy, up they soar, the pouch laden with the fish scooped up during their momentary submersion. The number of fish the pouch of this species will con- tain may be easily imagined when we state that it is so dilatable as to be capable of containing two gallons of water ; yet the bird has the power of contracting this membranous expansion, by wrinkling it up under the lower mandible, until it is scarcely to be seen. In shallow inlets, which the pelicans often frequent, it nets its prey with groat adroitness. The pelican chooses remote and solitary islands, isolated rocks in the sea, the borders of lakes and rivers, as its breeding place. The nest, placed on the ground, is made of coarse grasses, and the egss, which are white, are two or three in number. "While the female is incubating, the male brings fish to her in his pouch, and the young, when hatched, are assidiously attended by the parents, who feed them by pressing the pouch, against the breast, ko as to transfer the fish from the former into the throats of the young. This action has doubtless given origin to the old fable of the pelican feeding its young with blood drawn from its own breast. Knight's Animal Kingdom. 1094. Why do the smaller animals breed more abundantly titan the larger ones ? Because the smaller ones are designed to be the food of the larger ones, and are therefore created in numbers adapted to that end. An elephant produces but one calf; the whale but one young one ; a butterfly lays six hundred eggs ; silk-worms lay from 1,000 to 2,000 eggs ; the wasp, 5,000; the ant, 4,000 to 5,000; the queen bee, 5,000 to 6,000, or 40,000 to 50,000 in a season ; and a species of white ant (termes fatalis) produces 86,400 eggs in a day. Birds of prey seldom produce more than two eggs ; the sparrow and duck tribe frequently sit upon a dozen ; in rivers there prevail a thousand minnows for one pike ; and in the sea, a million of herrings for a single shark; while of the animalcules upon which the whale subsists, there must exist hundreds of millions for one whale. 1095. Why has the whale feathery-like lamince of whale- lone extending from its jaws ? Because these feathery bones., lying side by side, form a sieve, or strainer, for the large volumes of water which the whale rcceivei into its its mouth, drawing off tbsrefrom millions of small animal^ 278 THE SEASON WHY. " Hast thou given the horse strength ? hast thou clothed his neck with thunder 1 * He paveth the valley, and rejoiceth in his strength : he goeth on to meet the armed men." JOB xxxix. which form a jelly-like mass upon which the whale feeds. A whale has been known to weigh as much as 249 tons, and its blubber yielded 4,000 gallons of oil. How many millions of living creatures must have gone to make up that enormous mass of animal matter ! 1096. Why have cats, and various other animals, whiskers ? The whiskers of cats, and of the cat tribe, are exceedingly sensitive, enabling them, when seizing their prey in the dark, iofeel its position most acutely. These hairs are supplied, through their roots, with branches of the same nerves that give sensibility to tho lips, and that in insects supply their "feelers." 1097. Why has the horse a smaller stomach proportion- ately than other animals ? Because the horse was created for speed. Had he the ruminating stomach of the ox, he would be quite unfitted for the labour which he now so admirably performs. 1098. Why has the horse no gall-lladder ? Because the rapid digestion of the horse, by which its fitness for speed is greatly increased, does not require the storing up of the bile as in other animals in which the digestive process is a slower operation. 1099. Why do certain butter/lies lay their eggs upon callage leaves ? Because the cabbage leaves are the food of the young caterpillars ; and although the butterfly does not subsist herself upon the leaf, she knows by instinct that the leaf will afford food to her future young ; she therefore lays her eggs where her young ones will find food. This explanation applies to many insects that lay their eggs upon other 1-lants 1100. Why have insects long projections from their heads, like horns or feathers f Because those organs (the antenna), are those through which eome insects hear and others feel; and the projecting of these antenna from their bodies probably enables them to hear or feel THE EEASON "WHY. 279 " My pon, eat thou honey, because it is good ; and the honey-comb, which ia sweet to thy taste." PEOVEEBS xxiv. more acutely while their wings are in motion, without the inter- feren<:e of the vibrations of their ivings, 1101. Why have bees stings? Because they gather and store up honey which would constantly attract other insects, and the bees would be robbed of their food but for the sting, which is giten to them for protection. 1102. Why have flies fine hairs growing at the extremities of their leas? Because they require to cleanse their bodies and wings, and to free them from particles of dust. And as they cannot turn their heads for this purpose, they have hairy feet, which serve as brushes, by which any part of their bodies can be reached and cleaned. CHAPTER LVI, 1103. Why when the perfume of flowers is unusually perceptible may wet weather be anticipated ? Because when the air is damp it conveys the odours of flowers mora effectively than it does when dry. 1104. Why when swallows fly low may wet weather be expected? Because the insects which the swallows pursue in their flight are flying low, to escape the moisture of the upper regions of the atmosphere. 1105. Why do ducks and geese go to the water, and dash it over their backs on the approach of rain ? Because by wetting the outer coat of their feathers before the rain falls, by sudden dashes of water over the surface, they prevent the drops of rain from penetrating to their bodies through the open and dry feathers. HOG. Why do houses and cattle stretch out their necks and snuff the air on the approach of rain? Because they smell the fragrant perfume which is diffused in th* air by its increasing moistness. 280 THE EEASON \VHT. will remember the works of the Lord: Surely I will remember thy wonders of old." PSAIM LXXVII. 1107. Why may change of weather be anticipated when domestic animals are restless ? Because their skins are exceedingly sensitive to atmospheric influences, and they are oppressed and irritated by the changing condition of the atmosphere. 110S. Why may fine weatl'er le expected when spiders are seen lusily constructing their icels ? Because those insects are highly sensitive to the state of the atmosphere, and when it is setting fine they build their webs, because they know instinctively that flies will be abroad. 1109. Why is wet weather to le expected when spiders hide ? Because it shows that they are aware that the state of the atmosphere does not favour the flight of insects. 1110. Why if gnats fly in large numbers may flne weather le expected ? Because it shows that they feel the state of the atmosphere to be favourable, which induces them all to leave their places of shelter 1111. Why if owls scream during foul weather, will it change to fine ? Because the birds are pleasurably excited by a favourable change in the atmosphere. 1112. Why is it said that the moping of the owl foretels death ? Because owls scream when the weather is on the change ; and when a patient is lingering on a death bed, the alteration in the state of the atmosphere frequently induces death, because the faint and expiring flame of life has not strength enough to adapt itself to the change. 1113. Why may wet weather le expected wJien spiders break off their webs, and remove them? Because the insects, anticipating the approach of rain, remove their webs for preservation. THE BEASON WHY. 281 " There shall the groat owl make her nest, and lay, and hatch, and gather under her shadow : there shall the vultures also be gathered, every one with her mate." ISAIAH xxxir. 1114. Why may ive expect a continuance of fine weather when lees wander far from their hives? Because the bees feel instinctively that from the state of ths atmosphere they may wander far in search of honey, without th* danger of being overtaken by rain. 1115. Why if people feel their corns ache, and their bones rheumatic, may rain }fe expected ? Because the dampness of the atmosphere affects its pressure upon the body, and causes a temporary disturbance of the system. All general disturbances of the body, manifest themselves in those parts which are in a morbid state as in a corn, a rheumatic bone, or a decayed tooth. 1116. Why if various flowers close may rain be expected ? Because plants are highly sensitive to atmospheric changes, and close their petals to protect their stamens. 1117. Why when moles throw up their hills may rain be expected ? Because the moles know instinctively, that on the approach of wet, worms move in the ground; the moles therefore become active, and form their hills. 1118. Why is a magpie, when seen alone, said to fortell ba d weather ? Because magpies generally fly in company ; but on the approach of wet or cold, one remains in the nest to talce care of the young, ' while the other one wanders alone in search of food. 1119. Why do sea-gulls appear numerous in fine weather ? Because the fishes swim near to the surface of the sea, and the birds assemble over the sea to catch the fish, instead of sitting on rocks, or wading on the shore. 1120. Why do sea-gulls fiy over the land, on the approach of stormy weather? Because in stormy weather they cannot catch fish ; and th tarth-worms come up on the Lind wher. the rain falls. 282 THB BEASON TTHY. " And I said, Oh, that I had wings like a dove ! for then would I fly away, and ba at rest." PSJLLX IT. 1121. Why if birds cease to sing, mat/ wet, and probably thunder, be expected. Because birds are depressed by an unfavourable change in the atmosphere, and lose those joyful spirits which give rise to their tongs. 1122. Why tf cattle run around in meadows, may thunder be expected T Because the electrical state of the atmosphere has the effect of making them feel uneasy and irritable, and they chase each other about to get rid of tJie irritability. 1123. Why if birds of passage arrive early, may severe weather be expected ? Because it shows that the indications of unfavourable weather have set in, in the latitudes from which the birds come, and that they have taken an early flight to escape it. 1124. Why if the webs of the gossamer spider Jly about in the autumn, may east winds be anticipated? Because an east wind is a dry and dense wind, and suitable to the flight of the gossamer spider ; the spider feeling instinctively the dry ness of the air, throws out its web, and finds it more than usually buoyant upon the dense air. The observation of the changing phenomema which attend the various states of the weather is a very interesting study, though no general rules can be laid down that can be relied upon, because there are modifying circum- stances which influence the weather in various localities and climates. To observe weather indications accurately, no phenomenon should be taken alone, but several should be regarded together. The character and the duration of the weather of the preceding days, the direction of the wind, the forms of the clouds, the indications of the barometer, the rise or fall of the thermometer, and the instinctive forewarnings of bi.-ds, beasts, insects, and flowers, should all be taken into account. Although no direct material advantages attend such a tudy, it induces a habit of observation, and developes the inductive faculty of the mind, which, when applied "o more significant things, may trace importrj sffocU to their grater causes. THE BEASOX WHY. 283 Go to the ant, thou sluggard; consider her ways, and be wise. ' PHOT. CHAPTER LVII. 1125. Why can gossamer spiders float through the air ? Because, having no wings, and beiug deficient in the active muscular powers of other spiders, they have been endowed with the power of spinning a web which is so light that it floats in the air, and bears the body of the gossamer spider from place to place. Each web acts as a balloon, and the spider attached thereto is a little aeronaut. 1126. Why do crickets make a peculiar chirping sound ? Because they have hard wing cases, by the friction of the edges of which they cause their peculiar noise, to make known to each other where they are, in the dark crevices in which they hide. Fig. 74. GLOW-WOK^ TJSI3TG HI8 BETJSH. 1127. Why has the glow-worm a brush attached to itt tail? Because it is necessary to keep its back very clean, that the light which its body emits may not be dimmed. 1128. Why does the glow-worm emit a light ? Because the female glow-worm is without wings, but th male it A winged insect. The female, therefore, is endowed with the power of displaying a phosphorescent light. The light is only visible by 284 THE SEASON WHY. " They that go down to the sea in great ships, that do business in great waters these see the works of the Lord, and his wonders in the deep." PSALM CVTI. night, but it is, nevertheless, beautifully adapted for the purpose stated, because the male is a night-flying insect, and never ventures abroad by day. There exists some difference of opinion between naturalists upon the uses ol the light of a glow-worm ; there are some who doubt that it is exhibited to attract the flying insect. The objectors, however, offer no explanation of the luminous properties of the worm. Sir Charles Bell says the preponderance of the argument is decidedly in favour of the explanation we have given. 1129. Why does not the iris of the fish's eye contract ? Because the diminished light in water is never too strong for the retina. 1130. Why is the eye of the eel covered with a transparent horny covering ? Because, as the eel lives in holes, and pushes its head into mud, and under stones, &c., it needed such a covering to defend the eye. 1131. Why is the whale provided with an eye, having remarkably thick and strong coats ? Because, when he is attacked by the sword-fish and the shark, he is almost helpless against his enemies, as they fix themselves upon his huge carcase. He therefore dives with them down to a depth where the pressure of the water is so great that they cannot bear it. The eye of the whale is expressly organised to bear the immense pressure of extreme ocean depths, without impairing the sight. 1132. Why have fishes no eye-lids? Because the water in which they swim keeps their eyes moist. Eyelids would therefore be useless to them. 1133. Why have fishes the power of giving their eye-lalls very sudden motion T Because, having no eyelids (such organs being unnecessaiy to keep their eyes moist), they still need the power of freeing their eyes from the contact of foreign matters ; and this is secured to them by the power they have of giving the eye-ball a very rapid motion, which causes reaction in the fluid surrounding it, and sweej.it the surface. This motion may frequently be seen in the eyes of fishes, in glass globtt. THE REASON. WHY. 285 "And God made the beast of the earth after his kind, and cattle after theii kind, and everything that creepeth upon the earth after his kind : and God saw that it was good." GENESIS i. 1134. Why is the lachrymal secretion of the horse's eye thick and glutinous ? Because, as his eye is large, and constantly exposed to dust on journies, it is provided with a viscid secretion, which cleanses the eye, and more instantly and securely removes the dust, than a watery secretion would. 1135. Why does the lower hill of the sea-crow project beyond the upper one ? Because the bird obtains his food by skimming along the water, into which he dips his bill, and lifts his food out. 1136. Why do the mandibles of the cross-bill overlap each other ? Because the bird requires a peculiar bill, to enable it to split seeds into halves, and to tear the open cones of the fir-tree. 1137. Why are the tails of fishes so much larger than their fins? Because their tails are their chief instruments of motion, while their fins are employed simply to direct their progress, and steady their movements. 1138. Why have oxen, and other Quadrupeds a tough ligament called the "pax-wax," running from their lacks to their heads ? Because their heads are of considerable weight; and having frequent occasion to lift them, they are provided with an elastic ligament, which is fastened at the middle of their backs, while its other extremity is attached to the head. This enables them to raise their heads easily ; otherwise the effort to do so would be a work of great labour. To the horse, the pax-wax acts as a natural bearing-rein, assisting it to hold its head in that position which adds to the grace and beauty of the animal. In carving beef, this ligament may be seen passing along the vertebra of tin nock, the chuck, and the fore ribs. 286 THE SEASON WHY. 1 He shall feed his flock like a shepherd ; he shall gather the lambs with his arm, aud carry them in his bosom, and shall gently lead those that are with young." ISAIAH sx. 1139. Why have the females of the kangaroo and opossum tribes pouches, or pockets, formed in the skin of their breasts for the reception of their young T Because their young ones are remarkably small and helpless ; in fact, more so than those of any other animal of equal proportions. Besides which, the full grown animals have very long hind- legs, and they progress by a series of extraordinary leaps. It would consequently be impossible for their helpless young ones to follow them : God has therefore given to female kangaroos and opossums curious pockets, formed out of their own skin, in which they place their little young ones, and bear them through their surprising leaps with the greatest ease and safety. CHAPTER LVIII. 1140. What is the difference between an animal, a plant, and a mineral ? The great naturalist, Linnaeus, used to say that minerals, and animals grow, live, and. feel; plants grow and live; and mineral* grow. Animals are here defined to enjoy three conditions of existence ; plants two conditions ; and minerals one condition. This definition has, in latter days, been held to be unsatisfactory, since there are a few plants that are supposed to feel, and a few animals that are supposed to have even less feeling than tho sensitive plants alluded to. The concise definition by Linnaeus, nevertheless, is true, as far as regards a vast majority of the bodies constituting the three great kingdoms of nature. And it may be sufficient to say that Animals grow, live, feel, and move. Plants grow and live. Minerals grow, by the addition of particles of inorganic matter. If we now state the few exceptions that are admitted to this definition, we Bhall bring the explanation as near to the truth, as th present state at knowledge will permit. THE EEASON "WHY. 287 "And God said, Behold, I have given you eveiy herb bearing seed . upon the face of all the earth, and every trie, in the^Sis L of a tree, yielding seed ; to you it shall be for meat .-GZMS i 1141. Why is it understood that some plants feel ? Because the sensitive plant closes its leaves on being touched; the Venus s fly trap closes its leaves upon flies that alight upon them ; others close upon the approach of rain, and at sunset, and open at sunrise, and turn towards the sun during its daily transit. 1142. Why is it understood that some plants move ? Because certain sea-weeds throw off undeveloped young plants. which move through the water by the aid of fine cilia, or mus- cular hairs, until they find a suitable place upon which to attach themselves. The roots of plants will penetrate through the ground in the direction of water, and of favourable soil. 11-43. Of what elementary substances are plants composed? Ot carbon, oxygen, hydrogen, arid nitrogen. 1144. Whence do plants derive those substances? From the air, the earth, and water. 1145. How do plants obtain carbon ? They obtain it chiefly from the air, in the form of carbonic acid gas. The carbon, of the carbonic acid gas, which is thrown out by the breath of animals, and by other processes in nature, is absorbed by the leaves of plants, and the oxygen which had united with the carbon to form the carbonic acid gas, is again set free for the use of animals. 1146. How do plants obtain oxygen ? They obtain it from the atmospheric air. But as they d(; not require a large amount of oxygen for their own use, they throw off the amount which is in excess, after having separated it from the other elements' with which it was combined when taken up by them. From the humble blade of grass, to the stately tree of the forest, plants operate to purify the air, and to correct and counteract the corruption of the air, by the myriads of animals inhabiting the earth. It has been generally stated that plants in rooms purify the air by absorbing carbonic acid by day, and releasing a part of the oxygen ; but that, as the pro- f once of light is necessary to produce this action, they do not restore oxygen to 288 THB REASON WHY. ' The heavens declare the glory of God : and the firmament shuwcth his ha work. Day unto day uttereth speech, and night uuto night showeth knowledge." PSJLLM inc. the air, by night, but, on the contrary, give off carbonic acid pas. Therefore il has been stated that plants in rooms by night are unhealthy. Mr. Robert Hunt, one of the ablest chemists of the present time, makes the following remarks upon this subject in his " Poetry of Science :" " The power of decomposing carbonic acid is a vital function which belongs to the leaves and bark. It has been stated, on the authority of Leibk', that during the night the plant acts only as a mere bundle of fibres that it 'allows of the circulation of carbonic acid and its evaporation, unchanged. In his eagerness to support his chemical hypothesis of respiration, the al)lc chemist neglected to enquire if this was absolutely correct. The healthy plant never ceases to decompose carbonic acid during one moment of its existence; but during the night, when the excitement of light is removed, and the plant reposes, its vital powers are at their minimum of action, and a much less quantity is decomposed than when a stimulating sun, by the action of its rays, is compelling the exertion of every vital function." In hot, swampy countries, where vegetation is very rapid, and the soil loaded with decomposing carbonic matter, the plants absorb more carbonic acid than they require, and they then evolve carbonic acid gas from their leaves. Hence such climates as the West Indies are injurious to life, though favourable to vegetation. 1147. How do plants obtain liydrogen? They obtain 'hydrogen in combination with oxygen in water, and with nitrogen, in the form of ammonia, as which it exists in animal manures. 1148. How do plants obtain nitrogen ? From the atmospheric air, and from the soil, in which it is combined with other elements. 1149. How do plants apply these elements to the formation of their own structures ? When those substances which form the food of plants are absorbed, either by their leaves or their roots, they are converted, with the aid of water, into a nutritive sap, which answers the same purposes in plants as blood does in animals. 1150. How is the nutritive sap applied to the growth and enlargement of the plant f Ever}' seed contains a small amount of nutrition, sufficient for the ustentation of the germ of the plant, until those vessels are formed, by. which the nutritive elements din be absorbed and ured for the further development of the living structure. The earth, penetrated by the sun's rays, warms the sleeping gwm, and quickens it into life. For a short time the ger>n lives upon f THE SEASON WHY. 289 1 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." PSALM crv. the seed, which, moistened and warmed by the soil, yields a kind of glutinous sap, out of which the first members of the plant are formed. And then the tender leaf, looking up tc the sky, and the slender rootlet penetrating the soil, begin to draw their sustenance from the vast stores of nature. 1151. Ofichat do vegetable structures consist? Of membranes, or thin tissues, which, being variously arranged, form cells, tubes, air passages, &c. Of fibres, which form a stronger kind of membrane, and which is variously applied to the production of the organs of the plants. And of organs, formed by those elementary substances, by which the plants absorb, secrete, and grow, and fulfil the conditions of their existence. 1152. Why are seeds generally enveloped in hard cases ? Because the covering of the seed, like the shell of an egg, ia designed to preserve the germ within from the influence of external agencies, until the time for development has arrived, and the conditions of germination are fulfilled. 1153. Why does a seed throw out a root, lefore it forms a leaf? Because moisture, which the root absorbs from the earth, is necessary to enable the germ to use the nutrition which the seed itself contains, and out of which the leaf must be eliminated. Moisture forms a kind of gluten, in which the starch of the seed is dissolved, and converted into sugar, the sugar into carbonaceous sap, and the sap into cellular tissue and woody fibre, as the leaves present themselves to the influence of the air and light, 1154. Why does a plant grow ? Because, as soon as membranes and vessels are organised in the young germ, the nutritive fluid, formed by its first organs, begins to move through the fine structures, and from that time the plant commences to incorporate with its own substance the element* with which it is surrounded, that are suitable to its development. ' 13 290 TnE REASON WHY. 'Can the rush grow up without mire? can the flag grow witlim-t \vator 1 Whilst it is yet in his greenness, and not cut down, it withnvth buf".---, any other herb."- JOB Till. CHAPTER LIX. 1155. Why, if tee break the stem of a hyacinth, do ice a glutinous fluid exude ? Because, by breaking the stem, we rupture the vessels of tlio plant, and cause the nutritive fluid to escape. The sap of the plant is analagous to the Hood of man, and the vessels, to the arteries and veins of the animal body. 1156. Why, if we split the petal of a tulip, do tee see cells containing matter of various colours? Because, by splitting the petal of the flower, we disclose the anatomy of its structure, and bring to view those cells, or organs, of the vegetable body, by which the different colouring matter* are secreted. 1157. Why, if we IreaJc a pea-shell across, do we discover a transparent membrane which may be removed from the green cells underneath ? Because we separate from the cellular, or fleshy part of the .shell, the membrane, which forms the epidermis, and answers to the skin of the animal body. 1158. Why, if we cut through a callage stump, do ice find an outer coat of woody fibre, and an inner substance of cellular matter ? Because the woody fibre forms a kind of skeleton, which supports the internal stricture of the plant, and gives form and character to its organisation. The woody fibre of plants is analagous to the bony structure of animal bodies. 1159. Why, if we cut across the stem of a plant do we see umerous tubes arranged in parallel lines ? Because we thereby bring to view the vessels formed by the membranes and fibres of the vegetable body, for the transmission of the fluids, by which the structure is sustained. Skeleton leaves, and seed vessels of plants, form exceedingly interesting THE EEA90N TVHY 291 " It was planted in a good soil by great waters, that it might bring forth branches, and that it might bear fruit, that it might be a go dly vine." EZEKIEL xvn. objects, and serve to illustrate the wonderful structure of plants. With patience and care, they maybe produced by any person, and will afford an interesting occupation. The leaves should be gathered when they arc in perfection- that is, when some of the earliest leaves begin to fall from the trees. Select perfect leaves, taking care that they are not broken, or injured by insects. Lay them in pans of rain water, and expose them to the air to undergo decomposition. Rcnsw the water from time to time, taking care not to damage the leaves. Tiiey need not be examined more than once a week, and then only to see that the water is sufficient to cover them. Give them sufficient time for their soft parts to become decomposed, then take them out, and laying them on a white plate with a little water, wash away carefully, with a camel-hair pencil, the green matter that clings to the fibres. The chief requirement is patience on the part of the operator, to allow the leaves and seed vessels sufficient time to decompose. Some leaves will take a few weeks, and others a few months, but a large panful may bo put to decompose at the same time, and there will always be some ready lor the process of cleansing. When they are thorougly cleaned, they should be bleached, by steeping fora short time in aweak solution of chloride of lime. They should then be dried, and cither pressed flat, or arranged in boquets for preservation under glass shades. The result will amply reward the perse- verance of the operator. 11GO. Why are clayey soils unfavourable to vegetation ? Because the soil is too close and adhesive to allow of the free passage of air or water to the roots of the plants ; it also obstructs the expansion of the fibres of the roots. 1161. Why are sandy soils unfavourable to vegetation? Because they consist of particles that have too little adhesion to each other ; they do not retain sufficient moisture for the nourishment of the plants ; and they allow too much solar heat to pass to the roots. 1162. Why are chalk soils unfavourable to vegetation ? Because they do not absorb the solar rays, and arc therefore sold to the roots of plants. 1163. Why are mixed soils favourable to vegetation ? Because they contain the elements of nutrition essential to the development of the vegetables, and the plants absorb from them those constituents which are necessary to their growth. 1164. Why do farmers sow different crops in rotation ? Because every plant takes something horn the soil, and *ive 892 THE SEASON WHT. " He watereth the hills from his chambers ; the earth is satisfied ' fruit of thy works." PSALM civ. something back ; but all kinds of plants do not absorb nor restore the elements in the same proportions. Therefore a succession of crops of one kind would goon impoverish the soil ; but a succes- sion of crops of different kinds will compensate the soil, in some degree, for the nourishment withdrawn. 1165. Why do farmers manure their lands ? Because, as soils vary, and crops impoverish tie soils, the farmer employs manure to restore fertility, and to adapt the soils to the wants of the plants he desires to cultivate. It is remarkable that Nature herself points out to man the necessity for changing the succession of vegetable growths. When plants have exhausted the soil upon which they grow, tkey will push their roots far in search of sustenance, and in time migrate to a new soil, while other plants will spring up and thrive upon the area vacated. When a forest in North America is destroyed by fire, the trees that grow afterwards are unlike those that the fire consumed, and evidently arise from seeds that have long lain bizried in the earth, waiting the time when the ascendancy of the reigning order of plants should cease. 1166. Why are grasses so widely diffused throughout nature? Because they form the food of a very large portion of the animal kingdom. They have therefore been abundantly provided. No spot of earth is allowed to remain idle long. When the foot of man ceases to tread down the path, grass immediately begins to appear ; and by its universality and the hardihood of its nature, it clothes the earth as with a carpet. Many grasses, whose leaves are so dry and withered that the plants appear dead, revive and renew their existence in the spring by pushing forth new leaves from the bosom of the former ones. Withering 's Botany. Grasses are Nature's care. With these she clothes the earth ; with these she sustains its inhabitants. Cattle feed upon their leaves ; birds upon their smaller seeds ; men upon the larger ; for, few readers need be told that the plants which produce our bread-corn, belong to this class. In those tribes which are more generally considered as grasses, their extraordinary means and powers of preservation and increase, their hardiness, their almost unconquer- able disposition to spread, their faculties of revivisuence, coincide with the intention of nature concerning them. They thrive under a treatment by which other plants are destroyed. The more their leaves are consumed, the more their roots increase. The more they are trampled upon, the thicker they grow. Many of the seemingly dry and dead leaves of grasses revive, and renew their verdure in the spring. In lofty mountains, where the summer heats are not sufficient to ripen the seeds, grasses abound which are viviparous, and consequently able to propagate themselves without seed. It is an observa'ion, likewise, which has often been made, that herbivorous animals attach themselves to the leaves of grasses j and, if at liberty in their pastures to range md choose, leave untouched the straws which support the flowers. Paley. THE SEASON WHY. 293 ' For tlie e'f.h bringeth forth fruit of herself; first the blade, then the ear, after that the full ear in the corn." MAEK V. CHAPTER LX. 1167. Why do some plants droop, and turn to the earth after sunset ? Because, when the warmth of the sun's rays is withdrawn, they turn downwards, and receive the warmth of the earth by radiation. 1167* Why does the young ear of corn first appear enfolded in two green leaves ? Because the light and air would act too powerfully for the young ear ; two leaves therefore join, and embrace the ear, and protect it until it has acquired strength, when they divide, and leave the ear to swell and ripen. 1168. Why are the seeds of plants usually formed within the corollas of flowers ? Because the petals of the flowers, surrounding the seeds, afford them protection until they are ripened, when the flower dies, and the petals fall to the ground. 1169. Why does the flower of the poppy turn down during the early formation of seed? Because the heat would probably be too great for the seed in its early stage. The plant is therefore provided with a curious curvt in its stalk, which turns the flower downward. But when the seeds are prepared for ripening, the stalk erects itself, and the 1170. Why have plants of the pea tribe, a folding blossom called the "boat," or "keel?" Because, within that blossom the pea is formed, and the shape of the blossom is exactly suited to that of the pea which is formed therein. The blossom is itself protected by external petals ; and when the wind blows, and threatens to destroy the parts upon which the seeds depend, tte plants turn their back* to the wind* and shelter the seed. 294 THE EEASON WHT. " The fruit of the righteous is a tree of life ; and he that winneth souls is wise." PKOVEEBS xi. 1171. Why are the leaf buds enclosed in scales which fall off as the leaf opens ? Because the scales serve as a shelter to the tender structure of the young leaf. The scales are rudimentary leaves, formed at the end of the previous season, and which, being undeveloped then, serve to guard the young leaves of the future year. In trees, especially those which are natives of colder climates, this point is taken up earlier. Many of these trees (observe in particular the ash and the horse-chestnut) produce the embryos of the leaves and flowers in one year, and bring them to perfection the following. There is a winter therefore to be gotten over. Now what we are to remark is, how nature has prepared for the trials and severities of that season. These tender embryos are, in the first place wrapped up with a compactness, which no art can imitate ; in which state they compose what we call the bud. This is not all. The bud itself is enclosed in scales ; which scales are formed from the remains of past leaves, and the rudi- ments of future ones. Neither is this the whole. In the coldest climates, a third preservative is added, by the bud having a coat of gum or resin, which, being congealed, resists the strongest frosts. On the approach of warm weather this gum is softened, and ceases to be an hinderance to the expansion of the leaves and flowers. All this care is part of that system of provisions which has for its object and consummation, the production and perfecting of the seeds. Paley. 1172. Why are the seeds of many plants enclosed in a rich juice, or pulp ? Because the matter by which the seed is surrounded, as well as being intended fix the nourishment and care of the seed, is designed for the use of man and of animals, by whom the seed is set free to take its place in the earth. By virtue of this process, so necessary, but so diversified, we have the seed, a.i length, in stone-fruits and nuts, incased in a strong shell, the shell itself enclosed in a pulp or husk, by which the seed within is, or hath been, fed ; or, more generally (as in grapes, oranges, and the numerous kinds of berries), plunged overhead in a glutinous syrup, contained within a skin or bladder ; at other times (as in apples and pears) embedded in the heart of a firm fleshy substance ; or (as in strawberries) pricked into the surface of a soft pulp. These and many more varieties exist in what we cull fruits. In pulse, and grain, and grasses ; seeds (as in the pea tribe) regularly disposed in parchment pods, which, though soft and membranous, completely exclude the wet even in the heaviest rains; the pod also, not seldom, (as in the bean), lined with a fine down; at other times (as in the senna) distended like a blown bladder; or we have the seed enveloped in wool (as in the cotton-plant), lodged (as in pines) between the hard and compact scales of a cone, or barricadoed (as in the artichoke and thistle) with spikes and prickles ; in mushrooms, placed under a pent-houao; in ferns, witUiu slits in the back part of the leaf; or (which in th* THE BEASON WHY. 295 1 And J will send grass in thy fields for thy cattle, that thou mayest eat, and be full." DEUTERONOJIT xi. most general organisation of all) we find them covered by strong, close tunicles and attached to the stem according to an order appropriated to each plant, as is seen in the several kinds of grains and of grasses. In which enumeration, \vhat we have first to notice is, unity of purpose under variety of expedients. Nothing can be more single than the design; more diversified than the means. Pellicles, shells, pulps, pods, husks, skin, scales armed with thorns, are all employed in prosecuting the same intention. Secondly ; we may observe, that in all these cases, the purpose is fulfilled within a just and limited degree. "We can perceive, that if the seeds of plants were more strongly guarded than they are, their greater security would interfere with other uses. Many species of animals would suffer, and many perish, if they could not obtain access to them. The plant would overrun the soil ; or the seed bo wasted for want of room to sow itself. It is, sometimes, as necessary to destroy particular species of plants, as it is, at other times, to encourage their growth. Here, as in many cases, a balance is to be maintained between opposite uses. The provisions for the preserration of seeds appear to be directed, chiefly against the inconstancy of the elements, or the sweeping destruction of inclement seasons. The depredation of animals, and the injuries of accidental violence, are allowed for in the abundance of the increase. The result is, that out of the many thousand different plants which cover the earth, not a single species, perhaps, has been lost since the creation. When nature has perfected her seeds, her next care is to disperse them. The seed cannot answer its purpose, while it remains confined in the capsule. After the seeds therefore are ripened, the pericarpium opens to let them out, and the opening is not like an accidental bursting, but for the most part, is according to a certain rule in each plant. What I have always thought very extraordinary; nuts and shells, which we can hardly crack with our teeth, divide and make way for the little tender sprout which proceeds from the kernel. Handling the nut, I could hardly conceive how the plantule was ever to get out of it. There are cases, it is said, in which the seed-vessel, by en elastic jerk, at the moment of its explosion, casts the seeds to a distance. We all, however, know, that many seeds (those of most composite flowers, as of the thistle, dande- lion, &c.) are endowed with what are not improperly called wings; that is, downy appendages, by which they are enabled to float in the air, and are carried oftentimes by the wind to great distances from the plant which pro- duces them. It is the swelling also of this downy tuft within the seed-vessel that seems to overcome the resistance of its coats, and to open a passage for the seed to escape. But the constitution of seeds is still more admirable than either their preservation or their dispersion. In the body of the seed of every species of plant, or nearly of every one, provision is made for two grand purposes : first, for the safety of the germ ; secondly, for the temporary support of the future plant. The sprout, as folded up in the seed, is delicate and brittle beyond any other substance. It cannot be touched without being broken. Yet in beans, peas, grass-seeds, grain, fruits, it is so fenced on all sides, K shut up and protected, that whilst the seed itself is rudely handled, tossed into sacks, shovelled into heaps, the sacred particle, the miniature plant remains unhurt. It is wonderful, also, how long many kinds of seeds, by the ielp of their integuments, and perhaps of their oils, stand out against decay. A grain of m istard-seed has been known to lie in the earth for a huudw* 296 THE BEJ.SON WHY " Say not ye, There are four months, and then cometh harvest ? behold, I raj unto you, Lift up your eyes, arid look on the fields ; for they are white already to harvest." Jons iv. years ; and as soon as it had acquired a favourable situation, to shoot a vigorously as if just gathered from the plant. Then, as to the second point, the temporary support of the future plant, the matter stands thus. In grain, and pulse, and kernel, and pipins, the germ composes a very small part of the seed. The rest consists of a nutritious substance, from which the sprout draws its aliment for some considerable time after it is put forth j viz., until the fibres, shot ont from the other end of the seed, are able to imbibe juices from the earth, in a sufficient quantity for its demand. It is owing to this constitu- tion that we see seeds sprout, and the sprouts make a considerable progress, without any earth at all. From the conformation of fruits alone, one might be led, even without ex- perience, to suppose, that part of this provision was destined for the utilities of animals. As limited to the plant, the provision itself seems to go beyond its object. The flesh of an apple, the pulp of an orange, the meat of a plum, the fatness of the olive, appear to be more than sufficient for the nourishing of the seed or kernel. The event shows, that this redundancy, if it be one, ministers to the support and gratification of animal natures ; and when we observe a provi- sion to be more than sufficient for one purpose, yet wanted for another purpose, it is not unfair to conclude that both purposes were contemplated together. Paley. 1173. Why have climbing plants tough curly tendrils ? Because, having no woody stalks of their own to support them, they require to take hold of surrounding objects, and raise them- selves from the ground by climbing. Their spiral tendrils are, therefore, so many hands, assisting them to rise from the earth. 1174. Why does the pea put forth, tendrils, and the lean not? Because the bean has in its stalk sufficient woody fibre to support itself, but the pea has not. We do not know a single tree or shrub having a firm strong stem sufficient for its support which is also supplied with tendrils. 1175. Why do the ears ofivheat stand up ly day, and turn- down by night f Because, when the ear is becoming ripe, the cold dew falling into the ear, might induce blight ; the ears therefore turn down to the earth, and recei.ve warmth by radiation. 1176. Why have grasses, corn, canes, fyc., joints, or knots in their stalks. Because a long hollow stem would be liable to bend and break. But the joints are so many points where the fibres are bound together, and the structure greatly strengthened THE EEASOK WHY. * Then shall the sarth yield her increase ; and God, even our own God, shall bless us." PSALM XLYII. 1177. Why have the berries of the mistletoe a thick viscid juice ? Because the mistletoe is a parasitical plant, growing upon the bark of other tress. It will not grow in the ground ; its seeds are therefore filled with an exceedingly sticky substance, which serves to attach them to the bark of trees, to which the berries attach them- selves at once, by throwing out tough fibres ; and the next year the plant grows. Fig. 75.-THE MISTLETOE. 1178. How are the seeds of the mistletoe transferred from its own stem to the bark of trees. Various birds, and particularly the missel thrush, feed upon the berries. As the bird moves in pursuit of its food, the viscid berries attach themselves to its feathers, and in this way the thrush is the instrument which conveys the seed to the spot to which it adheres, and from which the tree ultimately grows, 1179. What is the circulation of the sap in plants f The circulation of the sap is the movement of the nutritive juices by which the p.ant is sustained. There is a slow uninterrupted 13* 298 THE SEASON WHY. " For the sun is no sooner arisen with a burning heat, but it withereth the grass, and the flower thereof falleth, and the grace of the fashion of it perisheth : so also shall the rich man fade away in his ways." JAMES i. movement of the sap from the root through the stems to the leaves, and downwards from the leaves through the bark to the root. 1180. Why docs the sap of plants thus ascend and descend ? Because it conveys upward from the ground some of the matter by which the plant is to be nourished, and which must undergo digestion in the leaves ; and it brings doionward from the leaves the matters absorbed, for the nourishment of the plant, and dis- charges through the root the substances which the plant cannot use. The movement of the sap is most active in the spring ; but in the depths of the winter it almost ceases. There arc other motions of tho sap in plants, which are called special, in distinction from the ascending arfd descending of tho sap, which is called general, or common to all plants. The special movements of the sap are peculiar to certain plants, in some of which a fluid, full of little green cells, is found to have a rotatory motion; in other plants, a milky fluid is found to move through particular tissues of the vegetable structure. 1181. WJiy are the leaves of plants green ? Because they secrete a carbonaceous matter, named chlorophyl, from which they derive their green colour. 1182. Why are the hearts of callages, lettuces, fyc., of a pale yellow colour ? Because the action of light is necessary to the formation of chlorophyl ; and as the leaves are folded upon each other, they exclude the light, and the green matter is not formed. 1183. Why do leaves turn brown in the autumn ? Because, when their power of decomposing the air declines, the oxygen absorbed in the carbonic acid gas, lodges in the leaf, imparting to it a red or brown colour. 1184<. Why do succulent fruits, such, as gooseberries, plums, fye., taste acid ? Because, in the formation of juices, a considerable amount of xygen is absorbed, and the oxygen imparts, acidity to the taste. THE EEASON TVHY. 299 " The earth is full of the goodness of the Lord." PSALM xxxm. 1185. Why do ripe fruits taste sweet, and unripe fruits taste sour ? Because the juices of the ripe fruit contain a large proportion of sugar, which in the unripe fruit has not been formed. 1186. Why do some leaves turn yellow ? Because they retain an excess of nitrogen. Leaves undergoing decay turn either yellow, red, crimson, or violet. Yellow is due to the excess of nitrogen ; red and crimson to various proportions of oxygen; violet to a mixture of carbon; and green to chlorophyl. 1187. Why do leaves fall off in the autumn ? Because they have supplied for a season the natural wants of the tree. Every part has received nutrition through the spring and summer months ; and the wants of the tree being supplied, the chief use of the leaf ceases, and it falls to the ground to decay, and enrich the soil. 1188. Why do plants suffer from the smoJce of cities ? Because the smoke injures the porous structure of the leaves, and interferes with their free respiration. LESSON LXI. 1189. Why are vegetable productions so widely diffused? Because they everywhere form the food of the animal creation, Without them, neither man nor beast could exist. Even the flesh- eating animals are sustained by them, since they live by preying upon the bodies of vegetable-eaters. They also enrich and beautify the earth. They present the most charming diversities of proportions and features. From the cowslip, the primrose, and the blue-bell of our childish days, to the broad oak under which we recline, while children gambol round us, they are all beautiful or sublime, and eminently useful in countless ways to man. They spread a carpet over the surface of the earth ; they cling to eld ruins, and civer hard rocks, as though they would hide decay, and 300 THE SEASON WHY. "The glory of the Lord shall endure for ever: the Lord shall rejoice iu works." PSALM civ. give warmth to the coldness of stone. In tropical climates they supply rich fruits full of cool and refreshing juices, and they epread out upon the crests of tall trees those broad leaves whidi shelter the native from the scorching heat of the sun. They supply our dwellings with furniture of every kind, from the plain deal table, to the handsome cabinet of satin or rosewood ; they afford rich perfumes to the toilette, and luscious fruits and wines to the desert ; they charm the eye of the child in the daised field; they adorn the brow of the bride ; they are laid in the coffin with the dead ; and, as the cypress or the willow bend over our graves, they become the emblems of our grief. 119U. What is mahogany ? Mahogany is the wood of trees brought chiefly from South America and Spain. The finest kind is imported from St. Domingo, and an inferior kind from Honduras. We all krow the beiuty of mahogany wood. But we do not all know that mahogany was first employed in the repair of some of Sir Walter Raleigh's ships at Trinidad in 1597. The discovery of the beauty of its grain for furniture and cabinet work was accidental. Dr. Gibbons, a physician of eminence, was build- ing a house in King-street, Covent-garden ; his brother, captain of a West I ndiaman, had brought over some planks of mahogany as ballast, and he thought that the wood might be used up in his brother's building, but the carpenters found the wood too hard for their tools, and objected to use it. Mrs. Gibbons shortly afterwards wanted a small box made, so the doctor called upon his cabinet-maker, and ordered him to make a box out of some wood that lay in his garden. The cabinet-maker also complained that the wood was too hard. But the doctor insisted upon its being used, as he wished to preserve it as a memento of his brother. When the box was completed, its fine colour and polish attracted much attention ; and he, therefore, ordered a bureau to be made of it. This was done, and it presented so fine an appearance that the cabinet-maker invited numerous persons to see it, before it was sent home. Among the visitors was her Grace the Duchess of Buckingham, who immediately begged some of the wood from Mr. Gibbons, and employed the cabinet-maker to make her a bureau also. Mahogany from this time became a fashionable wood, and the cabinet- maker, who at first objected to use. it, made a great sucpess by i(,s introduction. 1191. What is rosewood? Bosewood is the wood of a tree which grows in Brazil. It is, generally speaking, too dark for large articles of furniture, but is admirably adapted for smaller ones. It is expensive, and the hardness of the wood renders the cost of making articles of is very high THE BEASOST WHY. 3Q1 * I am come up to the height of the mountains, to the sides of Lebanon, and will cut down the tall cedars thereof, and the choice fir trees thereof." ii. KINGS xxin. Respecting the other woods used in the manufacture of furniture, we have nothing special to say, except of the oak the emblem of our native land. This tree yields a most useful and durable wood, and as it not only defends our country by supplying our " wooden walls," but gives to us the floors of our houses, furnishes our good substantial tables, and comfortable arm-chairs, it will be well for us to kiuw a few facts about this celebrated tree. It is said that there are no less than one hundred and fifty species of the oak. The importance of the growth of oaks ir.ay be gathered from the fact, that the building of a 70-gun ship would take forty acres of timber. The building of a 70-gun ship is estimated to cost about 70,000. Oak trees attain to the age of 1,000 years. The oak enlarges its circumference from 104 inches to 12 inches in a year. The interior of a great oak at Allonville, in Normandy, has been converted into a place of worship. An oak at Kiddington, served as a village . prison. A large oak at Salccy, was used as a cattle fold ; and others have served as tanks, tombs, prisons, and dwelling-houses. The Mammoth tree, which is exhibiting at the Crystal Palace, is one of the great wonders of the vegetable creation. It is the grand monarch of the Californian forest, inhabiting a solitary district on the elevated slopes of the Sierra Nevada, at 5,000 feet above the sea-level. From 80 to 90 trees exist, all within the circuit of a mile, and these varying from 250 to 320 feet in height, and from 10 to 20 feet in diameter. The bark is from 12 to 15 inches in thickness; the branchlets are somewhat pendent, and resemble those of cypress or juniper, and it has the cones of a pine. Of a tree felled in 1853, 21 feet of the bark from the lower part of the trunk were put in the natural form as a room, which would contain a piano, with seats for forty persons ; and on one occasion 150 children were admitted. The tree is reputed to have been above 3,000 years old ; that is to say, it must have been a little plant when Samson was slaying the Philistines. The portion of the tree exhibiting at the palace is 103 feet in height, and 32 feet iu diameter at the base. 1192. What is tea ? Tea is the leaf of a shrub (Thea Chitiensis). The plant usually grows to the height of from three to six feet, and resembles in appearance the well-known myrtle. It bears a blossom not unlike that of the common dog-rose. The climate most congenial to it is that between the 25th and 33rd degrees of latitude. The growth of good tea prevails chiefly in China, and is confined to a few provinces. The green and black teas are mere varieties, depending upon the culture, time of gathering, mode of drying, &c. Coffee was used in this country before tea. In 1664, it is recorded, the East India Company bought 21b. 2oz. of coffee as a present for the king. In the year 1832, there were 101,687 licensed tea dealers in the United Kingdom. Green tea was first used in 1715. A -dispute with America about the duty upon tea led to the American war, out of which arose American independence. The consumption of tea 302 THE BEASON WHY. ' Erery man should eat and drink, and enjoy the good of all his labour, it if the gift of God." -EcciESiASTES HI. throughout the whole world is estimated at above 52,000,000 Ibs., of which the consumption of Great Britain alone amounts to 30,000,000. (See 1225). 1193. What it coffee? Coffee is the berry pf the coffee plant, which wts a native of that part of Arabia called Yemen, but it is now extensively cultivated in India, Java, the West Indies, Brazil, &c. (See 1224). The first coffee-house iu London was opened in 1632, under the following circumstances. A Turkey merchant named Edwards, having brought along with him from the Levant, some bags of coffee, and a Greek servant who was skilful in making it, his house was thronged with visitors to see and taste this new beverage. Being desirous to gratify his friends without putting himself to inconvenience, ho allowed his servant to open a coffee-house, and to sell coffee publicly. Here we have another illustration of the great results springing from trifling causes. Coffee soon became so extensively used that taxes were imposed upon it. In 1660 a duty of 4d. a gallon was imposed upon all coffee made and sold. Before 1732 the duty upon coffee was 2s. a pound ; it was afterwards reduced to Is. 6d., at which it yielded to the revenue, for many years, 10,000 per annum. The duty has been gradually reduced, and the consumption has gone on increasing, until at last above 25,000,000 of pounds are consumed annually ! Fancy this great result springing from a " friendly coffee party" that assembled in the year 1652. 1194. What is chocolate ? It is a cake prepared from the cocoa-nut. The nut is first roasted like coffee, then it is reduced to powder and mixed with water, the paste is then put into moulds and hardened. The properties are very healthful, but its consumption is very insignifi- cant, as compared with tea or coffee. The cocoa tree grows chiefly in the West Indies and South America. 1195. What is cocoa? Cocoa is also a preparation from the seeds or beans of the cocoa tree. But the best form of cocoa for family use is to obtain the beans pure, as they are now commonly sold ready for use, and to break them and then grind them in a large cofiee mill. 119G. W hat is chicory ? Chioory is the root of the common endive, dried and roasted as toffee, for which it is used as a substitute. Some persons prefer the flavour of chicory admixed with coffee. But very opposite THE BEASON WHY. 3Q? ' He that tilleth the laud shall have plenty of bread : but he that followeth after vain persons shall have poverty enough." PBOVEEBS xxvm. opinions prevail respecting the qualities of chicory. We belive it to be perfectly healthful, and attribute the prejudice that prevails against it, to its having been used, from its cheapness, to adulterate coffee. 1197. What is sugar? Sugar is a sweet granulated substance, which may be derived from many vegetable substances, but the chief source of which is the sugar cane. The other chief sources that supply it are the maple, beet-root, birch, parsnip, &c. It is extensively used all over the world. Sugar is supposed to have been known to the ancient Jews. It was found in the East Indies by Newcheus, Admiral of Alexander, 325 B.C. It was brought into Europe from Asia. The art of sugar refining was first practised in England, in 1G59, and sugar was first taxed by name by James II., 1685. Sugar is derived from the West Indies, Brazil, Surinam, Java, Mauritius, Bengal, Siam, the Isle de Bourbon, &e. Ac. Before the introduction of sugar to this country, honey was the chief substance employed in making sweet dishes ; and long after the introduction of sugar it was used only in the houses of the rich. The consumption in England in 1700 reached only 10,000 tons; in 1831 it had reached 180,000 tons. The English took possession of the West Indies in 1G72, and in 1646 began to export sugar. In 1676 it is recorded that 400 vessels, averaging 150 tons, were employed in the sugar trade of Barbadoes. Jamaica was discovered by Columbus, and was occupied by the Spaniards, from whom it was taken by Cromwell, in 1636, and has since continued in our own possession. When it was conquered there were only three sugar plantations upon it. But they rapidly increased. Until the abolition of slavery in the West Indies, the productidn of sugar was almost exclusively limited to slave labour. (See 1226). 1198. What is wheat ? Wheat, rye, barley, oats, millet, and maize, all belong to tho natural order of grain-bearing plants. They all grow in a similar manner, and all yield starch, gluten, and a certain amount of phos- phates. They are commonly spoken of as farinaceous foods. From tho Sacred writings we learn that unleavened bread was common in the days of Abraham. In the earlier periods of our own history, people h.w no other method of making bread than by roasting corn, and beating it in mortars, then * etting it into a kind of coarse cake. In 1596, rye bread and catmeal formed a rczsiderable part of the diet of servants, even in great families. In the time of Charles the First, barley bread was the chief food of the people. In many i arta of England it was more the custom to make bread at home then at present. In 1804, there was not a single public baker in Manchester. In France, when tha use of yeast was first introduced, it was deemed by the faculty of medicine to lx o injurious to ivjalth that its use was prohibited undor tho severest penaiti** 304 THE BEASON WHY I clothed theo also with broidered work, and shod thee with badgers' ikln. and I girded thee about with fine linen, and I covered thee with silk." EZEKIEL XVI. Hcrault says that, during the siege of Paris by Henry the Fourth, a famine raged, and bread sold at a crown a pound. When this was consumed, the dried bones from the charnel house of the Holy Innocents were exhumed, and a kind of bread made therefrom. Bread-street, in London, was once a bread market. From the year 1266, it had been customary to regulate by law the price of bread in proportion to the price of wheat or flour at the time. This was called the assize of bread ; but, in 1815, it was abolished. In the year 272 there was a famine in Britain so severe that people ate the bark of trees ; forty thousand persons perished by famine in England in 310 ! In the year 450 there was a famine in Italy so dreadful that people eat their own children. A famine, com- mencing in England, Wales, and Scotland, in 954, lasted four years. A famine in England and France, in 1193, led to a pestilential fever, which lasted until 1195- In 1315 there was again a dreadful famine in England, during which people devoured the flesh of horses, dogs, cats, and vermin ! In the year 1775, 16,000 people died of famine in the Cape de Verds. These are only a few of the remark- able famines that have occurred in the course of history. Let us thank God that we live in times of abundance, when improved cultivation, the pursuit of industry, and the settlement of the laws, render such a calamity as a famine almost an impossibility. 1199. What is cotton? Cotton is a species of vegetable wool, produced by the cotton shrub, called, botanically, Gossypium herbaceum, of which (here are numerous varieties. It grows naturally in Asia, Africa, and America, and is cultivated largely for purposes of commerce. The precise time when the cottr i manufacture was introduced into England it unknown ; but probably it was not before the 17th century. Since then, what wonderful advances have been made ! The cotton trade and manufacture have become a vast source of British industry, and of commerce between nations. It was some years ago calculated that the cotton manufacture yielded to Great Britain one thousand millions sterling. The names of Hargreaves, Arkwright, Crompton, Cart wright, and others, have become immortalised by their inventions for the improvement of the manufacture of cotton fabrics. Little more than half a century has passed since the British cotton manufactory was in its infancy now it engages many millions of capital keeps millions of work people employed ; freights thousands of ships that are ever crossing and re-crossing the seas ; and binds nations together in ties of mutual interest. The present yearly value of cotton manufactures in Great Britain is estimated at .$4,000,000. About 6,044,000 of the above sum is distributed yearly among working people as wages. 1200. What is silk ? Silk, though not directly a vegetable product, is, nevertheless, indirectly derived from the vegetable creation, since it is a thread spun by the silk -worm from matter which the worm derives from the mulberry leaf. Silk is supplied by various parts of the world, including China, the E* THE EEASON WHY. "And there was a man in Maon, whose possessions were in Carmel and the man was very great, and he had three thousand sheep, and a thousand goats and he was shearing his sheep in Carmel." i SAMUEL xxv. Indies, Turkey, Ac., where the silk-vrorm has been found to thrive. The attempts that have been hitherto made to cultivate it in this country have proved unsuccessful. At Rome, in tl.3 time of Tiberius, a law passed the senate which, as well as prohibiting the wearing of massive gold jewels, also forbade the men to debase themselves by wearing silk. There was a time when silk was of the same value as gold weight for weight and it was thought to grow upon trees. It is recorded that silk mantles were worn by some noble ladies at a ball at Kenilworth Castle, 1286. It was first manufactured in England in 1604. In the reign of Elizabeth, the manufacture of silk in England made rapid strides. In loGG, there were 40,000 persons engaged in the silk trade. The silk throwsters of the metropolis were enrolled in a fellowship in 1562, and were incorporated la 1629. In 16S5, a considerable impetus was givt-n to the English silk manu- factures. Louis the Fourteenth of France revoked the edict of Nantes. The edict of Nantes was promulgated by Henry the Fourth of France in 1598. It pave to the Protestants of France the free exercise of their religion. Louis the Fourteenth revoked this edict in 1683, and thereby drove the Pro- testants as refugees to England, Holland, and parts of Germany, where they established various manufactures. Many of these French refugees settled in Spitalflelds, and there founded extensive manufactories, which soon rivalled those of their own country; and thus the intolerance of the king was justly punished. What important facts we see connected with the simple thread of the silk-worm ! 1201. What is wool ? Wool is a kind of soft hair or coarse down, produced by various Animals, but chiefly by sheep. This is another of the useful productions of nature, for which we are Indirectly indebted to the vegetable kingdom ; for were it not for the rich pastures forming the green carpet of the earth, it would be impossible for man to keep large flocks of sheep for the production of wool. Wool, like the hair of most animals, completes its growth in a year, and then exhibits a tendency to fall off. For the production of wool in England and Wales it has been estimated that there are no less than 27,000,(HK) sheep and lambs; and, in Great Britain and Ireland, the total number is estimated at 32,000,000. Wool was not manufactured in any quantity in England until 1331, when the weaving of it was introduced by John Kempe and other artizans from Flanders. The expor- tation or non -exportation of wool has from time to time formed a vexed subject for legislators. Woollen clothes were made an article of commerce in the reigu of Julius Caesar. They were made in England prior to 1200. Blankets were first made in England in 1340. The art of dyeing wools was first introduced into England in 1603. The annual value of the raw material in wool is set down at 6,000,000 ; the wages of workmen engaged in the wool trade, 9,000,000, The number of people employed is said to be 500,000. 1202. What is starch? Starch is one of the most useful products of the vegfetabh kingdont. As a rule, a vegetable, if nutritious at all, is to i06 THE KEASON WHY. "Every good gift and every perfect gift is from above, and cometh down from the Father of lights, with whom is no variableness, neither shadow o.' turning." JAMES I. according to the amount of sta/vh which it contains. It is moat abundantly found in the seeds of plants, and especially in the wheat tribe. It is also met with in the cellular tissues of plants, and especially in such underground stems as the potatoe, carrot, turnip, 4"c., and the stems of the sago-palm fig, &c. It is also found in the baric of some trees. 1203. Why is the Jiorse chesnut, though containing a great quantity of starch, unfit for food? Because (like many other vegetable productions) it contains with the starch an acrid juice, which renders it unhealthy ; and although the juice can be separated from the starch, the process is too expensive to be made generally available. The starch which is used for domestic purposes is an artificial preparation, and does not properly represent the starch of nutrition, A better idea of it is afforded by the meal of a flowery potatoe. The starch used by laundresses is frequently prepared from diseased potatoes. This does not impair the quality of the starch, for the purposes of the laundress, and the reason why potatoes that are diseased are thus applied is, that it is one method of saving some part of their value. The finest kinds of starch are prepared from rice. It is prepared by breaking the pulp, and disengaging the starch from the cells ; and it is then put through other processes to remove the fragments of the broken cells. But in the flowery meal of the potatoe, the starch cell may be seen entire. CHAPTER LXII. 1204. What are vegetable oils and fats ? Vegetable oils and fats constitute, next to starch and sugar, the most important secretion of the vegetable creation. There are very few plants from which some amount of oil cannot be obtained ; and those which are famed for yielding it owe their celebrity rather to the abundance that they yield, and the peculiar qualities of their oil, than to the secretion of oil being rare for probably there is no plant without it. Oil is most commonly found in seeds, as rape-seed, linseed, &c. t but it is found also in leaves, as in the rose, sweet-briar, peppermint &c., where its presence may be recognised by the distinguishing THE SEASON WHY. 307 1 Ointment and perfume rejoice the heart ; so doth the sweetness of a man's friend by hearty counsel." PEOVEBBS xxvn. perfume ; and it is also found in the wood of a few trees, such as the sassafras and the sandal-wood ; the bark frequently yields an oily secretion. The London and North "Western Railway Company alone use about 50,000 gallons of oil yearly. 1205. Why are fat and oil found most abundantly in the bodies of animals in cold climates ? Because they contribute to keep the bodies of animals warm, not only by their non-conducting property keeping in the heat of the animals, but by supplying carbon abundantly to combine with oxygen during respiration, and thereby developing animal heat. 1206. Why are oil and fat-forming trees found most abundantly in hot climates ? Because, in hot countries, the formation of large quantities of fat in animal bodies would oppress living creatures with heat ; fats and oils are, therefore, produced in those countries chiefly by vegetables, and are used externally by the Asiatics and Africans as an external unction for cooling the skin, and as perfumes which give inspiriting properties to the air, rendered oppressive by excess of heat. 1207. Why are succulent fruits most abundant in tropical climates ? Because they are rendered necessary in those climates by the excessive heat, and are found to have a most beneficial effect in cooling, purifying the blood of the inhabitants of tropical countries ; while the grandeur of their foliage, and the richness of their flowers, are in perfect keeping with the intensity of light and heat, and serve, by throwing dense shades over the earth, to cool its surface, and to offer to living creatures a pleasant retreat from the rays of the burning sun. The following sketch of Botanical Geography should be read attentively after the reader has gone through the whole of the Chapters of "Reasons." Tho technical terms employed in the course of the article are nearly all explained at 1212, and should be committed to memory at the commencement of the perusal. Mimosa means a sensitive plant ; concentric zones, circular lines spreading from a centre; arborescent, resembling trees j Gramineee, grass-like. The botanical names represent individual plants. 1208. When treating of the geographical distribution of vegetables, we hive to Bark the general arrangements indicated, and the agencies that have evidently 308 THE REASON WHY. "Blessed is the man that walketh not in the counsel of the ungodly, nor standeth in the way of sinners, nor sitteth in the seat of the scornful : " operated in promoting the diffusion of floral tribes. Vegetation occurs over the whole globe, therefore, under the most opposite conditions. Plants flourish in the bosom of the ocean as well as on land, under the extremes of cold and heat in polar and equatorial regions, on the hardest rocks and the soft alluvium of the plains, amidst the perpetual snow of lofty mountains, and in springs at the temperature of boiling water, in situations never penetrated by the solar rays, as the dark vaults of caverns, and the walls of mines, as well as freely exposed to the influences of light and air. But these diverse circumstances ha~o different species and genera. There is only one state which seems fatal to the existence of vegetable lifu-the entire absence of humidity. 1209. By species we understand so many individuals as intimately resemble each other in appearance and properties, and agree in all their permanent characters, which are founded in the immutable laws of creation. An established species may frequently exhibit new varieties, depending upon local and accidental causes, but these are imperfectly, or for a limited time, if at all, perpetuated. 1210. A genus comprises one or mere species similar to each other, but essentially differing in formation, nature, and in many adventitious qualities from other plants. A tribe, family, group, or order, comprises several genera. 1211. The known number of species in the vegetable kingdom has been gradually enlarged by the progress of maritime and inland discovery; but owing to great districts of the globe not having yet been explored by tho botanist, the interior of Africa, and Australia, with sections of America, Asia, and Oceanica, it is impossible to state the exact amount. The successive augmentation of the catalogue appears from the numbers below : Species. Theophrastus 600 Pliny 1,000 Greek, Roman, and Arabian botanists . . 1.400 Bauhin 6,000 Linnaeus 8,800 Persoon 27,000 Humboldt and Brown 38,000 DeCandolle 66,000 Lindley 8(5,000 Hinds 89,000 1212. Vegetable forms are divided into three great classes which differ materially in their structure:!. Cryptogamous plants those which have no flowers, properly so called, mosses, lichens, fungi, and ferns : as distinguished from those which are phsenogamous, or flower-bearing, to which the two following classes belong. 2. Endogenous plants, which have stems increasing from within, also called Monocotyledons, from having only one soed-lobe, as the numerous grasses, lilies, and the palm family. 3. Exogenous plants, which have stems growing by addi tie-as fro -n without, also called Dicoteledons, from the seed consisting of two lobes, the most perfect, beautiful, and numerous class, embracing the forest trees, and most flowering shrubs and herds. 1213. The oxosens furnish examples of gigantic size, and great longevity. In South America on the banks of the Atabapo, Humboldt measured a Bombax caiba more than 120 feet high, and 15 in diameter ; and near Cumana, he found THB BEAtON WHY. 309 He shall oe like a tree planted by the rivers of water, that bringeth forth his fruit in season : his leaf also shall not wither; and whatsoever he doeth shall prosper." PSAIM i. tho Zamang del Guayra, a species of mimosa, the pendant branches of tho hemispherical head having a circumference of upwards of 000 feet. The Adansonia, or baobab of Senegal, though attaining no great height, rarely more than fifty feet, has a trunk with a diameter sometimes amounting to 34 feet ; while the Pinus Lambertiana, growing singly on the plains west of the Eockj Mountains, has been found 250 feet high, 60 feet in circumference at the base, 4^ feet in girth at the height of 190 feet, yielding coues 11 inches round, and 16 long. The Ficus Indlcus, or banian tree, sending out shoots from its horizontal branches, which reaching the ground take root, and form new stems till a single tree multiplies almost to a forest, has been observed covering an area of 1700 square yards. 1214. From the number of concentric zones observed in a transverse section of the stems De Caudolle advances proof of the following ages : Elm 835 years. Cypre&s about 350 Oheirostemon 400 Ivy 450 fc Larch ....'.... 576 , Orange 630 Olive 700 Oriental Piano 720 and upwards. Cedar of Lebanon 800 Oak 810, 1080, 1500 Lime 1076; 1147 Yew 1214, 1458, 25S8, 2830 Taxodium 4000 to 6000 Boabab 5150 1215. Admitting, with Professor Henslow, that De Cmndolle overrated the ages of these trees one-third, they are examples of extraordinary longevity. Yew trees upwards of 700 years old remain at Fountains Abbey, Yorkshire, as there is historic evidence of their existence in the year 1133. But a yew in the church- yard of Darley-in-the-Dale, Derbyshire, is considered by Mr. Bowman as 2000 years old. 1216. The cryptogamous plants afford the most numerous examples of wide diffusion. an enables us to reach. These researches show us, that where the mean temperature of the climate is 50 cleg., the temperature of t tie rock at 59 fathoms from the surface is GO deg. ; at 132 fathoms it is 70 dog; at 239 fathoms it is 80 deg. ; being an increase of 10 deg. at 59 fathoms deep, or 1 deg. in 35 4 feet of 10 deg. more at 73 fathoms deeper, or 1 deg. in 43.8 feet ; and of 10 deg more at 114 fathoms still deeper, or 1 deg. in 64.2 feet. Although this would indicate an increase to a certain depth of about one degree in every fifty feet, yet it would appear that the rate of increase diminishes with the depth. It appears therefore probable, that the heat of the earth, so far as man can examine it, is due to the absorption of the solar rays by the surface. The evidences of intense igneous action at a great depth cannot be denied but the doctrine of a cooling mass, and of the existence of an incandescent mass, at the earth's centre, remains but one of those guesses which active minds delight in." Upon the subject of hunger and thirst, by which living creatures are prompted to feast upon the bounties of nature, Sir Charles Bell says, in " Appendix to Paley's Natural Theology :" 1337. "Hunger is defined to beapeculiar sensation experienced in the stcmach from a deficiency of food. Such a definition does not greatly diifer from th'o notions of those who referred the sense of hunger to the mechanical action ol the surfaces of the stomach upon each other, or to a threatening of chemical action of the gastric juice on the stomach itself. But an empty stomach does not cause hunger. On the contrary, the time when the meal has passed the stomach is the best suited for exercise, and when there is the greatest alacrity of spirits . The beast of prey feeds at long intervals; the snake and other cold- blooded animals take food after intervals of days or weeks. A horse, on the con- trary, is alwavs feeding. His stomach, at most, contains about four gallons, yet throw before him a truss of tares or lucerne, and he will eat continually. Tho emptying of the stomach cannot, therefore, be the cause of hunger. " The natural appetite is a sensation related to the general condition of tho system, and not simply referable to the state of the stomach; neither to its action, nor its emptiness, nor the acidity of its contents ; nor in a starved creature will a full stomach satisfy the desire of food. Under the same impulse which makes us swallow, the ruminating animal draws the morsel from its own stomach. 13 ">8. " Hunger is well illustrated by thirst. Suppose we take the definition of thirst that it is a sense of drvness and constriction in the back part of the mouth and fauces ; the moistening of these parts will not allay thirst after much fatiguo or during fever. In making along speech, if a man's mouth is parched, and tho di'vness is merely from speaking, it will be relieved by moistening, but if it comes from the feverish anxiety and excitement attending a public exhibition, his thirst will not be so removed. The question, as it regards thirst, was brought to a demonstration by the following circumstance. A man having a wound low d-)\v:i in his throat, was tortured with thirst: but no quantity of fluid passing tl rough lib mouth and gullet, and escaping by the wound, was found in au.y degree to quanch his thirst. " Thirst, then, like hunger, has relation to the general condition of the aniiiisl ystem to the necessity fo- fluid in tli o circulation. For this reason, a man dying 15* 346 THE SEASON WHY. Let us hear the conclusion of the whole matter; Fear God. and keephii commandments: for this is the whole duty of man." ECCLESIASTES in. from loss of blood suffers under intolerable thirst. In both thirst and hunger, the supply is obtained through the gratification of an appetite; and as to thrso appetites, it will be acknowledged that the pleasures resulting from them far exceed the pains. They gently solicit for the wants of the body ; they are I ho perpetual motive and spring to action." Our task draws near to a conclusion ; and we hope that those who have followed our teachings will thirst after further know- ledge ; that they will henceforward regard the great Book of Mature as the work of an Almighty Hand, and endeavour to find, for everything that Nature does, the Reason Why. A high perception of the wisdom of the Divine Being, must necessarily be the result of an intelligent contemplation of the Divine works. To the ignorant, the name of God is an unmeaning word ; it may inspire fear, but it does not develope love. To the dark mind of the untaught man, God is no more than one of those mysterious existences that awe the superstitious, and deter the wicked. There is no grafting of the soul of the man upon the eternal love. But knowledge brings man into communion with that Almighty wisdom which is the fountain of all truth and happiness. To the enlightened man, God is the sun of all goodness, around whom the attributes of Power, Wisdom, and Love, radiate and fill the universe. As man's physical eye cannot withstand the light of the sun, neither can man's spiritual eye see the whole glory of God. But as we can rejoice in the sunshine, and interpret the mission of the sunbeam, so can we find happiness in the Divine presence, and gather wisdom by the contemplation of the Creator's works. Nature is a great teacher. What a lesson may be gathered from the germination of a seed ; how uniformly the germs obey their destiny. However carelessly a seed may be set in the ground, the germ which forms the root, and that which is the architect of the stem, will seek their way the one to light, the other to darkness to fulfil their duty. The obstruction of granite rocks, cannot force the rootlet upward, nor drive the leaflet down. They may kill the Brorms by exhausting their vital powers in an endeavour to find the proper elements ; but no obstruction can make a single blade of grass do aught but strive to fulfil the end for which it was created. Would that man were equally true to the purpose of his existence, and suffered neither the rocks of selfishness, nor the false light of temptation, to force or allure him from duty to his God. THE E.VD. A BOOK OF UNIVERSAL KNOWLEDG-E. IUST PUBLISHED, THE MOST USEFUL AND EXTRAORDINARY VOLUME Ever yet issued from the Press, as It comprises all the essence contained in a Dozen of any other Books of Information that have hitherto been printed. THE TITLE OF THIS WONDERFUL BOOK, 18 AS FOLLOWS: INQUIRE WITHIN FOR ANY THING YOU WISH TO KNOW ; OR OVEE 3,700 FACTS FOE THE PEOPLE. A Large Volume of 436 pages Cloth, gilt Price $1. Sent free of Postage. This Book, as its title imports, will give you correct information on every possible subject that you ever heard or thought of ! It tells you how to cook a dinner to cure a sick friend, or cut an acquaintance to get up a dinner parly, or dine abroad to play at cards, at chess, or any other popular game, whether you wish to establish yourself in life accord- ing to the rules of etiquette, to get up a sumptuous entree for the dinner table, or arrange aplain dinner to fold fancy napkins to start business to make money to dress with taste to conduct a courtship to tie any kind of a knot to get married to give an evening parly to your friemu to behave well in company to keep house properly to dance-^-to make ornamental vases, by the new art of Porchomanie, or Wax work, and other fancy employments for the ladies : to establish acquaintances according to the rules of etiquette to enjoy an hour at curious puzzles and arith- metical questions to do up a neat parcel to relieve the invalid to ac- quaint yourself with the technical terms in literature, law, and medicine in short, to do every useful thing that can be thought cf or imagined, whether at home or abroad, or among your friends, or in your business, or an your farm, or in your garden, or at a public meeting, or at a private assembly. It contains tables of all weights and measures ; Interest Tables from SI to $10,000 at six and seven percent., besides innumerable tables on Interesting and Curious Subjects. It gives complete directions how to wash, starch, and iron how to keep the eves, hair, teeth and complexion in perfect order how to punctuate, spell and write correctly how to com- pose all kinds of letters, from the billet-deaux to the business letter how to clean furniture, take care ofpei animals how to measure all kinds of mechanic's work how to dft eel fraudulent scales and all about the proper- ties and uses of different medicines. Indeed this is really and truly or.e of the most wonderful and valuable books ever printed. Besides all this in- formation and we have not room to give an idea of a hundredth part of it it contains so many Valuable and Useful receipts that an enumeration of them requires SEVENTY-TWO CO LttMNS OF FINE TYPE FOH THE INDEX. If you wish to consult law cr physic, buy this book! If you want to learn mechanically how to do a little of everything that is vscful, buy it ! If you have any literary vanity, and wish to become a blue-sU>ck- ing or if you desire to make & sensation in almost any way, this book will tell you exactly how to do it ! It is no collation of ancient sayings and receipts, but the whole 616 fresh and new, and suited to the present limes. As a book to keep in the family for reference, it is unequalcd, com- prising as it does all kinds ofliooks of Information in a single volume. Bend ciieh orders to . DICK & FITZGERALD. No. 18 Ann Street, New York. A Book of Neyer-Ending Entertainment. THE SOCIABLE; OR, One Thousand and One Home Amusements, CONTAINING ACTING PROVERBS, DRAMATIC CHARADES, ACTING CHARADES, OR DRAWING-ROOM PANTOMIMES, MUSICAL BURLESQUES, TABLEAUX VIVANTS, PARLOR GAMES, GAMES OF ACTION, FORFEITS, SCIENCE IN SPORT AND PARLOR MAGIC, AND A CHOICE COLLECTION OS CURIOUS MENTAL AND MECHANICAL PUZZLES, &c. By the author of "The Magician's Own Book." Illustrated with nearly 300 Engravings and Diagrams, THE WHOLE BEING A FUND OP NEYER-ENDING ENTERTAINMENT. Nearly 400 pages, 12mo., Cloth, gilt side stamp, $1.00. " The Sociable" will be found one of the most extensively popular family books ever issued from the press. As its title implies, it is a collection a com- plete repertoire of the AMUSEMENTS OF HOME, Embracing a large and comprehensive list of recreative pastime, arranged as follows: Parlor Theatricals, including Acting Proverbs, Acting Charades, Dramatic Charades and Tableaux Vivants; Games of Action ; Games requiring Memory and Attention; Games requiring Wit and Intelligence ; Ruses, or Catch Games ; Forfeits ; Puzzles ; Fireside Games forWinter Evenings, and Science in Sport, and Parlor Magic, Many of these Games the majority of them are ENTIKELT NBW, as arc, also, the PARLOR THEATRICALS TABLEAUX VIVANTS, Which were PREPARED EXPRESSLY FOB THIS WORK. Everything in the book is superior of its kind-^-tho greatest care Ira-ing been taken to exclude cvcrthing that was not above the standard of mer diocrity in interest and ingenuity. It is THE ONLY BOOK OF THIS KIND Ever Published in America, And as it will be invaluable to Families, Schools, Social Clubs, etc., as a book of reference on Jill matters of Amusement and Recreation, there must be a steady and permanent demand for it at all sea- sons and in all yenrs, although few of the so-called "Holiday Books" are as appropriate for Gifts as THE SOCIABLE. Each department is AMPLY ILLUS- TRATED with BEAUTIFUL WOOD ENGRAVINGS Which render the Text clear, and fully explain all the Puzzles, the Mechanical Contrivances mentioned, and other things difficult to describe in writing. It is elegantly bound, so as to be an ornament to any center-table, and its typographical execution is a specimen of the highest excellence. The need of such a collection of HOME GAMES has long been felt, and the pub- lishers believe that this endeavor on their part, to supply that want, must meet with the fullest success. They have spared neither trouble nor expense to render it a complete and invaluable vade mccum of Domestic Amusements, so that its name may bo familiar as a "Household Word" in all families, north, south, east and west, where the value of wholesome and innocent recreation is recognised, Price only One Dollar, bound in. cloth, with gilt side and back stamp, gent to any aJJrcss in the United States, free of postage. Send cash orders to DICK & FITZGERALD, Publishers, IS Arm Street, New York. lH VERY MAN A MAG-IOIAIST. THE MAGICIAN'S OWN BOOK; OR, 0f Cwtjurmg. B*ing a Complete Hand-Book of Parlor Magic, confining over One Thousand Optical, Chemical, Mechanical, Magnetical, and Magical Experiments, Amusing Transmutations, Astonishing Sleigbta and Subtleties, Cele- brated Card Deceptions, Ingenious Tricks wich Numbers, Curious and Entertaining Puzzles Together with all the most Noted Tricks of Modern Performers. The whole Illustrated with GOO "WOOD CUTS, And intended as a source of amusement for ONE THOUSAND AND ONE EVENINQS. 12mo., cloth, 400 pages ; gilt side and back stamp. Price, OXE DOLLAB, sent free of postage. Here is a book for the long winter evenings, and one that will make all merry and happy. It contains over a THOUSAND TRICKS, of every descrip- tion, and they are all explained so clear and explicitly that any person can comprehend and perform them with ease. Jt also contains numerous CURIOUS PUZZLES, with patterns showing how they are done, any one of which will afford amusement enough for a whole evening. There is, aiso, the best collec- tion of wonderful CARD DECEPTIONS ever yet published, any one of which is worth more than double the price of the book. This work also contains a splendid collection of CURIOUS TRICKS WITH NUMBERS, and embraces several hundred tricks never before in print. It is ao catchpenny affair, but a standard work, containing every variety of Experiment in Conjuring, Cards, Legerdemain, Transmutations, the Magic of Che.tiistry, the Magic of Me- chanics, the Magic of Pneumatics, the Magic of Numbers, the Magic of Art, the Magic of Strength, the Magic of Magnetism, tie Magic of Secret Writing, Miscellaneous Curious Tricks and Fancies, &c. This book is beautifully bound in One cloth, with gilt side and back stamp, and is illustrated with OVER 500 WOOD ENGRAVINGS, Besides a Tintel Title Page and Frontispiece. Price, ONE DOLLAR, and sent to any address, free of postage. Send cash crders to DICK & FITZGERALD, INo. 18 Ann Street, New York. ROMANTIC INCIDENTS IN THE LIVES OF THE QUEENS OF ENGLAND. By J. F. SMITH, AUTHOR OF "STANFIELD HALL," "AMY LAWRENCE, 1 HOWARD," ETC. 12mo. Beautiful Illustrations. Extra Cloth, gilt, Sl.OO. This is a beautiful volume of 350 pages, elegantly illustrated. It contains truthful and admirably drawn literary portraits of Elizabeth Woodville, Queen Consort of Edward IV., Eleanora of Aquitaine, Queen Consort of Henry II., Matilda of Flanders, Queen Consort of William the Conqueror, and Matilda Atheling, Queen Consort of Henry I. The writer, in giving us the history of these eminent women, has remark- ably exemplified the old adage that " truth is stranger than fiction ;" for no pure romance could excel it in stirring incident, and the various vicissitudes of love, pleasure, sorrow and suffering, which form the staple of all works of fiction. Each sketch is a complete narrative in itself, possessing all the charms of a novel, with the additional value and merit of historical truth. The book may be read with equal entertainment and profit. Portraits of my Married Friends; OR, A PEEP INTO HYMEN'S KINGDOM. BY UNCLE BEN. BEAUTIFULLY ILLUSTRATED FROM DESIGNS BY BARLEY AND OTHER EMINENT AUTISTS. Large ISnao. Cloth, $1.^5. These sketches are six in number. The first is that of "Alice," whose husband, resisting her gentle influence in the commencement of their married life, falls into the hands of a gambler, who first ruins his fortune, and then induces him to commit forgery. He is arrested and imprisoned, while she dies broken-hearted. The second is that of " Harry Weatherall," who spends the best part of his life in attendance upon a nervous, selfish wife, and is killed just as she has determined to reform. The third is that of " Sam Percival and the Widow," who both marry for money, and both find themselves dsceived in their expectations. The fourth is that of " Jerome and Susan Daly," honest, industrious, and ultimately successful people. The fifth is that of " Ringold Hopkins." who is very exacting and very jealous. His wife, who is young enough to be his daughter, is totally unfit to superin- tend a family, and not finding himself entirely comfortable at home, he tries board- ing at a hotel. There he suffers from a severe attack of the " green-eyed monster," and concludes to recommence house-keeping. The sixth is that of " Kate Kearney," a beautiful but uneducated Irish girl. Sho marries a French emigrant, who is ashamed of and neglects her. He dying, she goes to live with his father, in France, and by incredible exertions fits herself to teach English, and thus supports herself. Copies of either of the above popular books sent to any address, free of postage. Send cash orders to DICK & FITZGERALD, 18 Ann St., N. Y. THE FAMILY AQUARIUM: Oi\ Aq^ia Vivarium. A NEW PLEASURE FOR THE DOMESTIC CIRCLE. Being a Familiar and Corny. lete Instructor upon the subject of the Construction, Fitting np. Stocking, and Maintenance of the Marine and Fresh Water Aquarium, or River and Ocean Gardens. By IT. D. BUTLER, Esq. 12mo. Cloth, with gilt side stamp. Price 50 Cents. We flatter ourselves that we know something of the character and principles of the Aquarium, as well as of its management, and we feel capable of doing justice to Mr. Butler, who, in this production, has succeeded in arraying even the drycst portion of the topic in g;ty and vivacious, not to say really pleasing colors. His style is easy, simple, interesting, full of good nature, and his pages abound with salient points of humor, as well as occasionally, flashes of truly eloquent thought, and moral commentary. The " Family Aquarium" we do not hesitate to pronounce the mo~t perfect- work of the kind extant in our language. It is not mere.y a rehash of English books having reference to English habits and English localities. It is American in all respects, and re- markably original, not on?y teaching the " young idea how to shoot," in pre- paring an Aquarium as a substitute for the old fish globe, but showing why the water need never be changed, and illustrating the grand compensating princi- ple by means of which nature avoids all that redundant waste of exertion. The " Family Aquarium," also instructs the reader how and whereto supply himself with the most appropriate iteh.the most suitable river or sea-plunts, insects, Crustacea, anemones, or animal flowers, &c., and the best mode of sustaining them in health and vigor. With this little adviser on her parlor tab;e, any lady may fit up an Aquarium to please her own taste. She cannot go astray Everything is set down and intelligibly explained, and though she may live a thousand miles from the sea-board, she will be able to present as perfect an Aquarium as a resi- dent .on the Atlantic coast. The volume has our heartiest and most conscien- tious commendation New. York Times. Tlie A/rts of Beauty; Or, SECKETS OF A LADY'S TOILET. WITH HINTS TO GENTLEMEN ON THE ART OF FASCINATING. By MADAM LOLA MONTEZ, COUNTESS OF LANDSFELD* Beau.tifu.lly "bound in. cloth. ZPrice 5O Cents. This wonderful book contains an account, in detail, of all the arts employed by the ladies of all the chief cities of Europe for the purpose of developing and preserving their charms. Independent of its rare and useful recipes, the book is a curiosity as apiece of art itself, for the most delicate subjects are handled with a skill and an unexceptional propriety of language that is truly sur- prising. The hints to gentlemen on the artof fascinating, form one of the most amusing and biting pieces of irony and sarcasm that was ever written. The wit of this portion of the "Book is inimitable, and the " coarser sex," as Lola quaintly calls the men, ought universally to bow to her with thanks and admira- tion for the work which she has performed. Copies of either of the above books sent to any address in the United States or Canada. Send cash orders to DICK &FITZGERALD, Publishers, No. 1 8 Ann Street, New York. Modest yet Amusing Curious yet Chaste. CTTJST ISSTJEID! One of the most piquant and unique volumes, upon a peculiar, singular, and uni- versally interesting subject that has ever found its way into print. A work at onco MODEST AND AMUSING, CURIOUS, YET CHASTE, on that world-wide and thrilling topic LOVE being, as it were, the history, philosophy, character, and peculiarities of the passion as illustrated by the AMATORY ANNALS OF ALL NATIONS, This novel production is entitled ANECDOTES OF LOVE, And is from the pen of that celebrated Lady, Madame LOLA MONTEZ, Countess of Landsfeldt, .And embraces about a THOUSAND SPRIGHTLY CHAPTERS, in which the "ten- der passion" is treated under as many different phases. Each chapter is a STORY CF LOVE in itself, and includes: Alexander and Thais, I The Love of Acliomath, The Loves of Colatiiic C'amlna* } Love a Great Teacher, Curious Story of Love, A'an Anna of Cauuioiit, Humorous Sequel to Love, | The Virtuous Chioiiiare, Archbishop Unfitted by Love, Countess of Salisbury, POJII-* Created and Destroyed j Death of the Innocent, by Love, i Madame de Maintciioii, The Charming Yota, The Gentle Agues, Loves of a Great, General, Countess of Chateaubrisiiit, Love in Babylon, Love and Surgery, The Amorous Leag Loves of Cresar, Loves of a Pop Kingdom Lost by Love, Love between Armies, Duke de Loiigueville, Jvlng Ex- press. Large 12mo. Paper, price 59 cents. Cloth, 75. Copies of either of the above popular books sent to any address, free of postage. Send cash orders to DICK & FITZGERALD, No. 18 Ann Street, New York. MRS. PARTINGTON'S CARPET BAG OF FUN. ILLUSTRATED WITH OVER 150 OF THE MOST LAUGHABLE ENGRAVINGS Ever designed, from drawings by Barley, McLennan, Leach, Phiz, Henning, nine, Tenniel, Crovquill, Cruikshank, Meadows, Doyle, Goder, and others, and a collec- tion of over 1000 of the most Comical Stories, Amusing Adventures, Side-splittinsr Jokrs, Cheek-extending Poetry, Funny Conun- drums, QUEER SAYINGS OF MRS. 1'ARTINGTON, Heart-rending Vuns, Willy Repartees, etc., etc. In offering this book to the public, we must caution all weakly find nervous people against buying it. It is only intended for those hearty and robust persons who c;m laugh long and loud, and grow fat, being a perfect Encyclopedia of Wit and Witty Sayings. To those fond of Fun it will bo a treasure. To enumerate tho Ludicrous, Curious, Sentimental, Essential, Witty, Pretty, Funny and many Cuts, would consume too much space ; however, any one of them is well worth the price of the whole book. This entertaining book is well printed on fine white paper, with an ornamental cover, designed by McLennan, at tiie amnzingly low price of 50 Cents ; bound in cloth, gilt, 75 Cents. Sent to any address in the United States free of postage. Dr, Valentine's Comic Lectures. A budget of Wit and Humor ; or, Morsels of Mirth for the Melancholy. A certain cure for the Blues, and all otiier serious complaints. Comprising Comic Lecture* on Heads, Faces, Noses, Mouths, Animal Magnetism, etc., with Specimens of Elo- quence, Transactions of Learned Societies. Delineations of Eccentric Characters, Comic Songs, etc., etc. By Dr. W. VALENTINE, the favorite delineator of Eccen- tric Characters. Illustrated with twelve portraits of Dr. Valentine, in his most celebrated characters. 12mo. Cloth, gilt, price 75 Cents. Ornamental paper cover, price 50 Cents. DR. VALENTINE'S COMIC METAMORPHOSES. Being the second series of Dr. Valentine's Lectures, with characters as given by the late Yankee Hill. Embellished with numerous portraits. Ornamental paper cover, price 50 Cents. Cloth, gilt, price 75 Cents. The celebrated Dr. Valentine, whose name alone, to those who have heard him, is sufficient to excite the risibilities of the most sedate. All who want a good laugh must get this book, and they will not bo disappointed. A lively, sparkling, humor- ous affair. Dr. Valentine is one of the best delineators of character since the days of Matthews, of facetious memory. His Yankees, O!<1 Women and Frenchmen, are wonderfully fine, and always draw down heavv rounds of applause from his audiences. We recommend the book cordially to our reacfers, for its wit, humor, and originality. Saturday Courier. Copies of tho above books sent to any address in the United States free of postage. Send cash orders to DICK 2 Cents. HOW TO DRESS WITH TASTE. Containing Hints upon the Harmony of Colors, the Theory of Contrast, the Com- plexion, Shape or Height, a Cents. BRIDAL ETIQUETTE. A sensible Guide to the Etiquette and Observant containing complete directions for Bridal Reoeptio Bridesmaids, Groomsmen, sending cards, &c. Cents. BLUNDERS IN BEHAVIOR CORRECTED. A concise code of deportment for both sexes. " It will polish and refine either sex, and is Chesterfield superseded." Home Companion. Price 13K Cents. Copies of either of the above books sent to any address in the United States or Canada. Send cash orders to DICK & FITZGERALD, Publishers, No 18 Ann Street, H&w Yox-lt- 9 ft 2. e THE LIBRARY UNIVERSITY OF CALIFORNIA Santa Barbara THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW. 000 850 572 9