THE UNIVERSITY 
 
 OF ILLINOIS 
 
 LIBRARY 
 
 580.4- 
 v. I 
 
 *<*<*> 
 
 M 
 
 Hi 
 

 
 M AV 11 1970 
 W*- ^ 49 ^UL201970 
 
 M>R2 6**S* 
 
 s 
 
 Qa ') 
 
 
 r> 
 
 5 i * 
 
 A/rv * ' *° 
 
 19 5*0 
 
 JUN1 01353 
 
 MAR 
 
 ? SB 
 
 MA? 
 
 2 6 1958 
 
 DEC 2 7 1361 
 DEC 12 1 Q *2 
 

 
 
STATICAL ESSAYS: 
 
 CONTAINING 
 
 VEGETABLE STATICKS; 
 
 Or, an Account of feme 
 
 Statical Experiments 
 
 O N T H E 
 
 SAP in VEGETABLES. 
 
 BEING 
 
 An Essay towards a Natural Hiftory of 
 Vegetation: Of Ufe to thofe who 
 are curious in the Culture and Improve- 
 ment of Gardening, &c. 
 
 ALSO 
 
 A Specimen of an Attempt to Analyfe the Air, 
 by a great Variety of Chymio-Statical 
 Experiments, which were read at fevei*al 
 Meetings before the Royal Society. 
 
 VOL. I. 
 
 Quid eft in his, in quo non natura ratio intelligent is appareat f Tul. de Nat. Deor. 
 ——Etenim Experimentorum longe major eft fubtilitas y quam fen jus ipfius 
 
 ltd que eo rem deducimus, utfenfus tantum de Experiment o t Experimentum 
 
 de re judicet. Fran, de Verul. Inftauratio magna. 
 
 By STEPH. HALES, D. D. F. R. S. 
 
 Rector of Faringdon, Ha?npJJAre, and Minifter 
 of Teddwgton, Middle/ex. 
 
 The Third Edition, with Amendments. 
 
 LONDON: 
 Printed for W. Inn y s and R. Manb y, at the Weft-End of 
 St. Paul's; T.Woodward, at the Half-Moon ovcr-ag i 
 St. Dwiflan's Church in Fleet-flrcet ; and J. Pe f. l e, at locks' s 
 Head in Amm-Corner. M.dcc. xxxviii. 
 
Feb. 1 6, 1726-7. Imprimatur. 
 
 Isaac Newton, Pr.Reg.Soc. 
 
5 8 
 H }3 
 
 V, t 
 
 T O 
 
 His Royal Highness 
 
 GEORGE 
 
 Prince of WALES. 
 
 May it pleafe Tour Royal Highnefs, 
 
 1 Humbly offer the following Expe- 
 riments to Your Highnefs's Patro- 
 nage, to protect them from the 
 reproaches that the ignorant are apt 
 
 A 2 unrea- 
 
DEDICATION. 
 
 unreasonably to call: on refearches of 
 this kind, notwithstanding they are 
 the only folid and rational means 
 whereby we may ever hope to make 
 any real advance in the knowledge 
 of Nature : A knowledge, worthy the 
 attainment of Princes* 
 
 And as Solomon, the greateft and 
 wifeft of men, difdained not to in- 
 quire into the nature of Plants, from 
 the Cedar in Lebanon, to the Hyjfop 
 that fpringeth out of the wall : So it 
 will not, I prefume, be an unaccept- 
 able entertainment to Your Royal 
 Hicrhnefs, at leaft at Your leifure 
 hours ; but will rather add to the 
 pleafure, with which vegetable Na- 
 ture in her prime verdure charms us : 
 To fee the fteps flie takes in her pro- 
 ductions, and the wonderful power 
 (he therein exerts: The admirable 
 
 pro- 
 
DEDICATION. 
 
 provision fhe has made for them, not 
 only vigorotifly to draw to great 
 heights plenty of nouriihment from 
 the earth ; but alfo more fublimed 
 and exalted food from the air, that 
 wonderful fluid, which is of fach 
 importance to the life of Vegetables 
 and Animals ; and which, by infinite 
 combinations with natural bodies, pro- 
 duces innumerable furprizing effedts, 
 many inftances of which I have here 
 fhewn. 
 
 The fearching into the works of 
 Nature, v/hile it delights and inlarges 
 the mind, and ftrikes us with the 
 ftrongeft affurance of the wifdom and 
 power of the divine Architect, in 
 framing for us fo beautiful and well- 
 regulated a world, it does at the fame 
 time convince us of his conftant bene- 
 volence and goodnefs towards us. 
 
 A 3 That 
 
DEDICATION. 
 
 That this great Author of Nature 
 may fhower down on Your Royal 
 Highnefs an abundance of his Blef- 
 lings, both Spiritual and Temporal, 
 is the fincere prayer of 
 
 Tour Royal Highnefs \s 
 Moji Obedient^ 
 
 Humble Servant^ 
 
 Stephen Hales 
 
 the 
 
THE 
 
 PREFACE. 
 
 THERE have been, within lefs 
 than a Century ', very great and 
 ufeful di [cover ies made in the amazingly 
 beautiful Jlruclure and nature of the 
 animal ceconomy ; neither have Plants 
 faffed unobferved in this inquifitive age, 
 which has with fuch dilige?ice extended 
 its iitquiries, infome degree ', into almofl 
 every branch of Nature s inexhauflible 
 fund of wonderful works. 
 
 We fnd in the Philofophical Tranf- 
 a&ions, and in the Hiflory of the Royal 
 Academy of Sciences ', accounts of many 
 curious Experiments and Obfervations 
 made from time to time on Vegetables, 
 by fever al ingenious and inquifitive Per- 
 Jons : But our countryman Dr. Grew, 
 and Malpighi, were the firfi, who, thd 
 
 A 4 in 
 
li The Preface. 
 
 in very dijiant countries, did nearly at 
 the fame tim$ t unhumm to each other ', 
 engage in a very diligent '• and thorough 
 inquiry into the JlruEiure of the vejfels 
 of Plaitts \ a province y which till then 
 had lain uncultivated. They have given 
 us very accurate and faithful accounts 
 of the JlruEiure of the parts, which they 
 carefully traced, from their firjl minute 
 origin, the feminal Plants, to their full 
 growth and maturity, thro their Roots, 
 Trunk, Bark, Branches, Gems, Shoots, 
 Leaves, Blojfoms and Fruit. In all 
 which they obferv\d ait exaEl and regular 
 fymmetry of parts moft curioufly wrought 
 in fuch manner, that the great work of 
 Vegetation might effeElually be carried 
 on, by the uniform co-operation of the 
 fever al parts, according to the differ e?it 
 offices ajftgiied them by Nature. 
 
 Had they fortuned to have fallen into 
 this ftatical way of inquiry, perfons of 
 
 their 
 
The Preface. iii 
 
 their great application aiid fagacity had 
 doubtlefs i?iade confiderable adva7ices in 
 the know/edge of the nature of Plaiits. 
 'This is the only fure way to 7neafure the 
 fever al quantities of nouriflxnent, which 
 Plants imbibe and perfpire, a7td thereby 
 to fee what influence the different flat es 
 of Air have on them. This is the likeliefl 
 7nethod to find out the Sap's velocity p , and 
 the force with which it is imbibed : As 
 aljo to eflimate the great power that 
 Nature exerts in extending and pufjoinv 
 forth her productions by the expanfion of 
 the Sap. 
 
 About twenty years fince^ I made 
 feveral hcemaflatical Experiments on 
 Dogs \ and fix years afterwards re- 
 peated the fame on Horfes and other 
 Animals^ in order to find out the real 
 force of the blood in the Arteries \ fome 
 of which are mentioned in the third 
 chapter of this book : At whicb times I 
 
 wifijed 
 
iv The Preface. 
 
 wijhed I could have made the like Ex- 
 periments \ to dif cover the force of the 
 Sap in Vegetables ; but defpaired of 
 ever efieEling it, till, about feven years 
 fince, by mere accident I hit upon it, 
 while I was endeavouring by fever always 
 to flop the bleeding of a?i old Jlem of a 
 Vine, which was cut too near the bleed- 
 ing feaf on, which I feared might kill it: 
 Havings after other means proved inef- 
 fectual, tied a piece of bladder over the 
 tranfverfe cut of the Stem, I found the 
 force of the Sap did greatly extend the 
 bladdery whe?tce I CG?tcluded, that if a 
 long glafs-tube were fixed there in the 
 fame manner, as I had before done to 
 the Arteries of feveral living Animals, 
 I fhould thereby obtain the real afc end- 
 ing force of the Sap in that Stem, which 
 fucceeded according to my expeElation : 
 and hence it is, that I have bee?i infen- 
 fibly led on to make farther pjid far- 
 ther 
 
The Preface. v 
 
 ther refearches by variety of Experi- 
 7ne?its. 
 
 As the Art ofPhyftck has of late years 
 been much improved by a greater know- 
 ledge of the ani7nal ceco?W7?iy ; fo doubt- 
 lefs a farther infight into the vegetable 
 ceconomy mujl needs proportionably im- 
 prove our skill in Agriculture and Gar- 
 denings which gives me reafon to hope, 
 that inquiries of this kind will be accept- 
 able to many, who are intent upo?t im- 
 proving thofe innocent, delightful, a7id 
 benefcial Arts : Since they cannot be in- 
 fenfble, that the 7710ft ratwial groimd 
 for Succefs i7i this laudable Purfuit tnt ft 
 arifefro7n a greater infight into the na- 
 ture of Plants. 
 
 Finding by many Expe7~i7ne7tts i7i the 
 
 ffth chapter, that the Air is plentifully 
 
 infpired by Vegetables, not only at their 
 
 roots, but alfo thro fever al parts of their 
 
 trunks a7id branches ; this put 77te upon 
 
 7naki7i<y 
 
 o 
 
vi The Preface. 
 
 making a more particular inquiry into 
 the nature of the Air, and to dif cover, 
 if poffble, wherein its great importance 
 to the life and fupport of Vegetables 
 might cojififl ; on which account I was 
 obliged to delay the Publication of the 
 reft of thefe Experiments, which were 
 read two years jince before the Royal So- 
 ciety, till I had made fome progrefs in 
 this i?iquiry : An account of which I 
 have given in the fixth chapter. 
 
 Where it appears by many chymio- 
 fiatical Experiments, that there is dif- 
 fufed thro all itatural mutually attract- 
 ing bodies, a large proportion of parti- 
 cles, which, as the firjl great Author of 
 this important difcovery. Sir Ifaac 
 Newton, obferves, are capable of being 
 thrown off from denfe bodies by heat or 
 fermentation into a vigoroufly elaflick 
 and permanently repelling fate ; and 
 alfo of returning by fermentation, and 
 
 fome- 
 
The Preface. vii 
 
 fometimes without it, i?ito denfe bodies : 
 It is by this amphibious property of the 
 Air, that the mam and principal ope- 
 rations of Nature are carried on ; for 
 a mafs of?nutually attraBing particles, 
 without being blended with a due pro- 
 portion of elajlick repelling ones, would, 
 in many cafes, foon coalefce into a fug- 
 gifj lu?np. It is by theje properties of 
 the particles of matter, that he fo Ives 
 the principal Ph<z?w?nena of Nature. 
 And Dr. Freind has from the fame 
 principles given a very i?tgenious Ratio- 
 nale of the chief operations in Chymijlry. 
 It is therefore of importance to have 
 thefe very operative properties of -natu- 
 ral bodies further afcertaiiied by more 
 Experiments and Obfervations : And it 
 is with fatisfaSlion, that we fee them 
 more and more confrtmd to us, by every 
 far 't her inquiry we make, as the follow- 
 ing Experiments will plainly prove, by 
 
 Jhewing 
 
viii The Preface. 
 
 (hewing how great the power 9 of the at- 
 traEiion of acid fulphureous particles 
 mufi be at fome little diflance from the 
 point of contaEl, to be able mofi readily 
 tofubdue and fix elaflick aereal parti-* 
 clesy which repel with a force fuperior 
 to vafl incumbent preffures : Which 
 particles we find are thereby changed 
 from aflrongly repelling, to as Jlrongly 
 an attraEling Jlate : And that elafli- 
 city is no immutable property of air, 
 is further evident from thefe Experi- 
 ments ; becaufe it were impoffible for 
 fuch great quantities of it to be confined 
 in the fubjlances of Animals and Vege- 
 tables^ in an elaflick jlate, without rend- 
 ing their c&nfiituent parts with a vafl 
 explofion. 
 
 I have been careful in making, and 
 
 faithful in relating the rejult of thefe 
 
 'Experiments ', and wifh I could be as 
 
 happy in drawing the proper inferences 
 
 from 
 
The Preface. ix 
 
 from them. However I may falljhort 
 at jirji fetting out in this Jlatical way 
 of inquiring into the nature of Plants^ 
 yet there is good reafon to believe, that 
 conjiderable advances in the knowledge 
 of their ?iature may, in procefs of time, 
 be made by refearches of this kind. 
 
 And I hope the publication of this 
 Specimen of what I have hitherto do?te y 
 will put others upo?t the fame purfuits, 
 there beings in fo large a feld y and 
 among fuch a?i innumerable variety of 
 fubje&Sy abunda?it room for many heads 
 and hands to be employed in the work : 
 For the wonderful andfecret operations 
 of Nature are fo involved and intricate, 
 fo far out of the reach of our fenfes, as 
 they prefent themf elves to us in their na- 
 tural order, that it is impojpble for the 
 mofl fagacious and penetrat'mg Genius 
 to pry into them, unlefs he will be at the 
 pains of analyfmg Nature by a ?iu7nerous 
 
 a?id 
 
x The Preface. 
 
 and regular feries of Experiments > which 
 are the only folid foundation whence we 
 7nay reafonably expeEl to make any ad- 
 vance in the real knowledge of the nature 
 of things. 
 
 I muft not omit here publiekly to ac- 
 knowledge ', that I have in fever al refpeSls 
 been much obliged to my late ingenious 
 and learned neighbour and friend Robert 
 Mather, of the Inner-Temple, Efq\for 
 his ajjijla?tce herein. 
 
 Whereas fome complain, that they do not under- 
 fland the fignification of thofe fhort figns or 
 characters, which are here made ufe of in many 
 of the calculations, and which are ufual in 
 Algebra ; this mark -f- fignifies more, or to be 
 added to. Thus page 18, line 4, 6 ounces -(- 240 
 grains, is as much as to fay, 6 ounces more by, 
 or to be added to 240 grains. And in line 16, 
 of the fame page, this mark x or crofs figni- 
 rles multiplied by ; the two fnort parallel lines 
 fignify equal to -, thus 1820 x 4= 7280 : 1, is 
 as much as to fay, 18 20 multiplied by 4 equal to 
 7280 is to 1. 
 
 THE 
 
THE 
 
 CONTENTS. 
 
 CHAP. I. 
 
 Experiments, Jkewing the quantities of 
 ?noifiure imbibed and perfpired by Plants * 
 and Trees. Page 4 
 
 CHAP. II. 
 
 Experiments, whereby to find out the force y 
 with which Trees imbibe moifiure. 84 
 
 CHAP. III. 
 
 Experiments, /hewing the force of the fap in 
 the Vine in the bleeding feafo?i. 108 
 
 CHAP. IV. 
 
 Experiments, JJ:ewi?ig the ready lateral motion 
 of the Sap, and confequently, the lateral 
 communication of the Sap- r oe][els t The free 
 P a Jf a S e °f *ty from the fmall Branches to- 
 wards the Stem, as well as from the Stem 
 to the Branches, with an account of fome 
 Experime?its, relating to the Circulation, 
 or Non-circulation of the Sap. J 28 
 
 a C H AP. 
 
 v 
 
The Contents, 
 
 CHAP. V. 
 
 f Experiments, whereby to prove, that a con-. 
 
 Jiderable quantity of air is infpired by 
 
 Plants. 155 
 
 CHAP. VI. 
 
 A Specimen of an attempt to analyfe the Air 
 by chymio-ftatical Experiments, which Jhew 
 in how great a proportion Air is wrought 
 into the compofition of Animal, Vegetable \ 
 and Mineral Subfances : And withal, how 
 readily it refumes its elajlick State, when 
 in the dijfolution of thofe Sub/lances it is 
 dij engaged from them. i6z 
 
 CHAP. VII. 
 
 Of Vegetation. 318 
 
 The Conclufion. 358 
 
A Table where to find each Experiment. 
 
 Experiment 
 I 
 
 2 
 
 3 
 
 4 
 
 5 
 6 
 
 7 
 S 
 
 9 
 io. 
 
 n- 
 
 12. 
 
 i3> I4> 
 
 15- 
 16. 
 
 17. 
 18. 
 
 l 9> 
 20. 
 
 21. 
 
 22. 
 
 23. 
 24. 
 
 25. 
 26. 
 
 27. 
 
 28, 29. 
 
 30. 
 
 31. 
 
 3 2 - 
 
 33- 
 
 34. 
 
 35. 
 
 36. 
 
 37- 
 
 Page 
 
 Experiment 
 
 Page 
 
 4 
 
 38. 
 
 
 Il8 
 
 14 
 
 39- 
 
 
 126 
 
 17 
 
 40. 
 
 
 128 
 
 J 9 
 
 41. 
 
 
 131 
 
 20 
 
 42. 
 
 
 133 
 
 27 
 
 43. 
 
 
 134 
 
 28 
 
 44. 
 
 
 137 
 
 29 
 
 45, 46. 
 
 
 138 
 
 3i 
 
 47- 
 
 
 155 
 
 39 
 
 48. 
 
 
 156 
 
 41 
 
 49> 50, 
 
 5'. 
 
 173 
 
 43 
 
 5 2 > 53> 
 
 54. 
 
 175 
 
 45 
 
 55. 5 6 - 
 
 
 176 
 
 46 
 
 57. 
 
 
 177 
 
 47 
 
 5 8 , 59- 
 
 
 178 
 
 49 
 
 60, 61, 
 
 62. 
 
 179 
 
 50 
 
 63, 64. 
 
 
 180 
 
 5 2 
 
 65, 66. 
 
 
 l8l 
 
 57 
 
 67, 68, 
 
 69, 70. 
 
 182 
 
 85 
 
 71,72. 
 
 
 183 
 
 86 
 
 73* 74. 
 
 
 184 
 
 9° 
 
 75. 
 
 
 187 
 
 9 1 
 
 76. 
 
 
 l88 
 
 94 
 
 77- 
 
 
 189 
 
 95 
 
 Exper. 
 
 Dn Calc. 
 
 } 193 
 
 97 
 
 Human. 
 
 9 8 
 
 78, 79- 
 
 
 199 
 
 99 
 
 80, 81. 
 
 
 202 
 
 JOI 
 
 82. 
 
 
 203 
 
 102 
 
 83. 
 
 
 204 
 
 103 
 
 84. 
 
 
 205 
 
 108 
 
 85, 86. 
 
 
 206 
 
 no 
 
 87. 
 
 
 207 
 
 112 
 
 88,89. 
 
 
 209 
 
 115 
 
 90, 91. 
 
 
 217 
 
 Expe- 
 
A Table where to find each Experiment. 
 
 Experiment 
 
 Page 1 
 
 Experiment 
 
 Page 
 
 92. 
 
 219 
 
 I IO. 
 
 244 
 
 93- 
 
 220 
 
 III. 
 
 248 
 
 94. 
 
 221 
 
 112. 
 
 252 
 
 95- 
 
 222 
 
 113. 
 
 253 
 
 9 6 >97- 
 
 224 
 
 II4. 
 
 255 
 
 98. 
 
 225 
 
 H5. 
 
 263 
 
 99- 
 
 226 
 
 1 16. 
 
 264 
 
 100. 
 
 227 
 
 117. 
 
 273 
 
 IOI. 
 
 228 
 
 Il8. 
 
 281 
 
 102. 
 
 229 
 
 119. 
 
 288 
 
 103. 
 
 230 
 
 120. 
 
 299 
 
 104. 
 
 2 3* 
 
 121. 
 
 304 
 
 105, 106. 
 
 232 
 
 122. 
 
 3 2 9 
 
 107. 
 
 236 
 
 I23. 
 
 33i 
 
 108. 
 
 238 
 
 I24. 
 
 344 
 
 109. 
 
 2 39 
 
 
 
 A Table 
 
 where to 
 
 find each Figure. 
 
 Figure 
 
 Page 
 
 Figure 
 
 Page 
 
 I, 2. 
 
 28 
 
 24. 
 
 132 
 
 3, 4, 5- 
 
 42 
 
 25, 26. 
 
 134 
 
 6. 
 
 44 
 
 27, 28, 29, 30 
 
 152 
 
 7, 8, 9. 
 
 5o 
 
 3^,32. 
 
 160 
 
 10, 11, 12. 
 
 94 
 
 33> 34- 
 
 168 
 
 i3> 14. 
 
 98 
 
 35. 3 6 > 37- 
 
 2IO 
 
 15, 16, 17, 1 
 
 S. 112 
 
 3 8 > 39- 
 
 266 
 
 19. 
 
 **5 
 
 40,41,42,43, 
 
 44. 34<5 
 
 20, 21. 
 
 118 
 
 45, 46. 
 
 350 
 
 22, 23. 
 
 130 
 
 
 
 T H £ 
 
THE 
 
 INTRODUCTION. 
 
 TH E farther refearches we make in- 
 to this admirable fcene of things, 
 the more beauty and harmony we 
 fee in them : And the ftronger and clearer 
 convictions they give us, of the being, power 
 and wifdom of the divine Architect, who 
 has made all things to concur with a won- 
 derful conformity, in carrying on, by va- 
 rious and innumerable combinations of mat- 
 ter, fuch a circulation of caufes and effefts, 
 as was neceflary to the great ends of na- 
 ture. 
 
 And fince we are aflured that the all-wife 
 Creator has obferved the mod exad: propor- 
 tions, of nwnber, weight and meafure, m 
 the make of all things; the moft likely way 
 therefore, to get any infight into the na- 
 ture of thofe parts of the creation, which 
 come within our obfervation, muft in all 
 reafon be to number, weigh and meafure* 
 And we have much encouragement to pur- 
 
 B iue 
 
% Vegetable Statich. 
 
 fue this method, of fearching into the nature 
 of things, from the great fuccefs that has 
 attended any attempts of this kind. 
 
 Thus, in relation to thofe Planets which 
 revolve about our Sun, the great Philofo- 
 pher of our age has, by numbering and 
 meafuring, difcovered the exact proportions 
 that are obferved in their periodical revo- 
 lutions and diftances from their common 
 centres of motion and gravity : And that 
 God has not only comprehended the duft 
 cf the earth in a meafure^ and weighed the 
 mountains in fcales, and the hills in a ba~ 
 lance \ Ifai. xl. J2. but thathealfo holds the 
 vaft revolving Globes, of this our folar Sy- 
 ftem, moft exactly poifed on their common 
 centre of gravity. 
 
 And if we reflect: upon the difcoveries 
 that have been made in the animal (Econo- 
 my, we fhall find that the moft confider- 
 able and rational accounts of it have been 
 chiefly owing to the ftatical examination 
 of their fluids, viz. by inquiring what quan- 
 tity of fluids, and folids diflblved into fluids, 
 the animal daily takes in for its fupport 
 and nourishment : And with what force, 
 and different rapidities, thofe fluids are car- 
 ried 
 
Vegetable Staticks. j 
 
 ried about in their proper channels, accord- 
 ing to the different fecretions that are to 
 be made from them : And in what pro- 
 portion the recrementitious fluid is convey- 
 ed away, to make room for frefh fupplies; 
 and what portion of this recrement nature 
 allots to be carried off, by the feveral kinds 
 of emunctories, and excretory duels. 
 
 And fince in vegetables, their growth, and 
 the prefervation of their vegetable life, is 
 promoted and maintained, as in animals, 
 by the very plentiful and regular motion 
 of their fluids, which are the vehicles or- 
 dained by nature, to carry proper nutriment 
 to every part; it is therefore reafonable to 
 hope, that in them alfo, by the fame me- 
 thod of inquiry, confiderable difcoveries 
 may in time be made, there being, in many 
 refpefts, a great analogy between plants and 
 animals. 
 
 B 2 CHAP 
 
4 Vegetable Staticks. 
 
 CHAP. I. • 
 
 Experiments, Jhewing the quantities imbibed 
 and perjpired by Plants and Trees. 
 
 Experiment I. 
 
 JUL Y 3. 1724. in order to find out the 
 quantity imbibed and perfpired by the 
 Sun-flower, I took a garden-pot (Fig. 1.) 
 with a large Sun-flower, a, 3 feet~j--f high, 
 which was purpofely planted in it when 
 young; it was of the large annual kind. 
 
 I covered the pot with a plate of thin 
 milled lead, and cemented all the joints fait, 
 fo as no vapour could pafs, but only air, thro* 
 a fmall glafs tube d, nine inches long, which 
 was fixed pufpofely near the Hem of the 
 plant, to make a free communication with 
 the outward air, and that under the leaden 
 plate. 
 
 I cemented alfo another fhort glafs tube 
 g into the plate, two inches long, and one 
 inch in diameter. Thro* this tube I watered 
 the plant, and then flopped it up with a 
 cork y I flopped up alfo the holes /, /, at the 
 bottom of the pot with corks. 
 
 I weighed 
 
Vegetable Staticks. 5 
 
 I weighed this pot and plant morning 
 and evening, for fifteen feveral days, from 
 July 3. to Aug. 8. after which I cut off the 
 plant *clofe to the leaden plate, and then 
 covered the Hump well with cement ; and 
 upon weighing found there perfpired thro* 
 the unglazed porous pot two ounces every 
 twelve hours day ; which being allowed in 
 the daily weighing of the plant and pot, I 
 found the greateft perfpiration of twelve 
 hours in a very warm dry day, to be one 
 pound fourteen ounces -, the middle rate of 
 perfpiration one pound four ounces. The 
 perfpiration of a dry warm night, without 
 any fenfible dew, was about three ounces ; 
 but when any fenfible, tho" fmall dew, then 
 the perfpiration was nothing; and when a 
 large dew, or fome little rain in the night, 
 the plant and pot was. increafed in weight 
 two or three ounces. TM. B. The weights 
 I made ufe of were Avoirdupoife weights. 
 
 I cut off all the leaves of this plant, and 
 laid them in five feveral parcels, according 
 to their feveral fizes ; and then meafured 
 the furface of a leaf of each parcel, by lay- 
 ing over it a large lattice made with threads, 
 in which the little fquares were \ of an inch 
 
 B 3 each; 
 
6 Vegetable Statich. 
 
 each ; by numbring of which I had the fur- 
 face of the leaves in fquare inches, which 
 multiplied by the number of the leaves in 
 the correfponding parcels, gave me the area 
 of all the leaves j by which means I found 
 the furface of the whole plant, above ground, 
 to be equal to 5616 fquare inches, or 39 
 fquare feet. 
 
 I dug up another Sun-flower, nearly of 
 the fame fize, which had eight main roots, 
 reaching fifteen inches deep and fideways 
 from the ftem : It had befides a very thick 
 bum of lateral roots, from the eight main 
 roots, which extended every way in a he- 
 miiphere, about nine inches from the ftem 
 and main roots. 
 
 In order to get an eftimate of the length 
 of all the roots, I took one of the main roots, 
 with its laterals, and meafured and weighed 
 them ; and then weighed the other ieven 
 roots, with their laterals ; by which means 
 I found the fum of the length of all the 
 roots, to be no lefs than 1448 feet. 
 
 And fuppofing the periphery of thefe 
 roots, at a medium, to be 0.13 1 of an inch, 
 then their furface will be 2276 fquare 
 inches, or 15. 8 fquare feer -> that is equal 
 
 to 
 
Vegetable Statkhs. 7 
 
 to 0.4. of the farface of the plant above 
 ground. 
 
 If, as above, twenty ounces of water, at 
 a medium, perfpired in twelve hours day, 
 iV. c.) thirty-four cubick inches of water, (a 
 cubick inch of water weighing 254 grains) 
 then the thirty-four cubick inches divided 
 by the furface of all the roots, is = 2286 
 fquare inches ; (/. e.) -gfa is = fa this gives 
 the depth of water imbibed by the whole 
 furface of the roots, viz £j part of an 
 inch. 
 
 And the furface of the plant above ground 
 being 5616 fquare inches, by which divide- 
 ing the 34 cubick inches, viz. s ffi 6 = y^-, 
 this gives the depth perfpired by the whole 
 furface of the plant above ground, viz. 7^-. 
 part of an inch. 
 
 Hence, the velocity with which water 
 enters the furface of the roots to fupply the 
 expence of perfpiration, is to the velocity, 
 with which their fap perfpires, as 165 : 6j y 
 or as $f : ,|- 7 , or nearly as 5 : 2. 
 
 The area of the tranfverfe cut of the mid- 
 dle of the ftem is a fquare inch ; therefore 
 the areas, on the furface of the leaves, the 
 rpots and ftem, are 5616, 2276. j. 
 
 B 4 The 
 
8 Vegetable Stattcks. 
 
 The velocities, in the furface of the leaves, 
 roots, and tranfverfe cut of the ftem, are 
 gained by a reciprocal proportion of the 
 furfaces. 
 
 ^ ^leaves =5616 
 g >roots = 2276 
 < Sftem = 1 
 
 > 
 
 rh' mch 
 ^j inch 
 
 34 inch. 
 
 Now, their perfpiring 34 cubicle inches in 
 twelve hours day, there mud: fo much pafs 
 thro* the ftem in that time; and the velo- 
 city would be at the rate of 34 inches in 
 twelve hours, if the ftem were quite hollow. 
 
 In order therefore to find out the quan- 
 tity of folid matter in the ftem, July 2jth at 
 7. a. m. I cut up even with the ground a 
 Sun-flower ; it weighed 3 pounds ; in thirty 
 days it was very dry, and had wafted in all 
 2 pounds 4 ounces ; that is f of its whole 
 weight: So here is a fourth part left for 
 folid parts in the ftem, (by throwing a piece 
 of green Sun-flower ftem into water, I found 
 it very near of the fame fpecifick gravity 
 with water ) which filling up fo much of the 
 ftem, the velocity of the fap muft be increaf- 
 ed proportionably, viz. f part more, (by 
 
 reafon 
 
Vegetable Staticks. 9 
 
 reafon of the reciprocal proportion) that 34 
 cubick inches may pafs the ftera in twelve 
 hours 5 whence its velocity in the ftem will 
 be 45 -j inches in twelve hours, fuppofing 
 there be no circulation, nor return of the 
 fap downwards. 
 
 If there be added to 34, (which is the lead 
 velocity) -j of it = 1 1 §, this gives the greateft 
 velocity, viz. 457. The fpaces being as 3 : 4. 
 the velocities will be 4 : 3 : : 45 1: 34. 
 
 But if we fuppofe the pores in the iurface 
 of the leaves to bear the fame proportion, 
 as the area of the fap-veffels in the ftem do 
 to the area of the ftem ; then the velocity, 
 both in the leaves, root and ftem, will be 
 increafed in the fame proportion. 
 
 A pretty exact account having been taken, 
 of the weight, fize, and furface of this 
 plant, and of the quantities it has imbibed 
 and perfpired, it may not be improper here, 
 to enter into a comparifon, of what is taken 
 in and perfpired by a human body, and this 
 plant. 
 
 The weight of a well-fized man is equal 
 to 160 pounds: The weight of the Sun- 
 flower is 3 pounds ; fo their weights are to 
 each other as 160: 3, or ^53: 1. 
 
 The 
 
id Vegetal Je Staticks. 
 
 The furface of fuch human b®dy is equal 
 to 15 fquarefeet, or 2160 fquare inches. 
 
 The furface of the Sun-flower is 5616 
 fquare inches 5 fo its furface is, to the furface 
 of a human body, as 26 : 10. 
 
 The quantity perfpired by a man in twenty- 
 four hours is about 3 1 ounces, as Dr. Keill 
 found. Vid. Medic. Stat. Brit an. p. 1 4, 
 
 The quantity perfpired by the plant, in 
 the fame time, is 22 ounces, allowing two 
 ounces for the perfpiration of the beginning 
 and ending of the night in July, viz. after 
 evening, and before morning weighing, juft 
 before and after night. 
 
 So the perfpiration of a man to the Sun- 
 flower is as 141 : 100. 
 
 Abating the fix ounces of the thirty-one 
 ounces, to be carried off by refpiration from 
 the lungs in the twenty- four hours 5 ( which 
 I have found by certain experiment to be fo 
 much, if not more ) the twenty-five ounces 
 multiplied by 438, the number of grains 
 in an ounce Avoirdupois, the product is 
 10950 grains; which divided by 254, the 
 number of grains in a cubick inch of water, 
 gives 43 cubick inches perfpired by a man : 
 which divided by the furface -of his body, 
 
 vizu 
 
Vegetable Staticks. i \ 
 
 viz. 2160 fquare inches, the quotient is near- 
 ly ' part of a cubick inch perfpired off a 
 fquare inch in twenty-four hours. Therefore 
 in equal furfaces, and equal times, the man 
 perfpires-f 6 , the plant T £ T , or as 50 : 15. 
 
 Which excefs in the man is occafioned 
 by the very different degrees of heat in each : 
 For the heat of the plant cannot be greater 
 than the heat of the circumambient air, 
 which heat in Summer is from 25 to 35 de- 
 grees above the freezing point, (vide Exp. 
 20.) but the heat of the warmeft external 
 parts of a man's body is 54 fuch degrees, 
 and the heat of the blood 64 degrees -, 
 which is nearly equal to water heated to 
 fuch a degree as a man can well b,ear to hold 
 his hand in, ftirring it about ; which heat is 
 fufficient to make a plentiful evaporation. 
 
 $u. Since then the perfpirations of equal 
 areas in a man and a Sun-flower, are to each 
 other as 1 65 : 50, or as 3 ^ : 1 ; and fmce the 
 degrees of heat areas 2:1, muftnot the turn 
 or quantity of the areas of the pores lying 
 jn equal furfaces, in the man and Sun-flower, 
 be as 1 4. : 1 ? for it feems that the quantities 
 of the evaporated fluid will be as the degrees 
 of heat, and the fum of the areas of the pore?, 
 taken together. Dr. 
 
\i Vegetable Staticks. 
 
 Dr. Keill y by eftimating the •quantities of 
 the fevcral evacuations of his body, found 
 that he eat and drank every 24 hours, 4 
 pounds 10 ounces. 
 
 The Sun-flower imbibed and perfpired in 
 the fame time 22 ounces; fo the man's food, 
 to that of the plant, is as 74 ounces to 22 
 ounces, or as 7 : 2. 
 
 But compared bulk for bulk, the plant im- 
 bibes 17 times more frefri food than the man: 
 For deducing 5 ounces, which Dr. Keill al- 
 lows for the faces alvi, there will remain 4 
 pounds 5 ounces of frefh liquor, which en- 
 ters a man's veins; and an equal quantity 
 paffes off every 24 hours. Then it will be 
 found, that 17 times more new fluid enters 
 the fap-veffels of the plant, and paffes off in 
 24 hours, than there enters the veins of a 
 man, and paffes off in the fame time. 
 
 And fince, compared bulk for bulk, the 
 plant perfpires feventeen times more than 
 the man, it was therefore very neceffary, by 
 giving it an extenfive furface, to make a large 
 provifion for a plentiful perfpiration in the 
 plant, which has no other way of dis- 
 charging fuperfluities ; whereas there is pro- 
 vifion made in man 3 to carry off above 
 
 half 
 
Vegetable Statkks. 13 
 
 half of what he takes in, by other eva- 
 cuations. 
 
 For fince neither the furface of his body 
 wasextenfive enough to caufe fufficient ex- 
 halation, nor the additional wreak, arifing 
 from the heat of his blood, could carry off 
 above half the fluid which was neceffary to 
 be difcharged every 24 hours ; there was a 
 neceffity of providing the kidneys, to per- 
 colate the other half through. 
 
 And whereas it is found, that 17 times 
 more enters, bulk for bulk, into the fap-vef- 
 fels of the plant, than into the veins of a man, 
 and goes off in 24 hours: One reafon of 
 this greater plenty of frefli fluid in the vege- 
 table than the animal body, may be, becaufe 
 the fluid which is filtrated thro' the roots im- 
 mediately from the earth, is not near fo full 
 freighted with nutritive particles as the chyle 
 which enters* the lacteals of animals; which 
 defect it was neceffary to fupply by the en- 
 trance of a much greater quantity of fluid. 
 
 And the motion of the lap is thereby much 
 accelerated,, which in the heartlefs vegetable 
 would otherwife be very flow; it having 
 probably only a progreffive, and not a circu- 
 lating motion, as in animals. 
 
 Since 
 
l 4 Vegetable Statuks. 
 
 Since then a plentiful perforation is 
 found fo neceffary for the health of a plant 
 or tree, 'tis probable that many of their dis- 
 tempers are owing to a ftoppage of this per- 
 fpiration, by inclement air. 
 
 The perfpiration in men is often flopped 
 to a fatal degree ; not only by the inclemen- 
 cy of the air, but by intemperance, and vio-* 
 lent heats and colds. But the more tempe- 
 rate vegetables perfpiration can be flopped 
 only by inclement air ; unlefs by an un- 
 kindly foil, or want of genial moifture, it is 
 depriv'd of proper or fufficient nourifhment. 
 
 As Dr. Keill obferv'd in himfelf a con- 
 fiderable latitude of degrees of healthy per- 
 fpiration, from a pound and a half to 3 pounds ; 
 I have alfo obferved a healthy latitude of 
 perfpiration in this Sun-flower, from 16 to 
 28 ounces, in twelve hours day. The more 
 it was watered, the more plentifully it per- 
 fpired, (ceteris paribus ) and with fcanty 
 watering the perfpiration much abated. 
 
 Experiment II. 
 
 From Juty$i- to Aug. 3 d . I weighed 
 for nine feveral mornings and evenings a 
 
 middle- 
 
Vegetable Staticks. \ 5 
 
 middle- fized Cabbage plants which grew in 
 a garden pot, and was prepared with a leaden 
 cover, as the Sun-flower, Exper. \Jt % Its 
 greatefl perfpiration in twelve hours day 
 was 1 pound 9 ounces; its middle perfpira- 
 tion 1 pound 3 ounces, = 32.7 cubick inches. 
 Its furface 2736 fquare inches, or 19 fquare 
 feet. Whence dividing the 32 cubick inches 
 by 2736 fquare inches, it will be found 
 that a little more than the-g^ of an inch 
 depth perfpires off its furface in twelve hours 
 day. 
 
 The area of the middle of the Cabbage 
 flem is -fy£ of a fquare inch ; hence the ve- 
 locity of the fap in the flem is, to the ve- 
 locity of the perfpiring fap on the furface 
 of the leaves, as 2736 : f§g : : 4268 : 1 . 
 
 for 2 J 3 6x ^ 6 = 42 63. But if an allow- 
 
 100 T 
 
 ance is to be made for the folid parts of the 
 flem, ( by which the paffage is narrowed) the 
 velocity will be proportionably increafed. 
 
 The length of all its roots 470 feet, their 
 periphery at a medium ~ T of an inch, hence 
 their area will be 256 fquare inches nearly; 
 which being lb fmall in proportion to the 
 area of the leaves, the fap muft go with 
 
 above 
 
\6 Vegetable Staticks. 
 
 abo^e ten times the velocity through the 
 furface of the roots, that it does thro' the 
 furface of the leaves. 
 
 And fetting the roots, at a medium, at 12 
 inches long, they muft occupy a hemifphere 
 of earth two feet diameter, that is, 2.1 cu- 
 bick feet of earth. 
 
 By comparing the furfaces of the roots of 
 plants, with the furface of the fame plant 
 above ground, we fee the neceflity of cut- 
 ting off many branches from a tranfplanted 
 tree: For if 256 fquare inches of root in 
 furface was neceflary to maintain this Cab- 
 bage in a healthy natural itate: fuppofe, upon 
 digging it up, in order to tranfplant, half the 
 roots be cut off, ( which is the cafe of mod: 
 young tranfplanted trees ) then it's plain, that 
 but half the ufual nourishment can be car- 
 ried up through the roots on that account ; 
 and a very much lefs proportion on account 
 of the fmall hemifphere of earth, the new 
 planted fhortened roots occupy ; and on ac- 
 count of the loofe pofition of the new turn- 
 ed earth, which touches the roots at firft 
 but in few points. This (as well as experi- 
 ence ) ftrongly evinces the great neceflity of 
 well watering new plantations. 
 
 Which 
 
Vegetable Staticks. 17 
 
 Which yet muft be done with caution, for 
 the skilful and ingenious Mr. Philip Miller 
 R R. S. Gardener of the Botanick garden at 
 Cbelfea, in his very ufeful Gardeners Dicti- 
 onary, fays, " As to the watering of all new- 
 " planted trees, I mould advife it to be done 
 " with great moderation, nothing being 
 cc more injurious to them than over-water- 
 <c ing of them. Vide Planting!' And I ob- 
 ferved, that the dwarf pear-tree, whofe root 
 was fet in water, in Exper. 7. decreafed very 
 much daily in the quantity imbibed -, viz. be- 
 caufe the fap-veffels of the roots, like 
 thofe of the cut off boughs, in the fame 
 Experiment, were fo faturated and clogged 
 with moifture, by ftanding in water, that 
 more of it could not be drawn up to fup- 
 port the leaves* 
 
 Experiment III. 
 
 From July 28. to Aug. 25. I weighed for 
 twelve feveral mornings and evenings, a 
 thriving Vine growing in a pot ; I was fur- 
 nimed with this and other trees, from his 
 Majefty's garden at Hampton-court y by the 
 
 C favour 
 
1 8 Vegetable Staticks. 
 
 favour of the eminent Mr. Wife. This 
 vine was prepared with a cover, as the Sun- 
 flower was. Its greateft perfpiration in 12 
 hours day, was 6 Ounces + 240 grains; its 
 middle perfpiration 5 ounces -p 240 grains 
 — to 9- cubick inches. 
 
 The furface of its leaves was 1820 fquare 
 inches, or 12 lquare feet -f- 92 fquare 
 inches ; whence dividing 9- cubick inches, 
 by the area of the leaves, it is found that 
 ■^y part of an inch in depth, perfpires offin 
 12 hours day. 
 
 The area of a tranfverfe cut of its ftem, 
 was equal to \ of a fquare inch : hence the 
 fip's velocity here, to its velocity on the fur- 
 face of the leaves, will be as 1820 x 4 = 
 7280: 1. Then the real velocity of the fap's 
 motion in the ftem is == 7 **f = 38 inches 
 in twelve hours. 
 
 This is fup poling the ftem to be a hollow 
 tube: but by drying a large vine-branch, (rn 
 the chimney corner) which I cut off in the 
 bleeding feafon, I found the folid parts were 
 | of the ftem ; hence the cavity thro' which 
 the lap pafies, being fo much narrowed, its 
 velocity will be 4 times as great, vkti. 152 
 inches in 12 hours, 
 
 But 
 
Vegetable Staticks. ip 
 
 But it is further to be confidered, that if 
 the fap moves in the form of vapour, and 
 not of water, being thereby rarefied, its ve- 
 locity will be increafed in a direct propor- 
 tion of the fpaces, which the fame quan- 
 tity of water and vapour would occupy ; 
 And if the vapour is fuppofed to occupy 10 
 times the fpace which it did, when in the 
 form of water, then it muft move ten times 
 fafter; fo that the fame quantity or weight 
 of each' may pafs in the fame time, thro* 
 the fame bore or tube : And fuch allow- 
 ance ought to be made in all thefe calcu- 
 lations concerning the motion of the fap in 
 vegetables. 
 
 Experiment IV. 
 
 From July 29. to Aug. 2^. I weighed 
 for 12 feveral mornings and evenings, a pa- 
 radife flock Apple-tree^ which grew in a 
 garden pot, covered with lead, as the Sun- 
 flower : it had not a bufhy head full of 
 leaves, but thin fpread, being in all but 163 
 leaves, whcfe fnrface was equal to 1589 
 fquare inches, or 11 fquare feet + 5 fquare 
 inches. 
 
 C 2 The 
 
ao Vegetable Staticks. 
 
 The greatefr, quantity it perfpired in iz 
 hours day, was 1 1 ounces, its middle quan- 
 tity 9 ounces, or 15 -f- cubick inches. 
 
 The 15- cubick inches perfpired, divided 
 by the furface 1589 fquare inches, gives the 
 depth perfpired off the furface in 12 hours 
 day, viz. T ~r of an inch. 
 
 The area of a tranfverfe cut of its ftem, £ of 
 an inch fquare, whence the fap's velocity 
 here, will be to its velocity on the furface 
 of the leaves, as 1589 x 4 = 6356 : 1. 
 
 Experiment V. 
 
 From J 'uly 28. to Aug. 25. I weighed for 
 10 feveral mornings and evenings a very 
 thriving Limon-tree, which grew in a gar- 
 den pot, and was covered as above: Its great- 
 eft perfpiration in 12 hours day was 8 ounces, 
 its middle perfpiration 6 ounces, equal to 
 ic-| cubick inches. In the night it perfpired 
 fometimes half an ounce, fometimes nothing, 
 and fometimes increafed 1 or 2 ounces in 
 weight, by large dew or rain. 
 
 The furface of its leaves was 2557 
 fquare inches; or 17 fquare feet -(- 109 
 fquare inches; diyiding then the 10 cubick 
 inches perfpired by this furface, gives the 
 
 depth 
 
So the feveral fore- 
 going perfpirations 
 in equal areas are, 
 
 Vegetable Staticks. i\ 
 
 depth perfpired in 12 hours day, viz. jfa 
 of an inch, 
 
 ( T 7rr m the vine in 12 
 ! hours day. 
 Ijo in a man, in aday 
 and a night. 
 ~j in a fun-flower, 
 in aday and night, 
 -^o in a cabbage, in it 
 hours day. 
 
 T ^ T in an apple-tree, 
 
 in 12 hours day. 
 
 -\^ in a limon-tree, 
 
 in 12 hours day. 
 
 The area of the tranfverfe cut of the ftem 
 
 of this Limon-tree was = 1 44 of a 
 
 fquare inch ; hence the fap's velocity here, 
 
 will be to its velocity on the furface of the 
 
 leaves, as 1768 : 1 for 2 ** 7 x 10 °^ 17. 
 
 144 
 
 This is fuppofing the whole ftem to be a hol- 
 low tube j but the velocity will be increafed 
 both in the ftem and in the leaves, in propor- 
 tion as the paffage of the fap is narrowed by 
 the folid parts. 
 
 By comparing the very different degrees 
 of perfpiration, in thefe 5 plants and trees. 
 
 C 3 we 
 
21 Vegetable Stathks. 
 
 we may obferve, that the Limon-tree, which 
 is an ever-green, perfpires much lefs than the 
 Sun-flower, or than the Vine or the Apple- 
 tree, whofe leaves fall off in the winter; 
 and as they perfpire lefs, fo are they the 
 better able to furvive the winter's cold, 
 becaufe they want proportionably but a very 
 fmall fupply of fre(h nourifhment to fup- 
 port them j like the exangueous tribe of 
 animals, frogs, toads, tortoifes, ferpents, 
 infects, &c. which as they perfpire little, 
 fo do they live the whole winter without 
 food. And this I find hold true in 12 
 other different forts of ever-greens, on which 
 I have made Experiments. 
 
 The above- mention'd Mr. Miller made 
 the like Experiments in the Botanick-gar- 
 den at Chelfca^ on a Plantain- tree, an Aloe, 
 and a Paradife Apple-tree 5 which he weigh- 
 ed morning, noon, and night, for feveral 
 fucceiiive days. I (hall here infert the di- 
 aries of them, as he communicated them to 
 me, that the influence of the different tem- 
 peratures of the air, on the perfpiration of 
 thefe plants, may the better be feen. 
 
 The pots which he made ufe of were 
 glazed, and had no holes in their bottoms as 
 
 garden 
 
Vegetable Staticks. 25 
 
 garden pots ufually have ; fo that all the 
 moifture, which was wanting in them upon 
 weighing, muft necefiarily be imbibed by 
 the roots of thofe plant?, and thence per- 
 fpired off thro' their leaves. 
 
 A Diary of the perfpiration of the Mufa Ar- 
 bor, or Plantain- tree of the Weft-Indies. 
 The whole fur face oj the plant was 14 
 Jquare feet, 8 + ~ inches. The different 
 degrees of heat of the air are here noted 
 by the degrees above the freezing point in 
 my Thermometer, defcrifrd in Exper. 20. 
 
 1726 Weigh 
 at 6 
 Morn 
 pd. ou 
 
 M3y. 
 z8 
 
 *9 
 
 20 
 21 
 
 22 
 *3 
 
 33 j 
 37 iJ- 
 
 37 4 
 
 ;6 14 
 36 10 
 
 36 14 
 36 6 
 
 
 1 
 "-9 
 
 Weight 5 H 
 at 12 
 Noon, 
 pd. ou. 
 
 33 
 37 J-I45- 
 
 3* 
 
 34 
 3° 
 
 3 1 
 3* 
 
 37 * 
 
 36 12 
 
 37 
 
 3^ rl 
 
 35- 
 
 43 
 
 3*i 
 
 Weight 
 at 6 
 Even. 
 
 pd. ou. 
 
 37 14 
 37 3* 
 
 37 ° 
 
 36 1 1 
 36 if 
 
 36 n| 
 
 5* T 
 
 7~ 
 
 34 
 2 1 
 
 3 1 
 
 3* 
 44 
 
 3 >~ 
 3 1 
 
 This evening 12 ounces of water were poured 
 removed from the ftove into a cool room, where 
 Sun, the windows being North-weft. 
 
 N. B. This plant 
 ftcod in a ftove, with a 
 'mill fire in it j the af- 
 pedfc of the ftcve was 
 South- ea ft. 
 
 A hot clear day. Thi 
 morning he pbferve 
 large drops of water a 
 the extremity of ever 
 'leaf, and we may otlerve 
 that it peripires very 
 much this da) , 
 
 An extreme hot clear 
 'day. 
 
 fcfoderately hot, but clear. 
 . This morn. I; ounces cf 
 •water poured into the 
 'pot. Mixture of Sun and 
 
 Clouds. 
 
 Much thunder, fome rain 
 
 and hail at a diftance. 
 
 A gloomy day, but no 
 
 rain. 
 
 into the potj and it v.ai 
 it had a free air, but no 
 
 C 4 
 
 Calm 
 
14 
 
 Vegetable Statich. 
 
 iyi6 
 
 at 
 
 ight 
 6 
 
 
 Weight 
 at 12 
 
 
 Weight 
 at 6 
 
 H 
 
 3- 
 
 
 May. 
 
 Morn. 
 
 3 
 
 Noon. 
 
 3 
 
 Even. 
 
 3 
 3 
 
 
 
 pd. 
 
 ou. 
 
 
 pd. 
 
 ou 
 
 
 pd. 
 
 ou. 
 
 
 
 24 
 
 37 
 
 00 
 
 *7 
 
 37 
 
 00 
 
 ^ 
 
 3<5 
 
 '>£ 
 
 **i 
 
 Calm cloudy weather* 
 
 *S 
 
 37 
 
 00 
 
 zii 
 
 16 
 
 Hi 
 
 26 
 
 36 
 
 *3 
 
 *3 
 
 A pretty clear day. 
 
 26 
 
 3^ 
 
 12 
 
 22 
 
 36 
 
 1 1 
 
 z 5* 
 
 36 
 
 10 
 
 24 
 
 A hot day. 
 
 *7 
 
 36 
 
 ioi 
 
 2 3 
 
 36 
 
 *i 
 
 26i 
 
 36 
 
 6 
 
 1 
 
 A very hot day. 
 
 28 
 
 36 
 
 6 
 
 iz£ 
 
 3* 
 
 s 
 
 24 
 
 3<* 
 
 3j 
 
 l 3 
 
 Some rain and cloudy, 
 
 
 
 
 
 
 
 
 
 
 At this time, the under 
 
 
 
 
 
 
 
 
 
 
 
 leaves of the plant be- 
 
 
 
 
 
 
 
 
 
 
 
 gan to wither and decay j 
 
 
 
 
 
 
 
 
 
 
 
 and the top leaf to un- 
 
 
 
 
 
 
 
 
 
 
 
 fold, and fpread abroad j 
 
 
 
 
 
 
 
 
 
 
 
 butthey areobferved ne- 
 
 
 
 
 
 
 
 
 
 
 
 ver to grow bigger, af- 
 
 29 
 
 36 
 
 2 
 . 1 
 
 20 
 
 3* 
 
 3* 
 
 ±± 
 
 21^ 
 
 36 
 
 1 
 
 22 
 
 ter they are fully opened. 
 A temperate day. 
 
 3° 
 June. 
 
 1 2 
 
 '9 
 
 1 
 
 21 
 
 3<S 
 
 
 
 '9 
 
 Temperate weather not 
 
 
 
 
 
 
 
 
 
 
 very clear. 
 
 ■ 1 
 
 3>~ 
 
 'J 
 
 18 
 
 35" 
 
 Mr 
 
 •97 
 
 35- 
 
 'Ji 
 
 18 
 
 Some rain. The whole 
 plant begins to change 
 colour,and appear fickly. 
 
 2 
 
 35- 
 
 1 2 
 
 1 
 195 
 
 35" 
 
 ri| 
 
 *3 
 
 35" 
 
 I I 
 
 Hi 
 
 He then removed the 
 plant into the ftove again 
 in order to recover it $ 
 but it continued to fade, 
 and in 2 or 3 days died. 
 
 
 If 
 
 10 
 
 2Si 
 1 
 
 35" 
 
 4 
 
 36 
 
 35" 
 
 1* 
 
 34 
 
 A cool and cloudy day. 
 
 4 
 
 35- 
 
 00 
 
 26 34 
 
 14 
 
 3i 134 
 
 I I 
 
 19 1 
 
 A warm day ; and the 
 
 
 
 l 
 
 1 
 
 
 
 1 
 
 
 
 whole plant decayed. 
 
 We may obferve from this diary, that 
 this plant, when in the flove, ufually per- 
 fpired more in fix hours before noon than 
 in fix hours after noon 5 and that it perfpired 
 much lefs in the night, than in the day time: 
 And fometimes increafed in weight in the 
 night, by imbibing the moiflure of the 
 ambient air 5 and that both in the flove and 
 
 in 
 
 
 
Vegetable Statich. 25 
 
 in the cool room. Upon making an e.ftimate 
 of the quantity perfpired off a fquare inch of 
 this plant, in 12 hours day, it comes ban to 
 twj of a cubick inch, on the 2 Sth day of 
 May, when by far its greate ft perforation was s 
 for on feveral other days it was much lefs. 
 
 Diary of the Aloe Africana Cauletcens 
 foliis fpinofis, maculis ab atraquc parte ah 
 bicantibus notatis, Commelini Hort. Amji. 
 commonly called the Carolina Aloe. It 
 was a large plant of its kind. It flood 
 in a glajs-cafe, which had a South afpect 
 without a fire. 
 
 1726 
 
 May 
 
 |9 
 
 «? 
 
 20 
 21 
 22 
 
 *3 
 
 Weight 
 
 rr 
 
 Weight' 
 
 
 Weight 
 
 
 at 6 | q 
 
 at 1 2 1 s 
 
 at 6 
 
 
 ■-t 
 
 Morn. | 3 
 
 Noon. 3 
 
 Night 
 
 a 
 
 pd. ou. * 
 
 !' 
 
 
 
 41 6 2,5- 
 
 41 ^73^ 
 
 +1 3 
 
 3°i 
 
 41 ii2S4 
 
 40 14 |2lA 
 
 4.0 12 
 
 30 
 
 40 \iji6j; 
 
 40 IO (31 
 
 40 8$ ( *9$ 
 
 40 9^27 
 
 40 6^30 
 
 40 5-328 
 
 40 6 
 
 *ri 
 
 +° fi 
 
 *9 
 
 40 4 
 
 *7? 
 
 41 10 
 
 24* 
 
 41 *i 
 
 2 9 
 
 4- 1 5" 
 
 *?i 
 
 This evening promif- 
 ingfome rain, he let the 
 pot out to receive a little j 
 and then wiping the 
 leaden furnace of the pot 
 dry, he fet it into the 
 glafs-cafe again. 
 
 Now the pot broke, 
 and hindered any fur- 
 ther obfei vations. 
 
 We may obferve, that this Aloe increafed 
 in weight moft nights, and perfpired mod: in 
 the morning. A Diary 
 
26 Vegetable Statich. 
 
 A Diary of a fmall Paradife- Apple, with one 
 upright Jlem 4 feet high •> and two fmall 
 lateral branches about 8 inches long. This 
 pla?it flood under a cover of wood, which 
 was open on all fides. 
 
 1716 
 
 May. 
 j8 
 
 *9 
 
 20 
 
 21 
 22 
 
 24. 
 
 26 
 
 2 7 
 
 37 
 37 
 36 
 3<S 
 36 
 
 4 
 
 1 
 
 12 
 
 7 
 3* 
 
 26 00 
 
 ( 1 
 
 M 
 
 !*7 
 '18* 
 
 26 
 
 3T 4 5*5 
 
 34 9 28 i 
 
 33 7^8 
 
 37 
 3<* 
 
 3<* 
 36 
 
 3* 
 
 5 
 14. 
 
 1 
 
 35" 13 
 
 34 ^,34 
 
 22 
 2 1 
 
 217 
 24. 
 
 37* 
 
 37 
 3* 
 3* 
 3<* 
 3* 
 
 35" fi 
 
 35" 
 
 34 
 
 00 
 
 34i 
 
 3° 
 
 3* 
 
 1 [20 
 
 1 3 2 ' 9 The leaves very dry, 
 9 2 °-j and become fpeckled for 
 A 20 want of dew. 
 
 2 J. 1 2_±\ Then he removed the 
 * plant into the ftove, to 
 
 try what effedt. that 
 would have on its per- 
 fpiration. 
 
 At this time the leaves 
 were withered with the 
 heat, and hung down 
 as if they would fall off. 
 
 At this time feveral 
 of the leaves began to 
 fall off. 
 
 All the leaves hllai 
 off, except a few fmall 
 ones, at the extremities 
 of the branches which 
 had put out, fince the 
 plant was in the ftove. 
 The earth it flood in 
 was very moift all the 
 time. 
 
 In OBober 1725. Mr. Miller took up an 
 African Briony-root y which when cleared 
 from the mould, weighed eight ounces I> 
 he laid it on a fhelf in the ftove, where it 
 remained till the March following - y when 
 upon weighing he found it had loft of its 
 
 weight. 
 
Vegetable Staticks. 27 
 
 weight. In April it mot out 4 branches, 
 two of which were 3- feet long, the other 
 two were one of them 14 inches, the other 
 9 inches, in length : Thefe all produced 
 fair large leaves. It had loft \\ ounce in 
 weight, and in three weeks more it loft 
 2\ ounces more, and was much withered. 
 
 Experiment VI. 
 
 Spear-mint being a plant that thrives moft 
 kindly in water, ( in order the more ac- 
 curately to obferve what water it would 
 imbibe and perfpire by night and day, in 
 wet or dry weather ) I cemented at r a plant 
 of it m. into the inverted fyphon ryxb 
 (Fig. 2.) The fyphon was \ inch diam. at b y 
 but larger at r. 
 
 I filled it full of water, the plant imbibed 
 the water fo as to make it fall in the 
 day (in Marc!:) near an inch and half from 
 b to t 9 and in the night ~ inch from / to 1 : 
 but one nighr, when it was fo cold, as to 
 make the thermometer fink to the freezing 
 point, then the mint imbibed nothing but 
 hung down its head 3 as did alfo the youno- 
 beans in the garden, their fap being o- rcat _ 
 
1% Vegetable Staticks. 
 
 ly condenfed by cold. la a rainy day the 
 mint imbibed very little. 
 
 I purfued this Experiment no farther, Dr. 
 Woodward having long fince, from feveral 
 curious experiments and obfervations, given 
 an account in the Philofophical Tranfadtions, 
 of the plentiful perfpirations of this plant. 
 
 Experiment VII. 
 
 In Augufl) I dug up a large dwarf Pear- 
 tree, which weighed 71 pounds 8 ounces; 
 I fet its root in a known quantity of wa- 
 ter ; it imbibed 15 pounds of water in ten 
 hours day, and perfpired at the fame time 
 1 k, pounds 8 ounces. 
 
 In July and Augujl I cut off feveral 
 branches of Apple-trees, Pear, Cherry, and 
 Apricot-trees, two of a fort ; they were of 
 feveral fizes from 3 to 6 feet long, with pro- 
 portional lateral branches ; and the tranfverfe 
 cut of the largeft part of their ftems was 
 about an inch diameter. 
 
 I dripped the leaves off of one bough of 
 each fort, and then fet their ftems in fepa- 
 rate glaffes, pouring in known quantities of 
 
 water. 
 
 The 
 
Vegetable Staticks. 29 
 
 The boughs with leaves on them im- 
 bibed fome 15 ounces, fome 20 ounces 
 25 or 30 ounces in 12 hours day, more or 
 lefs, in proportion to the quantity of leaves 
 they had ; and when I weighed them at night, 
 they were lighter than in the morning. 
 
 While thofe without leaves imbibed but 
 one ounce, and were heavier in the even- 
 ing than in the morning, they having per- 
 fpired little. 
 
 The quantity imbibed by thofe with leaves 
 decreafed very much every day, the (ap- 
 veffels being probably fhrunk at the tranf- 
 verfe cut, and too much faturate with wa- 
 ter, to let any more pafs; fo that ufually in 
 4 or 5 days the leaves faded and withered 
 much. 
 
 I repeated the fame Experiment with Elm- 
 branches, Oak, Ofier, Willow, Sallow, 
 Afpen, Curran, Goosberry, and Philbert 
 branches -, but none of thefe imbibed fo 
 much as the foregoing, and feveral forts of 
 ever-greens very much lefs. 
 
 Experiment VIII. 
 Augufi 15. I cut off a large Ruffet-pipin, 
 with two inches Item, and its iz adjoining 
 
 leaves; 
 
20 Vegetable Staticks. 
 
 leaves ; I fet the ftem in a little phial of wa- 
 ter : it imbibed and perfpired in three days 
 |- of an ounce. 
 
 At the fame time I cut off from the fame 
 tree another bearing twig of the fame length, 
 with 12 leaves on it, but no apple; it im- 
 bibed in the fame three days near -| of an 
 ounce. 
 
 About the fame time I fet in a phial of 
 water a fhort ftem of the fame tree, with 
 two large Apples on it without leaves ; they 
 imbibed near \ ounce in two days. 
 
 So in this Experiment, the apple and the 
 leaves imbibe -f. of an ounce ; the leaves 
 alone near |, but. the two large apples im- 
 bibed and perfpired but \ part fo much as the 
 12 leaves; then one apple imbibed the £ part 
 of what was imbibed by the 1 2 leaves ; there- 
 fore two leaves imbibe and perfpire as much 
 as one apple; whence their perfpirations 
 feem to be proportionable to their furfaces ; 
 the furface of the apple being nearly equal 
 to the fum of the upper and under furfaces 
 of the two leaves. 
 
 Whence it is probable, that the ufe of 
 thefe leaves ( which are placed, juft where 
 the fruit joins to the tree) is to bring nou- 
 
 rifhment 
 
Vegetable Statich. 3 t 
 
 riftiment to the fruit. And accordingly I 
 obferve, that the leaves, next adjoining to 
 bloflbms, are, in the fpring, very much ex- 
 panded, when the other leaves, on barren 
 fhoots, are but beginning to {hoot : And 
 that all peach leaves are pretty large before 
 the bloflbm goes off: And that in apples 
 and pears the leaves are one third or half 
 grown before the bloflbm blows : So 
 provident is nature in making timely pro- 
 vifion for the nourishing the yet embryo 
 fruit. 
 
 Experiment IX. 
 
 July 15. I cut off two thriving Hop-vines 
 near the ground, in a thick fhady part of 
 the garden, the pole ftill {landing; I {trip- 
 ped the leaves off one of thefe vines, and fet 
 both their ftems in known quantities of 
 water, in little bottles 5 that with leaves 
 imbibed in 12 hours day 4 ounces, and that 
 without leaves \ of an ounce. 
 
 I took another hop-pole with its vines 
 on it, and carried it out of the hop-ground, 
 into a free open expofure ; thefe imbibed 
 and perfpired as much more as the former 
 
 in 
 
}i Vegetable Statkks. 
 
 in the hop- ground: Which is doubtlefs 
 the reafon why the hop-vines on the out- 
 fides of gardens, where mod expofed to the 
 air, are fhort and poor, in comparifon of 
 thofe in the middle of the ground ; viz. be- 
 caufe being much dried, their fibres harden 
 fooner, and therefore they cannot grow fo 
 kindly as thofe in the middle of the ground ; 
 which by fhade are always kept moifter, and 
 more ductile. 
 
 Now there being iooo hills in an acre 
 of hop-ground, and each hill having three 
 poles, and each pole three vines, the num- 
 ber of vines will be 9000 ; each of which 
 imbibing 4 ounces, the fum of all the ounces, 
 imbibed in an acre in 12 hours day, will 
 be 36000 ounces, = 15768000 grains = 
 62047 cubick inches or 202 ale gallons; which 
 divided by 6272640, the number of fquare 
 inches in an acre, it will be found, that the 
 quantity of liquor perfpired by all the hop- 
 vines, will be equal to an area of liquor, 
 as broad as an acre, and -— part of an inch 
 deep, befidcs what evaporated from the 
 earth. 
 
 And this quantity of moifture in a kind- 
 ly Hate of the air is daily carried off, in 
 
 afuffi- 
 
Vegetable Statkks. 35 
 
 a fufficient quantity, to keep the hops in 
 a healthy ftate; but in a rainy moift ftate 
 of air, without a due mixture of dry wea- 
 ther, too much moifture hovers about the 
 hops, fo as to hinder in a good meafure the 
 kindly perfpiration of the leaves, whereby 
 the ftagnating fap corrupts, and breeds mol- 
 dy fen, which often fpoils vaft quantities of 
 flourifhing hop-grounds. This was the cafe 
 in the year 1723, when 10 or 14 days al- 
 moft, continual rains fell, about the latter 
 half of Jul)', after four months dry weather; 
 upon which the moft flourishing and pro- 
 mifing hops were all infected with mold or 
 fen, in their leaves and fruit, while the then 
 poor and unpromifing hops efcaped, and oro- 
 duced plenty; becaufe they being fmali, did 
 not perfpire fo great a quantity as the others; 
 nor did they confine the perfpired vapour, io 
 much as the large thriving vines did, in their 
 fhady thickets.. 
 
 This rain on the then warm earth made 
 the grafs (hoot out as fa ft as if it were in a 
 hot-bed ; and the apples grew fo precipi- 
 tately, that they were of a very flaflry confu- 
 tation, fo as to rot more remarkably than 
 had ever been remembred. 
 
 D The 
 
34 Vegetable Statkks. 
 
 The planters obferve, that when a mold or 
 fen has once feized any part of the ground, it 
 foon runs over the whole 5 and that the grafs, 
 and other herbs under the hops, are infected 
 with it. 
 
 Probably becaufe the fmall feeds of this 
 quick growing mold, which foon come to 
 maturity, are blown over the whole ground: 
 Which fpreading of the feed may be the 
 reafon why fome grounds are infected with 
 fen for feveral years fucceflively ; viz. from 
 the feeds of the laft year's fen: Might it not 
 then be advifeable to burn the fenny hop- 
 vines as foon as the hops are picked, in hopes 
 thereby to deftroy fome of the feed of the 
 mold? 
 
 H Mr. Aujlin of Canterbury obferves fen 
 < c to be more fatal to thofe grounds that 
 tc are low and fheltered, than to the high 
 " and open grounds; to thofe that are fhelv- 
 " ing to the North, than to the (helving 
 " to the South - y to the middle of grounds, 
 " than to the outfides; to the dry and 
 <c gentle grounds, than to the moift and ftiff 
 " grounds. This was very apparent through- 
 <f out the Plantations, where the land had 
 <c the fame workmanfhip and help beftowed 
 
 < c upon 
 
cc 
 
 cc 
 
 Vegetable Statkks. 35 
 
 ic upon it, and was wrought at the fame 
 u time ; but if in either of thefe cafes there 
 " was a difference, it had a different effect ; 
 and the low and gentle grounds, that lay 
 neglected, were then feen lefs diitempered 
 than the open and moid, that w r ere care- 
 fully managed and looked after. 
 " The honey dews are obferved to come 
 <c about the 1 ith of June, which by the mid- 
 <£ die of July turn the leaves black, and make 
 « them ftink." 
 
 I have in July (the feafon for fire-blaflsj 
 as the planters call them) feen the vines in 
 the middle of a hop-ground all fcorched 
 up, almoft from one end of a large ground 
 to the other, when a hot gleam of Sun- 
 fhine has come immediately after a mower 
 of rain ; at which time the vapours are of- 
 ten feen with the naked eye, but efpecially 
 with reflecting Telefcopes, to afcend fo 
 plentifully, as to make a clear and diftincft 
 object become immediately very dim and 
 tremulous. Nor was there any dry gravelly 
 vein in the ground, along the courfe of this 
 fcorch. It was therefore probably owing 
 to the much greater quantity of fcorch- 
 ing vapours in the middle than outfides of 
 
 D 2 the 
 
3 6 Vegetable Statzcks. 
 
 the ground ; and that being a denfer me- 
 dium, it was much hotter than a more rare 
 medium. 
 
 And perhaps, the great volume of afcend- 
 ing vapour might make the Sun-beams con- 
 verge a little toward the middle of the ground, 
 that being a denfer medium, and thereby 
 increafe the heat confiderably \ for I obferv- 
 ed, that the courfe of the fcorched hops 
 was in a line at right angles, to the Sun- 
 beams about eleven o' clock, at which time 
 the hot gleam was: The hop-ground was 
 in a valley which run from South-weft to 
 North-eaft : And, to the beft of my remem- 
 brance, there was then but little wind, and 
 that in the courfe of the fcorch ; but had 
 there been fome other gentle wind, either 
 North or South, 'tis not improbable but 
 that the North wind gently blowing the 
 volume of riling wreak on the South fide 
 of the ground, that fide might have been 
 moft fcorched, and fo vice verfd. 
 
 As to particular fire-blafts, which fcorch 
 here and there a few hop-vines, or one or 
 two branches of a tree, without damaging 
 the next adjoining; what Ajironomers ob- 
 ferve, may hint to us a no very improbable 
 
 caufc 
 
Vegetable Statkh. 37 
 
 caufe of it; viz. they frequently obferve 
 ( efpecially with the reflecting Telefcopes ) 
 fmall feparate portions of pellucid vapors 
 floating in the air; which tho' not vifible to 
 the naked eye, are yet confiderably denfer 
 than the circumambient air : And vapors of 
 fuch a degree of denfny may very proba- 
 bly, either acquire fuch a fcalding heat from 
 the Sun, as will fcorch what plants they 
 touch, efpecially the more tender : an effecT: 
 which the gardeners about London have too 
 often found to their coft, when they have 
 incautioufly put bell-glaffes over their col- 
 lyflowers early in a frofly morning, before 
 the dew was evaporated off them ; which 
 dew being raifed by the Sun's warmth, and 
 confined within the glafs, did there form a 
 denfe tranfparent fcalding vapor, which burnt 
 and killed the plants. Or perhaps, the up- 
 per or lower furface of thefe tranfparent fe- 
 parate flying volumes of vapors may, among 
 the many forms they revolve into, fometimes 
 approach fo near to a hemifphere, or hemi- 
 cylinder, as thereby to make the Sun-beams 
 converge enough, often to fcorch the more 
 tender plants they fhall fall on : And fome- 
 times alfo, parts of the more hardy plants 
 
 D 3 and 
 
58 Vegetable Statkks, 
 
 and trees, in proportion to the greater or lefs 
 convergency of the Sun's rays. 
 
 The learned Boerhaave, in his 'Theory of 
 Chemiftry, Dr. State's Edition, p. 245. ob- 
 ferves, " That thofe white clouds which ap- 
 * c pear in fummer-time, are, as it were, fo 
 " many mirrors, and occafion exceffive heat. 
 Ci Thefe cloudy mirrors are fometimes round, 
 <£ fometimes concave, polygonous, &c. When 
 cc the face of heaven is covered with fuch 
 " white clouds, the Sun mining among 
 cc them, muft of neceffity produce a vehe- 
 u ment heat 5 fince many of his rays, which 
 cc would other wife, perhaps, never touch 
 " cur earth, are hereby reflected to us -, thus* 
 ci if the Sun be on one fide, and the clouds 
 cc on the oppofice one, they will be perfect 
 a burning- glaffes. 
 
 <c I have fometimes (continues he) ob- 
 rc ferved a kind of hollow clouds, full of 
 ci hail and fnow, during the continuance 
 ?' of which the heat was extreme; fince by 
 < c fuch cendenfation they were enabled to 
 " reflect much more ftrongly. After this 
 ci came a fharp cold, and then the cloud s 
 " difcharged their hail in great quantity ; 
 u to which fucceeded a moderate warmth. 
 
 " Frozen 
 
Vegetable Staticks. 39 
 
 u Frozen concave clouds therefore, by their 
 cc great reflections, produce a vigorous heat, 
 " and the fame, when refolved, exceffive 
 
 « cold." 
 
 Whence we fee that blafls may be occa- 
 lioned by the reflections of the clouds, as 
 well as by the above mentioned refraction of 
 denfe tranfparent vapors. 
 
 July 21. I obferved that at that feafon 
 the top of the Sunflower being tender, and 
 the flower near beginning to blow, if 
 the Sun rife clear, the flower faces towards 
 the Eaft ; and the Sun continuing to fhine, 
 at noon it faces to the South 5 and at fix in 
 the evening to the Weft: And this not by 
 turning round with the Sun, but by nuta- 
 tion; the caufe of which is, that the fide of 
 the ftem next the Sun perfpiring moft, it 
 fhrinks, and this plant perfpires much. 
 
 I have obferved the fame in the tops of 
 Jerufalem-artichokeSy and of garden-beans* 
 in very hot Sun-fhine. 
 
 Experiment X. 
 
 July 27. I fixed an Apple-branch, m, 3 
 feet long, ~ inch diameter, full of leaves, 
 
 D 4 and 
 
40 Vegetable Staticks. 
 
 and lateral fhoots to the tubq /, y feet 
 long, £ of an inch diameter, {Fig. 3.) I fil- 
 led the tube with water, and then immerfed 
 the whole branch as far as over the lower 
 end of the tube, into the veffel nu full of 
 water. 
 
 The water fubfided 6 inches the firft two 
 hours, (being the firft filling of the fap-vef- 
 fels) and 6 inches the following night, 4 
 inches the next day ; and 2 + ^ the following 
 night. 
 
 The third day in the morning I took the 
 branch out of the water, and hung it, with 
 the tube affixed to it, in the open air; it im- 
 bibed this day 27 + ' inches in 12 hours 
 
 This experiment fhews the great power 
 of perfpiration ; fince, when the branch was 
 immerfed in the vefiel of water, the 7 feet 
 column of water in the tube, above the fur- 
 face of the water, could drive very little 
 thro' the leaves, till the branch was expofed 
 to the open air. 
 
 This alio proves, that the perfpiring mat- 
 ter of trees is rather actuated by warmth, 
 and ib exhaled, than protruded by the force 
 01 the fap upwards. 
 
 And 
 
Vegetable Staticks. 41 
 
 And this holds true in animals, for the 
 perfpiration in them is not always greater!: in 
 the grcateft force of the blood ; but then often 
 leaft of all, as in fevers. 
 
 I have fixed many other branches in the 
 fame manner to long rubes, without immerf- 
 ingthem in water; which tubes, being filled 
 with water, I could fee precifely, by the 
 defcent of the water in the tube t, how faft 
 it perfpired off; and how very little perfpired 
 in a rainy day, or when there were no leaves 
 on the branches. 
 
 Experiment XL 
 
 Aug. 17. At 1 1 a : m y I cemented to 
 the tube ab (Fig. 4.) 9 feet long, and \ inch 
 diameter, an Apple-branch d y 5 feet long, -f 
 inch diameter; I poured water into the tube, 
 which it imbibed plentifully, at the rate of 
 3 feet length of the tube in an hour. At 
 1 o' clock I cut ofT the branch at r, 13 inches 
 below the glafs tube. To the bottom of 
 the remaining {tern I tied a glafs ciftern z, 
 covered with ox-gut, to keep any of the 
 water which dropped from the Hem c b, from 
 evaporating. At the lame time I let the 
 
 branch 
 
4 1 Vegetable Statuks. 
 
 branch d r, which I had cut off in a known 
 quantity of water, in the veffel x (Fig. 5.). 
 The branch in the veffel x imbibed 18 ounces 
 of water in 18 hours day and 12 hours night; 
 in which time only 6 ounces of water had 
 paffed thro' the ftem/ b, (Fig. 4.) which had 
 a column of water 7 feet high, preffing upon 
 it all the time. 
 
 This again fhews the great power of per- 
 fpiration; to draw thrice as much water, 
 in the fame time, through the long flender 
 parts of the branch r, (Fig. 5.) as was pre/Ted 
 thro' a larger ftem cb (Fig. 4.) of the fame 
 branch; but 13 inches long, with 7 feet 
 preffure of water upon it, in the tube a b. 
 
 I tried in the fame manner another Ap- 
 ple-branch, which in 8 hours day imbibed 
 20 ounces, while only 8 ounces paffed thro' 
 the ftem c b, (Fig. 4.) which had the column 
 of water on it. 
 
 The fame I tried with a quince branch, 
 which in 4 hours day imbibed 2 ounces -f-i, 
 while but a ounce paffed thro' the ftem cb 
 (Fig. 4.) which had 9 feet weight of water 
 preffing on it. 
 
 Note> All thele (under this experiment 
 11,) were made the firft day, before the 
 
 ftem 
 
Vegetable Statlcks. 45 
 
 ftem could be any thing faturate with water, 
 or the fap-veffels fhrunk fo as to hinder its 
 paflage. 
 
 Experiment XII. 
 
 I cut off from a dwarf Apple-tree e w the 
 top of the branch /, (Fig. 6.) which was an 
 inch diameter, and fixed to the ftem/, the 
 glafs tube lb: then I poured water into the 
 tube, which the branch would imbibe, at 
 fuch a rate as to drink down 2 or 3 pints in 
 a day, efpecially if I fucked with my mouth 
 at the top of the tube b y fo as that a few air- 
 bubbles were drawn out of the ftem l-> then 
 the water was imbibed fo faft, that if I im- 
 mediately fcrewed on the mercurial gage, 
 mryz, the mercury would be drawn up 
 to r, 12 inches higher than in the other 
 leg. 
 
 At another time I poured into the tube /, 
 fixed to a golded Renate-tree, a quart of 
 high redified fpirit of wine camphorated, 
 which quantity the ftem imbibed in 3 hours 
 fpacc ; this killed one half of the tree : this 
 I did to try if I could give a flavour of cam- 
 phire to the apples which were in great 
 
 plenty 
 
44 Vegetable Staticks. 
 
 plenty on the branch. I could not perceive 
 any alteration in the tafte of the -apples, tho* 
 they hung feveral weeks after; but the fmell 
 of the camphire was very ftrong in the ftalks 
 of the leaves, and in every part of the dead 
 branch. 
 
 I made the fame experiment on a vine, 
 with ftrongly-fcented orange-flower- water; 
 the event was the fame, it did not penetrate 
 into the grapes, but very fenfibly into the 
 wood and ftalks of the leaves. 
 
 I repeated the fame experiment on two 
 diftant branches of a large Catharine pear- 
 tree, with ftrong deco<flions of SafTafrafs, and 
 of Elder-flowers, about 30 days before the 
 pears were ripe ; but I could not perceive any 
 tafte of the deco&ions in the pear's. 
 
 Tho' in $11 thefe cafes the fap-veffels of 
 the ftem were ftrongly impregnated with a 
 good quantity of thefe liquors; yet the capil- 
 lary fap-veffels near the fruit were fo fine, 
 that they changed the texture of, and affimi- 
 lated to their own fubftance, thofe high-tafted 
 and perfumed liquors; in the fame manner 
 us grafts and buds change the very different 
 ftp of the flock to that of their own fpecifick 
 nature. 
 
 This 
 
Vegetable Staticks* 45 
 
 This experiment may fafely be repeated 
 with well-fcented and perfumed common 
 water, which trees will imbibe at // with- 
 out any danger of killing them. 
 
 Experiment XIII. 
 
 In order to try whether the capillary fap- 
 veffels had any power to protrude fap out at 
 their extremities, and in what quantity, I made 
 the three following experiments, viz. 
 
 In Anguji I took a cylinder of an apple- 
 branch, 12 inches long, \ diameter: I fet it 
 with its great end downwards in a mint glafs, 
 (full of water) tied over with ox-gut. The 
 top of the flick was moift for ten days, while 
 another flick of the fame branch (but out 
 of water) was very dry. It evaporated an 
 ounce of water in thofe ten days. 
 
 Experiment XIV. 
 
 In Sept. I fix'd a tube / (Fig. 7.) 7 feet 
 ong, to a like flemy^ as the former, and 
 fet the flem in water „v, to try if, as the wa- 
 ter evaporated out of the top of the flem r, 
 it would rife to any height in the tube t\ but 
 
 it 
 
46 Vegetable Statich. 
 
 it did not rife at all in the tube, tho' the 
 top of the ftem was wet: I then filled the 
 tube with water, but it pafled freely into the 
 veffel x. 
 
 Experiment XV. 
 
 Sept. 10. 2+ i. feet from the ground, I 
 cut off the top of a half ftandard Duke Cherry- 
 tree againft a wall, and cemented on it the 
 neck of a Florence flask f y (Fig. 8.) and 
 to that flask neck a narrow tube g> five feet 
 long, in order to catch any moifture that 
 fhould arife out of the trunk y\ but none 
 arofe in four hours, except a little vapor that 
 was on the flask's neck. 
 
 I then dug up the tree by the roots, and 
 fet the root in water, with the glaffes affixed 
 to the top of the ftem ; after feveral hours 
 nothing rofe but a little dew, which hung 
 on the infide of f-> yet it is certain by many 
 of the foregoing experiments, that if the 
 top and leaves of this tree had been on, 
 many ounces of water would in this time 
 have pafled thro' the trunk, and been eva- 
 porated thro' the leaves. 
 
 I have 
 
Vegetable Staticks. 47 
 
 I have tried the fame experiment with 
 feveral vine branches cut off, and fet in water 
 thus, but no water rofe into/! 
 
 Thefe three laft experiments all mew, that 
 tho' the capillary fap-veffels imbibe moifture 
 plentifully; yet they have little power to 
 protrude it farther, without the afliftance of 
 the perfpiring leaves, which do greatly pro- 
 mote its progrefs. 
 
 Experiment XVI. 
 
 In order to try whether any fap rofe in 
 the winter, I took in January feveral par- 
 cels of Filberd-fuckers, Vine-branches, green 
 Jefiamine-branches, Philarea and Laurel- 
 branches, with their leaves on them ; and dip- 
 ped their tranfverfe cuts in melted cement, to 
 prevent any moifture's evaporating thro* the 
 wounds ; I tied them in feparate bundles, and 
 weighed them. 
 
 The Filberd-fuckers decreafed in 8 days, 
 (fome part of which were very wet, but the 
 laft 3 or 4 days drying winds) the nth part 
 of their whole weight. 
 
 The Vine-cuttings in the fame time the 
 
 "h P art - 
 
 The 
 
48 Vegetable Statich. 
 
 The Jeflamine in the fame time the * part. 
 
 The Philarea decreafed the ^'part in five 
 days. 
 
 The Laurel the \ part in 5 days, and more. 
 
 Here is a confiderable daily wafte of fap, 
 which mull therefore neceffarily be fupplied 
 from the root ; whence it Is plain, that fome 
 fap rifes all the winter, to fupply this con- 
 tinual wafte, tho' in much lefs quantity than 
 in fummer. 
 
 Hence we fee good reafon why the Ilex 
 and the Cedar of Lib anus (which were graft- 
 ed the firft on an Englijh Oak, the other on the 
 Larix) were verdant all the winter, notwith- 
 ftanding the Oak and Larix leaves' were de- 
 cayed and fallen off; for tho', when the win- 
 ter came on, there did not fap enough rife 
 to maintain the Oak and Larix leaves, yet by 
 this prefent experiment we fee, that fome 
 fap is continually rifing all the winter ; and 
 by experiment the 5th on the Limon-tree, 
 and by feveral other the like experiments, on 
 many forts of ever-greens, we find that they 
 perfpiring little, live and thrive with little 
 nourifhrnent; the Ilex and Cedar might 
 well therefore continue green all the win- 
 ter, notwithstanding the leaves of the trees 
 
 they 
 
Vegetable Staticks. 49 
 
 they were grafted on fell off. See the late 
 curious and induftrious Mr. Fair child's ac- 
 count of thele graftings in Mr. Miller's 
 Gardeners Dictionary 3 vide Sap. 
 
 Experiment XVII. 
 
 Having by many evident proofs in the 
 foregoing experiments feen the great quan- 
 tities of liquor that were imbibed and per- 
 fpired by trees, I was dcfirous to try if I 
 could get any of this perfpiring matter ; 
 and in order to it, I took feveral glafs chy- 
 mical retorts, bap (Fig. 9. ) and put the 
 boughs of feveral forts of trees, as they 
 were growing with their leaves on, into 
 the retorts, flopping up the mouth p of the 
 retorts with bladder. By this means I got 
 feveral ounces of the perfpiring matter of 
 Vines, Fig-trees, Apple-trees, Cherry-trees, 
 Apricot and Peach-trees -, Rue, Horfe-radifh, 
 Rheubarb, Parfnip, and Cabbage leaves: 
 the liquor of all of them was very clear, 
 nor could I difcover any different tafle in 
 the feveral liquors: But if the retort ftand 
 expofed to the hot fun, the liquor will 
 tatte of the clodded leaves. Its fpecitick 
 gravity was nearly the fame with that of 
 
 £ common 
 
jo Vegetable Statich. 
 
 common water; nor did I find many air- 
 bubbles in it, when placed ia the exhaufted 
 receiver, which I expected to have found 5 
 but when referved in open viols, it ftinks 
 fooner than common water; an argument 
 that it is not pure water ; but has fome he- 
 terogeneous mixtures with it. 
 
 I put ajfo a large Sun-flower full-blown, 
 and as it w T as growing, into the head of a 
 glafs-ftill, and put its roftrum into a bottle, 
 by which means there diftilled a good quan- 
 tity of liquor into the bottle. It will be 
 very eafy in the fame manner to collect the 
 perfpirations of fweet-fcented Flowers, tho' 
 the liquor will not long retain its grateful 
 odor, but ftink in few days. 
 
 Experiment XVIII. 
 
 In order to find out what ftores of moi- 
 flure nature had provided in the earth, 
 (againft the dry fummer feafon) that might 
 anfwer this great expence of it, which is fo 
 neceiTary for the production and fupport of 
 vegetables 3 
 
 July 31. 1724. I dug up a cubick foot 
 earth, in an alley which was very little 
 trampled on ; it weighed ( after deducting 
 the weight of the containing veffel ) 104 
 
 pounds 
 
 
Vegetable Staticks. 5 1 
 
 pounds 4 ounces +4-. A cubick foot of 
 water weighs nearly 62- pounds, which is 
 little more than half the fpecifick gravity 
 of earth. This was a dry feafon, with a 
 mixture of fome few mowers, fo that the 
 grafs-plat adjoining was not burnt up. 
 
 At the fame time I dug up another cubick 
 foot of earth, from the bottom of the for- 
 mer; it weighed 106 pound 6 ounces-}- -J. 
 
 I dug up alfo a third cubick foot of earth, 
 at the bottom of the two former $ it weighed 
 ill pounds -j--j. 
 
 Thefe three feet depth were a good brick 
 earth, next to which was gravel, in which 
 at 2 feet depth, viz. 5 feet below the fur- 
 face of the earth, the fprings did then run. 
 
 When the firft cubick foot of earth was 
 fo dry and dufty, as to be unfit for vegeta- 
 tion, I weighed it, and found it had loft 
 6 pounds -j- n ounces, or 184 cubick in- 
 ches of water, near y part of its bulk. 
 
 Some days after, the fecond cubick foot 
 being drier than either the firft or third, 
 was decreaied in weight 10 pounds. 
 
 The third cubick foot, bting very dry 
 and dufty, had loft 8 pounds 8 ounces, or 
 247 cubick inches, viz. } part of its 
 bulk. 
 
 E 2 Now 
 
5* Vegetable Statich. 
 
 Now fuppofing the roots of the Sun-flower 
 (the longeft of which reached 15 inches eve- 
 ry way from the ftem) to occupy and draw 
 nouriftiment from 4 cubick feet of earth, 
 and fuppofe each cubick foot of earth to 
 afford 7 pounds of moifture, before it be 
 too dry for vegetation; the plant imbibing 
 and perfpiring 22 ounces every 24 hours, 
 that will be 28 pounds of water, which will 
 be drawn off in 21 days, and 1 6 hours ; after 
 which the plant would perifh, if there were 
 not frefh fupplies to thefe 4 cubick feet of 
 earth, either from dew or moifture arifing 
 from below 15 inches (the depth of the 
 roots) up into the earth occupied by the 
 roots. ^ 
 
 Experiment XIX. 
 
 In order to find out the quantity of Dew 
 that fell in the night, Aug. 15. at 7. p.m. I 
 chofe two glazed earthen pans, which were 
 3 inches deep, and 12 inches diameter in 
 furface; I filled them with pretty moift earth 
 taken off the furface of the earth. I fet 
 thefe pans in other broader pans, to pre- 
 vent any moifture from the earth flicking 
 to the bottoms of them. The moifter the 
 earth, the more dew there falls on it in a 
 
 night 7 
 
Vegetable Staticks. 5} 
 
 night -, and more than a double quantity of 
 Dew falls on a furface of water, than there 
 does on an equal furface of moift earth. 
 The evaporation of a furface of water, in 
 9 hours winter's dry day, is T V of an inch- 
 The evaporation of a furface of ice, fet in 
 the fhade during 9 hours day, was - J -p 
 
 Thefe Pans increafed in weight by the 
 night's Dew 180 grains; and decreafed in 
 weight by the evaporation of the day 
 1 ounce, 282 grains. So here are 540 
 grains more evaporated from the earth every 
 l\ hours in fummer, than falls in Dew in 
 the night -, that is, in 21 days near 26 ounces, 
 from a circular area of a foot diameter 5 
 and circles being as the fquares of their ^dia- 
 meters, 10 pounds -j- 2 ounces will in 21 
 days be evaporated from the hemifphere of 
 30 inches diameter, which the Sun-flower's 
 root occupies: Which, with the 26 pounds 
 drawn off by the Plant in the fame time, 
 make 36 pounds, that is, 9 pounds out 
 of every cubick foot of earth, the Plant's 
 roots occupying more than 4 cubick feet ; 
 but this is a much greater degree of drinefs 
 than the furface of the earth ever fuffers for 
 15 inches depth, even in the dried feafons 
 in this country. 
 
 E 7 In 
 
54 Vegetable Stathh. 
 
 In a long dry fcafon, therefore, efpecially 
 within the Tropicks, we muff have recourfe 
 for fufficient moifture (to keep Plants and 
 Trees alive) to the moift ftrata of earth, 
 which lie next below that in which the 
 roots are. Now moift bodies always com- 
 municate of their moifturc to more dry 
 adjoining bodies; but this flow motion of 
 the afcent of moifture is much accelerated 
 by the Sun's heat to considerable depths in 
 the earth, a$ is probable from the following 
 20th Experiment. 
 
 Now 180 grains of Dew falling in one 
 night, on a circle of a foot diameter, == 
 113 fquare inches; thefe 180 grains being 
 equally fpread on this furface, its depth 
 
 will be ttu part of an inch = 
 
 M9 r U 3 x 254 
 
 J found the depth of Dew in a winter night 
 to be the -^ part cf an inch ; fo that, if we 
 allow 1 59 nights for the extent of the fu tu- 
 rner's Dew, it will in that time arife to one 
 jnch depth. And reckoning the remaining 
 zo r o njghts for the extent of the winter'^ 
 Dew, it will produce 2.28 inches depth, 
 which makes the Dew of the whole year 
 amount to 3.28 inches depth. 
 
 And the quantity which evaporated in a 
 
 fair fummer's day from the fame furface, be- 
 ing 
 
Vegetable Staticks. 55 
 
 ing 1 ounce + 282 grains, gives -fe part of 
 an inch depth for evaporation, which is 
 four times as much as fell at night. 
 
 I found, by the fame means, the evapo- 
 ration of a winter's day to be nearly the 
 fame as in a fummer's day, for the earth 
 being in winter more faturate with moi- 
 fture, that excefs of moifture anfwers to the 
 excefs of heat in fummer. 
 
 Nic. Cruquius, N° 381 of the Philofo- 
 phical Tranfadions, found that 28 inches 
 depth evaporated in a whole year from wa- 
 ter, /. e. T '-j of an inch each day, at a mean 
 rate ; but the earth in a fummer's day evapo- 
 rates -fa of an inch ; fo the evaporation of 
 a furface of water, is to the evaporation of 
 a furface of earth in fummer, as ~j to ^ 
 
 The quantity of Rain which falls in a 
 year is at a medium 22 inches: The quan- 
 tity of the earth's evaporation in a year is 
 at lead 9.15 inches, fince that is the rate, 
 at which it evaporates in a fummer's day : 
 From which 9.15 inches, are to be deduct- 
 ed 3.39 inches for circulating daily Dew; 
 there remain 5.76 inches, which 5.76 inches 
 deducted from the quantity of Rain' which 
 falls in a year, there remain at leaft 16.24 
 
 E 4 inches 
 
5 6 Vegetable Staticks. 
 
 inches depth, to replenish the earth with 
 moifture for vegetation, and' to fupply the 
 Springs and Rivers. 
 
 In the cafe of the hop-ground, the eva- 
 poration from the hops may be confidered 
 only for three months at-^T P art °f an inc ^ 
 each day, which will be 7% of an inch ; 
 but before we allowed 5.76 inches vapour to 
 evaporate from the furface of the ground, 
 which added to T ^ inch, gives 6.66 inches 
 which is the utmoft that can be evaporated 
 from a furface of hop-ground in a year. So 
 that of 22 inches depth of rain, there re- 
 main 15.34 inches to fupply fprings; which 
 are more or lefs exhaufted, according to 
 the drinefs or wetnefs of the year. Hence 
 we find that 22 inches depth of rain in a 
 year is fufficient for all the purpofes of na- 
 ture, in fuch flat countries as this about 
 ^eddington near Hampton-Court* But in 
 the hill countries, ac in Lancafoire, there 
 falls 42 inches depth of rain-water; from 
 which deducting 6.66 inches for evaporation, 
 there remains 35.34 inches depth of water 
 for the fprings j befides great fupplies from 
 much more plentiful dews, than fall in plain 
 countries: Which vaft flores feem fo abun- 
 dantly fufficient to anfvvcr the great quantity 
 
 of 
 
Vegetable Statich. 57 
 
 of water, which is conveyed away, by fprings 
 and rivers, from thofe hills, that we need 
 not have recourfe, for fupplies, to the great 
 Abyfs, whofe furface, at high water, is fur- 
 mounted fome hundreds of feet by ordi- 
 nary hills, and fome thoufands of feet by 
 thofe vaft hills from whence the longeft 
 and greateft rivers take their rife. See vol. II. 
 
 A 2 57- 
 
 Experiment XX. 
 
 I provided me fix Thermometers, whofe 
 items were of different lengths, viz. from 
 18 inches to 4 feet. I graduated them all by 
 one proportional fcale, beginning from the 
 freezing point* which may well be fixed as 
 the utmoft boundary of vegetation on the fide 
 of cold, where the work of vegetation ceafes, 
 the watry vehicle beginning then to condenfe 
 and be fixed -, tho' many trees, and fome plants 
 as grafs, mofs, &c. do furvive it 5 yet they 
 do not vegetate at that time. 
 
 The greateft degree of heat, which I at 
 firft marked on my Thermometers, was equal 
 to that of water, when heated to the great- 
 eft degree that I could bear my hand in it, 
 without ftirring it about. But finding by 
 experience, that plants can endure, with- 
 out 
 
58 Vegetable Staticks. 
 
 out prejudice, a fome thing greater heat 
 than this, I have pitched upon the heat in 
 which melted wax fwimming on hot water 
 firfl begins to coagulate ; for fince a greater 
 heat than this will diflblve the wax, which 
 is a vegetable fubftance, this may therefore 
 well be fixed as the utmoft boundary of ve- 
 getation, on the warm fide ; beyond which 
 plants will rather fade than vegetate, fuch 
 degree of heat feparating and difperfing, in- 
 ftead of congregating and uniting the nu- 
 tritive particles. 
 
 This /pace I divided into 100 degrees 
 on all the Thermometers, beginning to num- 
 ber from the freezing point. Sixty-four of 
 thefe degrees are nearly equal to the heat of 
 the blood of animals ; which I found by 
 the rule given in the Philofophical Tranf- 
 aftions, Vol. II. p. 1. of Mr. Motte's Abridg- 
 ment, which is fuppofed to be Sir Ifaac 
 Neictons eflimate 5 viz. by placing one of 
 the Thermometers in water heated to the 
 greater!: degree that I could bear my hand 
 in it ftirring it about : And which I wa s 
 further aflured of, by placing the ball of my 
 Thermometer in the flowing blood of an ex- 
 piring Ox. The heat of the blood to that 
 of boiling water is as 14.27 to 33. 
 
 By 
 
Vegetable Stattcks. 59 
 
 By placing the ball of one of thefe Ther- 
 mometers in my bofom, and under an arm- 
 pit, I found the external heat of the body 
 54 of thefe degrees. The heat of milk, as 
 it comes from the Cow, is equal to 55 de- 
 grees, which is nearly the fame with that 
 for hatching of eggs 5 the heat of urine 
 58 degrees. The common temperate point 
 in thermometers is about 18 degrees. 
 
 The hotteft Sun-fhine in the year 1727 
 raifed the fpirit in the thermometer expofed 
 to it, 88 degrees j a heat 24 degrees greater 
 than that of the blood of animals: And 
 tho' plants endure this, and a confiderably 
 greater heat within the Tropicks, for fome 
 hours each day, yet the then hanging of the 
 leaves of many of them mews that they 
 could not long fublift under it, were they 
 not frequently refrefhed by the fucceeding 
 evening and night. 
 
 The common noon-tide heat in the Sun 
 in "July is about 50 degrees : The heat of 
 the air in the made in July is at a medium 
 38 degrees. The May and June heat is from 
 17 to 30 degrees: the moll genial heat for 
 the generality of plants, in which they flou- 
 rim moft, and make the greateft progrefs in 
 their growth. The autumnal and vernal 
 
 heat 
 
6o Vegetable Staticks. 
 
 heat may be reckoned from 10 to 20 de- 
 grees: The winter heat from the freezing 
 point to 10 degrees. 
 
 The fcorching heat of a hot-bed of horfe- 
 dung, when too hot for plants, is equal to 
 85 degrees and more ; and hereabout is pro- 
 bably the heat of blood in high fevers. 
 
 The due healthy heat of a hot-bed of 
 horfe-dung, in the fine mold, where the 
 roots of thriving Cucumber-plants were, 
 in Feb. was equal to 56 degrees, which is 
 nearly the bofom heat, and that for hatch- 
 ing of eggs. The heat of the air under the 
 glais- frame of this hot-bed was equal to 
 34 degrees; fo the roots had 26 degrees 
 more heat than the plants above ground. 
 The heat of the open air was then 17 de- 
 grees. 
 
 It is now grown a common and very rea- 
 fonable pradtice, to regulate the heat of 
 ftoves and green-houfes, by means of Ther- 
 mometers hung up in them. And for 
 greater accuracy, many have the names of 
 fome of the principal exoticks written up- 
 on their Thermometers, over-againft the fe- 
 veral degrees of heat, which are found by 
 experience to be propereft for them. And 
 I am informed that many of the moft cu- 
 rious 
 
Vegetable Staticks. 6\ 
 
 rious Gardeners about London have agreed 
 to make ufe of Thennometers of this fort ; 
 which are made by Mr. John Fowler in 
 Swithin's- Alley, near the Royal-Exchange • 
 which have the names of the following: 
 plants, oppofite to their refpective mod 
 kindly degrees of heat; which in my Ther- 
 mometers anfwer nearly to the following de- 
 grees of heat above the freezing point, viz. 
 Melon-thiflle 31, Ananas 29, Piamento 26, 
 Euphorbium 24, Cereus 2J~, Aloe 19, In- 
 dian-fig 164, Ficoides 14, Oranges i2 5 Myr- 
 tles 9. 
 
 Mr. Boyle, by placing a 'Thermometer in 
 a cave, which was cut ftrait into the bot- 
 tom of a cliff, fronting the Sea, to the depth 
 of 130 feet, found the fpirit flood, both in 
 winter and fummer, at a fmall divifion above 
 temperate; the cave had 80 feet depth 
 of earth above it. Boyle's Works, Vol. III. 
 p. 54. 
 
 I marked my fix Thermometers numeri- 
 cally, 1, 2, 3, 4, 5, 6. The Thermometer 
 numb. 1, which was (honed, I placed with 
 a South afpect, in the open air; the ball 
 of numb. 2, I fet two inches under ground; 
 that of numb. 3, four inches under ground; 
 numb. 4, 8 inches; numb. 5, 16 inches ; and 
 
 numb. 
 
6 1 Vegetable Staticks. 
 
 numb. 6, 24 inches underground. And that 
 the heat of the earth, at thefe' feveral depths, 
 may the more accurately be known, it is 
 proper to place near each 'Thermometer a 
 glafs-tube fealed at both ends, of the fame 
 length with the items of the feveral Ther- 
 mometers ; and with tinged fpirit of wine 
 in them, to the fame height, as in each 
 correfponding Thermometer ; the fcale of 
 degrees, of each Thermometer, being mark- 
 ed on a Aiding ruler, with an index at the 
 back of it, pointing to the correfponding 
 tube. When at any time an obfervation is 
 to be made, by moving the index, to point 
 to the top of that fpirit in the tube, an ac- 
 curate-allowance is hereby made, for the 
 very different degrees of heat and cold, on 
 the ftems of the Thermometers , at all depths ; 
 by which means the fcale of degrees will 
 {hew truly the degrees of heat in the balls 
 of the Thermometers, and confequently, the 
 refpedlive heats of the earth at the feveral 
 depths where they are placed. The ftems 
 of thefe Thermometers, which were above 
 ground, were fenced from weather and in- 
 juries by fquare wooden tubes -, the ground 
 they were placed in was a brick earth in 
 the middle of my garden. 
 
 A 
 
Vegetable Staticks. 63 
 
 July 30. I began to keep a regifter of 
 their rife and fall. During the following 
 month of Auguji^ J obferved that when 
 the fpirit in the thermometer^ numb. 1, 
 ( which was expofed in the Sun ) was about 
 noon rifen to 48 degrees, then the fecond 
 thermometer was 45 degrees, the fifth 33, 
 and the fixth 3 1 ; the third and fourth at 
 intermediate degrees. The fifth and fixth 
 Thermometer kept nearly the fame degree 
 of heat both night and day, till towards 
 the latter end of the month ; when, as the 
 days grew morter and cooler, and the nights 
 longer and cooler, they then fell to 25 and 
 27 degrees. 
 
 Now, fo considerable a heat of the Sun, 
 at two feet depth, under the earth's furface, 
 muft needs have a ftrong influence in raif- 
 ing the moifture at that and greater depths ; 
 whereby a very great and continual wreak 
 muft always be afcending, during the warm 
 fummer feafon, by night as well as day; for 
 the heat at two feet depth is nearly the fame 
 night and day, the impulfe of the Sun- 
 beams giving the moifture of the earth a 
 briilc undulating motion, which watery par- 
 ticles, when feparated and rarefied by heat, 
 do afcend in the form of vapour : And the 
 
 vigour 
 
*>4 Vegetable Statkks. 
 
 vigour of warm and confined vapour (luch 
 as is that which is i, 2, or 5 f eec deep in 
 the earth) muft be very considerable, fo as 
 to penetrate the roots with fome vigour; 
 as we may reafonably iuppofe, from the 
 vaft force of confined vapour in /Eolipiles, 
 in the digefter of bones, and the engine to 
 raife water by fire. See. Vol. II. p. 259. 
 
 If plants were not in this manner fup- 
 plied with moifture, it were impoffible for 
 them to fubfifr under the fcorching heats 
 within the Tropicks, where they have no 
 rain for many months together: For tho' 
 the dews are much greater there, than in 
 thefe more Northern climates - 9 yet doubdefs, 
 where the heat fo much exceeds ours, the 
 whole quantity evaporated in a day there, 
 does as far exceed the quantity that falls 
 by night in dew, as the quantity evaporat- 
 ed here in a fummer's day, is found to ex- 
 ceed the quantity of dew which falls in the 
 night. But the dew, which falls in a hot 
 fummer feafon, cannot poffibly be of any 
 benefit to the roots of trees; becauie it is 
 remanded back from the earch by the fol- 
 lowing day's heat, before fo fmall a quantity 
 of moifture can have foaked to any con- 
 fiderable depth. The great benefit there- 
 fore 
 
Vegetable Staticks. 6 s 
 
 fore of dew, in hot weather, muft be, by 
 being plentifully imbibed into vegetables ; 
 thereby not only refrefhing them for the 
 prefent, but alfo furniming them with a 
 frefh fupply of moifture towards the great 
 expences of the fucceeding day. 
 
 'Tis therefore probable, that the roots of 
 trees and plants are thus, by means of the 
 Sun's warmth, conftantly irrigated with 
 frefh fupplies of moifture ; which, by the 
 fame means, infinuates itfelf with fome 
 vigour into the roots. For, if the moifture 
 of the earth were not thus actuated, the roots 
 muft then receive all their nourifhment 
 merely by imbibing the next adjoining 
 moifture from the earth; and confequently 
 the (hell of earth, next the furface of the 
 roots, would always be confiderably drier, 
 the nearer it is to the root; which I have 
 not obferved to be fo. And by Exper. 1 8, 
 and 19, the roots would be very hard put to 
 it to imbibe fufficient moifture in dry fum- 
 mer weather, if it were not thus conveyed 
 to them by the penetrating warmth of the 
 Sun : Whence by the fame genial heat, in 
 conjunction with the attraction of the ca- 
 pillary fap-veffels, it is carried up thro* the 
 bodies and branches of vegetables; and 
 
 F thence 
 
66 Vegetable St Micks. 
 
 thence pa (Ting into the leaves, it is there 
 moft vigoroufly acted upon, in thofe thin 
 plates, and put into an undulating motion, 
 by the Sun's warmth, whereby it is moft 
 plentifully thrown off, and perfpired thro' 
 their furface ; whence, as foon as it is dif- 
 intangled, it mounts with great rapidity in 
 
 the free air. 
 
 But when, towards the latter end of 
 OBtober y the vigour of the Sun's influence is 
 fo much abated, that the firft thermometer 
 was fallen to 3 degrees above the freezing 
 point, the fecond to 10 degrees, the fifth 
 to 14 degrees, and the fixth Thermometer to 
 16 degrees ; then the brisk undulations of 
 the moifture of the earth, and alfo of the 
 afcending fap, much abating, the leaves faded i 
 
 and fell off 
 
 The greateft degree of cold, in the fol- 
 lowing winter, was in the firft 12 days of 
 November \ during which time, the fpirit in 
 the firft Thermometer was fallen 4 degrees 
 below the freezing point, the deepeft Ther- 
 mometer 10 degrees, the ice on ponds was 
 an inch thick. The Sun's greateft warmth 
 at the winter folftice, in a very ferene, calm 
 frofty-day, was, againft a South afpedt of \ 
 wall, 19 degrees, and in a free open air, bu 
 
 11 de 
 
Vegetable Staticks. 6/ 
 
 1 1 degrees above the freezing point. From 
 the ioth of January to the 29th of March 
 was a very dry feafon ; when the green 
 Wheat was generally the fineft that was 
 ever remembred. But from the 29th of 
 March J725, to the 29th of September fol- 
 lowing, it rained more or lefs almoft every 
 day, except ten or twelve days about the 
 beginning of July ; and that whole feafon 
 continued fo very cool, that the fpirit in 
 the firft Thermometer rofe but to 24 degrees? 
 except now and then in a fhort interval of 
 Sunfhine ; the fecond only to 20 degrees ; 
 the fifth and fixth to 24 and 23 degrees, 
 with very little variation: So that during 
 this whole fummer, thofe parts of roots which 
 were two feet under ground, had three or 
 four degrees more warmth than thofe which 
 were but two inches under ground : And at 
 a medium the general degree of heat thro' 
 this whole fummer, both above and under 
 ground, was not greater than the heat of 
 the middle of the preceding September. 
 
 The year 1725 having b°en, both inthis 
 iiland, and in the neighbouring nations, mod 
 remarkably wet and cold; and the year 
 J 723, in the other extreme, as remarkably 
 dr" 355 has ever been known ; it may not 
 
 F 2 be 
 
6% Vegetable Statich. 
 
 be improper here to give a fhort account of 
 them, and the influence they had on their 
 productions. 
 
 Mr. Miller, in the account which he 
 took of the year 1723, obferved, u That the 
 tc winter was mild and dry, except that in 
 February it rained almoft every day, which 
 kept the fpring backward. March, April, 
 May, June, to the middle of July, proved 
 " extremely dry, the wind North.eaft mod 
 " part of the time. The fruits were for- 
 " ward, and pretty good ; but kitchen-fluff, 
 €C efpecially Beans and Peas, failed much, 
 <c The latter half of July the weather proved 
 " very wet, which caufed the fruits to 
 <c grow: fo fail, that many of them rotted 
 " on the trees; fo that the autumn fruits 
 " were not good. There were great plenty 
 <c of Melons, very large, but not well rafted. 
 Great plenty of Apples ; many kinds of 
 fruits bloffomed in Augujl, which pro- 
 duced many fmall Apples and Pears in 
 <{ October, as alfo Strawberries and Rafp- 
 " berries in great plenty. Wheat was good, 
 " little Barley, much of which was very un- 
 equally ripe, fome not at all, becaufe fown 
 late, and no timely rain to fetch it up. 
 JJ There were innumerable Wafps -, how it 
 
 " fared 
 
 cc 
 cc 
 cc 
 
 cc 
 <c 
 
Vegetable Staticks. 69 
 
 * fared with the hops this dry year, is men- 
 u tioned under Exper. 9. 
 
 " The following winter, 1724, proved 
 u very mild ; the fpring was forward in J a- 
 u miary, £0 that the Snow-drops, Crocus '4, 
 " Polyanthus's, Hepat tea's, and Narcijfus's, 
 " were in flower. And it was remarkable, 
 u that moft of the Colliflower-plants were 
 M deftroyed by the mildew, of which there 
 u was more, ail this winter, than had been 
 < c known in the memory of man. In Fe- 
 u bruary we had cold fharp weather, which 
 u did fome damage to the early crops, and 
 M it continued variable till April-, fo that 
 •" much of the early Wall-fruit was cut off: 
 <l And again the 6th of May was a very 
 £C (harp froft, which much injured tender 
 t( plants and fruits. The fummer in general 
 '* was moderately dry, the common fruits 
 " proved pretty good, but late: Melons 
 ■ <c and Cucumbers were good f<5t little: 
 cc Kitchen-fluff was in great plenty in the 
 " markets." 
 
 In the very wet and cold year 1725, mod 
 things were a full month backwarder than 
 ufual. Not half the Wheat in by the 24th 
 of Aaguft, in the Southern parts of England ; 
 very few Melons or Cucumbers, and thofe 
 
 F 3 not 
 
70 Vegetable Staticks. 
 
 not good. The tender Exoticks fared but ill; 
 fcarce any grapes, thofe {matt, and of very 
 unequal fizes, on the fame bunch, not ripe 5 
 Apples and Pears green and infipid ; no fruit 
 nor products of the ground good, but crude: 
 Pretty good plenty of Wheat, tho' coarfe, 
 and long ftraw ; Barley coarfe, but plenty 
 of it in the uplands. Beans and Peas mod 
 flourishing and plentiful 5 few Wafps or 
 other infects, except Flies on hops. Hops 
 were very bad thro' the whole kingdom. Mr. 
 Aafiin of Canterbury fent me the following 
 particular account, how it fared with them 
 there ; where they had more than at Farnham, 
 and moft other places, viz. 
 
 " At mid-April not half the fhoots ap- 
 < c peared above ground ; fo that the plant- 
 " ers knew not how to pole them to the 
 <c beft advantage. This defect of the moot, 
 " upon opening the hills, was found to be 
 " owing to the multitude and variety of 
 <c vermin that lay preying upon the root ; 
 c< the increafe of which was imputed to 
 << the long and almoft uninterrupted feries 
 <c of dry weather, for three months paft : 
 <{ Towards the end of April, many of the 
 f c hop-vines were infefted with the Flies. 
 * c About the 20th of May there was a 
 
 cc 
 
 very 
 
 
Vegetable Statkks. 71 
 
 u very unequal crop, fome Vines being 
 " run feven feet, others not above three or 
 " four feet ; fome juft tied to the poles, and 
 " fome not vilible : And this difpropor- 
 <c tionate inequality in their iize continued 
 " through the whole time of their growth. 
 u The Flies now appeared upon the leaves 
 Cf of the forwarder! Vines, but not in fuch 
 « c numbers here, as they did in moft other 
 <* places. About the middle of June, the 
 lf Flies increafed, yet not fo as to endanger 
 iC the crop; but in diftant plantations they 
 cl were exceedingly multiplied, fo as to 
 <c fvvarm towards the end of the month. 
 u "June 27th fome fpecks of Fen appeared : 
 " From this day to the 9th of July, was 
 very fine dry weather. At this time, 
 when it was faid that the Hops in moft 
 other parts of the kingdom looked black 
 and fickly, and feemed pall: recovery, ours 
 held it out pretty well, in the opinion 
 of the moft skilful planters. The great 
 leaves were indeed difcoloured, and a 1 it— 
 <f tie withered, and the Fen was fomewhat 
 " increafed. From the 9th of July to the 
 t c 23d the Fen increafed a good deal, but 
 <c the Flies and Lice decreafed, it raining 
 " daily much ; In a week more the Fen, 
 
 F 4 <c which 
 
 u 
 
 cc 
 a 
 
 c< 
 
 iC 
 
71 Vegetable Staticks. 
 
 " which feemed to be almoft at a ftand, 
 " was confiderably increafed, 'efpecially in 
 u thofe grounds where it firft appeared. 
 cc About the middle of Augujl, the Vines 
 <l had done growing, both in Item and 
 <c branch; and the forwarded: began to be 
 <c in Hop, the reft in Bloom : The Fen 
 " continued fpreading, where it was not 
 <l before perceived, and not only the leaves, 
 <c but many of the Burs alfo were tainted 
 " with it. About the 20th of Angujl, 
 " fome of the Hops were infected with the 
 " Fen, and whole branches corrupted by it. 
 €t Half the Plantations had hitherto pretty 
 tc werl efcaped, and from this time the Fen 
 H increafed but little: But feveral days vio~ 
 " lent wind and rain, in the following 
 ;c week, fo difordered them, that many of 
 " them began to dwindle, and at laft came 
 " to nothing 5 and of thofe that then re- 
 " mained in bloom, fome never turned to 
 u Hops; and of the reft which did, many 
 " of them were fo fmall, that they very 
 '* little exceeded the bignefs of a good 
 lc thriving Bur. We did not begin to pick 
 " till the eighth of September, which was 
 « eighteen days later than we began the 
 «' year before. The crop was little above 
 
 " two 
 
Vegetable Staticks. * /j 
 
 tf< two hundred on an acre round, and ..ot 
 " good." The befl Hops fold this year 
 at Way -Hill Fair for fixteen pounds the 
 hundred. 
 
 The almoft uninterrupted wetnefs and 
 coldnefs of the year 1725, very much af- 
 fected the produce of the Vines the enfu- 
 ing year -> and we have fufficient proof from 
 the obfervations that the four or five laft 
 years afford us, that the moifture or drinefs 
 of the preceding year has a confiderable in- 
 fluence on the productions of the Vine the 
 following year. Thus in the year 1722, 
 there was a dry feafon, from the beginning 
 of Augujl thro' the following autumn and 
 winter, and the next fummer there was 
 good plenty of Grapes. The year 1723 was 
 a remarkably dry year, and in the following 
 year 1724, there was an unufuai plenty of 
 Grapes. The year 1724 was moderately 
 dry, and the following fpring the Vines 
 produced a fufficient quantity of bunches; 
 but by reafon of the wetnefs and coldnefs 
 of the year 1725, they proved abortive, and 
 produced hardly any Grapes. This very 
 wet year had an ill effect, not only upon its 
 own productions, but alfo on thofe of the 
 following year: For notwithfhnding there 
 
 was 
 
74 Vegetable St at his. 
 
 was a kindly fpring, and blooming feafon, in 
 the year 1726, yet there were* few bunches 
 produced, except here and there in fome 
 very dry foils. This many Gardeners fore- 
 faw early, when, upon pruning of the Vines, 
 they obferved the bearing (hoots to be crude 
 and immature; which was the reafon why 
 they were not fruitful. The firft crop thus 
 failing in many places, the Vines produced 
 a fecond, which had not time to come to 
 maturity before the cold weather came on. 
 
 Mr. Miller fent me the following ac- 
 count of the long and fevere winter in the 
 year 1728; and of the effect it had on the 
 plants and trees in this and the neighbour- 
 ing countries, viz. 
 
 " The autumn began with cold North 
 M and Eaft winds, and early in November 
 cc the nights were generally frofty 5 tho' the 
 * c froft did not enter the ground deeper than 
 " the fucceeding days thaw'd. But towards 
 <c the end of November the winds blew ex- 
 <c tremely cold from the North, which was 
 " fucceeded by a great fnow, which fell in 
 <c fuch quantities in one night, as to break 
 <{ off large arms and tops of many ever-green 
 " trees, on which it lodged. 
 
 <c 
 
 After 
 
 
Vegetable Statlch. 7j 
 
 <c Afcer the fnow was down, it began to 
 cc freeze again, the wind continuing to 
 < c blow from the North ; the days were 
 " dark and cloudy for fome time, but af- 
 " ter wards it cleared up, and the Sun ap# 
 peared almoft every day, which melted 
 the fnow where expofed to it, whereby 
 the froft penetrated the deeper into the 
 ground. It was obfervable, that during 
 thefe clear days, a great mift or vapour 
 appeared in the evenings, floating near 
 " the furface of the ground, till the cold 
 " of the night came on, when it was fud- 
 " denly condenfed and difappeared $ the 
 " nights now began to be extreme fharp. 
 tc The ipirit in the Thermometer was 18 de- 
 * c grees below the freezing point, (as mark- 
 ed upon Mr. Fowler's Thermometers) and 
 it was at this time that van; quantities of 
 cc Laurujiinuss, Phyllyrea 's^Alaternns K s;Rq/e- 
 mary, and other tender plants began to 
 fufferj efpecially fuch as were trimm'd 
 up to naked items, or had been clipp'd 
 " late in the fummer. At this time alfo 
 " there were great numbers of trees dif- 
 " barked, fome of which were of a confi- 
 ci derablebulkj particularly two Weft-India 
 H Pla?ie Trees, in the Phyjick Garden at 
 
 " Cbelfea, 
 
 cc 
 
 CC 
 
 cc 
 <c 
 cc 
 
 cc 
 
 cc 
 
 cc 
 cc 
 cc 
 
?6 Vegetable Stathks* 
 
 " Chelfea, which are near forty feet high, 
 £t and a fathom in circumference, were dif- 
 f* barked almoft from the bottom to the 
 5f top, on the weft fide of the trees. And 
 " in a nurfery belonging to Mr. Francis 
 tl Hurjl, great numbers of large Pear-trees 
 tl were all of them disbarked on the Weft or 
 €C South- Weft fides of 'em. And in feveral 
 & other places I obferved the like accident, 
 <c and foun^ it was conftantly on the fame 
 £ fide of the trees. 
 
 " About the middle of December the 
 " froft abated of its intenfenefs, and feemed 
 € < to be at aftand, till the 23d of the month, 
 < c when the wind blew extreme fharp and 
 11 cold from the Eaft, and the froft continued 
 " very hard to the 28 th day, at which time 
 << it began to abate again, and feemed to be 
 il going off, the wind changing to the Scuth ; 
 <c but it did not continue long in this point, 
 " before it changed to the Eaft again, and 
 " the froft returned, tho' not fo violent as 
 y before. 
 
 <c Thus the weather continued for the 
 <c moft part frofty, till the middle of March, 
 <c with a few intervals of mild weather, 
 cC which brought forv/ard fome of the early 
 u flowers j but the cold returning, loon de~ 
 
 < c ftroved 
 
Vegetable Statkks* 77 
 
 " ftroyed them ; fo that thofe plants which 
 " ufually flower in Ja?tuary and February, 
 " did not this year appear till the latter end 
 " of March, or the beginning of April-, as 
 " the Crocus's, Hepatica's, Perjian Iris's, 
 u Black Hellebores, Polyanthus's, Mezereons, 
 " and many others. 
 
 Cl The Colliflower- plants which were 
 " planted out during the intervals between 
 the froft, were moft of them deftroyed, 
 or fo much pinched, as to lofe the great- 
 eft part of their leaves ; whereas thofe 
 which had been planted out in Oclober 
 efcaped very well. The early Beans and 
 ? Peas were moft of them deftroyed; and 
 " great quantities of timber and fruit-trees, 
 " which had been lately removed, were quite 
 \\ killed. 
 
 " The lofs was very great in moft cu- 
 rious collections of plants; there being 
 a great deftruction made of many trees, 
 fhrubs, and plants, which had endured 
 the open air many years, without being 
 the leaft hurt by cold ; as the Granadilla 
 or Paffio?i- flower % Arbutus o: Straw- 
 P berry Tree, Cork Tree, with moft of the 
 " Aromatick Plants, as Rofemary, L ->ven- 
 V der> Stcechas, Sage, Maflick, Marum, 
 
 u 
 u 
 
 U 
 u 
 
 <c 
 cc 
 CI 
 
 (C 
 
 <c 
 <c 
 
 << 
 
 and 
 
€C 
 
 78 Vegetable Staticks. 
 
 " and many others, which were deftroyed 
 " to the ground, and were by many people 
 " pulled up and thrown away ; but in warm 
 *' dry foils, where they were fuffered to re- 
 <c main undifturbed, many of them broke 
 " out from the root again, tho' it was very 
 cc late in the fummer before they {hewed any 
 
 figns of recovery. 
 
 The plants in the confervatories fuffered 
 < c very much by being fo long fhut up clofe; 
 Cc for the days being for the moft part cloudy, 
 <c and the wind blowing very iharp, the 
 * c windows of the green-houfes could not be 
 cc with fafety opened, which occafioned a 
 c< noxious damp in the houfes, whereby the 
 <c plams became fickly, languifhed and de- 
 " cayed foon afcer. 
 
 u Nor was the froft more fevere with us 
 " than in other parts of Europe, but on 
 " the contrary in comparifon favourable ; 
 ct for in the Southern parts of France the 
 * c Olives, Myrtles, Ciftus J s, and other trees 
 <c and fhrubs, which grow there almoft 
 c< fpontaneoufly, were deftroyed ; and in the 
 " Nonhern parts of France, as about Paris, 
 " &c, the buds of many kinds of fruit-trees 
 cc - were deftroyed, although clofed, fo that 
 u many of them never opened, but decayed 
 
 « and 
 
Cc 
 
 ii 
 
 <( 
 
 Vegetable Staticks. yp 
 
 and perifhed; and the Fig-trees which 
 1 were expofed to the open air, were alfo 
 
 deftroyed. 
 
 "In Holland the Pines, Firs, and other 
 
 hardy refinous trees, were moft of them 
 < c killed, altho' many of them are natives 
 <c of the Alps, and other mountainous cold 
 <c countries ; but this I apprehend to be ow- 
 <c ing to the lownefs of their fituation and 
 " foil, whereby their roots eafily ran down 
 " into the water, which is more injurious to 
 " thefe trees than froft. 
 
 <c But it was obferved, that the trees and 
 €C fhrubs which are natives of Virginia and 
 cc Carolina, efcaped well in Holland; when 
 <c almoft all thofe which were brought from 
 " Italy, Spain, or the South parts of France, 
 li were intirely deftroyed. Which will greatly 
 <c inhance the value of the former trees, ef- 
 " pecially fuch of them as are either proper 
 w for ufe or beautv. 
 
 <£ In Germany the winter was fo fevere as 
 " to deftroy almoft all their plants and flowers, 
 <l which were not either removed into the 
 <c green - houfes, or protected by coverings 
 Xi from the froft, as I was informed by letters 
 ct from thence. 
 
 « 
 
 And 
 
8© Vegetable Statich. 
 
 " And in Scotland the froft and fnow did 
 " great damage, fome of the' particulars of 
 11 which I fhall tranfcribe from a letter* 
 li which I received from a gentleman living 
 <c near 'Edinburgh who is a curious ob- 
 " ferver. 
 
 cc About the 20th of November ', he fays, 
 " they had much fnow, which lay ten days, 
 <c and then went off very pleafantly without 
 " rain ; and from that time till the middle 
 <c of December, we had very good winter 
 <c weather, when a great fnow fell, which 
 u was attended with a ftorm from the North- 
 cc eaft; which fnow lay very thick upon the 
 ground till the 12th day of January, du- 
 ring which time there was a very intenfe 
 " froft: After which the cold abated, and 
 u the fnow went off gradually ; and about 
 " the end of January, I obferved in my 
 " green- houfe the flowers and young fhoots 
 of the Orange and other exotick trees did 
 begin to appear, and all of them began to 
 prepare for vegetation. In the open ground 
 c< we had Spring Cyclamens, Primrofes, Win- 
 " ter Aconites, Snowdrops, Hellebores, Poly- 
 " anthuss, Glajlenbury Thorn, Winter Hya- 
 " cinthsy and Mezereons in flower. 
 
 " But 
 
 tc 
 it 
 
cc 
 
 cc 
 <c 
 CI 
 
 Vegetable Staticks. 55 1 
 
 But before I proceed to give a farther 
 account of the weather, I (hail offer you 
 my thoughts upon the reafon of this ve- 
 getation fo early, whilft the cold was fo 
 iC intenfe with you. Firft, it is to be obferved, 
 " that our ftorms of fnow at that feafon 
 " came on before the froft had entered the 
 " ground; fo that the fnow kept the ground 
 " warm and feenre from the froft, which 
 " only crufted the top of the fnow : Du- 
 ring this feafon the wind blew from the 
 Eaft, which coming off the fea, (from 
 which we are but eight miles diftant) was 
 cc not attended with fo much cold as if it 
 " had blown over the land, which was 
 " covered with fnow, where there is no 
 " fea for two hundred miles. Till the fifth 
 " of February we enjoyed this weather ; at 
 " which time we had a violent fnow with 
 a ftorm from the South-weft, and the 
 froft having entered the ground before it 
 fell, checked our early flowers from ap- 
 pearing : During this fnow, which con- 
 tinued moft part of February, we had a 
 great deal of fun-mine, which contributed 
 very much to our early crops of Cu- 
 cumbers and Melons \ but during the nights 
 it froze very hard, which deftroyed great 
 
 G " numbers 
 
8 2 Vegetable Statkks. 
 
 numbers of plants that were not ftiel- 
 
 cc 
 
 <c tered. 
 
 
 t€ Every thing was now at a ftand ; the 
 Apricot and Peach bloffoms continued tur- 
 gid ; but not being opened, they fuffered 
 very little; the Laurujlinus s fuffered 
 extremely by this laft fevere feafon, efpe- 
 " cially where the fnow had been melted from 
 u their roots. 
 
 " This fnow went off with a violent 
 
 c£ South- weft wind, which was very bleak 
 
 <c and cold ; and where the fun had no ac- 
 
 " cefs, the fnow lay till the 12th of March, 
 
 " at which time we had for fix days very 
 
 cc mild weather, which occafioned our pat- 
 
 4C ting abroad our Carnatioyis^ whereby we 
 
 C£ loft moft of them. The wind continued 
 
 " cold, varying from the South-weft to the 
 
 << North-weft, and fometimes North-eaft; 
 
 " and upon the 23d day it was very cold, 
 
 " the wind at North-weft and by North; 
 
 " in the evening the fun was clouded, and 
 
 << the wind abated, the Mercury in the Ba- 
 
 " rometer fell at night; at two o' clock the 
 
 <c next morning a violent hurricane at 
 
 " North-eaft brought a fnow in many 
 
 " places, 6, 10, and 12 feet deep, with a 
 
 " moft piercing cold; the fnow continued 
 
 « to 
 
Vegetable Staticks. 83 
 
 " to fall till ten o' clock in the morning, 
 " when the wind chopped about to the 
 " North-weft with incredible iiercenefs, 
 " and extreme cold. Now it was that in- 
 " numerable fheep and other cattle were 
 (t loft in the mountains of fnow; and many 
 " poor people going that morning to 
 " look after their cattle, the remembrance 
 " of which is terrible, were equally fuf- 
 u ferers with them, being buried in the 
 cc fnow. 
 
 " The Apricots and Peaches which were 
 " now in bloffom upon warm walls, were 
 u all deftroyed, and not only the bloffoms, 
 " but the trees alfo, their bark burfting 
 " off." 
 
 I have often obferved from thefe Ther- 
 mometers, when that kind of hovering lam- 
 bent fog arifes, ( either mornings or even- 
 ings) which frequently betokens fair wea- 
 ther, that the air which in the preceding 
 day was much warmer, has upon the ab- 
 fence of the fun become many degrees 
 cooler than the furface of the earth; which 
 being near 1500 times denfer than the air, 
 cannot be fo ibon affected with the alter- 
 nates of hot and cold ; whence 'tis pro- 
 bable, that thofe vapours which ajre railed 
 
 G 2 by 
 
8 4 Vegetable Staticks. 
 
 by the warmth of the earth, are by the 
 cooler air foon condenfed into a vifible 
 form. And I have obferved the fame dif- 
 ference between the coolnefs of the air, and 
 the warmth of water in a pond, by putting 
 my Thermometer, which hung all night in 
 the open air in fummer time, into the water, 
 luft before the rifing of the fun, when the 
 like wreak or fog was rifing on the furface of 
 the water. 
 
 mm s& u&m&wsmi 
 
 CHAP. II. 
 
 Experiments, whereby to find out the force 
 with which trees imbibe moijlure. 
 
 HAving in the firfl: chapter feen many 
 proofs of the great quantities of li- 
 quor imbibed and perfpired by vegetables, 
 I propofe in [his, to inquire with what force 
 they do imbibe mbifture. 
 
 Tho' vegetables (which are inanimate) 
 have not an engine, which, by its alternate 
 dilatations and contractions, does in animals 
 forcibly drive the blood through the arte- 
 ries and veins \ yet has nature wonderfully 
 
 contrived 
 
Vegetable Staticks. 85 
 
 contrived other means, moft powerfully to 
 raife and keep in motion the fap, as will in 
 fome meafure appear by the experiments in 
 this and the following chapter. 
 
 I (hall begin with an experiment upon roots, 
 which nature has providently taken care to 
 cover with a very fine thick {trainer ; that 
 nothing (hall be admitted into them, but what 
 can readily be carried off by perfpiration, vege- 
 tables having no other provifion for difcharg- 
 ing; their recrement. 
 
 Experiment XXI. 
 
 Auguft 13. in the very dry year 1723, 
 I dug down 2+| feet deep to the root 
 of a thriving baking Pear-tree, and laid 
 bare a root 4 inch diameter n (Fig. 10.) I 
 cut off the end of the root at /, and put 
 the remaining flump i n into the glafs tube 
 dr y which was 1 inch diameter, and 8 inches 
 long, cementing it fan: at r; the lower part 
 of the tube d z was 18 inches long, and i 
 inch diameter in bore. 
 
 Then I turned the lower end of the tube 
 z uppermoft, and filled it full of water, and 
 then immediately immerfed the fmall end z 
 into the cittern of mercury x ; taking away 
 
 G 3 my 
 
86 Vegetable Stathks. 
 
 my finger, which flopped up the end of the 
 tube z. 
 
 The root imbibed the water with fo much 
 vigour, that in 6 minutes time the mercury 
 was raifed up the tube d z as high as z, viz, 
 
 8 inches. 
 
 The next morning at 8 o' clock, the mer- 
 cury was fallen to 2 inches height, and 2 
 inches of the end of the root i were yet im- 
 merfed in water. As the root imbibed the 
 water, innumerable air-bubbles iffued out at 
 /, which occupied the upper part of the tube 
 at r, as the water left it. 
 
 Experiment XXII. 
 
 The eleventh experiment (hews, with what 
 great force branches imbibe water, where a 
 branch with leaves imbibed much more than 
 a column of 7 feet height of water could in 
 the feme time drive through 13 inches length 
 of the biggeft part of its ftem. And in the 
 following experiments we mail find a farther 
 proof of their ftrong imbibing power. 
 
 May 25, I cut off a branch of a young 
 thriving Apple-tree b y (Fig. 11.) about 3 feet 
 lone, with lateral branches ; the diameter of 
 the tranfverfe cut /, where it was cut off, 
 
 was 
 
Vegetable Staticks. 87 
 
 was -J of an inch: The great end of this branch 
 I put into the cylindrical glafs e r 3 which 
 was an inch diameter within, and eight inches 
 long. 
 
 1 then cemented fa ft the joint r, firft fold- 
 ing a ftrap of fheeps-skin round the ftem, fo 
 as to make it fit well to the tube at r ; then 
 I cemented faft the joint with a mixture of 
 Bees-wax and Turpentine melted together in 
 fuch a proportion, as to make a very ftifF 
 clammy pafte when cold, and over the cement 
 I folded feveral times wet bladders, binding 
 it firm with packthread. 
 
 At the lower end of the large tube e was 
 cemented, on a leffer tube z e, £ inch dia- 
 meter in bore, and 1 8 inches long : The fub- 
 ftance of this tube ought to be full | of an 
 inch thick, elfe it will too eafily break in 
 making this experiment. 
 
 Thefe two tubes were cemented together 
 at e, firft with common hard brick-duft ce- 
 ment to keep the tubes firm to each other ; 
 but this hard cement would, both by being 
 long moift, and by the different dilatations 
 and contractions of the glafs and cement, 
 feparate from the glafs in hot weather, fo 
 as to let in air ; to prevent which incon- 
 venience, I further fecured the joint with 
 
 G 4 the 
 
88 Vegetable Staticks. 
 
 the cement of Bees-wax and Turpentine, 
 binding a wet bladder over all. If the hard 
 cement be made of powder'd chalk inftead 
 of brick-duft, it is more binding, and is not 
 fo apt to be loofened by water. 
 
 When the branch was thus fixed, I turned 
 it downwards, and the glafs tube upwards, 
 and then filled both tubes full of water -, 
 upon which I immediately applied the end 
 of my finger to clofe up the end of the 
 fmall tube, and immerfed it as faftaslcould 
 into the glafs ciftern x, which was full of 
 mercury and water. 
 
 When the branch was now uppermost, 
 and placed as in this figure, then the lower 
 end of the branch was immerfed 6 inches in 
 water, viz. from r to u 
 
 Which water was imbibed by the branch, 
 at its tranfverfe cut /; and as the water af- 
 cended up the fap-veffels of the branch, fo 
 the mercury afcended up the tube e z from 
 the ciftern x -, fo as in half an hour's time 
 the mercury was riien 5 inches and ^ high 
 gp to z. 
 
 And this height of the mercury did in 
 fome meafure (hew the force with which the 
 fip was imbibed, tho' not near the whole 
 jorce -, for while thp water was imbibing, 
 
 the 
 
Vegetable Staticks. 89 
 
 the tranfverfe cut of the branch was covered 
 with innumerable little hemifpheres of air, 
 and many air-bubbles iffued out of the fap- 
 vefTels, which air did in part fill the tube e r y 
 as the water was drawn out of it; fo that 
 the height of the mercury could only be 
 proportionable to the excefs of the quantity 
 of water drawn off, above the quantity of 
 air which ifTued out of the wood. 
 
 And if the quantity of air, which ifTued 
 from the wood into the tube, had been equal 
 to the quantity of water imbibed, then the 
 mercury would not rife at all ; becaufe there 
 would be no room for it in the tube. 
 
 But if 9 parts in 12 of the water be im- 
 bibed by the branch, and in the mean time 
 but three fuch parts of air iffuelnto the tube, 
 then the mercury muft needs rife near 6 
 inches, and fo proportionably in different 
 cafes. 
 
 I obferved in this, and moft of the follow- 
 ing experiments of this fort, that the mer- 
 cury role higheft, when the fun was very 
 clear and warm; and towards evening it 
 would fubfide 3 or 4 inches, and rife again 
 the next day as it grew warm, but feldom 
 to the fame height it did at firft. For I have 
 always found the fap-vefiels grow every day, 
 
 after 
 
oo Vegetable Staticks. 
 
 after catting, lefs pervious, not only for water, 
 but alfo for the fap of the vine, which never 
 paries to and fro fo freely thro* the tranfverfe 
 cut, after it has been cut 3 or 4. days, as at 
 firft ; probably, becaufe the cut capillary 
 veffels are fhrunk, the veficles alfo, and in- 
 terfiles between them, being faturate and 
 dilated with extravafated fap, much more 
 than they are in a natural ftate. 
 
 If I cut an inch or two off the lower 
 part of the ftem, which has been much fa- 
 turated by {landing in water, then the branch 
 will imbibe water again afrem 5 tho' not alto- 
 gether fo freely, as when the branch was firft 
 cut off the tree. 
 
 I repeated the fame experiment as this 
 2 2d, upon a great variety of branches of 
 feveral fizes and of different kinds of trees, 
 fome of the principal of which are as fol- 
 low, viz. , 
 
 Experiment XXIII. 
 
 July 6th and 8 th, I repeated the fame 
 experiment with feveral green fhoots of the 
 Vine, of this year's growth, each of them 
 full two yards long. 
 
 The mercury rofe much more leifurely in 
 thefc experiments, than with the Apple-tree 
 
 branch ; 
 
Vegetable Staticks. pi 
 
 branch ; the more the fun was upon it, the 
 fafter and higher the mercury rofe, but the 
 Vine-branches could not draw it above 4 
 inches the firft day, and 2 inches the third 
 day. 
 
 And as the fun fet, the mercury fometimes 
 fubfided wholly, and would rife again the 
 next day, as the fun came on the Vine- 
 branch. 
 
 And I obferved, that where fome of thefe 
 Vine-branches were fix'd on the North-fide 
 of the large trunk of a Pear-tree, the mer- 
 cury then rofe mofi in the evening about 6 o' 
 clock, as the fun came on the Vine-branch. 
 
 Experiment XXIV. 
 
 Augufi 9, at 10 ante Mend, (very hot 
 funmine) I fixed in the fame manner as Ex. 
 22. a Non-pareil branch, which had 20 Apples 
 on it ; it was 2 feet high, with lateral branches, 
 its tranfverfe cut { inch diameter : It imme- 
 diately began to raife the mercury mod vigo- 
 rously, fo as in 7 minutes it was got up to 
 z iz inches high. 
 
 Mercury being 13 | times fpecifically 
 heavier than water, it may eafily be eftima- 
 ted to what height the feveral branches in 
 
 thefe 
 
9 2 Vegetable Staticks. 
 
 thefe experiments would raife water; for 
 if any branch can raife mercury 12 inches, 
 it will raife water 13 feet 8 inches: A fur- 
 ther allowance being alfo made for the per- 
 pendicular height of the water in the tubes, 
 between r and z the top of the column of 
 mercury ; for that column of water is lifted 
 up by the mercury, be it more or lefs. 
 
 At the fame time, I tried a Golden Re- 
 nate branch 6 feet long ; the mercury rofe 
 but 4 inches, it riling higher or lower in 
 branches nearly of the fame fize and of the 
 fame kind of tree, according as the air hTued 
 thro* the ftem, more or lefs freely. In the 
 preceding experiment on the Nonpareil branch, 
 I had fucked a little with my mouth at the 
 fmall end of the tube, to get fome air-bub- 
 bles out of it, before I immerfed it in the 
 mercury ; (but thefe air-bubbles are beft got 
 out by a fmall wire run to and fro in the 
 tube) and this faction made air-bubbles arife 
 out of the tranfverfe cut of the branch : but 
 tho* the quantity of thofe air-bubbles thus 
 fucked out, was but fmall; yet in this and 
 many other experiments, I found, that after 
 luch faction, the water was imbibed by the 
 branch much more greedily, and in much 
 greater quantity, than the bulk of the air was, 
 
 which 
 
Vegetable Statick& 95 
 
 which was fucked out. Probably therefore, 
 thefe air-bubbles, when in the fap-veffels, do 
 flop the free afcent of the water, as is the cafe 
 of little portions of air got between the water 
 in capillary glafs tubes. 
 
 When the mercury is raifed to its great- 
 eft height, by precedent fudion with the 
 mouth, (which height it reaches fometimes 
 in 7 minutes, fometimes in half an hour or 
 an hour) then from that time it begins to 
 fall, and continues fo to do, till it is fallen 
 5 or 6 inches, the height the branch would 
 have drawn it to, without fucking with the 
 mouth. 
 
 But when, in a very warm day, the mer- 
 cury is drawn up 5 or 6 inches, (without 
 precedent fu&ion with the mouth) then it 
 will ufually hold up to that height for feve- 
 ral hours, viz. during the vigorous warmth 
 of the fun; becaufe the fun is all that time 
 ftrongly exhaling moifture from the branch 
 thro' the leaves ; on which account it muft 
 therefore imbibe water the more greedily, 
 as* is evident by many experiments in the firfl 
 chapter. 
 
 When a branch is fixed to a glafs tube 
 fet in mercury, and the mercury fubfides at 
 night, it will not, rife the next morning, 
 
 (as 
 
94 Vegetable Staticks. 
 
 (as the warmth of the fun increafes upon it) 
 unlefs you fill the tube firft full of water: 
 For if half or | of the large tube cr be full 
 of air, that air will be rarefied by the fun; 
 which rarefa&ion will deprefs the water in 
 the tube, and confequently the mercury can- 
 not rife. 
 
 But where little water is imbibed the firft 
 day, (as in the cafe of the green moots of the 
 Vine, Exper. XXIII.) then the mercury will 
 rife the fecond and third day, as the warmth 
 of the fun comes on, without refilling the 
 little water that was imbibed. 
 
 Experiment XXV. 
 
 In order to make the like experiment on 
 larger branches, (when I expected the mer- 
 cury would have rifen much higher than in 
 fmall ones) I caufed glaffes to be blown 
 of the fhape of this here defcribed (Fig. 12.) 
 of feveral dimenfions at r, from two to 
 five inches diameter, with a proportionably 
 large cavity c, the ftem z as near i. inch 
 diameter as could be, the length of the ftem 
 16 inches. 
 
 I cemented one of thefe glafs veflels to 
 a large fmooth barked thriving branch of an 
 
 Apple-. 
 
Vegetable Staticks. 95 
 
 Apple-tree ', which was 12 feet long, 1 -j- -| 
 inch diameter at i: I filled the glafs tube 
 with water, and immerfed the fmall end in 
 the mercury x, which rofe but 4 inches, yet 
 it imbibed water plentifully ; but the air iffued 
 too faft out of the branch at /, for the mer- 
 cury to rife high. 
 
 This, and many other experiments of this 
 kind, convince me, that branches of 2, 3, 
 or 4 years old, are the beft adapted to draw 
 the mercury higheft: The veffels of thofe 
 that are older being too large and pervious to 
 the air, which pafies mod freely thro* the 
 dark, efpecially at old eyes 5 as will be more 
 fully proved in the fifth chapter. 
 
 Experiment XXVI. 
 
 July 30th at noon, a mixture of fun and 
 clouds, the day and night before, 24 hours 
 continual rain : I cut off" a branch of a 
 Golden Pippin-tree bb, (Fig. 13.) about three 
 feet long, with feveral large lateral branches ; 
 its" diameter at the great end p near an inch, 
 which end I cemented well, and tied over it 
 a piece of wet bladder. 
 
 Then I cut off at i the main top twig, 
 where it was | inch diameter : I cemented 
 
 the 
 
$6 Vegetable Staticks. 
 
 the glafs tube z r, to the remaining branch 
 i r, and then filling the tube with water, fet 
 its lower end in the mercury x ; fo that now 
 the branch was placed with itjs top i down- 
 wards in the water, in the Aqueomercurial 
 
 gage. 
 
 It imbibed the water with fuch ftrength, as 
 to raife the mercury with an almoft equable 
 progreffion 1 1 + ~ inches by 3 o' clock (the 
 fun fhining then very warm) ; at which time 
 the water in the tube r i being all imbibed, 
 fo that the end i of the branch was out of the 
 water, then the air-bubbles pafiing more freely 
 down to /, and no water being imbibed, the 
 mercury fubfided 2 or 3 inches in an hour. 
 
 At a quarter pad 4 o' clock, I refilled the 
 gage with water $ upon which the mercury 
 rofe afrefh from the ciftern, viz. 6 inches 
 the firit \ of an hour, and in an hour more 
 the mercury reached the fame height as be- 
 fore, viz. 1 1 + i inches. And in an hour 
 and j more, it rofe -i inch more than at firft ; 
 but in half an hour after this it began gently 
 to fubfide; viz. becaufe the fun declining 
 and fetting, the perfpiration of the leaves 
 decreafed, and confequently the imbibing of 
 the water at i abated, for the end i was then 
 an inch in water. 
 
 July 
 
Vegetable Stathks. 97 
 
 JuJy 3 iff, it raining all this day, the mer- 
 cury rofe but 3 inches, which height it 
 flood at all the next night. Auguji ift, fair 
 fun-mine ; this day the mercury rofe to 8 in- 
 ches : This mews again the influence of the 
 fun, in raifing the mercury. 
 
 This Experiment proves that branches will 
 ftrongly imbibe from the fmall end immer- 
 fed in water to the great end; as well as 
 from the great end immerfed in water to 
 the fmall end; and of this we fhall have 
 further proof in the fourth chapter. 
 
 Experiment XXVII. 
 
 In order to try whether branches would 
 imbibe with the like force with the bark 
 off, I took two branches, which I call M 
 and N\ I fixed M in the fame manner as 
 the branch in the foregoing Experiment, 
 with its top downwards, but firft I took off 
 all the bark from i to r. Thenfix'dl in the 
 lame manner the branch JV, but with its 
 great end downwards, having alio taken off 
 all the bark from /tor; both the branches 
 drew the mercury up to z, 8 inches; fo 
 they imbibed with equal ftrength at either 
 end, and that without bark. 
 
 H Expe- 
 
98 Vegetable Statich. 
 
 Experiment XXVIII. 
 
 Auguji 13. I Gripped the leaves off an 
 Apple-tree branch, and then fixed the great 
 end of the ftem in the gage ; it raifed the 
 mercury 2 -j*| inches, but it foon fubfided, 
 for want of the plentiful perfpiration of 
 the leaves, fo that the air came in almoft as 
 faft as the branch imbibed water. 
 
 Experiment XXIX. 
 
 I tried alfo with what force branches 
 would imbibe at their fmall ends, as they 
 are in their natural ftate, growing to the 
 
 trees. 
 
 Jugujl 2d, I cemented faft the gage r i z 
 (Fig. 14.) to the pliant branch b, of a dwarf 
 Gotten Pippin-tree, the fame from which I 
 cut the branch in Experiment 26 : As the 
 tranfverfe cut if imbibed the water, the mer- 
 cury rofe 5 inches obliquely in the tube z, 
 and 4 inches perpendicular. 
 
 In this, as alfo in many of the precede- 
 ing Experiments, there were feveral wounds 
 in°that part of the branch which was with- 
 in the large tube r i ; which were made by 
 cutting off little lateral twigs, and fwelhng 
 eves "bat the branch might eafily enter the 
 ™ ' tube : 
 
Vegetable Staticks. 99 
 
 tube: And if thefe wounds (thro* which the 
 air always iffued plentifully) were well co- 
 vered with fheeps gut, bound over with 
 packthread, it would in a good meafurs 
 prevent the inconvenience : But I always 
 found that my experiments of this kind 
 fucceeded belt, when that part of the branch 
 which was to enter the tube r i, was clear 
 of all knots or wounds; for when there 
 were no knots, the liquor paffed moft free- 
 ly, and lefs air iffued out. 
 
 The fame day I fixed in the fame man- 
 ner a gage to an Aprkot-tree ; it raifed the 
 mercury three inches; and tho' all the water 
 was foon imbibed, yet the mercury role 
 every day an inch, for many days, and fub- 
 fided at night; fo that the branch muff 
 daily imbibe thus much air, and remit it at 
 night. 
 
 Experiment XXX. 
 
 We have a further proof of the influence 
 of the leaves in railing the fap in this fol- 
 lowing Experiment. 
 
 Augujl 6th, I cut off a large Rujfet 
 Pippin a, (Fig. 15.) with a ftalk 1 + | inch 
 
 l9 n g, £ n d 12 adjoining leaves g growing to 
 it. 
 
 H 2 I ce- 
 
too Vegetable Statich. 
 
 I cemented the ftalk fail into the upper 
 end of the tube d> which tube was 6 inches 
 long, and \ inch diameter ; as the ftalk im- 
 bibed the water, it raifed the mercury to z 3 
 four inches high. 
 
 I fixed another Apple of the fame fizea-nd 
 tree in the fame manner, but firft pulled 
 off the leaves ? it -raifed the mercury but I 
 inch. I fixed in the fame manner a like 
 bearing twig with 12 leaves on it, but no 
 apple; it raifed the mercury 3- inches. 
 
 I then took a like bearing twig, without 
 either leaves or apple ; it raifed the mercury 
 4 inch. 
 
 So a twig with an apple and leaves raif- 
 ed the mercury 4 inches, one with leaves 
 only 3 inches,, one with an apple without 
 leaves 1 inch. 
 
 A Quince which had two leaves, juft at 
 the twig's infertion into it, raifed the mer- 
 cury 2 +.7 inches, and held it up a confe- 
 derate time. 
 
 A fprig of Mint fix^d in the fame manner,, 
 raifed the mercury 3 -j- \ inch, equal to 4 
 feet 5 inches height of water. 
 
 Expe- 
 
Vegetable Staticks. 101 
 
 Experiment XXXL 
 
 I tried alfo the imbibing force of a great 
 variety of trees, by fixing Aqueo-mercurial 
 gages to branches of them cut off, as in Ex- 
 periment 22. 
 
 The Pear, Quince, Cherry, Walnut, Peach, 
 Apricot, Plum, Black-thorn, White-thorn, 
 Goofeberry, Water-elder, Sycamore, raifed 
 the mercury from 6 to 3 inches high : Thofe 
 which imbibed water moll: freely, in the Ex- 
 periments of the firft chapter, raifed the 
 mercury higheft in thefe Experiments, ex- 
 cept the Horfe-Chefnut, which, though it 
 imbibed water moft freely, yet raifed the 
 mercury but one inch, becaufe the air paf- 
 fed very fait through its fap-veffels into the 
 gage. 
 
 The following raifed the mercury but 1 
 or 2 inches, viz. the Elm, Oak, Horfe- 
 Chefnut, Filberd, Fig, Mulberry, Willow, 
 Sallow, Ofier, Afh, Lynden, Currans. 
 
 The Ever-greens, and following trees and 
 plants, did not raife it at all ; the Laurel, 
 Rofemary, Lauruftinus, Phyllyrea, Fuz, Rue, 
 Berberry, JelTamine, Cucumber-branch, Pum- 
 kin, Jerufalem Artichoke. 
 
 H 3 Expe- 
 
102 Vegetable Staticks. 
 
 Experimen t XXXII. 
 
 We have a further proof of the great 
 force with which vegetables imbibe moi- 
 fture, in the following Experiment, viz. I 
 filled near full with Peas and Water, the 
 iron Pot (Fig. 37.) and laid on the Peas a 
 leaden cover, between which and the fides 
 of the Pot, there was room for the air which 
 came from the Peas to pafs freely. I then 
 laid 184 pounds weight on them, which (as 
 the Peas dilated by imbibing the water) 
 they lifted up. The dilatation of the Peas 
 is always equal to the quantity of Water 
 they imbibe : For if a few Peas be put in- 
 to a VeiTel, and that Veflel be filled full of 
 water, tho' the Peas dilate to near double 
 their natural fize, yet the water will not 
 flow over the veiTel, or at moft very incon- 
 fiderably, on account of the expanfion of 
 little air-bubbles, which are hTuing from the 
 Peas. 
 
 Being defirous to try whether they would 
 raife a much greater weight, by means of a 
 lever with weights at the end of it, I com- 
 prefTed feveral frefh parcels of Peas in the 
 fame Pot, with a force equal to 1600, 800, 
 and 400 pounds; in which Experiments, tho* 
 
 the 
 
Vegetable Staticks. i o 3 
 
 the Peas dilated, yet they did not raife the 
 lever, becaufe what they increafed in bulk 
 was, by the great incumbent weight, preffed 
 into the interfaces of the Peas, which they 
 adequately filled up, being thereby formed 
 into pretty regular Dodecahedrons. 
 
 We fee in this Experiment the vaft force 
 with which fwelling Peas expand ; and 'tis 
 doubtlefs a confiderable part of the fame 
 force which is exerted, not only in pufhing 
 the Plume upwards into the air, but alfo in 
 enabling the firft (hooting radicle of the Pea, 
 and all its fubfequent tender Fibres, to pene- 
 trate and moot into the earth. 
 
 Experiment XXXIII. 
 
 We fee, in the Experiments of this chap- 
 ter, many inftances of the great efficacy of 
 attraction ; that univerfal principle which 
 is fo operative in all the very different 
 works of nature; and is mofl eminently fo 
 in vegetables, all whofe minuteft parts are 
 curioufly ranged in fuch order, as is beft 
 adapted, by their united force, to attract pro- 
 per nourishment. 
 
 And we mall find in the following Ex- 
 periment, that the diilevered particles of 
 vegetables, and of other bodies, have a 
 
 H 4 ftro 
 
1 04 Vegetable Staticks. 
 
 firong attractive power when they lie con- 
 
 fjfed. 
 
 That the particles of wood are fpecifical- 
 ly heavier than water, ( and can therefore 
 ftrongly attract it) is evident, becaufe feveral 
 forts of wood fink immediately; others 
 (even cork) when their interfaces are well 
 foaked, and filled with water: As Dr. Def- 
 aguliers informed me, he found a cork 
 which had been fealed up in a tube with 
 water for 4 years, to be then fpecificaJly 
 heavier than water ; others ( as the Peruvian 
 Bark) fink when very finely pulverized, be- 
 caufe all their cavities which made them 
 fwim, are thereby deftroyed. 
 
 In order to try the imbibing power of 
 common wood allies, I filled a glafs tube 
 c r /, 3 feet long, and -J of an inch diameter, 
 (Fig. 16.) with well dried and lifted wood 
 allies, prefnng them clofe with a rammer; I 
 tied a piece of linen over the end of the 
 tube at t\ to keep the allies from falling out; 
 I then cemented the tube c faft at r to the 
 Aqueo-mercurial gage r z ; and when I had 
 filled the gage full of water, I immerfed it 
 in the ciilern of mercury X $ the 1 to the 
 upper end of the tube c y at o } I fcrewed on 
 the mercurial gage a b % 
 
 The 
 
Vegetable Staticks. 105 
 
 The afhes, as they imbibed the water, drew 
 the mercury up 3 or 4 inches in a few hours 
 towards z ; but the three following days it 
 rofe but 1 inch, \ inch, and -£, and fo lefs 
 and lefs, fo that in 5 or 6 days it ceafed 
 rifing : The higheft it rofe was 7 inches, 
 which was equal to railing water 8 feet 
 high. 
 
 Tins had very little effect on the mer- 
 cury in the gage a b y unlefs it were, that it 
 would rife a little, viz: an inch or little 
 more in the gage at a, as it were by the fuc- 
 tion of the afhes, to fupply fome of the air- 
 bubbles which are drawn out at i. 
 
 But when I feparated the tube c from 
 the gage r z, and fet the end i in water, 
 then the moifture (being not reftrained as 
 before) rofe farter and higher in the afhes 
 c 0, and depreffed the mercury at a, fo as 
 to be 3 inches lower than in the leg b y by 
 driving the air upwards, which was inter- 
 mixed with the afhes. 
 
 I filled another tube 8 feet long, and ~ 
 inch diameter, with red lead 5 and affixed it 
 in the place of c to the gages a b, r z, 
 The mercury rofe gradually 8 inches to z. 
 In both thefe Experiments, the end i was 
 covered with innumerable air-bubbles, many 
 
 of 
 
1 06 Vegetable Stattcks. 
 
 of which continually paffed off, and were 
 fucceeded by others, as at the tranfverfe cuts 
 in the Experiments, of this chapter. And as 
 there, fo in thefe, the. quantity of air-bub- 
 I bles decreafed every day, fo as at laft to have 
 very few: The part i immerfed in the wa- 
 ter, being become fo fatarate therewith, as 
 to leave no room for air to pafs. 
 
 After 20 days I picked the minium out 
 . of the tube, and. found the water had rifen 
 3 feet 7 inches, and would no doubt have 
 rifen higher, if it had not been clogged 
 by the mercury in the gage z. For which 
 reafon the moifture rofe but 20 inches in 
 the allies, where it would other wife hav» 
 rifen 30 or 40 inches. 
 
 And as Sir Ifaac Newton (in his Op- 
 ticks, query 31.) obferves, "The water rifes 
 <c up to this height, by the action only of 
 " thofe particles of the ames which are up- 
 " on the furface of the elevated water ; the 
 " particles which are within the water, at- 
 " trading or repelling it as much down* 
 ." wards as upwards ; and therefore the ac- 
 cc tion of the particles is very ftrong : But 
 cc the particles of the afhes being not fo 
 " denfe and clofe together as thofe of glafs, 
 ". their adion .is not fo ftrong as that of 
 
 " "-lafs 
 
Vegetable St-aticks. 107 
 
 <c glafs, which keeps quick-filver fufpended 
 u to the height of 60 or 70 inches, and 
 " therefore acts with a force, which would 
 u keep water fufpended to the height of 
 11 above 60 feet. 
 
 " By the fame principle, a fponge fucks 
 <c in water; and the glands in the bodies of 
 " animals, according to their feveral natures 
 " and difpofitions, fuck in various juices 
 " from the blood." 
 
 And by the fame principle it is, that we 
 fee, in the preceding Experiments, plants im- 
 bibe moifture fo vigorouily up their fine ca- 
 pillary vefTels; which moifture, as it is car- 
 ried off in perfpiration, (by* the action of 
 warmth ) thereby gives the fap-veffels liber- 
 ty to be almoft continually attracting of 
 frefli fupplies ; which they could not do, if 
 they were full faturate with moifture : For 
 without perfpiration the fap muft necefTarily 
 ftagnate, notwithftanding the fap-veffels are 
 fo curioufly adapted by their exceeding fine- 
 nefs, to raife the fap to great heights, in a 
 reciprocal proportion to their very minute 
 diameters. 
 
 C H A P. 
 
108 Vegetable Staticks. 
 
 CHAP. III. 
 
 Experiments, Jhewing the force of the fap 
 in the Vine in the bleeding feafon* 
 
 HAVING in the firft chapter (hewn 
 many inflances of the great quanti- 
 ties imbibed and perfpired by trees, and in 
 the fecond chapter feen the force with 
 which they do imbibe moiflure -, I propofe 
 next to give an account of thofe Experi- 
 ments, which will prove with what great 
 force the fap of the Vine is pufhed forth, in 
 the bleeding feafon. 
 
 Experiment XXXIV. 
 
 March 30th at 3 p. m. I cut off a Vine 
 on a weftern afpect, within feven inches of 
 the ground \ the remaining Hump c (Fig. 17.) 
 had no lateral branches : It was 4 or 5 years 
 old, and | inch diameter. I fix'd to the top 
 of the flump, by means of the brafs collar 
 b y the glais tube b f 3 feven feet long, and 
 ^ inch diameter ; I fecured the joint b with 
 fliff cement made of melted Bees- wax and 
 Turpentine, and bound it fall over with fe- 
 veral folds of wet bladder and packthread : 
 
 I then 
 
Vegetable Staticks. i op 
 
 I then fere wed a fecond tube/g to the firft 
 and then a third g a, to 25 feet height. 
 
 The ftem not bleeding into the tube, I 
 filled the tube two feet high with water; 
 the water was imbibed by the ftem within 
 3 inches of the. bottom, by 8 o' clock that 
 evening. In the night it rained a fmall 
 fliower. The next morning at 6 and ~, the 
 water was rifen three inches above what it 
 was fallen to laft night at eight o' clock. 
 The Thermometer which hung in my porch 
 was 1 1 degrees above the freezing point. 
 March 3 1 from 6 and ~ a. m. to 10 p. m, 
 the fap rofe 8 -f- \ inches. April ift, at 6 
 a. m. Thermometer 3 degrees above the 
 freezing point, and a white hoar froft, the 
 fap rofe from ten o'clock laft night 3 +^ 
 inches more ; and fo continued rifing daily 
 till it was above 21 feet high, and would 
 very probably have rifen higher, if the joint 
 b had not feveral times leaked: After flop- 
 ping of which it would rife fometimes at 
 the rate of an inch in 3 minutes, fo as to 
 rife 10 feet or more in a day. In the chief 
 bleeding feafon it would continue rifing 
 night and day; but much more in the day 
 than night, and moft of all in the greateft 
 heat of the day ; and what little finking ic 
 
 had 
 
i to- Vegetable Staticks. 
 
 had of 2 or 3 inches was always after fun- 
 fet; which I fufpect was principally- occa- 
 fioned by the fhrinking and contraction of 
 the cement ac b, as it grew cool. 
 
 When the fun fhined hot upon the Vine, 
 there was always a continued feries of air- 
 bubbles, conftantly afcending from the ftem 
 thro' the fap in the tube, in fo great plenty 
 as to make a large froth on the top of the 
 fap, which fhews the great quantity of air 
 which is drawn in thro* the roots and ftem. 
 
 From this Experiment we find a confide- 
 rable energy in the root to pufh up fap in 
 the bleeding feafon. 
 
 This puc me upon trying, whether I 
 could find any proof of fuch an energy,' 
 when the bleeding feafon was over. In or- 
 der to which, 
 
 Experiment XXXV. 
 
 
 July 4th, at noon, I cut off within 3 in- 
 ches of the ground, another Vi?7c on a 
 fouth afpecl, and fixed to it a tube 7 feet 
 high, as in the foregoing Experiment: I 
 filled the tube with water, which was im- 
 bibed by the root the firft day, at the rate 
 of a foot in an hour, but the next day much 
 more flowlyj yet it was continually finking, 
 
 fo 
 
Vegetable Statich. x \ t 
 
 fo that at noon day I could not fee it fo 
 much as ftationary. 
 
 Yet by Experiment the 3^, on the Vine 
 in the garden pot, it is plain, that a very 
 confiderable quantity of fap was daily pref- 
 fing thro' this ftem, to fupply the perfpira- 
 tion of the leaves, before I cut the Vine off. 
 And if this great quantity were carried up by 
 pulfion or trufion, it mud needs have rife^ 
 out of the ftem into the tube. 
 
 Now, fince this flow of fap ceafes at once, 
 as foon as the Vine was cut off the ftem, 
 the principal caufe of its rife muft at the 
 fame time be taken away, viz. the great 
 perfpiration of the leaves. 
 
 For tho' it is plain by many Experiments, 
 that the fap enters the fap-veflels of plants 
 with much vigour, and is probably carried 
 up to great heights in thofe veffels, by the 
 vigorous undulations of the fun's warmth, 
 which may reciprocally caufe vibrations in 
 the veficles and fap-veffels, and thereby make 
 them dilate and contract a little ; yet it feems 
 as plain, ( from many Experiments, as parti- 
 cularly Exper. 13, 14, 15, and Exper. 43. 
 where, tho' we are affured that a great quan- 
 tity of water paffed by the notch cut 2 or 3 
 feet above the end of the ftem ; yet Was the 
 
 notch 
 
1 1 i Vegetable Statkks. 
 
 notch very dry, becaufe the attraction of the 
 perfpiring leaves was much greater than the 
 force of trufion from the column of water: 
 From thefe Experiments, I fay, it feems 
 evident) that the capillary fap-veifeis, out of 
 the bleeding feafon, have little power to pro- 
 trude fap in any plenty beyond their ori- 
 fices ; but as any fap is evaporated off, they 
 can by their ftrong attraction ( affifted by 
 the genial warmth of the fun) fupply the 
 great quantities of fap drawn off by perfpi- 
 ration. 
 
 Experiment XXXVI. 
 
 April 6th, at 9. a. m. rain the evening be- 
 fore, I cut off a Vine on a Southern afpecl, 
 at #, (Fig. 18.) two feet nine inches from 
 the ground 5 the remaining Hem a b had 
 no lateral branches ; it was | inch diameter -, 
 I fixed on it the mercurial gage ay. At 1 1 
 a. m. the mercury was rifen to z, 15 inches 
 higher than the leg x y being pufhed down 
 at x } by the force of t*he fap which came 
 out of the ftem at a. 
 
 At 4 />.;;/. it was funk an inch in the leg xy. 
 
 April 7th at 8 a. m. rifen very little, a 
 
 fog : at 1 1 a. ?n. 'tis 17 inches high, and the 
 
 fog gone. 
 
 April 
 
Vegetable Statich. \ \ j 
 
 April iotb, ar 7 a. m, mercury 18 inches 
 high ; I then added more mercury, fo as to 
 make the furrace z 23 inches higher than x; 
 the fip retreated very little into the flem 
 upon this additional weight, which fhews 
 with what an abfolute force it advances: at 
 noon it was funk one inch. 
 
 April nth, at 7 a.m. 24 -f \ inches high, 
 fun-fhine: at 7 p. m. 18 inches high. 
 
 April 14th, at 7 a. m. 20 + \ inches high, 
 ztga.m. 22 -j-j-, fine warm fun-fhine 5 here 
 we fee that the warm morning fun gives a 
 frefh vigour to the fap. At 1 1 a. m. the fame 
 day 1 6 + |, the great perfpiration of the ftem 
 makes it fink. 
 
 April 1 6th at 6 a. m. 19 -{- i rain. At 4 
 />. ;;;. 13 inches. The fap (in the foregoing 
 experiment, numb. 34.) rifcn this day fince 
 noon 2 inches, while this funk by the perfpi- 
 ration of the ftem ; which there was little 
 room for, in the very fhort ftem of the other. 
 April 17th, at 1 1 a. m. 24 + 1 inch high, 
 rain and warm ; at 7 p. m, 29 + ~, fine warm 
 rainy weather, which made the fap rife all 
 day, there being little perfpiration by reafon 
 of the rain. 
 
 "• April 18th, at 7 a. m. 32-j-J inches high, 
 and would have rifen higher, if there had 
 
 I been 
 
1 i 4 Vegetable Statkks. 
 
 been more mercury in the gage; it being all 
 forced into the leg y z. From this time to 
 May 5th, the force gradually decreafed. 
 
 The greateft height of the mercury being 
 3 2 -]- i- inches ; the force of the fap was 
 then equal to 36 feet 5 -f"* 7 inches height 
 of water. 
 
 Here the force of the rifing fap in the 
 morning is plainly owing to the energy of 
 the root and item. In another like mercurial 
 gage, (fixed near the bottom of a Vine, which 
 run 20 feet high) the mercury was raifed by 
 the force of the fap 38 inches equal to 43 
 feet -j~ 3 inches + 4- height of water. 
 
 Which force is near five times greater than 
 the force of the blood in the great crural ar- 
 tery of a Horfe ; feven times greater than 
 the force of the blood in the like artery of 
 a Dog; and eight times greater than the 
 blood's force in the fame artery of a fallow 
 Doe: Which different forces I found by 
 tying thofe feveral animals down alive upon 
 their backs ; and then laying open the great 
 left crural artery, where it firft enters die 
 thigh, I fixed to it (by means of two brafs 
 pipes, which run one into the other) a glafs 
 tube of above ten feet long, and £ of an 
 inch diameter in bore: In which tube the 
 
 blood 
 
Vegetable Staticks. 1 i 5 
 
 blood of one Horfe rofe eight feet three 
 inches, and the blood of another Horie eight 
 feet nine inches. The blood of a little 
 Dog fix feet and half high : In a large 
 Spaniel feven feet high. The blood of 
 the fallow Doe mounted five feet feven 
 inches. 
 
 Experiment XXXVII. 
 
 ^r//4th, I fixed three mercurial gages, 
 (Fig. 19.) A, B y C, to a Vine, on a South- 
 eaft afpedi, which was 50 feet long, from 
 the root to the end ru. The top of the wall 
 was 11 -f- \ feet high; from i to £, 8 feet; 
 from k to e, 6 feet + ± ; from e to A, 1 foot 
 10 inches , from e to 0, 7 feet ; from to B, 
 5 + ~ feet ; from to C, 22 feet 9 inches; 
 from to z/, 32 feet 9 inches. 
 
 The branches to which A and C were fixed, 
 were thriving moots two years old, but the 
 branch B was much older. 
 
 When I firft fixed them, the mercury was 
 puflied by the force of the lap, in all the gages 
 down the legs 4, 5, .13, fo as to rife nine 
 inches higher in the other legs. 
 
 The next morning at 7 a. M, the mercury 
 in A was pufiied 14 ~f- ~ inches high, in B 
 \z 4- \, in Ci3 -f-i.. 
 
 I 2 The 
 
1 1 6 Vegetable Statich. 
 
 The greateft height to which they pufhed 
 the fap feverally, was A 2 i inches, £26 inches, 
 C 26 inches. 
 
 The mercury conftantly fubfided by the 
 retreat of the fap about 9 or 10 in the morn- 
 ing, when the fun grew hot ; but in a very 
 moift foggy morning the fap was later before 
 it retreated, viz. till noon, or fome time after 
 the fog was gone. 
 
 About 4 or 5 o' clock in the afternoon, 
 when the fun went off the Vine, the fap be- 
 gan to pufli afrefh into the gages, fo as to 
 make the mercury rife in the open legs ; but 
 , k always rofe fafleil from fun-rife till 9 or 
 10 in the morning. 
 
 The Yap in B (the oldeft ftem) play'd the 
 .moft freely to and fro, and was therefore 
 fooneft affected with the changes from hot to 
 .cool , or. from wet to dry, and vice verfd. 
 
 And -April 10, toward the end of the 
 
 bleeding feafon, B began firft to fuck up the 
 
 .mercury from 6 to 5, fo as to be 4 inches 
 
 higher in that leg than the other. But 
 
 . April 24, after a night's rain, B pufhed the 
 
 mercury 4 inches up the other leg; A did not 
 
 begin to fuck tiller// 29, viz. 9 days after 
 
 By C did not begin to fuck till May 3, viz. 
 
 j 3 days after B> and 4 days after A\ May 5, 
 
 at 
 
Vegetable Statich. i 1 7 
 
 at 7 a. m. A pufhed 1 inch, Ci-|l; but to- 
 wards noon they all three fucked. 
 
 I have frequently obferved the fame dif- 
 ference in other Vine?, where the like gages 
 have been fixed at the fame time, to old and 
 young branches of the fame Vine, viz, the 
 oldeft began firft to fuck. 
 
 In this experiment we fee the great force 
 of the fap, at 44 feet 3 inches diftance from 
 the root, equal to the force of a column of 
 water 30 feet 11 inches 4*1 high. 
 
 From this experiment we fee too, that 
 this force is not from the root onlv, but 
 muft alio proceed from fome power in the 
 ftem and branches : For the branch B was 
 much fooner influenced by changes from 
 warm to cool, or dry to wet, and viceverfd, 
 than the other two branches A or C - y and 
 B was in an imbibing Hate, 9 days before 
 Ay which was all that time in a ftate of 
 pufhing fap 5 and C pufhed 13 days after B 
 had ceafed pufhing, and was in an imbibing 
 ftate. 
 
 Which imbibing flate Vines and Apple- 
 trees continue in, all the fummer, in every 
 branch, as I have found by fixing die like 
 gages to them in July. 
 
 I 3 Expe- 
 
1 1 8 Vegetable Staticks. 
 
 Experiment XXXVIIL 
 
 March 10, at the beginning of the bleed- 
 ing feafon, (which is many days fooner or 
 later, according to the coldnefs or warmth, 
 moifture or drinefs of the feafon) I then cut 
 off a branch of a tint bfcgzt b, (Fig. 20.) 
 which was 3 or 4 years old, and cemented 
 faft on it a brafs-collar, with a fcrew in it ; 
 to that I fcrewed another brafs collar, which 
 was cemented faft to the glafs tube z, 7 feet 
 long and f inch diam. (which I find to 
 be the propereft diam.) to that I fcrewed 
 others, to 38 feet height. Thefe tubes were : 
 fattened and fecured in long wooden tubes, 
 3 inches fquare, one fide of which was a 
 door opening upon hinges ; the ufe of thofe 
 wooden tubes was to preferve the glafs tubes 
 from being broke by the freezing of the fap 
 in them in the night. But when the danger 
 of hard frofts was pretty well over, as at the 
 beginning of April, then I ufually fix'd the 
 glaffes without the wooden tubes, fattening 
 them to fcaffold poles, or two long iron fpikes 
 drove into the wal£ 
 
 Before I proceed to give an account of 
 jhe rife and fall of the fap in the tubes, I 
 
 Tt'l I ! 
 
Vegetable Staticks. i j p 
 
 will firft defcribe the manner of cementing 
 on the brafs collar b, to the ftem of the 
 Vine, in which I have been often diiappointed, 
 and have met with difficulties; itmuft there- 
 fore be done with great care. 
 
 Where I defign to cue the Hem, I firft 
 pick off all the rough ftringy bark carefully 
 with my nails to avoid making any wound 
 thro' the green inner bark 5 then I cut off 
 the branch at /, (Fig. 21.) and immediately 
 draw over the ftem a piece of dried fheeps- 
 gut, which I tie faft, as near the end of the 
 ftem as I can, fo that no fap can get by it, 
 the fap being confined in the gut if: Then 
 I wipe the ftem at i very dry with a warm 
 cloth, and tie round the ftem a ftiff paper 
 funnel x /, binding it faft at x to the ftem , 
 and pinning clofe the folds of the paper from 
 x to i: Then I Hide the brafs collar r over 
 the gut, and immediately pour into the pa- 
 per funnel melted chalk cement, and then 
 fet the brafs collar into it -, which collar is 
 warmed, and dipped before in the cement, 
 that it may the better now adhere : When 
 the cement is cold, I pull away the gut, and 
 fcrew on the glafs tubes. 
 
 But finding fome inconvenience in this 
 hot cement, (becaufe its heat kills the fap- 
 
 I 4. veflels 
 
i 20 Vegetable Statich. 
 
 veffels near the bark, as is evident by their 
 being difcoloured) I have lince made ufe of 
 the cold cement of Bees-wax and Turpentine, 
 binding it fa ft over with wet bladder and pack- 
 thread, as in Exper. 34. 
 
 Inftead of brafs-collars, which fcrewed 
 into each other, I often (efpecially with the 
 Syphons in Exper, 36, and 37.) made ufe 
 of two brafs collars, which were turned a 
 little tapering, fo that one entered and exaclly 
 .fitted the other. 
 
 This joining of the two collars was ef- 
 fectually fecured from leaking, by firft 
 anointing them with a foft cement; and 
 they were fecured from being disjoined, by 
 the force of the afcending fap, by twifting 
 packthread round the protuberant knobs on 
 the iides of the collars. When I would 
 feparate the collars, I found it neceflary 
 (except in hot fun-fhine) to melt the foft 
 cement by applying hot irons on the out- 
 iide of the collars. 
 
 It is needful to made all the cemented 
 joints from the fun with loofe folds of pa- 
 per, elfe its heat will often melt them, and 
 fo dilate the cement, as to make it be drove 
 forcibly up the tube, which defeats the. ex- 
 periment. 
 
 The 
 
 
Vegetable Staticks. \ z i 
 
 The Fines to which the tubes in this ex- 
 periment were fixed, were 20 feet high from 
 the roots to their top; and the glafs tubes 
 fixed at feveral heights b from the ground, 
 from 6 to 2 feet. 
 
 The fap would rife in the tube the firft 
 day, according to the different vigour of the 
 bleeding ftate of the Vine, either i, 2, 5, 
 12, 15, or 25 feet; but when it had got 
 to its greateft height for that day, if it was 
 in the morning, it would conftantly begin 
 to fubfide towards noon. 
 
 If the weather was very cool about the 
 middle of the day, it would fubfide only 
 from 11 or 12 to 2 in the afternoon; but 
 if it were very hot weather, the fap would 
 begin to fubfide at 9 or 10 o' clock, and 
 continue fubfiding tilL], 5, or 6 in the even- 
 ing, and from that rime it would continue 
 ftationary for an hour or two j after which 
 it would begin to rife a little, but not 
 much in the night, nor till after the fori 
 was up in the morning, at which time ic 
 rofe fatten;. 
 
 The frefher the cut of the Vine was, and 
 the warmer the weather, the more the fap 
 would rife, and fubfide in a day, as 4 or 6 
 feet. 
 
 But 
 
121 Vegetable Staticks. 
 
 But if it were 5 or 6 days fince the Vine 
 was cut, it would rife or fubfide but little ; 
 the fap-veflels at the tranfverfc cut being 
 faturate and contracted. 
 
 But if I cut oft a joint or two off the 
 ftem, and new fixed the tube, the fap would 
 then rife and fubfide vigoroufly. 
 
 Moifture and warmth made the fap moil 
 vigorous. 
 
 If the beginning or middle of the bleed- 
 ing feafon, being very kindly, had made the 
 motion of the fap vigorous, that vigour would 
 immediately be greatly abated by cold eafterly 
 winds. 
 
 If in the morning, while the fap is in a 
 rifing ftate, there was a cold wind with a 
 mixture of fun-mine and cloud -, when the 
 fun was clouded, the fap would immediately 
 vifibly fubfide, at the rate of an inch in a 
 minute for feveral inches, if the fun con- 
 tinued fo long clouded: But as foon as the 
 fun-beams broke out again, the fap would 
 immediately return to its then rifing ftate, 
 iuft as any liquor in a Thermometer rifes and 
 falls with the alternacies of heat and cold ; 
 whence 'tis probable, that the plentiful rife 
 of the fap in the Vine in the bleeding feafon, 
 is effected in the fame manner. 
 
 When 
 
Vegetable Staticks. i£i 
 
 When three tubes were fixed at the fame 
 time to Vines on an eaftern, a fouthern, and 
 a weftern afpedt, round my porch, the fap 
 would begin to rife in the morning firft in 
 the eaftern tube, next in the fouthern, and 
 laft in the weftern tube : And towards noon it 
 would accordingly begin to fubfide, firft in 
 the eaftern tube, next in the fouthern, and 
 laft in the weftern tube. 
 
 Where two branches arofe from the 
 fame old weftern trunk, 15 inches from 
 the ground; and one of thefe branches 
 was fpread on a fouthern, and the other 
 on a weftern afpect ; and glafs tubes were 
 at the fame time fixed to each of them ; 
 the fap would in the morning, as the fun 
 came on, rife firft in the fouthern, then in 
 the weftern tube; and would begin to fub- 
 fide, firft in the fouthern, then in the weftern 
 tube. 
 
 Rain and warmth, after cold and dry, 
 would make the fap rife all the next day, 
 without fubfiding, tho' it would rife then 
 flowed about noon; becaufe in this cafe 
 the quantity imbibed by the root, and 
 raifed from it, exceeded the quantity per- 
 fpired. 
 
 The 
 
114 Vegetable Statich. 
 
 The fap begins to rife fooner in the morn- 
 ing in cool weather, than aicer hot days ; 
 the reafon of which may be, becaufe in 
 hot weather much being evaporated, it is not 
 fo foon fupplied by the roots as in cool wea- 
 ther, when lefs is evaporated. 
 
 In a prime bleeding feafon I fix'd a tube 
 25 feet long to a thriving branch two years 
 old, and two feet from the ground, where 
 it was cut off; the fap flowed fo briskly, 
 as in two hours to flow over the top of the 
 tube, which was feven feet above the top of 
 the Vine ; and doubtlefs would have rifen 
 higher, if I had been prepared to lengthen 
 the tube. 
 
 When at the diftance of four or five days, 
 tubes were affixed to two different branches, 
 which came from the fame item, the fap 
 would rife higheft in that which was laft 
 fixed ; yet if in the fixing the fecond tube 
 there was much fap loft, the fap would fub- 
 fide in the firft tube; but they would not 
 afterwards have their fap in equilibrio ; /. <?. 
 the furface of the fap in each was at very 
 unequal heights ; the reafon of which is, be- 
 caufe of the difficulty with which the fap 
 paffes thro' the almoft faturate and contradled 
 capillaries of the firft-cut ftem. 
 
 In 
 
Vegetable Staticks. 115 
 
 In very hot weather many air-bubbles would 
 rife, (0 as to make a froth an inch deep, on 
 the top of the fap in the tube. 
 
 I fix'd a fmall air-pump to the top of a long 
 tube, which had 12 feet height of fap in it; 
 when I pumped, great plenty of bubbles arofe, 
 tho' the fap did not rife, but fall a little, after 
 I had done pumping. 
 
 In Experiment 34. (where a tube was 
 fixed to a very fhort flump of a Vine, with- 
 out any lateral branches) we find the fap 
 rofe all day, and fafteft of all in the greateft 
 heat of the day : But by many obfervations 
 under the 37th and this 38th Experiments, 
 we find the fap in the tubes conftantly fub- 
 fided as the warmth came on towards the 
 middle of the day, and fafteft in the greateft 
 heat of the day. Whence we may reafon- 
 ably conclude, (conlidering the great perfpi- 
 rations of trees, fhewn in the firft chapter) 
 that the fall of the fap in thefe fap-gages, 
 in the middle of the day, efpecially in the 
 warmer days, is owing to the then greater 
 perfpiration of the branches, which perfpi- 
 ration decreafes, as the heat decreafes towards 
 evening, and probably wholly ceafcs when 
 the dews fall. 
 
 But 
 
ii 6 Vegetable Staticfa. 
 
 But when towards the latter end of April 
 the fpring advances, and many young moots 
 are come forth, and the furface of the Vine 
 is greatly increafed and inlarged by the ex- 
 panfion of feveral leaves, whereby the per- 
 fpiration is much increafed, and the fap more 
 plentifully exhaufted, it then ceafes to flow 
 in a vifible manner, till the return of the 
 following fpring. 
 
 And as in the Vine, fo is the cafe the 
 fame in all the bleeding trees, which ceafe 
 bleeding as foon as the young leaves begin 
 to expand enough to perfpire plentifully, and 
 to draw off the redundant fap. Thus the 
 bark of Oaks, and many other trees, moft 
 eafily feparates, while it is lubricated with 
 plenty of fap : But as foon as the leaves 
 expand fufficiently to perfpire off plenty of 
 fap, the bark will then no longer run, (as 
 they term it) but adheres moft firmly to 
 the wood. 
 
 Ex periment XXXIX. 
 
 In order to try if I could perceive the item 
 of the Vine dilate and contract with heat or 
 cold, wet or dry, a bleeding or not bleeding 
 feafon, fome time in February, I fix'd to the 
 
 ftem 
 
Vegetable Stathh. 1 1 7 
 
 ilem of a Vine an inftrument in fuch a man- 
 ner, that if the ftem had dilated or contra&ed 
 but the one hundredth part of an inch, it 
 would have made the end of the inftrument 
 (which was a piece of ftrong brafs-wire, 18 
 inches long) rife or fall very fenfibly about 
 one tenth of an inch; but I could not per- 
 ceive the inftrument to move, either by heat 
 or cold, a bleeding or not bleeding feafon. 
 Yet whenever it rained, the ftem dilated fo as 
 to raife the end of the inftrument or lever 
 -^ of an inch; and when the ftem was dry, 
 it fubfided as much. 
 
 This Experiment (hews, that the fap (even 
 in the bleeding feafon) is confined in its proper 
 veiTels, and that it does not confufedly per- 
 vade every interftice of the ftem, as the rain 
 does, which entering at the perfpiring pores, 
 foaks into the interftices, and thereby dilates 
 the ftem. 
 
 CHAP. 
 
1 28 Vegetable Staticks. 
 CHAP. IV. 
 
 Experiments, ftewing the ready lateral mo- 
 tion of the Jap, and confequently the late- 
 ral communication of the fap-vejfels. The 
 free pa/fage of it from the fmall branches 
 towards the fern y as well as from the Jle?n 
 to the branches. With an account of fome 
 'Experiments, relating to the circulation or 
 non- circulation of the fap. 
 
 Experiment XL. 
 
 IN order to find whether there was any 
 lateral communication of the fap and fap- 
 veflels, as there is of the blood in animals, 
 by means of the ramifications, and lateral 
 communications of their vefTels ; 
 
 Augujl 15th, I took a young Oak-branch 
 | inches diameter, at its tranfverfe cut, fix 
 feet high, and full of leaves. Seven inches 
 from the bottom, I cut a large gap to the 
 pith, an inch long, and of an equal depth 
 the whole length ; and four inches above 
 that, on the oppofite fide, I cut fuch ano- 
 ther gap ; I fet the great end of the ftem 
 in water : It imbibed and perfpired in two 
 nights and two dav? thirteen ounces, while 
 
 another 
 
 
Vegetable Staticks. 1 1 9 
 
 another like Oak-branch, fbmevvhat bigger 
 than this, but wirh no notch cut in its item, 
 imbibed 25 ounces of water. 
 
 At the fame time I tried the like experi- 
 ment with a Duke-cherry-branch , it imbibed 
 and perfpired 23 ounces in 9 hours the firft 
 day, and the next day 15 ounces. 
 
 At the fame time I took another Duke- 
 cherry-branch, and cut 4 fuch fquare gaps 
 to the pith, 4 inches above each other ; the 
 ifft North, 2d Eajl, 3d South, 4th Weft: It 
 had a long (lender ftem, 4 feet length, with- 
 out any branches, only at the very top -, yet 
 it imbibed in 7 hours day 9 ounces, and in 
 two days and two nights 24 ounces. 
 
 We fee in thefe experiments a moft free 
 lateral comuunication of thefap and fap-vef- 
 fels, thefe great quantities of liquor having 
 pafled laterally by the gaps j for byExperiment 
 13, 14, 15, (on cylinders of wood) little 
 evaporated at the gaps. 
 
 And in order to try whether it would not 
 be the fame in branches as they grew on trees, 
 I cut 2 fuch oppofue gaps in a 'Duke- cherry- 
 branch, 3 inches diftant from each other: The 
 leaves of this branch continued green, wichin 
 8 or 10 days, as long as the leaves on the other 
 branches of the fame tree. 
 
 K The 
 
1 30 Vegetable Stathks. 
 
 The fame day, viz. Aug. 15th, I cut two 
 fbch oppofite gaps four incnes diftant, in an 
 horizontal young thriving Oak-branch ; it was 
 one inch diameter, eighteen days after many 
 of the leaves begun to turn yellow, which 
 none of the leaves of other boughs did 
 then. 
 
 The fame day I cut off the bark for one 
 inch length, quite round a like branch of the 
 fame Oak; eighteen days after the leaves 
 were as green as any on the fame tree ; but 
 the leaves fell off this and the foregoing branch 
 early in the winter; yet continued on all the 
 reft of the boughs of the tree (except the top 
 ones) all the winter. 
 
 The fame day I cut four fuch gaps, two 
 inches wide, and nine inches diftant from 
 each other, in the upright arm of a Golden- 
 renate - tree -, the diameter of the branch 
 was 2 4-i inch, the gaps faced the four 
 cardinal points of the compafs; the apples 
 and leaves on this branch flourifhed as 
 well as thofe on ether branches of the fame 
 tree. 
 
 Here again we fee the very free lateral 
 
 palTage of the fap, where the direct paflage 
 
 is feveral times intercepted. See Vol. II. p. 
 
 262. 
 
 Expe- 
 
 
Vegetable Staticks. 1 3 1 
 
 Experiment XLI. 
 
 Aug. 13th, at noon I took a large branch 
 of an Apple-tree, (Fig. 22.) and cemented 
 up the tranfverfe cut, at the great end x, and 
 tied a wet bladder over it : I then cut off the 
 main top branch at b\ where it was -| inch 
 diameter, and fet it thus inverted into the 
 botile of water b. 
 
 In three days and two nights it imbibed 
 and perfpired four pounds two ounces -\- \ 
 of water, and the leaves continued green ; the 
 leaves of a bough cut off the fame tree at 
 the fame time with this, and not fet in 
 water, had been withered forty hours be- 
 fore. This, as well as the great quantities 
 imbibed and perfpired, fhews, that the wa- 
 ter was drawn from b moft freely to e, f y 
 g, l\ and from thence down their refpeclive 
 branches, and fo perfpired off by the leaves. 
 
 This experiment may ferve to explain 
 the reafon, why the branch b, (Fig. 23.) 
 which grows out of the root c x y thrives 
 very well, notwithstanding the root c x is 
 here fuppofed to be cut off at c, and to 
 be out of the ground : For by many expe- 
 riments in the fir ft and fecond chapters, it 
 
 K 2 is 
 
i 5 1 Vegetable Stations. 
 
 is evident, that the branch b attracts fap 
 at x with great force: And by this pre- 
 fent experiment, 'tis as evident, that Tap 
 will be drawn as freely downwards from 
 the tree to x, as from c to x y in cafe the 
 end c of the root were in the ground ; 
 whence 'tis no wonder, that the branch b 
 thrives well, tho' there be no circulation of 
 the fap. 
 
 This Experiment 41, and Experiment 26, 
 do alfo mew the reafon why, where three 
 trees ( Fig. 24. ) are inarched, and thereby 
 incorporated at x and z > the middle tree 
 will then grow, tho' it be cut off from its 
 roots, or the root be dug out of the ground, 
 and fufpended in the air; viz. becaufe the 
 middle tree b attracts nourifhment flrongly 
 at x and z, from the adjoining trees a c, 
 in the fame manner as we fee the inverted 
 boughs imbibed water in thefe Exper. 26, 
 and 41. 
 
 And from the fame reafon it is that 
 Elders, Sallows, Willows, Briars, Vines, 
 and moft Shrubs, will grow in an inverted 
 ftate, with their tops downwards in the 
 earth* 
 
 Expe- 
 
Vegetable Staticks. 1 3 3 
 
 Experiment XLII. 
 
 July 27th, I repeated Monfieur Perault's 
 Experiment ; viz, I took Duke-cherry, slp- 
 ple and Curran- boughs, with two branches 
 each, one of which a c (Fig. 25.) I immer- 
 fed in the large vefTel of water e d } the 
 other branch hanging in the open air: I 
 hung on a rail, at the fame time, other 
 branches of the fame forts, which were then 
 cut off. After three days, thofe on the rails 
 were very much withered and dead, but the 
 branches b were very green -, in eight days 
 the branch b of the Duke-cherry was much 
 withered : but the Cur ram and Apple-branch 
 b did not fade till the eleventh day: Whence 
 'tis plain, by the quantities that mufti be per- 
 fpired in eleven days, to keep the leaves b 
 green fo long, and by the wafte of the water 
 out of the veflel, that thefe boughs b mull 
 have drawn much water from and through 
 the other boughs and leaves c y which were 
 immerfed in the vefTel of water. 
 
 I repeated the like experiment on the 
 branches of Vines and Apple-trees, by run- 
 ning their boughs, as they grew, into large 
 glafs chymical retorts full of water, where 
 
 K 3 die 
 
M4 Vegetable Statlcks. 
 
 the leaves continued green for feveral 
 weeks, and imbibed conficterable quantities 
 
 of water. 
 
 This {hews how very probable it is, that 
 rain and dew is imbibed by vegetables, efpe- 
 cially in dry fealbns. 
 
 Which is further confirmed by experi- 
 ments lately made on new -planted trees; 
 where, by frequently warning the bodies of 
 the mod unpromiiing, they have out-ftrip- 
 ped the other trees of the fame plantation. 
 And Mr. Miller advifes, « Now and then 
 t£ in an evening to water the head, and with 
 << a brufli to warn, and fupple the bark all 
 « round the trunk, which (fays he) I have 
 < c often found very ferviceable." 
 
 Experiment XLIII. 
 
 Auguji 20th, at i p. m. I took an Apple- 
 branch b, (Fig. 26. ) nine feet long, 1 -j- 
 } inch diameter, with proportional latera 1 
 branches ; I cemented it faft to the tube a 
 by means of the leaden fyphon /: But firfl 
 I cut away the bark, and lail year's ringlet 
 wood, for three inches length to r. I thei 
 filled the tube with water, which was twelv« 
 feet long, and \ inch diameter, having firi 
 
 cu 
 
Vegetable Staticks. \ 3 5 
 
 cut a gap at y through the bark, and laft year's 
 wood, twelve inches from the lower end of 
 the ftem : the water was very freely imbibed, 
 viz. at the rate of three -j- i- inches in a 
 minute. In half an hour's time I could 
 plainly perceive the lower part of the gap y 
 to be moifler than before ; when at the fame 
 time the upper part of the wound looked 
 white and dry. 
 
 Now in this cafe the water muft nccef- 
 farily afcend from the tube, thro* the inner- 
 moft wood, becaufe the laft year's wood 
 was cut away, for 3 inches length, all round 
 the ftem; and confequently, if the fap in 
 its natural courfe defcended by the laft 
 year's ringlet of wood, and between that and 
 the bark, (as many have thought) the water 
 mould have defcended by the laft year's 
 wood, or the bark, and fo have firft moiftened 
 the upper part of the gap y - 3 but on the con- 
 trary, the lower part was moiftened, and not 
 the upper part. 
 
 I repeated this experiment with a large 
 T)ukc- cherry -branchy but could not perceive 
 more moifture at the upper than the lower 
 part of the gap ; which ought to have been, 
 if the fap defcends by the laft year's wood, 
 or the bark. 
 
 K 4 It 
 
i } 6 Vegetable Staticks. 
 
 It was the fame in a Quince-branch as the 
 Duke- cherry. 
 
 N. B. When I cut a notch in either of 
 thefe branches, 3 feet above r, at q> I could 
 neither fee nor feel any moifture, notwkh- 
 flanding there was at the fame time a great 
 quantity of water paffing by ; for the branch 
 imbibed at the rate of 4, 3, or 2 inches per 
 minute, of a column of water which was 
 half inch diameter. 
 
 The reafon of which drinefs of the notch 
 q is evident from Experiment 11, viz. be- 
 caufe the upper part of the branch above 
 the notch imbibed and perfpired three or four 
 times more water, than a column of feven 
 feet height of water in the tube could im- 
 pel from the bottom of the ft em to y, which 
 was three feet length of ftem ; and confe- 
 quently, the notch muft neceffarily be dry, 
 notwithftanding fo large a ftream of water 
 was paffing by ; viz. becaufe the branch and 
 ftem above the notch was in a ftrongly im- 
 bibing ftate, in order to fupply the great per- 
 ipiration of the leaves. 
 
 Expe- 
 
Vegetable Staticks. 1 3 7 
 
 Experiment XLIV. 
 
 Aagujl 9th, at 10 a. m. I fix'd in the fame 
 manner (as in the foregoing experiment) a 
 Duke-cberry-branch five feet high, and one 
 inch diameter, but did not cut away any of 
 the bark or wood at the great end j I filled the 
 tube with water, and then cut a flice off the 
 bark an inch long, 3 inches above the great 
 end ; it bled at the lower part mofl freely, 
 while the upper part continued dry. 
 
 The fame day I tried the fame experi- 
 ment on an Apple- branch, and it had the fame 
 effecl. 
 
 From thefe experiments 'tis probable, that 
 the lap afcends between the bark and wood, 
 as well as by other parts. 
 
 And fince by other experiments it is 
 found that the greateft part of the fap is 
 raifed by the warmth of the fun on the 
 leaves, which feem to be made broad and 
 thin for that purpofe ; for the fame reafon, 
 it's mofl: probable, it fhould rife alfo in thofe 
 parts which are mofl expofed to the fun, as 
 the bark is. 
 
 And when we confider, that the fap-vcf- 
 fels are fo very fine as to reduce the fan almoft 
 
 to 
 
i}8 Vegetable Statich. 
 
 to a vapour, before it can enter them, the 
 fun's warmth on the bark fhould moft eafily 
 difpofe fuch rarefied fap to afcend, inftead of 
 defcending. 
 
 Experiment XLV. 
 
 July 27th, I took fever al branches of Cur- 
 rans, Vines, Cherry, Apple, Pear and Plum- 
 tree ■ and fet the great ends of each in veffels 
 of water x (Fig. 3 1.) 5 but firft took the bark 
 for an inch off one of the branches, as at z, 
 to try whether the leaves above z at b would 
 continue green longer than the leaves of any 
 of the other branches a, c y d, but I could 
 find no difference, the leaves withering all at 
 the fame time : Now, if the return of the fap 
 was flopped at z, then it would be expe&ed, 
 that the leaves at b fhould continue green lon- 
 oer than thofe on the other branches; which 
 did not happen, neither was there any moi- 
 fture at z. 
 
 Experiment XL VI. 
 
 In Augujl, I cut off the bark for an inch 
 round, of a young thriving Oak -branch, 
 on the North -weft fide of the tree. The 
 
 leaves 
 
Vegetable Staticks. 1 3 9 
 
 leaves of this and another branch, which 
 had the bark cut at the fame time, fell early, 
 viz. about the latter end of Oftober^ when the 
 leaves of all the other branches of the fame 
 tree, except thofe at the very top of the tree, 
 continued on all the winter. 
 
 This is a further proof, that left fap goes 
 to branches which have the bark cut off, than 
 to others. 
 
 The 19th of April following, the buds of 
 this branch were 5 or 7 days forwarder than 
 thofe of other branches of the fame tree ; 
 the reafon of which may probably be, be- 
 caufe lefs frelh crude fap coming to this 
 branch than the others, and the perfpira- 
 tions in all branches being, ceteris paribus^ 
 nearly equal, the lefTer quantity of fap in 
 this branch muft fooner be infpiflated into 
 a glutinous fubftance, fit for new produc- 
 tions, than the fap of other branches, that 
 abounded with a greater plenty of freili 
 thin fap. 
 
 The fame is the reafon why Apples, 
 Pears, and many other fruits, which have 
 fome of their great fap-veffels eaten afun- 
 der by infe&s bred in them, are ripe many 
 days before the reft of the fruit on the 
 fame trees ; as alio that fruit which is ga- 
 thered 
 
140 Vegetable Staticks. 
 
 thered fome time before it is ripe, will ri- 
 pen fooner than if it had hung on the tree, 
 tho' it will not be fo good ; becaufe in thefe 
 cafes the worm-eaten fruit is deprived of part 
 of its nourishment, and the green-gathered 
 fruit of all. 
 
 And for the fame reafon fome fruits are 
 fooner ripe towards the tops of the trees, 
 than the other fruit on the fame tree; viz. 
 not only becaufe they are more expofed to 
 the fun ; but alfo, becaufe being at a greater 
 diilance from the root, they have fomewhat 
 lefs nourifhment. 
 
 And this is, doubtlefs, one reafon why 
 plants and fruits are forwarder in dry, fandy, 
 or gravelly foils, than in moifler foils; viz. 
 not only, becaufe thofe foils are warmer, 
 on account of their drinefs; but alfo, be- 
 caufe lefs plenty of moifture is conveyed up 
 the plants; which plenty of moifture, tho' 
 it promotes their growth, yet retards their 
 coming to maturity. And for the fame rea- 
 fon, the uncovering the roots of trees for 
 fome time, will make the fruit be confiderably 
 the forwarder. 
 
 And on the other hand, where trees abound 
 with too great a plenty of frefli-drawn fap, 
 as is the cafe of trees whofe roots are planted 
 
 too 
 
Vegetable Statich. 141 
 
 too deep in cold moift earth, as alfo of too 
 luxuriant Peach and other walTtrees; or, 
 which comes almoft to the fame, where 
 the fap cannot be perfpired off in a due pro- 
 portion \ as in orchards, where trees (land too 
 near each other, fo as to hinder perfpiration, 
 whereby the fap is kept in too thin and crude 
 a (late -, in all thefe cafes little or no fruit is 
 produced. 
 
 Hence alfo, in moderately dry fummers, 
 ceteris paribus , there is ufually greateft plenty 
 of fruit ; becaufe the fap in the bearing 
 twigs and buds is more digefted, and brought 
 to a better confidence, for mooting out 
 with vigour and firmnefs, than it is in 
 cool moid fummers : And this obfervation 
 has been verified in the years 1723, 1724, 
 and 1725. See an account of them under 
 it, Exper. 20. 
 
 But to return to the fubjecT: of the mo- 
 tion of the fap: When the fap has firft pafied 
 thro' that thick and fine ftrainer, the bark 
 of the root, we then find it in greateft quan- 
 tities, in the moft lax part, between the bark 
 and wood, and that the fame thro* the whole 
 tree. And if in the early fpring, the Oak 
 and feveral other trees were to be examined 
 near the top and bottom, when the fap firft 
 
 begins 
 
141 Vegetable Staticks. 
 
 begins to move, (o as to make the bark 
 eafily run, or peel off, I believe it would be 
 found, that the lower bark is firft moiftened ; 
 whereas the bark of the top branches ought 
 firft to be moiftened, if the fap defcends by 
 the bark: As to the Vine, lam pretty well 
 affured that the lower bark is firft moiftened. 
 See Vol II. p. 264. 
 
 We fee in many of the foregoing expe- 
 riments, what quantities of moifture trees 
 do daily imbibe and perfpire : Now the ce- 
 lerity of the fap muft be very great, if that 
 quantity of moifture muft, moft of it, afcend 
 to the top of the tree, then defcend, and 
 afcend again, before ic is carried off by per- 
 fpiration. 
 
 The defect of a circulation in vegetables 
 feems in fome meafure to be fupplied by 
 the much greater quantity of liquor, which 
 the vegetable takes in, than the animal, 
 whereby its motion is accelerated; for by 
 Experiment 1. we find the fun-flower, bulk 
 for bulk, imbibes and perfpires feven teen 
 times more frefh liquor than a man, every 
 24 hours. 
 
 Befides, nature's great aim in vegetables 
 being only that the vegetable life be carried 
 on and maintained, there was no occafion 
 
 to 
 
Vegetable Staticks. 145 
 
 to give its fap the rapid motion which was 
 neceflary for the blood of animals. 
 
 In animals, it is the heart which fets the 
 blood in motion, and makes it continually 
 circulate; but in vegetables we can disco- 
 ver no other caufe of the fap's motion, but 
 the ftrong attraftion of the capillary fap- 
 veflels, affifted by the brisk undulations and 
 vibrations, caufed by the fun's warmth, 
 whereby the fap is carried up to the top of 
 the talleft trees, and is there perfpired off 
 thro' the leaves: But when the furface of 
 the tree is greatly diminifhed by the lofs of 
 its leaves, then alfo the perfpiration and 
 motion of the fap is proportionably dimi- 
 nifhed, as is plain from many of the fore- 
 going experiments : So that the afcending 
 velocity of the fap is principally accelerated 
 by the plentiful perfpiration of the leaves, 
 thereby making room for the fine capillary 
 veflels to exert their vaftly attracting power, 
 which perfpiration is effected by the brisk 
 rarefying vibrations of warmth : A power 
 that does not feem to be any ways well 
 adapted to make the fap defcend from 
 the tops of vegetables by different veflels 
 to the root. 
 
 If 
 
144 Vegetable Staticks. 
 
 If the fap circulated, it muft needs have 
 been feen defcending from the upper pare 
 of large gafhes cut in branches fet in wa- 
 ter, and with columns of water preffing on 
 their bottoms in long glafs tubes, in Ex- 
 periment 43, and 44. In both which 
 cafes, it is certain that great quantities of 
 water paffed thro' the ftem, fo that it muft 
 needs have been feen defcending, if the return 
 of the fap downwards were by trufion or pul- 
 fion, whereby the blood in animals is re- 
 turned thro* the veins to the heart : And 
 that pulfion, if there were any, muft necef- 
 farily be exerted with prodigious force, to 
 be able to drive the fap thro' the finer capil- 
 laries. So that, if there be a return of the 
 fap downwards, it muft be by attraction, 
 and that a very powerful one, as we may 
 fee by many of thefe experiments, and par- 
 ticularly by Experiment 11. But it is hard 
 to conceive, what and where that power is, 
 which can be equivalent to that provifion 
 nature has made for the afcent of the fap 
 in confequence of the great perfpiration of 
 the leaves. 
 
 The inftances of the Jeffamine tree, and 
 of the Pafilon tree, have been looked upon 
 as ftrong proofs of the circulation of the 
 
 fap, 
 
Vegetable Staticks. 147 
 
 fap, becaufe their branches, which were far 
 below the inoculated Bud, were gilded : 
 But we have many vifible proofs in the Vine, 
 and other bleeding trees, of the fap's recede- 
 ing back, and pufhing forwards alternately, 
 at different times of the day and night. 
 And there is great reafbn to think, that the 
 fap of all other trees has fuch an alternate 
 receding and progreffive motion, occafioned 
 by the alternacies of day and night, warm 
 and cool, moift and dry. 
 
 For the fap in all vegetables does proba. 
 bly recede in fome meafure from the tops 
 of branches, as the fun leaves them ; be- 
 caufe its rarefying power then ceafing, the 
 greatly rarefied fap, and air mixt with it, 
 will condenfe, and take up lefs room than 
 they did, and the dew and rain will then 
 be flrongly imbibed by the leaves, as is pro- 
 bable from Exper. 42. and feveral others; 
 whereby the body and branches of the ve- 
 getable which have been much exhaufted by 
 the great evaporation of the day, may at 
 night imbibe fap and dew from the leaves; 
 for by feveral Experiments in the firft chap- 
 ter, plants were found to increafe confider- 
 ably in weight, in dewy and moift nights. 
 And by other experiments on the Vine in 
 
 L the 
 
146 Vegetable Staticks. 
 
 the third chapter, it wa§ found, that the 
 trunk and branches of Vines were always 
 in an imbibing ftate, caufed by the great 
 perfpiration of the leaves, except in the 
 bleeding feafon 5 but when at night that 
 perfpiring power ceafes, then the contrary 
 imbibing power will prevail, and draw the 
 fap and dew from the leaves, as well as 
 moifture from the roots. 
 
 And we have a farther proof of this in 
 Experiment 12, where, by fixing mercurial 
 gages to the ftems of feveral trees, which 
 do not bleed, it is found that they are al- 
 ways in a flrongly imbibing ftate, by draw- 
 ing up the mercury feveral inches: whence 
 it is eafy to conceive, how fome of the 
 "particles of the gilded Bud, in the inocu- 
 lated Jeflamine, may be abforbed by it 
 and thereby communicate their gilding 
 Miafma to the fap of other branches; efpe- 
 cially when fome months after the inocu 
 lation, the flock of the inoculated JefTa 
 mine is cut off a little above the Bud 
 whereby the flock, which was the counter 
 acting part to the flem, being taken away 
 the flem attracts more vigoroufly from th 
 Bud. 
 
 Anothe 
 
 
Vegetable Staticks. 147 
 
 Another argument for the circulation of 
 the fap, is that fome forts of graffs will 
 infect and canker the flocks they are grafted 
 on : But by Exper. 12, and 37, where mer- 
 curial gages were fixed to frefh cut flems of 
 trees, it is evident that thofe ferns were 
 in a ftrongly imbibing flate ; and confe- 
 quently the cankered flocks might very like- 
 ly draw fap from the graft, as well as the 
 grafF alternately from the flock; juft in the 
 fame manner as leaves and branches do 
 from each other, in the viciffitudes of day 
 and night. And this imbibing power of 
 the flock is fo great, where only fome of 
 the branches of a tree are grafted, that the 
 remaining branches of the flock will, by 
 their flrong attraction, flarve thofe graffs; 
 for which reafon it is ufual to cut off the 
 greateft part of the branches of the flock, 
 leaving only a few fmall ones to draw up 
 the fap. See. Vol. II. p. 265. 
 
 The inflance of the Ilex grafted upon the 
 Englijh Oak, feems to afford a very confix 
 derable argument againfl a circulation. For, 
 if there were a free uniform circulation of 
 the fap thro' the Oak and Ilex, why fhould 
 the leaves of the Oak fall in winter, and not 
 thofe of the Ilex? 
 
 L 2 Another 
 
148 Vegetable Staticks. 
 
 Another argument againft an uniform cir- 
 culation of the fap in trees, as in animals, 
 may be drawn from Exper. 37. where it 
 was found by the three mercurial gages 
 fix'd to the fame Vine, that while fome of 
 its branches changed their ftate of protrude- 
 ing fap into a ftate of imbibing, others con- 
 tinued protruding fap, one nine, and the 
 other thirteen days longer. 
 
 In the fecond Vol. of Mr. Lowthorp'% 
 Abridgment of the Philof. TranfaEt. p. 708. 
 is recited an Experiment of Mr. Brother- 
 ton's -, viz. A young Hazel n (Fig. 27.) was 
 cut into the body at x z with a deep gafh ; 
 the parts of the body below at z y and 
 above at x> were cleft upwards and down- 
 wards, and the fplinters x z by wedges were 
 kept off from touching each other, or the 
 reft of the body. The following year, the 
 upper fplinter x was grown very much, but 
 the lower fplinter x did not grow 5 but the 
 reft of the body grew, as if there had been 
 no gafh made: I have not yet fucceeded in 
 making this Experiment, the wind having 
 broken at x z all the trees I prepared for 
 it : But if there was a Bud at x which fhot 
 out leaves, and none at z, then, by Experi- 
 ment 41, 'tis plain that thofe leaves might 
 
 draw 
 
Vegetable Staticks. 149 
 
 draw much nourifhment thro'/ x, and there- 
 by make it grow ; and I believe, if, vice 
 verfa, there were a leaf-bearing Bud at z s 
 and none at x, that then the iplinter z 
 would grow more than x. 
 
 The reafon of my conjecture I ground 
 upon this Experiment, viz. I choie two 
 thriving fhoots of a dwarf Pear- tree, 1 1 a a y 
 Fig. 28, 29. At three quarters of an inch 
 diftance I took half an inch breadth of bark 
 off each of them, in feveral places, viz. 
 2,4,6,8, and at 10, 12, 14. Everyone of 
 the remaining ringlets of bark had a leaf- 
 bearing bud, which produced leaves the 
 following fummer, except the ringlet 13, 
 which had no fuch Bud. The ringlet 9 
 and 11 of a a grew and fwelled at their 
 bottoms till Augufl, but the ringlet 13 did 
 not increafe at all, and in Angujl the whole 
 fhoot a a withered and died; but the (hoot 
 / / lives and thrives well, each of its ringlets 
 fwelling much at the bottom: Whch fwel- 
 lings at their bottoms muft be attributed 
 to fome other caufe than the ftoppage of 
 the fap in its return downwards, becaufe in 
 the (hoot //, its return downwards is in- 
 tercepted three feveral times by cutting 
 away the bark at 2, 4, 6. The larger and 
 
 L 3 niore 
 
1 5 o Vegetable Statich. 
 
 more thriving the leaf-bearing Bud was, and 
 the more leaves it had on it, fo much the 
 more did the adjoining bark fwell at the 
 bottom. 
 
 Fig. 30. reprefents the profile of one of 
 the diviiions in Fig. 28. fplit in halves; in 
 which may be feen the manner of the 
 growth of the lad: year's ringlet of wood 
 mooting a little upwards at x x -, and (hoot- 
 ing downwards and fwelling much more at 
 z z; where we may obferve, that what is 
 fhot end-w T ays is plainly parted from the 
 wocd cf the preceding year, by the narrow 
 interflices x r, z r ; whence it mould feem, 
 that the growth of the yearly new ringlets 
 of wood confifts in the mooting of their 
 fibres lengthways under the bark. 
 
 That the fap does not defcend between 
 the bark and the wood, as the favourers 
 of a circulation fuppofe, feems evident from 
 hence 5 vfe. that if the bark be taken off 
 for three or four inches breadth quite round, 
 the bleeding of the tree above that bared 
 place will much abate, which ought to have 
 the contrary effect, by intercepting the courfe 
 of the refluent fap, if the fap defcended by 
 the bark. 
 
 But 
 
Vegetable Staticks. x 5 1 
 
 But the reafon of the abatement of the 
 bleeding in this cafe may well be account- 
 ed for, from the manifefl proof we have 
 in thefe Experiments, that the fap is flrong- 
 ly attracted upwards by the vigorous ope- 
 ration of the perfpiring leaves, and attract- 
 ing Capillaries : But when the bark is cut 
 off for fome breadth below the bleed in o- 
 place, then the fap which is between the 
 bark and the wood below that disbarked 
 place, is deprived of the flrong attra&ing 
 power of the leaves, &c. and confequently 
 the bleeding wound cannot be fupplied fo 
 fail with fap, as it was before the bark was 
 taken off. 
 
 Hence alfo we have a hint for a probable 
 conjecture, why in the alternately disbarked 
 flicks, 1 1 a a, Fig. 28 29. the bark fwclled 
 more at the upper part of the disbarked 
 places than at the lower; viz. becaufe thofe 
 lower parts were thereby deprived of the 
 plenty of nourimment which was brought 
 to the upper parts of thofe disbarked places 
 by the flrong attra&ion of the leaves on the 
 Buds 7, &c. of which we have a further 
 confirmation in the ringlet of bark, N°. 13, 
 Fig. 29. which ringlet did not fwell or grow 
 at either end, being not only deprived of 
 
 L 4 the 
 
152 Vegetable Static}.** 
 
 the attraction of the fuperior leaves, by the 
 bark placed N°. 12. but alfo without any 
 leaf-bud of its own, whofe branching fip-- 
 veffels, being like thofe of other leaf-buds 
 rooted downwards in the wood, might 
 thence draw fap, for the nourifhment of it- 
 felf and the adjoining bark, N°. 13. But 
 had thefe rooting fap veffels run upwards, 
 inflead of downwards, 'tis probable, that in 
 that cafe the upper part of each ringlet of 
 bark, and not the lower, would have fwel- 
 led, by having nourifhment thereby brought 
 to it from the inmoft wood. 
 
 We may hence alfo fee the reafon why, 
 when a tree is unfruitful, it is brought to 
 bear fruit, by the taking ringlets of bark off 
 from its branches; viz. becaufe thereby a 
 lefs quantity of fap arifing, it is better di- 
 gefted and prepared for the nourifhment of 
 the fruit ; which from the greater quantity 
 of oil, that is ufually found in the feeds, 
 and their containing veffels, than in other 
 parts of plants, fhews that more fulphur and 
 air is requifite for their production, than 
 there is for the production of wood and 
 leaves. 
 
 But the moft confiderable objection 
 againft this progreffive mo^on of the fap, 
 
 without 
 
Vegetable Staticks. 155 
 
 without a circulation, arifes from hence, 
 viz. that it is too precipitate a courfe, for 
 a due digeftion of the Tap, in order to nu- 
 trition : Whereas in animals nature has pro- 
 vided, that many parts of the blood {hall 
 run a long courfe, before they are either 
 applied to nutrition, or difcharged from the 
 animal. 
 
 But when we confider, that the great 
 work of nutrition, in vegitables as well as 
 animals, ( I mean, after the nutriment is got 
 into the veins and arteries of animals) is 
 chiefly carried on in the fine capillary vef- 
 fels, where nature feledts and combines, as 
 /hall beft: fuic her different purpofes, tne fe- 
 deral mutually attracting nutritious particles, 
 which were hitherto kept disjoined by the 
 motion of their fluid vehicle; we mall find 
 that nature has made an abundant provifion for 
 this work in the ftructure of vegetables \ all 
 whofe compofition is made up of nothing elfe 
 but innumerable fine capillary veflels, and glan- 
 dulous portions or veficles. See VoLW.p. 265. 
 
 Upon the whole, I think we have, from 
 thefe experiments and obfervations, fuffici- 
 ent ground to believe, that there is no cir- 
 culation of the fap in vegetables; notwith- 
 standing many ingenious perfons have been 
 
 induced 
 
M4 Vegetable Statkks. 
 
 induced to think there was, from feveral 
 curious obfervations and experiments, which 
 evidently prove, that the fap does in fome 
 meafure recede from the top towards the 
 lower parts of plants, whence they were 
 with good probability of reafon induced to 
 think that the fap circulated. 
 
 The likelieft method effectually and con- 
 vincingly to determine this difficulty, whe- 
 ther the fap circulates or not, would be by 
 ocular infpeclion, if that could be attained : 
 And I fee no reafon we have to defpair of 
 ir, fince by the great quantities imbibed and 
 perfpired, we have good ground to think, 
 that the progreffive motion of the fap is 
 confiderable in the largeft fap-veffels of ther 
 tranfparent ftems of leaves : And if our eyes, 
 affifted with microfcopes, could come at this 
 defirable fight, I make no doubt but that 
 we (hould fee the fap which was progreffive 
 in the heat of day, would on the com- 
 ing on of the cool evening, and the falling 
 dew, be retrograde in the fame veflels. 
 
 CHAP, 
 
Vegetable Staticks. 155 
 
 CHAP. V. 
 
 Experiments, whereby to prove, that a con- 
 fiderable quantity of air is infpired by 
 Plants. 
 
 IT is well known that air is a fine ela- 
 ftick fluid, with particles of very diffe- 
 rent natures floating in it, whereby it is ad- 
 mirably fitted by the great Author of na- 
 ture, to be the breath of life of vegeta- 
 bles, as well as of animals, without which 
 they can no more live nor thrive, than ani- 
 mals can. 
 
 In the Experiments on Vines, Chap. III. 
 we faw the very great quantity of air which 
 was continually afcending from the Vines, 
 thro' the fap in the tubes; which manifeftly 
 {hews what plenty of it is taken in by vege- 
 tables, and is perfpired off* with the fap thro* 
 the leaves. 
 
 Experiment XL VII. 
 
 Sept. 9th, at 9 a. m. I cemented an Apple- 
 branch b (Fig. 11.) to the glafs tube r i e z: 
 I put no water in the tube, but fet the end 
 of it in the ciftern of water x. Three 
 
 hours 
 
\$6 Vegetable Staticks. 
 
 hours after, I found the water fucked up in 
 the tube many inches to z'; which fhews, 
 that a confiderable quantity of air was im- 
 bibed by the branch, out of the tube r i ez ; 
 and in like manner did the Apricot-branch 
 (Exper. 29.) daily imbibe air. 
 
 Experiment XLVIII. 
 
 I took a cylinder of Birch with the bark 
 on, 16 inches long and | diameter, and ce- 
 mented it faft at z (Fig. 32.) to the hole 
 in the top of the air-pump receiver f />, 
 fetting the lower end of it in the ciftern of 
 water x \ the upper end of it at n was well 
 clofed up with melted cement. 
 
 I then drew the air out of the receiver, 
 upon which innumerable air-bubbles iflued 
 continually out of the flick into the wa- 
 ter x. I kept the receiver exhaufled all that 
 day, and the following night, and till the 
 next day at noon, the air all the while if- 
 fuing into the water x : I continued it thus 
 long in this ftate, that I might be well af- 
 fured, that the air muft pafs in through the 
 bark, to fupply that great and long flux of 
 air at x. I then cemented up five old eyes 
 in the flick, between z and n> where little 
 
 fhoots had formerly been, but were now 
 
 perifhed - x 
 
Vegetable Stathks. ' 1 57 
 
 perifhed ; yet the air ftill continued to flow 
 freely at x. 
 
 It was obfervable in this, and many of 
 the Experiments on flicks of other trees, 
 that the air which could enter only thro' 
 the bark between z and n, did not iflue in- 
 to the water, at the bottom of the flick, 
 only at or near the bark, but thro* the 
 whole and inmoft fubflance of the wood ; 
 and that chiefly, as I guefs, by the largenefs 
 of the bafes of the hemifpheres of air thro* 
 the largeft veflels of the wood ; which ob- 
 fervation corroborates Dr. Grew's and Mal- 
 pighi\ opinion, that they are air-veffels. 
 
 I then cemented upon the receiver the 
 cylindrical glafs y y y and filled it full of wa- 
 ter, fo as to fland an inch above the top n 
 of the flick. 
 
 The air ftill continued to flow at x, but 
 in an hours time it very much abated, and 
 in two hours ceafed quite; there being 
 now no paffage for frefh air to enter, and 
 fupply what was drawn out of the flick. 
 
 I then with a glafs crane drew off the 
 water out of the cylinder^ y; yet the air 
 did not iflue thro' the wood at x. 
 
 I therefore took the receiver with the 
 ftick in it, and held it near the fire, till the 
 
 bark 
 
158 Vegetable Staticks. 
 
 bark was well dried j after which I fet it 
 upon the air-pump, and exhaufted the air; 
 upon which the air iflfued as freely at x, as 
 it did before the bark had been wetted, and 
 continued fo to do, tho' I kept the receiver 
 exhaufted for many hours. 
 
 I fixed in the fame manner as the pre- 
 ceding Birch-ftick, three joints of a Vine- 
 branch, which was two years old, the up- 
 permoft knot r being within the receiver; 
 when I pumped 5 the air pafled moft freely 
 into the water x x. 
 
 I cemented faft the upper end of the flick n, 
 and then pumped; the air ftilliflued out at at, 
 tho* I pumped very long 5 but there did not 
 now pafs the twentieth part of the air which 
 pafled when the end n was not cemented. 
 
 I then inverted the flick, placing n fix 
 inches deep in the water, and covered all the 
 bark from the furface of the water to z 
 the top of the receiver with cement j then 
 pumping the air which entered at the top 
 of the ftick, pafled thro' the immerfed part 
 of the bark: When I ceafed pumping for 
 fome time, and the air had ceafed iflliing 
 out; upon my repeating the pumping it 
 would again iflue out. 
 
 I found 
 
a 
 <c 
 cc 
 cc 
 
 Vegetable Staticks. 159 
 
 I found the fame event in Birch and Mul- 
 berry flicks, in both which it iffued mofl plen- 
 tifully at old eyes, as if they were the chief 
 breathing places for trees. 
 
 And Dr. Grew obferves, that " the pores 
 <c are fo very large in the trunks of fome 
 plants, as in the better fort of thick walk- 
 ing canes, that they are vifible to a good 
 eye, without a glafs ; but with a glafs the 
 cane feems as if it were fluck top-full of 
 holes, with great pins, being fo large as 
 " very well to refemble the pores of the 
 <c skin, in the end of the fingers, and ball 
 " of the hand. 
 
 " In the leaves of Pine they are likewife, 
 <c thro* a glafs, a very elegant fhew, ftanding 
 " all mofl exadtly in rank and file, through 
 " the length of the leaves." Grew's Anatomy 
 of Plants, p. 127. 
 
 Whence it is very probable, that the air 
 freely enters plants, not only with the prin- 
 cipal fund of nourifhment by the roots, but 
 alfo through the furface of their trunks and 
 leaves, efpecially at night, when they are 
 changed from a perfpiring to a ftrongly im- 
 bibing ftate. 
 
 I fix'd in the fame manner to the top of 
 the air-pump receiver, but without the cy- 
 lindrical 
 
\6o Vegetable Statifks. 
 
 lindrical glafs yy> the young (hoots of the 
 Vine, Apple-tree, and Honey/tickle, both 
 ere&ed and inverted j but found little or no 
 air came either from branches or leaves, 
 except what air lay in the furrows, and the 
 innumerable little pores of the leaves, which 
 are plainly vifible with the microfcope. I 
 tried alfo the fingle leaf of a Vine, both by 
 immerling the leaf in the water x, and let- 
 ting the ftalk ftand out of the receiver, as 
 alfo by placing the leaf out of the receiver, 
 and the ftalk in the glafs of water*; but 
 little or no air came either way. 
 
 I obferve in all thefe Experiments, that 
 the air enters very flowly at the back of 
 young fhoots and branches, but much more 
 freely thro' old bark : And in different kinds 
 of trees it has very different degrees of more 
 or lefs free entrance. 
 
 I repeated the fame Experiment upon fe- 
 veral roots of trees : The air pafled moft 
 freely from n to x ; and when the glafs- vef- 
 fel^ was full of water, and there was no 
 water in x, the water pafled at the rate of 
 3 ounces in 5 minutes 5 when the upper 
 end n was cemented up, and no water in^, 
 fome air, tho' not in great plenty, would 
 enter the bark at zf> arid pafs thro' the wa- 
 ter at x. And 
 
Vegetable Statkks. \6i 
 
 And that there is fome air both in an 
 elaftick and unelailick ftate, mix'd with the 
 earth, (which may well enter the roots with 
 the nourifhment) I found by putting into 
 the inverted glafs z z a a full of water 
 (Fig. 35.) lbme earth dug up in an alley in 
 the garden, which, after it had flood foaking 
 for feveral days, yielded a little elaftick air, 
 tho' the earth was not half difiblved. And 
 in Experiment 68. we find that a cubick 
 inch of earth yielded 43 cubick inches of air 
 by diftillation, a good part of which was 
 roufed by the aclion of the fire from a fixed 
 to an elaftick ftate. 
 
 I fixed alfo in the fame manner young 
 tender fibrous roots, with the fmall end up- 
 wards at 77, and the veflel y y full of w r ater -> 
 then upon pumping large drops of water fol- 
 lowed each other fan;, and fell into theciftern 
 x } which had no water in it, See Vol. II, 
 p. 267. 
 
 M CHAP, 
 
1 6 1 JnaJyJis of the dk. 
 CHAP. VI 
 
 A Specimen of an attempt to analyfe the Air 
 by a great variety of chymio-ftatical Ex- 
 periments, which Jhew in how great a 
 proportion Air is wrought into the com- 
 poftion of animal, vegetable, and mineral 
 Sub fiances, and withal how readily it re- 
 fumes its former elafick fate, when in the 
 difjolution of thofe Subfances it is dij engaged 
 from them. 
 
 HAving in the preceding chapter pro- 
 duced many Experiments, to prove 
 that the Air is freely infpired by vegetables, 
 not only at their roots, but alfo thro' feveral 
 parts of their trunks and branches, which 
 Air was moil vifibly feen afcending in great 
 plenty thro' the fap of the Vine, in tubes 
 which were affixed to them in the bleeding 
 feafon -, this put me upon making a more 
 particular inquiry into the nature of a fluid, 
 which is fo abfolutely neceffary for the fup- 
 port of the life and growth of Animals and 
 Vegetables. 
 
 The excellent Mr. Boyle made many Ex- 
 periments on the Air, and among other dis- 
 coveries, 
 
 
Analyfis of the Ah. \6^ 
 
 coveries, found that a good quantity of Air 
 was producible from Vegetables, by putting 
 Grapes, Plums, Gooseberries, Cherries, Peas, 
 and feveral other forts of fruits and grains 
 into exhaufted and un exhaufted receivers, 
 where they continued for feveral days emit- 
 ting great quantities of Air. 
 
 Being defirous to make fome further re- 
 iearches into this matter, and to find what 
 proportion of this Air I could obtain out 
 of the different (ubftances in which it was 
 lodged and incorporated, I made the fol- 
 lowing chymio-ftatical Experiments : For, 
 as whatever advance has here been made in 
 the knowledge of the nature of Vegetables, 
 has been owing to ftatical Experiments, fo, 
 lince nature, in all her operations, acts con- 
 formably to thofe mechanick laws, which 
 were eftablifhed at her firft institution 5 it 
 is therefore reafonable to conclude, that the 
 likelieft way to inquire, by chymical ope- 
 rations, into the nature cf a fluid, too fine 
 to be the object of our fight, muft be by 
 rinding out fome means to eftimate what 
 influence the ufual methods of analyfing 
 the animal, vegetable, and mineral king- 
 doms, has on that fubtle fluid ; and this I 
 eftecTted by affixing to retorts and boltheads 
 
 M 2 hydro- 
 
1 64 Analyfis of the Air. 
 
 hydroftatical gages, in the following man- 
 ner, viz. 
 
 In order to make an eftimate of the quan- 
 tity of Air which arofe from any body by 
 diftillation or fufion, I firfl put the matter 
 which I intended to diftil into the fmall 
 retort r (Fig. 33.) ; and then at a cemented 
 faft to it the glafs veffel a b, which was very 
 capacious at b y with a hole in the bottom. 
 I bound bladder over the cement which was 
 made of tobacco-pipe clay and bean flour, 
 well mixed with fome hair, tying over all 
 four fmall flicks, which ferved as fplinters 
 to ftrengthen the joint 5 fometimes, inftead 
 of the glafs veffel a b, I made ufe of a large 
 bokhead, which had a round hole cut, with 
 a red hot iron ring at the bottom of it; 
 through which hole was put one leg of an 
 inverted fyphon, which reached up as far as 
 z. Matters being thus prepared, holding 
 the retort uppermoft, I immerfed the bolt- 
 head into a large veffel of water, to a the 
 top of the bolthead ; as the water rufhed in 
 at the bottom of the bolthead, the Air was 
 driven out through the fyphon: When the 
 bolthead was full of water to z, then I clofed 
 the outward orifice of the fyphon with the 
 end of my finger, and at the fame time drew 
 
 the 
 
Analyjis of the An. \ 6 5 
 
 the other leg of it out of the bolthead ; by 
 which means the water continued up to z, 
 and could not fubfide. Then I placed under 
 che bolthead, while it was in the water, the 
 veffel xx 5 which done, I lifted the veffel x x, 
 with the bolthead in it, out of the water, 
 and tied a waxed thread at z to mark the 
 height of the water : And then approached 
 the retort gradually to the fire, taking care 
 to fcreen the whole bolthead from the heat 
 of the fire. 
 
 The defcent of the water in the bolthead 
 fhewed the fums of the expanfion of the 
 Air in the retort, and of the matter which 
 was diftilling : The expanfion of the Air 
 alone, when the lower part of the retort was 
 beginning to be red hot, was, at a medium, 
 nearly equal to the capacity of the retorts, fo 
 that it then took up a double fpace ; and in 
 a white and almoft melting heat, the Air took 
 up a triple fpace, or fomething more : for 
 which reafon the leaft retorts are beft for 
 thefe Experiments. The expanfion of the 
 diftilling bodies was fometimes very little, 
 and fometime many times greater than that 
 of the Air in the retort, according to their 
 different natures. 
 
 M * When 
 
1 66 Analyjis of the -Air. 
 
 When the matter was fufficiently diftilled, 
 the retort, &c. was gradually removed from 
 the fire; and when cool enough, was carried 
 into another room, where there was no fire. 
 When all was throughly cold, either the 
 following day, or fometimes three or four 
 days after, I marked the farface of the water 
 y, where it then flood : if the furface of the 
 water was below z, then the empty fpace 
 between y and z (hewed how much Air was 
 generated, or raifed from a fix'd to an ela- 
 ftick (late, bv the action of the fire in diftil- 
 lation : But if y 9 the furface of the water, 
 was above #, the fpace between z and y, 
 which was filled with water, fhewed the 
 quantity of Air which had been abforbed id 
 the operation, i. e. was changed from a re- 
 pelling elaftick to a fix'd ftate, by the ftrong 
 attraction of other particles, which I there- 
 fore call abforbing. 
 
 When I would meafr.re the quantity of 
 this new generated air, I feparated the bolt- 
 head from the retort -, and putting a cork 
 into the fmall end of the bolthead, I inverted 
 it, and poured in water to z. Then from 
 another veffel (in which I had a known 
 quantity of water by weight) I poured in 
 yyater to y$ fo the quantity of water which 
 
 was 
 
Analyfis of the Air. 1 67 
 
 was wanting, upon weighing this vefiel again, 
 was equal to the bulk of the new generjred 
 Air. I chofe to meafure the quantities of Air, 
 and the matter from whence it arofe, by 
 one common meafure of cubick inches, 
 eftimated from the fpecifick gravities of the 
 feveral fubftances, that thereby the propor- 
 tion of one to the other might the more 
 readily be {ten. 
 
 I made ufe of the following means to 
 meafure the great quantities of Air, which 
 were either raifed and generated, or ab- 
 forbed by the fermentation arifing from the 
 mixture of variety of folid and fluid fub- 
 flances, whereby I could eafily eftimate the 
 furprizing efTecls of fermentation on the 
 Air; viz. 
 
 I put into the bolthead b (Fig. 34.) the 
 ingredients, and then run the long neck of 
 the bolthead into the deep cylindrical glafs 
 ay, and inclined the inverted glafs a y, and 
 bolthead, almoft horizontally in a large vef- 
 felj of water, that the water might run into 
 the glafs ay; when it was almoft up to a 
 the top of the bolthead, I then immerfed 
 the bottom of the bolthead, and lower part 
 y or the cylindrical glafs under water, rail- 
 ing at the fame time the end a uppermoft. 
 
 M 4 Then, 
 
1 6 8 Analyfn of the Ah. 
 
 Then, before I took them out of the water, 
 I kt the bolthead and lower part of the cylin- 
 drical glafs a y into the earthen veffel x x, 
 full of water ; and having lifted all out of 
 the great veffel of water, I marked the fur- 
 face z of the water in the glafs ay. 
 
 If the ingredients in the bolthead, upon 
 fermenting, generated Air, then the water 
 would fall from z toy, and the empty fpace 
 zy was equal to the bulk of the quantity 
 of Air generated : But if the ingredients, 
 upon fermentation, did abforb or fix the 
 active particles of Air, then the furface of 
 the water would afcend from z to n> and 
 the fpace z n, which was filled with water, 
 was equal to the bulk of Air, which was 
 abforbed by the ingredients, or by the fume 
 arifing from them: When the quantities of 
 Air, either generated or abforbed, were very 
 great, then I made nfe of large chymical re- 
 ceivers inftead of the glafs a y: But if thefe 
 quantities were very fmall, then, inftead of 
 the bolthead, and deep cylindrical glafs a y x 
 I made ufe of a fmall cylindrical glafs, or 
 a common beer glafs inverted, and placed 
 under it a phial or jelly-glafs, taking care that 
 the water did not come at the ingredients 
 ]n them;,, which was eafily prevented by 
 
 drawing 
 
Jnalyfis of the Air. 1 6 9 
 
 drawing the water up under the inverted 
 glafs to what height I pleafed by means of 
 a fyphon : I meafured the bulk of the fpaces 
 z y or z ;;, by pouring in a known quan^ 
 tity of water, as in the foregoing Experi- 
 ment, and making an allowance for the 
 bulk of the neck of the bolthead within 
 the (pace z y. 
 
 When I would take an eftimate of the 
 quantity of Air abforbed and fixed, or ge- 
 nerated by a burning candle, burning brini- 
 flone or nitre, or by the breath of a living 
 animal, &c. I firft placed a high ftand, or 
 pedeftal in the veffcl full of water x x 
 (Fig. 35.); which pedeftal reached a little 
 
 higher than z z. On this pedeftal I placed 
 the candle, or living animal, and then 
 whelmed over it the large inverted glafs 
 z z a a y which was fufpended by a cord, 
 fo as to have its mouth r r three or four 
 inches under water 5 then with a fyphon I 
 fucked the Air out of the glafs veffel, till the 
 water rofe to z z. But when any noxious 
 thing, as burning brimftone, aquafortis, or 
 the like, were placed under the glafs ; then 
 by affixing to the fyphon the nofe of a large 
 pair of bellows, whofe wide fucking orifice 
 s clofed up, as the bellows were inlarged, 
 
 they 
 
170 dnalyjis of the Air. 
 
 they drew the Air briskly out of the glafs 
 z z a a thro' the fyphon ; the other leg of 
 which fyphon I immediately drew from under 
 the glafs veflel, marking the height of the 
 water z z. 
 
 When the materials on the pedeftal ge- 
 nerated Air, then the water would fubfide 
 from z z to a a, which fpace z z a a was 
 equal to the quantity of Air generated : But 
 when the materials deftroyed any part of the 
 Air's elafticity, then the water would rife 
 from a a (the height that I in that cafe at 
 firft fucked it to) \.ozz y and the fpace a a z z 
 was equal to the quantity of air, whofe elafti- 
 city was deftroyed. 
 
 Ifometimes fired the materials on the pe- 
 deflal by means of a burning glafs, viz. fuch 
 as phofphorus and brown paper dipped in 
 water, ftrongly impregnated with nitre, and 
 then dried. 
 
 Sometimes I lighted the candle, or large 
 matches of brimftone, before I whelmed the 
 glafs z z a a over them ; in which cafe I 
 inftantly drew up the water to a a y which 
 by the expanfion of the heated Air would 
 at firft fubfide a little, but then immediately 
 turned to a rifing ftate ; notwithftanding the 
 flame continued to heat and rarefy the Air 
 
 for 
 
Analyjis of the Air. 1 7 1 
 
 for two or three minutes : As foon as the flame 
 was out, I marked the height of the water 
 z z ; after which the water would for twenty 
 or thirty hours continue rifing a great deal 
 above z z. 
 
 Sometimes, when I would pour violently 
 fermenting liquors, as aquafortis, &c. on any 
 materials, I fufpended the aquafortis in a phial 
 at the top of the glafs veffel z z a a, in fuch 
 manner, that by means of a firing, which 
 came down into the veffel x x y I could by 
 inverting the phial pour the aquafortis on 
 the materials, which were in a veffel on the 
 pedeftai. 
 
 I mall now proceed to give an account of 
 the event of a great many Experiments, which 
 I made by means of thefe inftruments, which 
 I have here at firft defcribed, to avoid the fre- 
 quent repetition of a defcription of 'em. 
 
 It is confonant to the right method of phi- 
 lofophifing, firft, to analyie the fubjecl, 
 whofe nature and properties we intend to 
 make any refearches into, by a regular and 
 numerous feries of Experiments : And then, 
 by laying the event of thofe Experiments be- 
 fore us in one view, thereby to fee what 
 J.ight their united and concurring evidence 
 
 will 
 
1 7 i JinaJyJis of the. Air. 
 
 will give us. How rational this method is, 
 the fequel of thefe Experiments will (hew. 
 
 The illuftrious Sir Ifaac Newton (query 
 31ft of his Opticks) obferves, That " true 
 << permanent Air arifes by fermentation or 
 « c heat, from thofe bodies which the chy- 
 " mifts call fixed, whofe particles adhere by 
 " a ftrong attraction, and are not therefore 
 u feparated and rarefied without fermenta- 
 <c tion ; thofe particles receding from one 
 " another with the greater! repullive force, 
 iC and being mod difficultly brought toge- 
 " ther, which UDon contadl were mod 
 u ftrongly united." And, query 30. <c Denfe 
 <c bodies by fermentation rarefy into feveral 
 " forts of Air ; and this Air bv fermen- 
 <l tation, and fometimes without it, re- 
 <c turns into denfe bodies." Of the truth of 
 which we have evident proof from many of 
 the following Experiments, viz. 
 
 That I might be well allured that no part 
 of the new Air which was produced in di- 
 ftillation of bodies, arofe either from the 
 greatly heated Air in the retorts, or from 
 the fubftance of the heated retorts, I firft 
 gave a red hot heat both to an empty glafs 
 retort, and alfo to an iron retort made of a 
 musket barrel 5 when all was cold, I found 
 
 the 
 
Analyfis of the Air. 1 7 > 
 
 the Air took up no more room than before it 
 was heated : whence I was afliired, that no 
 Air arofe, either from the fubftance of the re- 
 torts, or from the heated air. 
 
 As to animal fubjlances, a very confiderable 
 quantity of permanent Air was produced by 
 diftillation, not only from the blood and fat, 
 but alio from the moft folid parts of animals. 
 
 Experiment XLIX. 
 
 A cubick inch of Hogs blood, diftilled to 
 dry fcoria, produced 33 cubick inches of Air, 
 which Air did noc arife till the white fumes 
 arofe ; which was plain to be ktn by the 
 great defcent of the water at that time, in the 
 receiver azy (Fig. 33.) 
 
 Experiment L. 
 
 Lefs than a cubick inch of 'Tallow, being all 
 diftilled over into the receiver az y % (Fig, 33O 
 produced 18 cubick inches of Air. 
 
 Experiment LI. 
 
 241 Grains, or half a cubick inch of the 
 tip of a fallow Deer's born, being diftilled in 
 
 the 
 
1 7 4 Analyjis of the Air. 
 
 the iron retort, made of a musket barrel, 
 which was heated at a fmith's forge, pro- 
 duced nj cubick inches, that is, 234 times 
 its bulk of Air, which did not begin to rife 
 till the white fumes arofe -, but then ruihed 
 forth in great abundance, and in good plenty, 
 alfo with the fetid oil which came laft. The 
 remaining calx was two thirds black, the reft 
 afh-coloured; it weighed 128 grains, fo it 
 was not half wafted, whence there muft re- 
 main much fulphur in it ; the weight of water 
 to Air being nearly as 885 to one, as Mr. 
 Hawksbee found it, by an accurate Experi- 
 ment. A cubick inch of Air will weigh j of 
 a grain* whence the weight of air in the horn 
 was 33 grains, that is, near \ part of the 
 whole horn. 
 
 We may obferve in this, as alfo in the pre- 
 ceding Experiment, and many of the follow- 
 ing one?, that the particles of new Air were 
 detached from the blood and horn, at the 
 fame time with the white fumes, which con- 
 ftitute the volatile fait: But this volatile fait, 
 which mounts with great activity in the Air, 
 is fo far from generating true elaftick Air, that 
 on the contrary it abforbs it, as I found by the 
 following Experiment. 
 
 Expe- 
 
Analyjis of the Air. 1 7 j 
 
 Experiment LIL 
 
 A dram of volatile fait of fal armoniack 
 foon diftilled over with a gentle heat; but 
 tho* the expanlion in the receiver was double 
 that of heated Air alone, yet no Air was ge- 
 nerated, but two and an half cubick inches 
 were abforbed. 
 
 Experiment LIII. 
 
 Half a cubick inch of OyJler-fiell y or 266 
 grains, diftilled in the iron retort, generated 
 162 cubick inches, or 46 grains, which is a 
 litcle more than £ part of the weight of 
 the ihell. 
 
 Experiment LIV. 
 
 Two grains of Phofphorus eafily melted 
 at fome diftance from the fire, flamed and 
 filled the retort with white fumes ; it ab- 
 forbed three cubick inches of Air. A like 
 quantity of Phofphorus, fired in a large re- 
 ceiver, (Fig. 35.) expanded into a fpace equal 
 to fixty cubick inches, and abforbed 28 cu- 
 bick inches of Air: When three grains of 
 Phofphorus were weighed, foon after it was 
 burnt, it had loft half a grain of its weight; 
 but when two grains of Phofphorus were 
 
 weighed, 
 
\?6 Analyjis of the. Air. 
 
 weighed, fome hours after it was burnt, hav- 
 ing run more per deliquium by abforbing the 
 moiflure of the Air, it had increafed a grain 
 in weight. 
 
 Experiment LV. 
 
 As to vegetable fubfta?jces y from half a 
 cubick inch, or 135 grains of heart of Oak, 
 frelh cut from the growing tree, were gene- 
 rated 108 cubick inches of Air, i. e. a quan- 
 tity equal to 216 times the bulk of the piece 
 of Oak , its weight was above thirty grains, 
 -"- part of* the weight of 135 grains of Oak. 
 I took a like quantity of thin (havings from 
 the fame piece of Oak, and dried them gently 
 at fome diftance from a fire for twenty-four 
 hours, in which time 44 grains weight of 
 moiffure had evaporated ; which being de- 
 dueled from the 135 grains, there remain 91 
 grains for the folid part of the Oak : Then 
 the 30 grains of Air will be i. of the weight 
 of the folid part of the Oak. 
 
 Eleven days after this Air was made, I put a 
 live Sparrow into it, which died inftantly. 
 
 Experiment LVI. 
 
 From 388 grains weight of Indian Wheat, 
 which grew in my garden, but was not 
 
 come 
 
Analyjis of the Air. 177 
 
 come to full maturity, were generated 270 
 cubicle inches of air, the weight of which 
 air was yj grains, viz. ". of the weight 
 of the Wheat. 
 
 Experiment LVII. 
 
 From a cubick inch, or 318 grains of 
 Peas, were generated 396 cubick inches of 
 air, or 113 grains, /. e. fomething more 
 than ' of the weight of the Peas. 
 
 Nine days after this air was made, I 
 lifted the inverted mouth of the receiver 
 which contained it, out of the water, and 
 put a lighted candle under it, upon which 
 it inftantly flafhed: Then I immediately im- 
 merfed the mouth of the receiver in the wa- 
 ter, to extinguifh the flame : This I repeated 
 8 or 10 times, and it as often flafhed, after 
 which it ceafed, all the fulphureous fpirit be- 
 ing burnt. It was the fame with air of di- 
 ftilled Oyfler-ihell and Amber, and with new 
 diftilled air of Peas and Bees-wax. I found 
 it the fame alfo with another like quantity 
 of air of Peas; notwithflanding I wafhed 
 that air no lefs than eleven times, by pour- 
 ing it fo often under water, upwards, out 
 of the containing vefTel, into another in- 
 verted receiver full of water, 
 
 N Expe- 
 
1 7 8 Ana lyfis of the Air. 
 
 Experiment LV1II. 
 
 There were raifed from an ounce, or 437 
 grains of Muftard-feed, 270 cubicle inches 
 of air, or yj grains; which is fomething 
 more than £ part of the ounce weight. 
 There was doubtlefs much more air in the 
 feed ; but it rofe in an unelaftick ftate, be- 
 ing not difentangled from the Oil, which 
 was in fuch plenty within the gun-barrel, 
 that when I heated the whole barrel red hot, 
 in order to burn it our, it flamed vigoroufly 
 out at the mouth of the barrel. Oil alfo 
 adhered to the infide of the barrel, in the 
 diftillation of many of the other animal, 
 vegetable, and mineral fubftances ; fo that 
 the elaftick air which I meafured in the re- 
 ceiver, was not all the air contained in the 
 feveral diftill'd fubftances; fome remaining 
 in the Oil, for* there is unelaftick air in Oil, 
 part being alfo reforbed by the fulphureous 
 fumes in the receiver. 
 
 Experiment LIX. 
 
 From half a cubick inch of Amber, or 
 135 grains, were raifed 135 cubick inches 
 of air, or 38 grains, viz. jjj part of its 
 weight. E x p e- 
 
Analyfis of the Air. \ 7 9 
 
 Experiment LX. 
 
 From 142 grains of dry Tobacco were raifed 
 153 cubick inches of air, which is little 
 lei's than ■§■ of the whole weight of the To- 
 bacco -, yet it was not all burnt, part being 
 out of the reach of the lire. 
 
 Experiment LXI. 
 
 Camphire is a moil volatile fulphureous 
 fubftance fublimed from the Rofin of a tree 
 in the Eaft-Indies. A dram of it melted 
 into a clear liquor, at fome diltance from 
 the fire, and fublimed in the form of white 
 cryftals, a little above the liquor, it made 
 a very fmall expanfion, and neither gene- 
 rated nor abforbed air. The fame Mr. Boyle 
 found, when he burnt it in vacuo, Vol. II. 
 f. 605. 
 
 Experiment LXII. 
 
 From about a cubick inch of chymlcal 
 Oil of Ani feed, I obtained 22 cubick inches 
 of air 5 and from a like quantity of Oil of 
 Olives, 88 cubick inches of air. Finding 
 that the Oil of Aniieed came plentifully 
 over into the receiver, in the diftilla:icn of 
 
 N 2 the 
 
1 8o Analyjis of the Air. 
 
 the Oil of Olives, I raifed the neck of the 
 retort a foot higher ; by which means the 
 Oil could not fo eafily afcend, but fell back 
 again into the hotteft part of the retort; 
 whereby, as well as on account of the lefs 
 volatile nature of this Oil, more air was 
 feparated ; yet in this cafe good ftore of Oil 
 came over into the receiver ; in which 
 there was doubtlefs plenty of unelaftick 
 air : Whence, by comparing this with Ex- 
 periment 58, we fee that air is in greater 
 plenty feparated from the Oil, when in the 
 Muflard-feed, than it is from exprelTed or 
 chymical Oil. 
 
 Experiment LXIII. 
 
 From a cubick inch, or 359 grains of Ho- 
 ?iey, mixed with calx of bones, there arofe 
 144 cubick inches of air, or 41 grains, viz: 
 a little more than ~ part of the weight of 
 the whole. 
 
 Experiment LXIV. 
 
 From a cubick inch of yellow Bees-wax, 
 or 243 grains, there arofe 54 cubick inches 
 of air, or 15 grains; the j% part of the 
 whole. 
 
 Expe- 
 
Analyjis of the Ah. 181 
 
 Experiment LXV. 
 
 From 373 grains, or a cubick inch of 
 the coarfeft Sugar, which is the eflential 
 fait of the fugar-cane, there arofe 126 cu- 
 bick inches of air, equal to 36 grains, a lit- 
 tle more than ~ part of the whole. 
 
 Experiment LX VI. 
 
 I found very little air in 54 cubick inches 
 of Brandy, but in a like quantity of Well- 
 water I found one cubick inch. And it 
 was the fame in a little quantity of Brijlol 
 hot well water, and of Holt water. In 
 Piermont water there is near twice as much 
 air, as in Rain or common water, which air 
 contributes to the brisknefs of that and 
 many other mineral waters. I found thefe 
 feveral quantities of air, in thefe waters, 
 by inverting the nofes of bottles full of 
 thefe feveral liquors, into fmall glafs cif- 
 terns full of the fame liquor; and then 
 fetting them all together in a boiler, where 
 having an equal heat, the air was thereby 
 feparated, and afcended to the upper parts 
 of the bottles. See Vol. II. p. 269, 272. 
 
 N 3 Expe- 
 
1 8 1 Analyjis of the i Ah. 
 
 Experiment LXVII. 
 
 By the farne means alfo, I found plenty 
 of air might be obtained from minerals. 
 Half a cubick inch, or 158 grains of New- 
 caftle coah yielded in diflillation 180 cu- 
 bicle inches of air, which arofe very fa ft 
 from the coal, especially when the yel- 
 lowiih fumes afcended. The weight of this 
 air is 51 grains, which is nearly -§■ of the 
 weight of the coals. 
 
 Experiment LXVIII. 
 
 A cubick inch of frefh dug untried Earth 
 eff the common, being well burnt in diflil- 
 lation, produced 43 cubick inches of air. 
 From Chalk alfo I obtained air in the fame 
 manner. 
 
 Experiment LXIX. 
 
 From a quarter of a cubick inch of An- 
 timony> I obtained 28 times its bulk of air. 
 It was diftilled in a glafs retort, becaufe it 
 will demetalize iron. 
 
 Experiment LXX. 
 
 I procured a hard, dark, grey Pyrites, a 
 "jitriolick miner aljubftance, which was found 
 
 7 feet 
 
 
Analyfis of the Air. 1 8 3 
 
 7 feet under ground, in digging for fprings 
 on Walton-He at l\ for the fervice of the 
 Right Honourable the Earl of Lincoln , at 
 his beautiful Seat at Oatlands in Surrey, This 
 mineral abounds not only with fulphur, 
 which has been drawn from it in good plen- 
 ty, but alfo with faline particles, which 
 {hoot vilibly on its furface. A cubick inch 
 of this ?nineral yielded in diftillation 83 
 cubick inches of air. 
 
 Experiment LXXI. 
 Half a cubick inch of well decrepitated 
 Sea-falt) mix'd with double its quantity of 
 calx of bones, generated 32 times its bulk 
 of air: It had fo great a heat given it, that 
 all being diftilled over, the remaining fco- 
 ria did not run per detiqutuM. I cleared 
 the gun-barrel of thefe and the like fco- 
 ria, by laying the end of the retort on an 
 anvil, and ftriking long on the outfide with 
 a hammer. 
 
 Experiment LXXII. 
 
 From 2 1 1 grains, or half a cubick inch 
 of Nitre, mixed with calx of bones, there 
 arofe 90 cubick inches of air, i. e. a quanti- 
 ty equal to 180 times its bulk ; fo the weight 
 
 N4 of 
 
184 dnalyjis of the Jtr. 
 
 of air in any quantity of Vitre is about f 
 part. Vitriol diftilled in the fame manner 
 yields air too. 
 
 Experiment LXXIII. 
 
 From a cubick inch, or 443 grains of 
 Renijh Tartar, there arofe very fan: 504 cu- 
 bick inches of air; fo the weight of the air 
 in this Tartar was 144 grains, i. e. -J part of 
 the weight of the whole: The remaining 
 fcoria, which was very little, run per deli- 
 quiuniy an argument that there remained 
 ibme Sal Tartar , and confequently more air. 
 For, 
 
 Experiment LXXIV. 
 
 Half a cubick inch, or 304 grains of Sal 
 Tartar , made with nitre and tartar, and 
 mixed with a double quantity of calx of 
 bones, yielded in diftillation 112 cubick 
 inches of air ; that is, 224 times its bulk 
 of air; which 112 cubick inches weighing 
 32 grains, is nearly -J part of the weight of 
 the Sal Tartar. There is a more intenfe de- 
 gree of heat required to raife the air from 
 Sal Tartar than from nitre. 
 
 Hence we fee, that the proportion of 
 air in equal bulks of Sal Tartar and nitre is 
 
 as 
 
Analyjis of the Air. 185 
 
 as 224 to 180. But weight for weight, nitre 
 contains a little more air in it, than this Sal 
 Tartar made with nitre. But Sal Tartar 
 made without nitre, has probably a little 
 more air in • than this had, becaufe it is 
 found to make a greater explofion in the 
 Pulvis Fulminant than the nhra'ed Sal 
 Tartar. But fuppofing, as is found by this 
 Experiment, that Sal Tartar^ according to 
 its fpecifick gravity, contains 7 part more 
 in it than nitre ; yet this excefs of air is not 
 fufficient to account for the vaftly greater 
 explofion of Sal Tartar than of nitre ; which 
 feems principally to arife from the more 
 fix'd nature of Sal Tartar \ which therefore 
 requires a more intenfe degree of fire, to 
 feparate the air from the ftrongly adhering 
 particles, than is found requifite to raife the 
 air from nitre. Whence the air of Sal Tar- 
 tar muft neceflarily thereby acquire a greater 
 elaftick force, and make a more violent ex- 
 plofion, than that of nitre. And from the 
 fame reafon it is, that Aurum Fulminam 
 gives a louder explofion than Pulvis Ful- 
 minam. The fcoria of this operation did 
 not run per detiquiutn, 2l proof that all the 
 Sal Tartar was diftillcd over. See Vol II. 
 p. 2S2. 
 
 From 
 
1 86 Analyjis of the Jir. 
 
 From the little quantity of air which is 
 obtained by the diftillation of that very fixt 
 body fea-falt, in Experiment 71. in compa- 
 rifon of what arifes from nitre and Sal Tar- 
 tar, we fee the reafon why it will not go 
 off with an explofive force, likethofe when 
 fired. And at the fame time we may hence 
 obferve, that the air included in nitre and 
 Sal Tartar, bears a confiderable part in their 
 cxplofion. For fea-falt contains an acid 
 fpirit as well as nitre - y and yet that without 
 a greater proportion of air does not qualify 
 k for explofion, thro' mixed like nitre in the 
 eompoiition of gun-powder, with fulphur 
 
 and charcoal. 
 
 Mr. Boyle found, that Aqua-f or tts, poured 
 
 on a ftrong folution of fait of tartar, did not 
 fhoot into fair cryflals of falt-petre, till it 
 had been long expofed to the open air ; 
 whence he fufpedted, that the air contribu- 
 ted to that artificial production of falt-petre. 
 And fays, " Whatever the air hath to do in 
 tc this Experiment, we have known fuch 
 tl changes made in fome faline concretes 
 <c chiefly by the help of the open air, a 
 <c very few w ? ould be apt to imagine.'* Vol, 
 I. p. 302. and Vol. III. p. 80. And Chy- 
 rnifts obferve, that when the effemial falts 
 
 of 
 
Analyfts of the Air. 1 87 
 
 of vegetables are fee to cryftallize, it is 
 needful to take off the skin or Pellicle, 
 which covers the liquor, before the falts 
 will (hoot well. 
 
 We fee from the great quantity of air, 
 which is found in falts, of what ufe it is 
 in their cryftallization and formation; and 
 particularly, how neceffary it is in making 
 falt-petre from the mixture of falc of tartar, 
 and fpirit of nitre. For fince, by Experiment 
 72 and 73, a great deal of air flies away, in 
 the making of Sal Tartar, either from nitre 
 and tartar, or from tartar alone ; it mud 
 needs be neceflary, in order to the forming 
 of nitre from the mixture of Sal Tartar and 
 fpirit of nitre, tha: more air mould be in- 
 corporated with it, than it contained either 
 in the Sal Tartar or fpirit of nitre. 
 
 Experiment LXXV. 
 
 Near half acubickinch of compound Aqua- 
 fortis, which bubbled, and made a con- 
 fiderable expanfion in diftillation, was fbon 
 diftilled off: as it cooled, the expanfion 
 abated very faftj and a little air was abforb- 
 ed. Whence it is evident, that the air ge- 
 nerated by the diftillation of nitre, did not 
 arile from the volatile fpirituous particles. 
 
 Hence 
 
1 88 Analyfis of the Air. 
 
 Hence alfo it is probable, that there is 
 fome air in acid fpirits, which is reforbed 
 and fixed by them in diftillation. And this 
 is furthe rconfirmed from the many air- 
 bubbles which arife from Aqua-regia y in 
 the folution of gold ; for fince gold lofes 
 nothing of its weight in being diflblved, the 
 air cannot arife from the metalline part of 
 the gold, but muft either arife from the 
 Aqua-regia^ or from latent air in the pores 
 of the gold. 
 
 Experiment LXXVI. 
 
 A cubick inch of common Brimflone ex- 
 panded very little in diftillation in a glafs 
 retort 5 notwithftanding it had a great heat 
 given it, and was all diftilled over into the 
 receiver without flaming. It abforbed fome 
 air ; but flaming brimflone, by Experiment 
 103, abforbs much air. 
 
 A good part of the air thus raifed from 
 feveral bodies by the force of fire, was apt 
 gradually to loofe its elafticity, in ftanding 
 feveral days 5 the reafon of which was, ( as 
 will appear more fully hereafter) that the 
 acid fulphureous fumes raifed with that air, 
 did reforb and fix the elaftick particles. 
 
 Expe- 
 
Analyjls of the Air. 1 89 
 
 Experiment LXXVIL 
 
 To prevent which, I make ufe of the fol- 
 lowing method of diftillation, which is 
 much more commodious than with Glafs 
 Retorts, whofe juncture at a (Fig. 33.) it is 
 not eafy to fecure. Having firft put the 
 matter to be diftilled into the iron retorc 
 r r (Fig. 38.) which was made of a musket 
 barrel, I then fixed a leaden fyphon to the 
 nofe of the retort ; and having immerfed 
 the fyphon in the veflel of water x x> I 
 placed over the open end of the fyphon the 
 inverted chymical receiver a b> which was 
 full of water j fo that, as the air which was 
 raifed in diftillation, pafled thro' the water 
 up to the top of the receiver a b, a good 
 part of the acid fpirit and fulphureous fumes 
 were by this means intercepted and retain- 
 ed in the water 5 the confequence of which 
 was, that the new generated air continued 
 in a more permanently elaftick ftate, very 
 little of it lofing its elafticity, viz. not 
 above a 15th or 18th part, and that chiefly 
 the firft 24 hours; after which the remain- 
 der continued in a conftantly elaftick ftate ; 
 excepting the airs of tartar and cakullus hu- 
 mmts, which- in 6 or 8* days loft conftantly 
 
 above 
 
190 Analyjis of the Air. 
 
 above one third of their elafticity 5 after; 
 which the remainder was permanently ela- 
 ftical. In which ftate it has continued, 
 without any fenfible alteration, for thefe 
 fix years, that I have kept fome of the 
 air of calculus humanus by me. 
 
 That the great quantities of air, which are 
 thus obtained from thefe feveral fubftances 
 by diftiilation, are true air, and not a mere 
 flatulent vapour, I was allured by the fol- 
 lowing Trials; viz* I filled a large receiver, 
 which contained 540 cubick inches, with air 
 of tartar; and when it was cool, Ifufpended 
 the receiver on the end of a balance while its 
 mouth was inverted in water. Then, upon 
 lifting the mouth of the receiver out of water, 
 I immediately covered it by tying a piece of 
 bladder over it. When I had found the ex- 
 acT: weight, 1 blew out all the air of tartar 
 ,with a pair of bellows which had a long ad- 
 ditional nofe that reached to the bottom of 
 the receiver. And then tying the bladder 
 on, I weighed it again, but could find no 
 difference in the fpecifick gravity of the two 
 airs ; and it was the fame with an air of 
 tartar, which was 10 days old. 
 
 As to the other property of the air, elafti- 
 city, I found it exaclly the fame in the ait 
 
 of 
 5 
 
Avalyfis of the AW. 191 
 
 of tartar, which was 15 days old, and com- 
 mon air, by filling two equal tubes with 
 thefe different airs, the tubes were 10 inches 
 long, and fealed at one end ; I placed them 
 at the fame time in a cylindrical glafs con- 
 denfing receiver, where I compreffed them 
 with two additional atmofpheres, taking 
 care to fecure myfelf from danger in cafe 
 the glafs mould burft, by placing it in a 
 deep wooden veffel ; the water rofe to equal 
 heights in both tubes. This receiver was 
 gently annealed, and thereby toughened, by 
 being boiled in Urine, where it lay till all 
 was cold. 
 
 I put alfo into the fame tubes fome new- 
 made air of tartar, both the tubes /landing 
 in cifterns of water ; the air of one of thefe 
 tubes I compreffed in the condenfing en- 
 gine for fome days, to try whether in that, 
 compreffed ftate, more of the air's elafticity 
 would be deftroyed by the abforbing vapours, 
 than in an uncompreffed ftate ; but I did 
 not perceive any fenfible difference. 
 
 Lemery\ in his courfe of chymiftry, p. 592. 
 obtained, in the diftillation of 48 ounces of 
 Tartar, 4 ounces of phlegm, 8 of fpirits, 
 3 of oil, and 32 of fcoria, i. e. two thirds 
 ct the whole $ fo one ounce was loft in the 
 operation. I n 
 
\ pi Analyjis of the Air. 
 
 In my diftillation of 443- grains of Tar- 
 tar in Exper. 73. there remained but 42 
 grains of fcoria, which is little more than 
 ^ of the Tartar-, and in this remainder, 
 there was, by Exper. 74. air; for there was 
 Sal Tartar y it running /w deliquiunu 
 
 Whence, by comparing Lemerys and my 
 diftillation together, we fhall find, that there 
 remained in this 32 ounces of fcoria, and 
 in the ounce that was loft, ( which was 
 doubtlefs moft of it air) fubftance enough to 
 account for the great quantity of air, which 
 in Exper. 73. was raifed from Tartar -, efpe- 
 cially, if we take into the account the pro- 
 portion of air, which was contained in the 
 oil, which was tV part of the whole Tar- 
 tar, for there is much air in oil. 
 
 The bodies which I diftilled in this man- 
 ner, ( Fig. 38. ) were Horn, Calculus huma?2us> 
 Oyfter-fhell, Oak, Muftard-feed, Indian- 
 wheat, Peas, Tobacco, oil of Anifeed, oil 
 of Olives, Honey, Wax, Sugar, Amber, Coal, 
 Earth, Walton Mineral, Sea-falt, Salt-petre, 
 Tartar, Sal Tartar, Lead, Minium. The 
 greateft part of the air obtained from all 
 which bodies was very permanent, except 
 what the air of Tartar and calculus humanus 
 loft in ftanding feveral days. Particularly chat 
 
 from 
 
Analyfis of the AW. 193 
 
 from nitre loft little of its elafticity, where- 
 as moft of the air obtained from nitre, in 
 diftilling with the receiver (Fig. 33.) was 
 reforbed in a few days, as was alfo the air 
 which was generated from detonized nitre 
 in Experiment 102. Hence alfo we fee the 
 reafon why 19 parts in 20, of the air which 
 was generated by the firing of 'Gunpowder> 
 was in 18 days reforbed by the fulphureous 
 fumes of the Gunpowder ; as Mr. Hawksbee 
 obferved, in his phyfico-mechanical Experi- 
 ments, page 83. 
 
 In the diftillation of Horn, it was obferv- 
 able, that when towards the end of the ope- 
 ration the thick fetid oil arofe, it formed 
 very large bubbles, with tough unctuous 
 skins, which continued in that ftate fome 
 time ; and when they broke, there arofe 
 out of them volumes of fmoak, as out of 
 a chimney, and it was the fame in the di- 
 ftillation of Muftard-feed. 
 
 An Account of some Experiments mace 
 
 on Stones taken ou iof human 
 Urine, and Gall-bladders. 
 
 H 
 
 Aving procured, by the fivour cf Mr. 
 
 Ranb\\ Surgeon to His Majeflys 
 
 O Houf/old, 
 
1 94 Analyfis of the Air. 
 
 Houjhold, forne calculi humani, I made the 
 following Experiments with them, which I 
 fhall here infert, viz. 
 
 I diftilled a calculus in the iron retort 
 (Fig. 38.) 5 it weighed 230 grains, it was 
 fomething lefs in bulk than | of a cubicle 
 inch : There arofe from it very briskly, in 
 diftillation, 5i6cub:ck inches of elaftick air, 
 that is, a bulk equal to 645 times the bulk 
 of the ftone ; fo that above half the ftone 
 was raifed by the action of the fire into ela- 
 ftick air y which is a much greater propor- 
 tion of air than I have ever obtained by 
 fire from any other fubftances, whether ani- 
 mal, vegetable or mineral. The remaining 
 calx weighed 49 grains, that is, ^rH part 
 of the calculus -, which is nearly the fame 
 proportion of calx, that the worthy Dr. Slan 
 found remaining, afcer the diftilling and cal- 
 cining two ounces of calculus', " one ouna 
 " and three drams of which (he fays) eva- 
 " porated in the open fire, (a material cir- 
 <c cumftance, which the chymifts rarely ih 
 u quire after) of which we have no account.' 
 Pbilof. Tranfatf. Lo^thorf s Abridgment, Vol 
 III. p. 179. The greateft part of which was 
 we fee by the prefent Experiment, railed int< 
 permanently elaftick air. 
 
Analyfis of the Air. 195 
 
 By comparing this diftillation of the cal- 
 culus with that of RemJJj Tartar, in Expe- 
 riment 73, we fee that they both afford more 
 air in diftillation, than any other fubftances : 
 And it is remarkable, that a greater propor- 
 tion of this new raifed air from thefe two 
 fubftances, is reforbed, and lofes its elafti- 
 city, in {landing a few days, than that of any 
 other bodies -, which are ftrong fymptoms 
 that the calculus is a true animal Tartar. 
 And as there was very confiderably lefs oil, 
 in the diftillation of Remjh Tartar, than 
 there was in the diftillation of the feeds and 
 folid parts of vegetables; fo I found that 
 . this calculus contained much lefs oil than 
 the blood or folid parts of animals. 
 
 I diftilled in the fame manner as the above- 
 mentioned calculus, fome ftones taken out 
 of a human gall bladder j they weighed fifty- 
 two grains, fo their bulk was equal to ^ part 
 of a cubick inch, as I found by taking their 
 ipecifick gravity. There were 108 cubick 
 inches of elaftick air raifed from them in 
 diftillation, a quantity equal to 648 times 
 their bulk; much the farrae quantity that 
 was raifed from the calculus. About i. part 
 of this elaftick air was in four days reduced 
 into a fix'd ftate. There arofe much more 
 
 O 2 oi 
 
1 9 6 Analyfis of the Air. 
 
 oil in the diftillation of thefe Scones, than 
 from the calculus, part of which oil did 
 arife from the gall, which adhered to and 
 was dried on the furfaces of the ftones ; 
 which oil formed large bubbles, like thofe 
 which arofe in the diftillation of Deers- 
 horn, p. 193. 
 
 A fmall ftone of the gall bladder, which 
 was as big as a Pea, was diffolved in a Li- 
 xivium of Sal Tartar in feven days, which 
 Lixivium will alfo diffolve Tartar; yet it 
 will not diffolve the calculus, which is more 
 firmly united in its parts. 
 
 A quantity of calculus equal to one half 
 of what was diftilled, viz. 115 grains, did, 
 when a cubick inch of fpiric of nitre was 
 poured on it, diffolve in 2 or 3 hours, with 
 a large froth, and generated 48 cubick inches 
 of air, none of- which loft its elafticky, tho' 
 it flood many days in the glafs veflel. (Fig. 
 34.). And a like quantity of Tartar being 
 mixed with fpirit of nitre, was in the fame 
 time diffjlved ; but no elaftick air was gene- 
 rated, notwithstanding Tartar abounds (o 
 much with air. 
 
 Small pieces of Tartar and Calculus were 
 in 12 or 14 days both diffolved by oil of 
 Vitriol y the like pieces of Tartar and Cal- 
 culus 
 
Analyjis of the Air. 1 97 
 
 cuius were diflblved in a few hours by oil of 
 Vitriol, into which there was gradually poured 
 near an equal quantity of fpirit of Harts- 
 horn, made with Lime, which caufedacon- 
 fjderable ebullition and heat. 
 
 Tho' the remaining calx of the diftillation 
 of Tartar, in Experiment 73. run per deli- 
 fuium, and had therefore Sal 'Tartar in it ; 
 and tho* the calx of the diftilled Calculus did 
 not run per deliquiwn, and had confequently 
 no Sal Tartar in it ; yet it cannot thence 
 be inferred, that the Calculus is not a tar- 
 tarine fubftance : Becaufe by Experiment 74. 
 it is evident, that Sal Tartar itfelf, when 
 mixed with an animal calx, diftils all over, 
 fo that the calx will not afterwards run per 
 deli qui um. 
 
 By the great fimilitude there is therefore 
 in fo many refpects between thefe two fub- 
 ftances, we may well look upon the Calculus ^ 
 and the Stone in the Gall Bladder, as true 
 animal Tartars ; and doubtlefs Gouty concre- 
 tions are the fame. 
 
 From the great quantities of Air that are 
 found in thefe Tartars, we fee that unela- 
 ftick Air particles, which by their ftrongly 
 attracting property are fo inftrumental in form- 
 ing the nutritive matter of Animals and Ve- 
 
 O 3 getables, 
 
1 9 8 dnalyjis of the Air. 
 
 getables, are by the fame attractive power apt 
 ibmetimes to form anomalous concretions, 
 as the Stone, &c. in Animals, efpecially in 
 thofe places where any animal fluids are in 
 a ftagnant ftate, as in the Urine and Gall- 
 Bladders; they ftrongly adhere alfo to the 
 fides of Urinals, &6. The like tartarine con- 
 cretions are alfo frequently formed in fome 
 fruits, particularly in Pears; but they do then 
 efpecially coalefce in greateft plenty, when 
 the vegetable juices are in a ftagnant ftate, as 
 in wine veffels, &c. 
 
 This great quantity of ftrongly attracting, 
 unelaftick Air particles, which we find in the 
 calculus, mould rather encourage than dis- 
 courage us, in Searching after fome proper 
 difiblvent of the Stone in the Bladder, which, 
 upon the Analyfis of it, is found to be well 
 ftored with active principles, fuch as are the 
 principal agents in fermentation. For Mr. 
 Boyle found therein a good quantity of vola- 
 tile fait, with fome oil ; and we fee by the 
 prefent Experiment, that there is ftore of 
 unelaftick Air particles in it. The difficulty 
 feems chiefly to lie, in the over-proportion 
 of thefe laft-mentioned particles, which are 
 firmly united together by fulphur and fait; 
 
 the 
 
Anal)Jis of the Air. 1 9 9 
 
 the proportion of caput mortuum, or earth, 
 being very fmall. Vide Vol. II. p. 189. 
 
 Experiment LXXVJII. 
 
 One eighth of a cubick inch of Mercury 
 made a very infenfible expanfion in diftilla- 
 tion, notwithstanding the iron retort had an 
 almoft melting heat given it at a fmith's forge, 
 fo that it made an ebullition, which could be 
 heard at fome diftance, and withal fhook the 
 retort and receiver. There was no Air gene- 
 rated, nor was there any expanfion of Air in 
 the following Exper. yig. 
 
 Experiment LXXIX. 
 
 I put into the fame retort half a cubick 
 inch of Mercury, affixing to the retort a very 
 capacious receiver, which had no hole in the 
 bottom. The wide mouth of the receiver 
 Was adapted to the fmall neck of the retort 
 (which was made of a mufket barrel) by means 
 of two large pieces of cork,which entered and 
 filled the mouth of the receiver, they having 
 holes bored in them of a fit fize for the neck 
 of the retort; and the juncture was farther 
 fecured, by a dry fupple bladder tied over it ; 
 
 O 4 for 
 
2 oo Jnalyjis of the Jir. 
 
 for I purpofely avoided making ufe of any 
 moift lute, and took care to wipe the infide 
 of the receiver very dry with a warm cloth. 
 
 The Mercury made a great ebullition, and 
 came fo^cic of it over into the receiver, as foon 
 js the retort had a red heat given it, which 
 was increafed to a white and almoft melting 
 heat, in which ftate it continued for half an 
 hour. During which time, I frequently co- 
 hohated fome part of the Mercury, which 
 condenfed, and was lodged on an horizontal 
 level, about the middle of the neck of the 
 retort : And which, upon raifing the receiver, 
 flowed down into the bottom of the retort, and 
 there made a frefh ebullition -, which had 
 ceafed, when all the Mercury was diftilled 
 from the bottom of the retort. When all 
 was cool, I found about two drams of Mercury 
 in the retort, and loft in the whole forty-three 
 grains, but there was not the leaft moifturein 
 the receiver 
 
 Whence it is to be fufpected that Mr. Boyle 
 and ethers were deceived by fome unheeded 
 circumftance, when they thought they ob- 
 tained a water from Mercury in the diftilla- 
 tion of it ; which he fays he did once, but 
 could not make the like Experiment after- 
 wards fucceed. Boyle, Vol. III. p. 416. 
 
 I re 
 
 
Jnalyfis of the Air. 2 o t 
 
 I remember that about twenty years fince, I 
 was concerned with feveral others in making 
 this Experiment at the Elaboratory in Trinity 
 College Cambridge ; when imagining there 
 would be a very great expanfion, we luted a 
 German earthen retort to three or four large 
 Alodals, and a capacious receiver; as Mr. 
 Wilfon did in his courfeof chymiftry. Four 
 pounds of Mercury were poured by little and 
 little into the red hot retort, thro* a tobacco- 
 pipe purpofely affixed to it. The event was, 
 that we found fome fpoons full of water with 
 the Mercury in the Alodals, which I then fuf- 
 pected to arife from the moifture of the earthen 
 retort and lute, and am now confirmed in 
 that fufpicion. It rained inceffantly all the 
 day, when I made this prefent Experiment; 
 fo that, when water is obtained in the diftil- 
 lation of Mercury^ it cannot be owing to a 
 moifter temperature of the Air. 
 
 The Effects of Fermentation on the Air. 
 See Vol. II. page 295. 
 
 HAving from the foregoing Experiments 
 feen very evident proof of the produc- 
 tion of confiderable quantities of true elaftick 
 Air, from liquors and folid bodies, by means 
 
 of 
 
202 Analyjis of the Air. 
 
 of fire; we fhall find in the following Expe- 
 riments many inftances of the production, 
 and alfo of the fixing or abibrbing of great 
 quantities of Air, by the fermentation arifing 
 from the mixture of variety of folids and fluid?: 
 Which method of producing and of abibrbing, 
 and fixing the elaftick particles of Air by fer- 
 mentation, feems to be more according to 
 nature's ufual way of proceeding, than the 
 other of fire. 
 
 Experiment LXXX. . 
 
 I put into the bolthead b (Fig. 34.) fixteen 
 cubick inches of Sheep's blood y with a little 
 water to make it ferment the better. I found 
 by the defcent of the water from z to y y that 
 in eighteen days fourteen cubick inches of Air 
 were generated. 
 
 Exp e rim en t LXXXL 
 
 Volatile Salt of Sal Ammoniac ', placed in an 
 open glafs cittern, under the inverted glafs 
 z z a a, (Fig. 35.) neither generated nor ab- 
 forbed Air. Neither did feveral other vola- 
 tile liquors, as fpirits of Harts-horn, fpirits of 
 Wine, nor compound Aquafortis, generate 
 
 any 
 
Analyjis of the Air. 205 
 
 any Air. But Sal Ammoniac, Sal Tartar, 
 and fpirits of Wine mixed together, generated 
 twenty.fixcubick inches of Air, twoof which 
 were in four days reforbed, and after that ge- 
 
 nerated again. 
 
 Experiment LXXXII. 
 
 Haifa cubick inch of Sal Ammoniac, and 
 double that quantity of Oil of Vitriol, gene- 
 rated the firit. day 5 or 6 cubick inches: But 
 the following days it abforbed 15 cubick inches, 
 and continued many days in that ftate. 
 
 Equal quantities of fpirit of Turpe?itine, 
 and Oil of Vitriol, had near the fame effect, 
 except that it was fooner in an abforbing ftate 
 than the other. 
 
 Mr. Geoffroy mews, that the mixture of 
 any vitriolic falts, with inflammable fubftan- 
 ces, will yield common Brimftone; and by 
 the different compofitions he has made of 
 fulphur, and particularly from Oil of Vitriol, 
 and Oil of Turpentine, and by the Analyfis 
 thereof, when thus prepared, he difcovered 
 it to be nothing but vitriolic fait, united with 
 the combuftible fubftance. French Memoirs, 
 Anno 1704. p. 381. or Boyle § Works, Vol. 
 III. p. 273. Notes. 
 
 Expe- 
 
204 Analyjls of the Aw. 
 
 Experiment LXXXIII. 
 
 In February I poured on fix cubick inches 
 of powdered Oyjler-jhell, an equal quantity of 
 common white- wine Vinegar \ In five or fix 
 minutes it generated feventeen cubick inches 
 of Air, and in fome hours twelve cubick inches 
 more \ in ail twenty-nine inches. In nine 
 days it had {lowly reforbed 2 1 cubick inches 
 cf Air. The ninth day I poured warm water 
 into the vefiel x x, (Fig. 34.) and the follow- 
 ing day, when all was cool, I found that it 
 had reforbed the remaining eight cubick inches. 
 Hence we fee, that warmth will fcmetimes 
 promote a reforbing as well as a generating 
 flate, viz. by raifing the reforbing fumes, as 
 will appear more hereafter. 
 
 Half a cubick inch of OyJler-JJjell, and a 
 cubick inch of 0/7 of Vitriol, generated thirty- 
 two cubick inches of Air. 
 
 OyJicrJJ:el/ y and two cubick inches of four 
 Rennet, of a Calf's ftomach, generated in 
 four days eleven cubick inches. But Oy/ler- 
 fhcll with fome of the liquor of a Calf's fto- 
 mach, which had fed much upon Hay, did 
 not crenerate air. It was the fame with Oyjler- 
 (hell and Ox-gall, Urine and Spittle. 
 
 Half 
 
Analyfis of the Air. ley 
 
 Half a cubick inch of Oyjler-Jh-ell and Sevil 
 Orange juice generated the firit day thirteen 
 cubick inches of x^ir, and the following days 
 it reforbed that, and three or four more cu- 
 bick inches of Air, and would fometimes 
 generate again. It was the fame with Limon 
 juice. 
 
 Oyfterjliell and Milk generated a little Air: 
 But Limon juice and Milk did at the fame time 
 abforb a little Air ; as did alio Calves Rennet 
 and Vinegar; fome of the fame Rennet alone 
 generated a little Air, and reforbed it again the 
 following day. It had the fame effect when 
 mixed with crums of bread. 
 
 Experiment LXXXIV. 
 
 A cubick inch of Limon juice, and near an 
 equal quantity of fpirits of Harts-horn, perfe, 
 i. e. not made with Lime, did in four hours 
 abforb three or four cubick inches of Air; 
 and the following day it remitted or generated 
 two cubick inches of Air: The third day 
 turning from very warm to cold, it again re- 
 forbed that Air, and continued in an abforb- 
 ing ftate for a day or two. 
 
 That there is great plenty of Air incorpo- 
 rated into the fubftance of Vegetables, which 
 
 by 
 
2 06 AnaJyJls of the Air, 
 
 by the action of fermentation is rouzed into 
 an elaftick ftate, is evident by thefe following 
 Experiments, viz. 
 
 Experiment LXXXV. 
 
 March the fecond I poured into the bolt- 
 head b (Fig. 34.) forty-two cubicle inches of 
 Ale from the tun, which had been there fet 
 to ferment thirty-four hours before: From 
 that time to the ninth of June it generated 63 9 
 cubick inches of Air, with a very unequal 
 progreffion, more or lefs as the weather was 
 warm, cool, or cold ; and fometimes, upon a 
 change from warm to cool, it reforbed Air 3 
 in all thirty-two cubick inches-. 
 
 Experiment LXXXVI. 
 
 March the fecond, twelve cubick inches of 
 Malaga Raijins, with eighteen cubick inches 
 of water y generated by the 1 6th of April 4 1 1 
 cubick inches of Air; and then in tw 7 o or three 
 cold days it reforbed thirty-five cubick inches.- 
 From the 21ft of April to the 16th of May it 
 generated 78 cubick inches; after which to 
 the 9th of 'June it continued in a reibrbing 
 ftate, fo as to reforb 13 cubick inches; there 
 
 were 
 
Analyjis of the Air. 1 07 
 
 were at this feafon many hot days, with much 
 thunder and lightning, which deftroys the Air's 
 tlafticity 5 fo there were generated in all 489 
 cubick inches, of which 48 were reforbed. 
 The liquor was at laft very vapid. 
 
 From the great quantity of Air generated 
 from Apples, in the following Experiment, 'tis 
 probable, that much more Air would have 
 rifen from the laxer texture of ripe undried 
 Grapes, than did from thefe Raifins. 
 
 We fee from thefe Experiments on Raifins 
 and Ale, that in warm weather Wine and Ale 
 do not turn vapid by imbibing Air, but by fer- 
 menting and generating too much, whereby 
 they are deprived of their enlivening principle, 
 the Air 5 for which reafon thefe liquors are 
 beft preferved in cool cellars, whereby this 
 active invigorating principle is kept within due 
 bounds, which when they exceed, Wines are 
 upon the fret and in danger of being fpoiled. 
 
 Experiment LXXXVII. 
 
 Twenty-fix cubick inches of Apples being 
 mafbed Angnjl io, they did in thirteen days 
 generate 968 cubick inches of Air, a quantity 
 equal to 48 times their bulk ; after which they 
 did ia three or four days reforb a quantity equal 
 
 to 
 
i 6 8 Analyjis of the Air. 
 
 to their bulk, notwithstanding it was very 
 hot weather ; after which they were ftatio- 
 nary, neither reforbing nor generating Air in 
 many days. 
 
 A very coarfe Brown-fugar, with an equal 
 quantity of water, generated nine times its 
 bulk of Air 5 Rice-four fix times its bulk; 
 Scurvy-grafs leaves generated and abforbed 
 Air; Peas, Wheat and Barley did in Fer- 
 mentation alfo generate great quantities of 
 Air. 
 
 That this Air, which arifes in fuch great 
 quantities from fermenting and dhToiving 
 vegetables, is true permanent Air, is certain, 
 by its continuing in the fame expanded elaftick 
 ftate for many weeks and months; which ex- 
 panding watry vapours will not do, but foon 
 condenfe when cool. And that this new gene- 
 rated Air is elaftical, is plain, not only by its 
 dilating and contracting with heat and cold, 
 as common Air does, but alfo by its being 
 compreffible, in proportion to the incumbent 
 weight, as appears by the two following Ex- 
 periments, which (hew what the great force 
 of thefe aerial particles is, at the inftant they 
 cfcape from the fermenting vegetables. 
 
 E XPE- 
 
Analyjis of the AW. 209 
 
 Experiment LXXXVIII. 
 
 I filled the ftrong Hungary -water Bottle b c 
 (Fig. 36.) near half full of Peas, and then full 
 of water, pouring in, firft, half an inch depth 
 of Mercury \ then I fcrewed at b into the 
 bottle the long (lender tube a z, which reached 
 down to the bottom of the bottle ; the water 
 was in two or three days all imbibed by the 
 Peas, and they thereby much dilated ; the 
 Mercury was alfo forced up the flender glafs 
 tube near eighty inches high ; in which ftate 
 the new generated air in the bottle was com- 
 prelTed with a force equal to more than two 
 atmofpheres and an half 5 if the bottle and 
 tube were fwung to and fro, the Mercury 
 would make long vibrations in the tube be- 
 tween z and b y which proves the great elafti- 
 city of the compreffed air in the bottle. 
 
 EXPERIMENT LXXXIX. 
 
 I found the like elaftick force by the fol- 
 lowing Experiment, viz. I provided a ftrong 
 iron potabcd, (Fig. 37.) which was two and 
 ^ inches diameter within fide, and five inches 
 deep, I poured in:o it half an inch depth of 
 
 P Mercury •, 
 
1 1 o Analyfis of the Mt. 
 
 Mercury; then I put a little coloured honey 
 at x, into the bottom of the glafs-tube z x, 
 which was fealed at the top. I fet this tube 
 in the iron cylinder n n> to fave it from break- 
 ing by the fwelling of the Peas. The pot 
 being filled with Peas and water, I put a lea- 
 thern collar between the mouth and lid of the 
 pot, which were both ground even, and then 
 .preffed the Hd hard down in a Cyder-preis: 
 The third day I opened the pot, and found 
 all the water imbibed by the Peas ; the Honey 
 was forced up the glafs-tube by the Mercury 
 to z y (for fo far the glafs was dawbed) by 
 which means I found the preffure had been 
 equal to two atmofpheres and ' ; and the dia- 
 meter of the pot being two -f-| inches, its 
 area was fix fquare inches, whence the dilate- 
 ing force of the air againft the lid of the pot 
 was equal to 200 pounds. 
 
 And that the expanfive force of new gene- 
 rated air is vaflly fuperior to the power with 
 which it adted on the Mercury in thefe twe 
 Experiments, is plain from the force wit! 
 which fermenting Mud will burft the ftrongef 
 veflels ; and from the vaft explofive force witl 
 which the air generated from nitre in th 
 firing of gun-powder, w ill bur ft afunder th 
 
 ftronge 
 
AnalyfnoftheAk. tll 
 
 ftrongeft bombs or cannon, and whirl fortifi- 
 cations in the air. 
 
 This fort of mercurial gage, made ufe of 
 in Experiment 89, with fomeunduous mat- 
 ter, as Treacle, or the like tinged liquor 
 on the Mercury in the tube, to note how 
 high it riles there, might probably be of fer- 
 vice, in finding out unfathomable depths of 
 the fea, viz by fixing this fea-gage to fome 
 buoyant body, which mould be funk by a 
 we.ght fix'd to it, which weight might by 
 an eafy contrivance be detached from the 
 buoyant body, as foon as it touched the bot- 
 tom of the fea , fo that the buoyant body 
 and gage would immediately afcend to the 
 furface of the water. The buoyant body ought 
 to be pretty larg,, and much lighter than the 
 water, that by its greater eminence above the 
 water it might the better be feen : for 'tis 
 probable that from great depths it may rife 
 at a confutable diflance from the mip tho- 
 rn a calm. r ' 
 
 For greater accuracy it will be needful, 
 m, to try this fea-gage, at feveral differen 
 depths down to the greatefi depth that a 
 >ne will reach, thereby to difcover, whe ! 
 Act or how much the fpring of the air is 
 difturbcd or condenfej, not only by the great 
 
 P 2 prefiure 
 
2 1 2 Analyfis of the Ah. 
 
 preflure of the incumbent water, but alfo by 
 its coldnefs at great depths; and in what pro- 
 portion, at different known depths, and in 
 different lengths of time, that an allowance 
 may accordingly be made for it at unfatho- 
 mable depths. See Vol II. p. 332. 
 
 This gage will alfo readily (hew the de- 
 grees of compreffion in the condcnfing en- 
 
 gine. 
 
 But to return to the fubjetf: of the two laft 
 Experiments, which prove the elafticity of 
 this new generated air; which elafticity is 
 fuppofed to confift in the adive aerial par- 
 ticles, repelling each other with a force, 
 which is reciprocally proportional to their 
 diftances: That illuftrious Philoibpher, Sir 
 Jjaac Newton, in accounting how air and 
 vapour is produced, Opticks %uer. 31. fays, 
 " The particles, when they are fhaken off 
 " from bodies by heat or fermentation, fo 
 " foon as they are beyond the reach of the 
 m attraction of the body receding from it, 
 « as alfo from one another, with great ftrength 
 « and keeping at a diftance, fo as fometimes 
 JJ to take up above a million of times more 
 " fpace than they did before in the form of 
 M a denfe body ; which vaft contraction and 
 f expanfion feems unintelligible, by feign- 
 
 « ing 
 
AnaJyJis of the Air. 1 1 j 
 
 v - ing the particles of air to be fpringy and 
 ki ramous, or rolled up like hoops, or by any 
 " other means than by a repulfive power." 
 The truth of which is further confirmed by 
 thefe Experiments, which mew rhe great 
 quantity of air emitted from fermenting bo- 
 dies ; which not only proves the great force 
 with which the parts of thofe bodies muft 
 be diftended ; but (hews alio how very much 
 the particles of air muft be coiled up in that 
 ftate, if they are, as has been fuppofed, fpringy 
 and ramous. 
 
 To inftance in the cafe of the pounded 
 Apples, which generated above 48 times 
 their bulk of air ; this air, when in the 
 Apples, muft be comprefled into lefs than 
 a forty-eighth part of the fpace it takes up 
 when freed from them, and it will confe- 
 quently be forty-eight times more denfe - y 
 and fince the force of comprefled air is pro- 
 portional to its denfity, that force which 
 comprefles and confines this air in the Ap- 
 ples, muft be equal to the weight of forty- 
 eight of our atmofpheres, when the Mer- 
 cury in the Barometer ftands at fair, that is, 
 30 inches high. 
 
 P 3 Now 
 
1 1 4 Analyjis of the Air . 
 
 Now a cubick inch of Mercury weighing 
 3580 grains, thirty cubick inches (which is 
 equal to the weight of our atmofphere on 
 an area of a cubick inch) will weigh fifteen 
 pounds, five ounces, 215 grains 3 and forty- 
 eight of them will weigh above 836 pounds; 
 which is therefore equal to the force with 
 which an inch fquare of the furface of the 
 Apple would comprefs the air, fuppofing 
 there were no other fubflance but air in the 
 Apple : And if we take the furface of an 
 Apple at iixteen fquare inches, then the 
 whole force with;\vjhich that furface would 
 comprefs the included air, would be 13383 
 pounds. And fince action and reaction 
 are equal, this would be the force, with 
 which the air in the Apple would endea- 
 vour to expand itfelf, if it were there in 
 an elaftick and ftrongly compreffed ftate : 
 But fo great an expanfivc force in an Apple 
 would certainly rend the fubflance of it with 
 a ftrong explolion, efpecially when that force 
 was increafed by the vigorous influence of 
 the Sun's warmth. 
 
 We may make a like eftimate alfo, from 
 the great quantities of air which arofe either 
 by fermentation, or the force of fire from 
 ieveral orher bodies* Thus in Exp. 55. there 
 
 arofe 
 
udnahjis of the Air. i \ 5 
 
 arofe from a piece of heart of Oak, 216 
 
 times ics bulk of air. Now 216 cubick 
 
 inches of air, comprerTed into the fpace of 
 
 one cubick inch, would, if it continued there 
 
 in an elaftick ftate, prefs againft one fide of 
 
 the cubick inch with an expanfive force equal 
 
 to 3 ^93 pounds weight, fuppofing there were 
 
 no other fubftance but air contained in it j 
 
 and it would prefs againft the fix fides ot 
 
 the cube, with a force equal to 20350 
 
 pounds, a force furficient to rend the Oak 
 
 with a vaft explofion: It is very reafonable 
 
 therefore to conclude, that moft of thefe 
 
 now a&ive particles of the new generated 
 
 air, were in a fixed ftate in the Apple and 
 
 Oak before they were roufed, and put into 
 
 an aftive repelling ftate, by fermentation and 
 
 fire. 
 
 The weight of a cubick inch of Apple 
 being 191 grains, the weight of a cubick 
 inch of air } of a grain, forty-eight times, 
 that weight of air is nearly equal to the four- 
 teenth part of the weight of the Apple. 
 
 And if to the air thus generated from a 
 veflel of any vegetable liquor by fermenta- 
 tion, we add the air that might afterwards 
 be obtained from it by heat or diftillation ; 
 and to that alfo the vaft quantity of air which 
 
 P 4 by 
 
2 \ 6 Analyjis of the Ak. 
 
 by Experiment 73 is found 10 be contained 
 in its Tartar, which adheres to the fides of 
 the veffel ; it would by this means be found 
 that air makes a very confiderable part of 
 the fubftance of Vegetables, as well as of 
 Animals. 
 
 But though from what has been faid, it 
 is reafonable to think, that many of thefe 
 particles of air were in a fixed ftate, ftrongly 
 adhering to, and wrought into the fubftance 
 of Apples ; yet on the other hand it is mod 
 evident from Exper. 34. and 38, where in- 
 numerable bubbles of air inceflantly arofe 
 through the fap of Vines, that there is a con- 
 fiderable quantity of air in Vegetables, upon 
 the wing, and in a very active {late, efpeci- 
 ally in warm weather, which inlarges the 
 fphere of their activity. 
 
 The Effefis of the Fermentation of mineral 
 Subjiances on the Air, 
 
 I Have above (hewn that Air may be pro- 
 duced from mineral Subftances, by the 
 action of fire in diftillation. And we have, 
 in the following Experiments, many inftances 
 of the great plenty of air, which is generated 
 by fome fermenting mixtures, a b for bed by 
 
 oth:rs, 
 
Jnalyfis of the Air. 1 1 7 
 
 others, and by others alternately generated 
 and abforbed. 
 
 Experiment XC. 
 
 I poured upon a middle-fized Gold Ring, 
 beat into a thin plate, two cubick inches of 
 Aqua Regia ; the Gold was all diffolved the 
 next day, when I found four cubick inches 
 of air generated ; for air-bubbles were conti- 
 nually arifing during the folution : But fmce 
 Gold lofes nothing of its weight in being thus 
 diffolved, the four cubick inches of air, which 
 weighed more than a grain, muft arife either 
 out of the pores of the Gold, or from the 
 Aqua Regia -, which makes it probable, that 
 there are air particles in acid fpirits ; for by 
 Experiment feventy - five, they abforb air ; 
 which air particles regained their elafticity, 
 when the acid fpirits which adhered to them 
 were more ftrongly attracted by the Gold y 
 than by the air particles. 
 
 Experiment XCI. 
 
 A quarter of a cubick inch of Antimons, 
 and two cubick inches of Aqua Regia, gene- 
 rated thirty-eight cubick inches of air, the 
 
 firft 
 
1 1 8 Analyjls of the Air. 
 
 firft three or four hours, ahd then abforhed, 
 fourteen cubick inches in an hour or two. 
 It is very obfervable, that air was generated 
 while the ferment was fmall, on the firft mix- 
 ing of the ingredients : But when the ferment 
 was greatly increafed, fo that the fumes rofe 
 verv vifibly, then there was a change made 
 frbrri a generating to an abforbing ftate; that 
 is, there was more air abforbed than gene- 
 rated. 
 
 That I might find whether the air was ab- 
 forbed by the fumes only of the Aqua Regia, 
 or by the acid fulphureous vapours, which 
 afcended from the Antimony^ I put a like 
 quantity of Aqua Regia into a bolthead b> 
 (Fig. 34.) and heated it, by pouring a large 
 quantity of hot Water into the ciftern x x t 
 which flood in a larger veffel, that retained 
 the hot water about it, but no air was ab- 
 forbed 5 for when all was cold, the water 
 Aood at the point z, where I firft placed it : 
 And I found it the fame, when, inftead of 
 Aqua Regia, I put only fpirit of Nitre into 
 the bolthead b; yet in the diftillation of com- 
 pound Aqna-fortisy Exper. 75. a little was ab- 
 forbed. Hence therefore it is probable, that 
 the greateft part, if not all the air, was ab- 
 forbed by the fumes which arofe from the 
 Antimony, E x- 
 
AnaJyJis of the Air. 2 1 p 
 
 Experiment XCII. 
 
 Some time in February, the weather very 
 cold, I poured upon a quarter of a cubick 
 inch of powdered Antimony, a cubick inch 
 of compound or double Aqua-fortis, in the 
 bolthead b (Fig. 34.) : in thefirft2o hours 
 it generated about 8 cubick inches of air ; 
 after that, the weather being fomewhat 
 warmer^ it fermented fafter, fo as in two or 
 three hours to generate 82 cubick inches of 
 air more 5 but the following night being very 
 cold, little was generated : So the next morn- 
 ing I poured hot water into the veffel x x> 
 which renewed the ferment, fo that it gene- 
 rated 4 cubick inches more, in all 130 cubick 
 inches, a quantity equal to 520 times the 
 bulk of the Antimony. 
 
 The fermented mafs looked like Brim- 
 flone, and when heated over the fire, there 
 fublimed into the neck of ihe bolthead a red 
 fulphur, and below it a yellow; which ful-. 
 phur, as Mr. Boyle obferves, Vol. III. p. 272, 
 cannot be obtained by the bare a&ion of fire, 
 without being fir ft well digefted in oil of 
 Vitriol, or fpirit of Nitre. And by com- 
 paring the quantity of air obtained by fermen- 
 tation in this Experiment, with the quantity 
 
 obtained 
 
2 1 o jinalyfis of the Air. 
 
 obtained by the force of fire in Exper. 69, 
 we find that five times more air was generatec 
 by fermentation than by fire, which mew< 
 fermentation to be a more fubtle diflblveni 
 than fire ; yet in fome cafes there is more aii 
 generated by fire than by fermentation. 
 
 Half a cubick inch of oil of Antimony, 
 
 with an equal quantity of compound Aqua* 
 
 forth, generated 36 cubick inches of elaftick 
 
 air, which was all reforbed the following 
 
 day. 
 
 Experiment XCIIL 
 
 Some time in February, a quarter of a 
 cubicle inch of filings of Iron, and a cubick 
 inch of compound Aqua-fort is, without any 
 water, did, in four days, ablbrb 27 cubick 
 inches of air. It having ceafed to abforb, I 
 poured hot water into the veffel x x, to try if 
 I could renew the ferment. The effect of 
 this was, that it generated three or four cu- 
 bick inches of air, which continued in that 
 ftate for fome days, and was then again re- 
 i orbed. 
 
 I repeated the fame Experiment in warm 
 weather in April, when it more briskly ab- 
 forbed 12 cubick inches in an hour. 
 
 Ex- 
 
Analyfis of the Air. z 1 1 
 
 Experiment XCIV. 
 
 March 12th, 1 of a cubick inch of filings 
 of Iron, with a cubick inch of compoiaid 
 Aqua-foi'tis, and an equal quantity of water, 
 for the firft half hour abforbed five or fix 
 cubick inches of air; but in an hour more 
 it had emitted that quantity of air; and in 
 two hours more it again reforbed what had 
 been juft before emitred. The day following 
 it continued abibrbing, in all 12 cubick in- 
 ches: And then remained flationary for 15 
 or 20 hours. The third day it had again re- 
 mitted or generated three or four cubick 
 inches of air, and thence continued flationary 
 for five or fix days. 
 
 It is remarkable, that the fame mixtures 
 fhould change from generating to abibrbing, 
 and from abibrbing to generating flates 5 fome- 
 times with, and ibmetimes without any fen- 
 lible alteration of the temperature of the air. 
 See Vol. II. p. 237 , 293. 
 
 A like quantity of filings pf Iron, and oil 
 of Vitriol y made no fenfible ferment, and 
 generated a very little air ; but upon pouring 
 in an equal quantity of water, it generated 
 in 21 days 43 cubick inches of air; and in 3 
 or 4 days more it reforbed 3 cubick inches of 
 
 air ; 
 
% ii Analyjis of the Air. 
 
 air ; when the weather turned warmer, it was 
 generated again, which was again reforbed 
 when it grew cool. 
 
 One fourth of a cubick inch of filings of 
 Iron, and a cubick inch of oil of Vitriol, with 
 three times its quantity of water, generated 
 1 08 cubick inches of air. 
 
 Filings of Iron, with fpirit of Nitre, either 
 with an equal quantity of water, or without 
 water, abfojbed air, but mofl without water. 
 
 One fourth of a cubick inch of filings of 
 Iron, and a cubick inch of Limon-juice, ab- 
 forbed two cubick inches of air. 
 
 Experiment XCV. 
 
 Half a cubick inch ofjpirits of Harts- 
 horn, with filings of Iron, abforbed 1 -j- i. 
 cubick inches of air, with filings of Copper, 
 double that quantity of air, and made a very 
 deep blue tinfture, which it retained long, 
 when expofed to the open air. It was the 
 fame with fpirit of Sal Armoniac, and filings 
 of Copper. 
 
 A quarter of a cubick inch of filings of 
 Iron, with a cubick inch of powdered Brim- 
 ftone, made into a pafle with a little water, 
 abforbed 19 cubick inches of air in two days. 
 
 N.B. 
 
AnaJyfts of the Att. 22$ 
 
 N B. I poured hot water into the ciftern xx % 
 (Fig. 34.) to promote the ferment. 
 
 A like quantity of filings of Iron, and pow- 
 dered Ne-ivcajlle Coal, did in three or four 
 days generate feven cubicle inches of air. I 
 could not perceive any fenfible warmth in 
 this mixture, as was in the mixture of Iron 
 and Brimfione. 
 
 Powdered Brimfione and Newcajtle Coal 
 neither generated nor abforbed. 
 
 Filings of Iron and Water abforbed three 
 or four cubick inches of air ; but they do not 
 abforb fo much, when immerfed deep in wa- 
 ter ; what they abforb isufually the firft three 
 or four days. 
 
 Filings of Iron, and the above-mentioned 
 Walton Pyrites, in Exper. 70. abforbed in 
 four days a quantity of air nearly equal to 
 double their bulk. 
 
 Copper Oar, and compound Aqua-fortis 9 
 neither generated nor abforbed air 3 but, mixed 
 with water, it abforbed air. 
 
 A quarter of a cubick inch of Tin, and 
 double that quantity of compound Aqua -fortis, 
 generated two cubick inches of air ; part of 
 the Tin was diffolved into a very white fub- 
 ftance. 
 
 E x p E- 
 
xa4 AnaJyJis of the Air. 
 
 Experiment XCVI. 
 
 'April 1 6th, a cubick inch of the afore- 
 mentioned Walton Pyrites powder'd, with a 
 cubick inch of 'compound Aqua-fortis, expanded 
 with great violence, heat and fume into a fpace 
 equal to 200 cubick inches, and in a little time 
 it condenfed into its former fpace, and then 
 abforbed 85 cubick inches of air. 
 
 But the like quantity of the fame Miner -al 9 
 with equal quantities oi compound Aqua-fort is 
 and Water \ fermented more violently, and ge-% 
 nerated above 80 cubick inches of air. 
 
 I repeated thefe Experiments feveral times, 
 both with and without water, and found con- 
 ftantly the fame effedt. Yet Oil of Vitriol 
 and Water, with fome of the fame Mineral, 
 abforbed air. It was very warm, but did not 
 make a great ebullition. 
 
 But this Walton Mineral, with equal quan- 
 tities of fpirit of nitre and water, generated 
 air, which air would abforb frefh admitted 
 air. See Vol. \l. p. 283, 292. 
 
 Experiment XCVII. 
 
 I chofe two equal-fi~ed boltheads, and 
 put into each of them a cubick inch of 
 
 powdered 
 
Analyfn of the Air. 225 
 
 powdered Walton Pyrites, with only a cu- 
 bick inch of compound Aqua-fortis into one, 
 and a cubick inch of Water and compound 
 Aqua-fortis into the other : Upon weighing 
 all the ingredients and veflels exaftly, both 
 before and after the fermentation, I found 
 the bolthead with compound Aqua-fortis alone 
 had loft in fumes 1 dram 5 grains : But the 
 other bolthead with Water and compound 
 Aqua-fortis, which fumed much more, had 
 loft 7 drams, 1 fcruple, 7 grains, which is 
 fix times as much as the other loft. 
 
 Experiment XCVIIL 
 A cubick inch of Newcajik Coal pow- 
 dered, and an equal quantity of compound 
 Aqua fort is poured on it, did in three days 
 abforb 18 cubick inches of air; and in 3 
 days more it remitted and generated 12 cu- 
 bick inches of air; and on pouring warm 
 Water into the veflel x x, (Fig. 34.) it re- 
 mitted all that had been abforbed. 
 
 Equal quantities of Brimjione and com- 
 pound Aqua-fortis neither generated nor ab- 
 forbed any air, notwithstanding hot Water 
 was poured into the veffel x x. 
 
 A cubick inch of finely powdered Flint, 
 and an equal quantify of compound Aqua- 
 
 Q_ j- 
 
ix6 Jnalyjis of the -Air. 
 
 fortis, abforbed in 5 or 6 days 12 cubick 
 inches of air. 
 
 Equal quantities of powdered Brijiol 
 Diamond, and compound Aqua-fortis, and 
 Water, abfored 16 times their bulk of air. 
 
 The like quantities without Water ab- 
 forbed more flowly 7 times their bulk of 
 
 air. 
 
 Powder'd Brijiol Marble (viz. the (hell 
 in which thofe Diamonds lay) covered pretty 
 deep with Water, neither generated nor 
 abforbed air ; and it is well known that 
 Brijiol Water does not fparkle like fome 
 other Mineral Waters. 
 
 I 
 
 Experiment XCIX. 
 
 When the Aqua Regia was poured on Oleum 
 Tartari per deliquium, much air was gene- 
 rated, and that probably chiefly from the 
 Oleum Tartar i -, for by Exper. 74. Sal Tar- 
 tar has plenty of air in ir. 
 
 It was the fame when the oil of Vitriol 
 w?s poured on Oleum Tartaric and Oleum 
 Tartari dropped on boiling Tartar generated 
 much air. 
 
 When equal quantities of Water and oi[ 
 of Vitriol were poured on fea fait, it ab- 
 forbed 15 cubick inches of air; but when 
 
 in 
 
Analyfis of the Air. nj 
 
 in the like mixture the quantity of Water 
 was double to that of the oil of Vitriol, 
 then but half fo much air was abforbed. 
 
 Experiment C. 
 
 I will next fhew, what effect feveral Al- 
 kaline Mineral bodies had on the air in fer- 
 menting mixtures. 
 
 A folid cubick inch of unpowdered Chalk, 
 with an equal quantity of oil of Vitriol, fer- 
 mented much at firft, and in fome degree 
 for 3 days; they generated 31 cubick inches 
 of air. The Chalk was only a little diffolved 
 on its furface. 
 
 One hundred and forty-fix grains, or near 
 one third of a cubick inch of Chalk, being 
 let fall on two cubick inches of fpirit of 
 fait, 8 1 cubick inches of air were generated, 
 of which 36 cubes were reforbed in 9 days. 
 
 Yet Lime made of the fame Chalk abforb- 
 ed much air, when oil of Vitriol was poured 
 on it ; and the ferment was fo violent, that 
 it breaking the glals veffcls, I was obliged to 
 put the ingredients in an Iron velTcl. 
 
 Two cubick inches of frefh Lime, and 
 four of common white wine Vinevar ablorb- 
 ed in 15 days 22 cubick inches of air. 
 
 Q_2 The 
 
1 2 S Analyjis of the Air. 
 
 The like quantity of frefli Lime and 
 V/ater abforbed in 3 days 10 cubick inches 
 of air. 
 
 Two cubick inches of Lime, and an equal 
 quantity of Sal Ammoniac ,- abforbed 115 cu- 
 bick inches: The fumes of this mixture are 
 therefore doubtlefs very fuffocating. 
 
 A quart of unflacked Lime, left for 44 
 days, to flacken gradually by it-felf, without 
 any mixture, abforbed no air. 
 
 March 3d, a cubick inch of powdered 
 Belemnitis, taken from a Chalk pit, and an 
 equal quantity of oil of Vitriol, generated 
 in five minutes 35 cubick inches of air. 
 March 5th, it had generated 70 more. 
 March 6th, it being a hard froit, it relbrb- 
 ed 12 cubick inches ; io it generated in all 
 105 inches, r*r,d refoibed 12. 
 
 powdered Belemnitis and Limon juice ge- 
 nerated plenty of air too; as did alfo the 
 Star-flow, Laps Judaicus, and Selantis 
 with oil of Vitriol, 
 
 Eyperiment CI. 
 
 Gravel, fchat is well burnt, Wood-aJJ:es y 
 decrepitated Salt, and Cdcoihar of Vitriol, 
 placed itveraily under the inverted glafs 
 zzaa, (Fig. 35.) increakd in weight by 
 
 irr> 
 
j4nalyjis of the Air. 229 
 
 imbibing the floating moifture of the air: 
 But they abfoibed no ekftick air. It was 
 the fame with the remaining lixivious Salt 
 of a diftillation of Nitre. 
 
 But 4 or 5 cubick inches of powdered 
 frefh Cinder of N ewe a/lie Coal did in feven 
 days abibrb 5 cubick inches of elaftick air. 
 And 13 cubick inches cf rir were in 5 days 
 abforbed by Pulvis Urcns, a powder which 
 immediately kindles into a live Cole, up- 
 on being expofed to the open air. 
 
 Experiment CII. 
 
 What effect burning and flaming bodies, 
 and the refpiration of Animals, have on the 
 air, we mall fee in the following Experi- 
 ments j viz. 
 
 I nVd upon the pedeftal under the in- 
 verted glafs z z a a, (Fig. 35.) a piece of 
 Brown Paper, which had been dipped in a 
 fojution of Nitre, and then well dried 3 I 
 fet fire to the Paper by means of a burn- 
 ing-glafs: The Nitre detonized, and burnt 
 briskly for fome time, till the glafs z z a a 
 was very full of thick fumes, which extin- 
 guished it. The expanfion cauied by the 
 burning Nitre, was equal to more than two 
 quarts: When all was cool, there were near 
 
 Q 1 80 cu- 
 
2 3° Analyfis of the AW. 
 
 80 cubick inches oi new generated air, which 
 arofe from a fmall quantity of detonized 
 Nitre ; but the elafticity of this new air dai- 
 ly decreafed, in the fame manner as Mr. 
 Hawksbce obferved the air of fired Gun- 
 powder to do, Phyfico- mechanical Exper. 
 p. 83. fo that he found 19 of 20 parts occu- 
 pied by this air to be deferted in 18 days, 
 and its fpace filled by the afcending water; 
 at which flation it refted, continuing there 
 for 8 days without alteration: And in like 
 manner, I found that a considerable part of 
 the air which was produced by fire in the 
 dift illation of feveral fubftances, did gra- 
 dually lofe its elafticity in a few days after 
 the diftillation was over ; but it was not fo 
 when I dialled air thro' water, as in Expe- 
 riment 77. (Fig. 38. ) 
 
 Experiment CHI. 
 
 I placed on the fame pedeflal large Matches 
 made of linen rags dipped in melted Brim- 
 Jione: The capacity of the veflel, (Fig. 35.) 
 above z z the furface of the water, was 
 equal to 2024 cubick inches. The quantity 
 of air which was abforbed by the burning 
 Match ', was 198 cubick inches, equal to -~q 
 part of the whole air in the vc({q} 9 
 
 I made 
 
Analyjis of the Air. 23 1 
 
 I made the fame Experiment in a lefler 
 veflel z z a a y (Fig. 35.) which contained 
 but 594 cubick inches of air, in which 150 
 cubicle inches were abforbed; /. e. full \ 
 part of the whole air in the receiver : So 
 that tho' more air is abforbed by burning 
 Matches in large vefTels, where they burn 
 longeft, than in fmall ones, yet more air, 
 in proportion to the bulk of the vefTel, is 
 abforbed in fmall than in large vefTels: If a 
 frefli Match were lighted and put into this 
 infected air, tho' it would not burn i. part 
 of the time that the former Match burnt 
 in frefh untainted air, yet it would abforb 
 near as much air in that fhort time ; and it 
 was the fame with Candles. 
 
 Experiment CIV. 
 
 Equal quantities of filings of Iron and 
 Brimftone, when let fall on a hot Iron on 
 the pedeftal under the inverted glafs zz a a, 
 (Fig. 35.) did in burning abforb much air; 
 and it was the fame with Antimony and 
 Brimjlone : Whence 'tis probable, that VuU 
 cano's, whofe fewel confills chiefly of Brim- 
 fione, mix'd with feveral mineral and me- 
 talline fubftances, do not generate, but ra- 
 ther abforb air. 
 
 CL4 We 
 
% 3 * Analyjls of the djr. 
 
 We find in the foregoing Experiment 102 
 on Nitre, that a great part of the new ge- 
 nerated air is in a few days reforbed, or 
 lofes its elafticity : But the air which is ab- 
 ibrbed by burning Brimjlone, or the flame 
 of a Candle, doe$ not recover its elafticity 
 again, at leaft, not while confined in my 
 glafles. 
 
 EXPERI MENT CV. 
 
 I made feveral attempts to try whether 
 air full of the fumes of burning Brimjlone 
 was as compreflible as common frefli air, 
 by comprefling at the fame time tubes full 
 of each of thefe airs in the condenfing en- 
 gine j and I found that clear air is very lit- 
 tle more compreflible than air with fumes 
 of Brimjlone in it : But I could not come to 
 an exaft certainty in the matter, becaufe the 
 fumes were at the fame time deftroying the 
 elafticity of the air. I took care to make 
 the air in both tubes of the fame tempera- 
 ture, by firft immerfing them in cold water, 
 before I comprefled them. See appendix 
 Vol 11./. 319, 320. 
 
 Experiment C VI. 
 I fet a lighted tallow Candle, which w^s 
 about S of an inch diameter, under the in- 
 
 yerted 
 
Analyjis of the* Air. 23} 
 
 verted receiver z z a a, (Fig. 35. ) and with 
 a fyphon I immediately drew the water up 
 to z z : Then drawing out the fyphon, the 
 water would defcend for a quarter of a mi- 
 nute, and afcer that afcend, notwithftand- 
 ing the Candle continued burning, and heat- 
 ing the air for near 3 minutes. It was ob- 
 fervabje in this Experiment, that the fur- 
 face of the water z z did not afcend with 
 an equal progreflion, but would be fome- 
 times ftationary ; and it would fometimes 
 move with a flow, and fometimes with an 
 accelerated motion ; but the denfer the fume?, 
 the fafter it afcended. As foon as the Can- 
 dle was out, 1 marked the height of the 
 water above z z, which difference was 
 equal to the quantity of air, whofe elafti- 
 city was deftroyed by the burning Candle. 
 As the air cooled and condenfed in the re- 
 ceiver, the water would continue rifing 
 above the mark, not only till all was cool, 
 but for 20 or 30 hours after that, which 
 height it kept, tho' it flood many days; 
 which (hews that the air did not recover the 
 elafticity which it had loft. 
 
 The event was the fame, when for great- 
 er accuracy I repeated this Experiment by 
 lighting the Candle after it was placed un- 
 der 
 
234 Analy/is of the Air. 
 
 der the receiver, by means of a burning-glafs, 
 which fet fire to a fmall piece of brown pa- 
 per fixed to the wick of a Candle, which 
 paper had been firft dipped in a ftrong folia- 
 tion of Nitre in Water; and when well 
 dried, part of it was dipped in melted Brim- 
 ftone ; it will alfo light the Candle without 
 being dipped in Bnm/ione. Dr. Mayoix, 
 found the bulk of the air leffened by -3— part, 
 but does not mention the fize of the elafs 
 veffel under which he put the lighted Can- 
 dle, T>e Sp. Nitro aereo, p. 10 1. The capa- 
 city of the veffel above z z, in which the 
 Candle burnt in my Experiment, was equal 
 to 2024 cubick inches; and the elafticity of 
 the *£ part of this air was deftroyed. 
 
 The Candle cannot be lighted again in 
 this infected air by a burning-glafs: But if 
 I firft lighted it, and then put it into the 
 fame infected air, tho' it was extinguifhed 
 in y part of the time, that it would burn in 
 the fame veffel, full of frefh air 5 yet it 
 would deftroy the elafticity of near as much 
 air in that fhort time, as it did in five times 
 that fpace of time in frefh air; this I re- 
 peated feveral times, and found the fame 
 event : Kence a grofs air, which is loaded 
 wuh vapours, is more apt in equal times to 
 
 lofe 
 
Analyfis of the Jtr. 23 j 
 
 lofe its elafticity in greater quantities, than 
 a clear air. 
 
 I obferve that where the veffels are equal, 
 and the fize of the Candles unequal, the 
 elafticity of more air will be deftroyed by 
 the large than by the fmall Candle : and where 
 Candles are equal, there moft air in propor- 
 tion to the bulk of the veffel will be ab- 
 forbed in the fmalleft veffel : tho* with 
 equal Candles there is always moft elaiii^L 
 air oeftroyed in the largtft vefll-l, where the 
 Candle burns longeft. 
 
 I found alfo in fermenting liquors, that, 
 cater is paribus, more air was either gene- 
 rated or abforbed in large, than in fmall 
 veffels, by generating or abforbing mixtures. 
 As in the mixture of Aqua Regia and Anti- 
 mony in Experiment 91. by inlarging the 
 bulk of the air in the veffel, a greater quan- 
 tity of air was abforbed. Thus alfo filings 
 of Iron and Bnmjlone, which in a more capa- 
 cious veffel abforbed 19 cubick inches of 
 air, abforbed very little, when the bulk of 
 air, above the ingredients, was but 3 or 4 
 cubick inches: For I have often obferved, 
 that when any quantity of air is faturated 
 with abforbing vapours to a certain degree, 
 then no more elaftick air is abforbed : Not- 
 withstanding 
 
%$6 Analyfa of the dir. 
 
 tvithftanding the fame quantity of abforbing 
 fubftances would, in a larger quantity of air, 
 have abforbed much more air; and this is 
 the reafon why I was never able to deftroy 
 the whole elafticity of any included bulk of 
 air, whether it was common air, or new 
 generated air. 
 
 Experiment CVII. 
 
 May 1 8. which was a very hot day, I 
 repeated Dr. Mayow\ Experiment, to find 
 how much air is abforbed by the breath of 
 Animals inclofed in glafles, which he found 
 with a moufe to be -^ part of the whole 
 air in the glafs veffel, De Sp. Nitro aere$> 
 f. 104. 
 
 I placed on the pedeftal, under the invert- 
 ed glafs zza a, (Fig. 35. ) a full-grown 
 Rat. At firft the water fubfided a little, 
 which was occafioned by the rarefa&ion of 
 the air, caufed by the heat of the animal's 
 body. But after a few minutes the water be- 
 gan to rife, and continued riling as long 
 as the Rat lived, which was about 14 hours. 
 The bulk of the air in which the Rat 
 lived fo many hours, was 2024 cubick inches; 
 the quantity of elaftick air which was ab- 
 forbed, was ji cubick inches, above vf part 
 
 of 
 
Analyfis of the Air. 237 
 
 of the whole, nearly what was abforbed 
 by a Candle in the fame veflel, in Experi- 
 ment 106. 
 
 I placed at the fame time, in the fame 
 manner, another almoft half-grown Rat 
 under a veffel, whofe capacity above the 
 furface of the water z z y (Fig. 35.) was but 
 594 cubick inches, in which it lived 10 
 hours , the quantity of elaftick air which 
 was abforbed, was equal to 45 cubick 
 inches, viz. 7^ part of the whole air, which 
 the Rat breathed in: A Cat of three months 
 old lived an hour in the fame receiver 
 and abforbed 16 cubick inches of air* 
 viz. -jk part of the whole; an allowance 
 being made in this eftimate for the bulk of 
 the Cat's body. A Candle in the fame vefiel 
 continued burning but one minute, and ab- 
 forbed 54 cubick inches, T \ part of the 
 whole air. 
 
 And as in the cafe of burning Brimjione 
 and Ca?idles, more air was found to be ab- 
 forbed in large veflels than in fmall ones ; 
 and vice verfa, more air, in proportion to the 
 capacity of the veiTel, was abforbed in fmall 
 than in large veflels, fo the fame holds true 
 here too in the cale of animals. 
 
 Expe- 
 
ij 8 Analyfis of the Air. 
 
 Experiment CVIII. 
 
 The following Experiment will {hew, 
 that the elafticity of the air is greatly de- 
 ftroyed by the refpiration of human Lungs 5 
 viz. 
 
 I made a bladder very fupple by wetting 
 of it, and then cut off fo much of the neck 
 as would make a hole wide enough for the 
 biggeft end of the largeft foffet to enter, to 
 which the bladder was bound fait. The 
 bladder and foffet contained 74 cubick 
 inches. Having blown up the bladder, I 
 put the fmall end of the foffet into my 
 mouth; and at the fame time pinched my 
 noflrils clofe, that no air might pafs that 
 way, fo that I could only breath to and fro 
 the air contained in the bladder. In lefs 
 than half a minute I found a considerable 
 difficulty in breathing, and was forced after 
 that to fetch my breath very faft; and at 
 the end of the minute, the fuffocating un- 
 eafinefs was fo great, that I was forced to 
 take awav the bladder from my mouth. 
 Towards the end of the minute the blad- 
 der was become fo flaccid, that I could not 
 blow it above half full with, the greatefl 
 expiration that I could make : And at the 
 
 fame 
 
AnaJyJis of the Ait . 259 
 
 fame time I could plainly perceive, that my 
 lungs were much fallen, juft in the fame 
 manner as when we breath out of them 
 all the air we can at once. Whence it is 
 plain that a confiderable quantity of the 
 elafticity of the air contained in my lungs, 
 and in the bladder, was deftroyed; which 
 fuppofing it to be 20 cubick inches, it will 
 be ^ part of the whole air, which I breath- 
 ed to and fro; for the bladder contained 
 74 cubick inches, and the lungs, by the 
 following Experiment, about 166 cubick 
 inches, in all 240. 
 
 Thefe effects of refpiration on the ela- 
 fticity of the air put me upon making an 
 -attempt to meafure the inward furface of 
 the lungs, which by a wonderful artifice 
 are admirably contrived by the divine Ar- 
 tificer, fo as to make their inward furface 
 to be commenfurate to an expanfe of air 
 many times greater than the animal's body; 
 as will appear from the following eflimate, 
 i)iz. 
 
 Experiment CIX. 
 
 I took the lungs of a Calf, and cut off 
 the heart and wind-pipe an inch above its 
 branching into the lungs; I got nearly the 
 
 fpecific^ 
 
240 Analyfis of the /fi r. 
 
 fpecifick gravity of the fubftance of the 
 lungs, (which is a continuation of the branch- 
 ings of the wind-pipe, and blood-veflels) by 
 finding the fpecifick gravity of the wind- 
 pipe, which I had cut off) it was to Well- 
 water as 1.05 to 1. And a cubick inch of 
 water weighing 254 grains; I thence found 
 by weighing the lungs the whole of their 
 folid fubftance to be equal to 37 +| cubick 
 inches. 
 
 I then filled a large earthen veflel brim- 
 full of water, and put the lungs in, which 
 I blew up, keeping them under water with 
 a pewter plate. Then taking the lungs out, 
 and letting the plate drop to the bottom of 
 the water, I poured in a known quantity of 
 water, till the veflel was brim-full again ; that 
 water was 7 pounds 6 ounces and ~, equal 
 to 204 cubick inches; from which deduct- 
 ing the fpace occupied '^by the folid fubftance 
 of the lungs, viz. 37 +{. cubick inches, 
 there remains 166 -{"*•£■ cubick inches foj: 
 the cavity of the lungs. But as the Pul- 
 monary Veins, Arteries and Lymphaticks, 
 will, when they are in a natural ftate, re- 
 plete with blood and lymph, occupy more 
 fpace than they do in their prefent empty 
 ftate; therefore fome allowance muft alfo 
 
 be 
 
Anatyjis of the Air. 141 
 
 be made out of the above taken cavity of 
 the lungs, for the bulk of thofe fluids; for 
 which 25 -f- -r cubick inches feem to be a 
 fufficient proportion, out of the 166 + 4 cu- 
 bick inches; fo there remain 141 cubick 
 inches for the cavity of the lungs. 
 
 I poured as much water into the Bronchite 
 as they would take in, which was one pound 
 eight ounces, equal to 41 cubick inches; 
 this deducted from the above-found cavity 
 of the lungs, there remain 100 cubick 
 inches for the fum of the cavity of the 
 veficles. 
 
 Upon viewing fome of thefe veficles with 
 a microfcope, a middle-fized one feems to 
 be about T i^ part of an inch diameter ; then 
 the fum of the furfaces in a cubick inch of 
 thefe fmall veficles (iuppofing them to be 
 fo many little cubes, for they are not fphe- 
 rical) will be 600 fquare inches; for if the 
 number of the diviiions of the fide of the 
 cubick inch be 100, there will be 100 
 planes, containing each one fquare inch, in 
 each dimenfion of the cube ; which having 
 three dimenfions, the fum of thofe planes 
 will be 300 fquare inches, and the fum of 
 the furfaces of each fide of thofe planes 
 Will be 600 fquare inches ; which multiplied 
 
 R by 
 
24 1 Analyjis of the- Air. 
 
 by the fum of all the veficles in the lungs, 
 viz. ioo cubick inches, will produce 60000 
 fquare inches ; one third of which muft be 
 deducted, to make an allowance for the ab- 
 fence of two fides in each little veficular 
 cube, that there might be a free communi- 
 cation among them for the air to pal's to 
 and fro ; fo there remain 40000 fquare 
 inches for the fum of the furface of all the 
 veficles. 
 
 And the Bronchia containing 41 cubick 
 inches, fuppofing them at a medium to be 
 cylinders of -~ of an inch diameter, their 
 furface will be 1635 fquare inches, which 
 added to the furface of the veficles, makes 
 the fum of the furface of the whole lungs 
 to be 41635 fquare inches, or 289 fquare 
 feet, which is equal to 19 times the furface 
 of a man's body, which at a medium is com- 
 puted to be equal to 15 fquare feet. 
 
 I have not had an opportunity to take in 
 the fame manner the capacity and dimen- 
 fions of human lungs; the bulk of which 
 Dr. James Keill, in his Tentamina Medico- 
 phxfica, p. 80. found to be equal to 226 cu- 
 bick inches. Whence he eftimated the fum 
 of the furface of the veficles to be 21906 
 fquare inches. But the bulk of human 
 
 lungs 
 
Jnalyjls of the Air. 243 
 lungs is much mote capacious than 226 cu- 
 bick inches; for Dr. Jurzn, by an accurate 
 Experiment, found that he breathed out, at 
 one large expiration, two hundred and twenty 
 cubick inches of air; and I found it nearly 
 the fame, when I repeated the like Experi- 
 ment in another manner: So that there mufl 
 be a lar^e allowance made for the bulk of the 
 remaining air, which could not be expired 
 from the lungs; and alfo for the fubfbnce 
 of the lungs. 
 
 Suppofing then, that, according to Dr.y#- 
 riris eft i mate, (mMctfs Abridgment of the 
 Philofophical Tranfacl. Vol. I. p. 415.) we 
 draw in at each common infpiration forty 
 cubick inches of air, that will be 48000 cu- 
 bick inches in an hour, at the rate of twenty 
 infpirations in a minute. A confiderable pare 
 of the elafticity of which air is, we fee by 
 the foregoing Experiment, conflantly de- 
 ftroyed, and that chiefly among the veficks, 
 where it is charged with much vapour. 
 
 But it is not eafv to determine how much 
 is destroyed. I attempted to find it out by 
 the following Experiment, which I (hall here 
 give an account of, tho 7 it did not tucceed 
 fo well as I could have wifhed, for want of 
 much larger veflels ; for if it was repeated 
 
 R 2 with 
 
244 Analyfis of the Air. 
 
 with more capacious veffels, it would deter- 
 mine the matter pretty accurately 5 becaufe 
 by this artifice frefh air is drawn into the 
 lungs at every infpiration, as well as in the 
 free open air. 
 
 Experiment CX. 
 I made ufe of the fyphon (Fig. 39.) take- 
 ing away the bladders, and diaphragms i i 
 n no: I fixed, by means of a bladder, one 
 end of a fhorc leaden fyphon to the lateral 
 foffet i i : Then I fattened the large fyphon 
 in a veffel, and filled it with water, till it 
 rofe within two inches of a y and covered 
 the other open end of the {hort fyphon, 
 which was depreffed for that purpofe. Over 
 this orifice I placed a large inverted chymi- 
 cal receiver full of water ; and over the other 
 leg s of the great fyphon, I whelmed an- 
 other large empty receiver, whofe capacity 
 was equal to 1224. cubick inches; the 
 mouth of the receiver being immerfed in 
 the water, and gradually let down lower 
 and lower by an affiftant, as the water 
 afcended in ir. Then flopping my noftrils, 
 I drew in breath at *z, thro' the fyphon from 
 the empty receiver : And when that breath 
 was expired, the valve b i flopping its return 
 
 down 
 
Analyjls of the An. 245 
 
 down thro* the lyphon, it was forced thro' 
 the valve r, and thence through the fmall 
 leaden fyphon into the inverted receiver full 
 of water, which water defcended as the 
 breath afcended. In this manner I drew all 
 the air, except five or fix cubick inches, out 
 of the empty receiver at 0, the water at the 
 fame time afcending into it, and filling it ; 
 by which means all the air in the empty 
 receiver, as alfo all the air in the fyphon 
 s b was infpired into my lungs, and breathed 
 out through the valve r into the receiver, 
 which was at firft full of water. I marked 
 the boundary of air and water, and then 
 immerfed the whole receiver, which had 
 the breath in it, under water, and there gra- 
 dually poured the contained breath up into 
 the other full receiver, which flood inverted 
 over S' y whereby I could readily find whe- 
 ther the air had loft any of its elafticity : 
 And for greater furety, I alfo meafured the 
 bulk of breath, by filling the receiver with a 
 known quantity of water up to the above- 
 mentioned mark; making alfo due allow- 
 ance for a bulk of air, equal to the capacity 
 of the large fyphon s b, which was at laft 
 fucked full of water. 
 
 R 3 The 
 
346 Jnalyjis of the Air. 
 
 The event was, that there were 18 cubick 
 inches of air wanting ; but as thefe receivers 
 were much too fmall to make the Experi- 
 ment with accuracy ; that fome allowance 
 may be made for errors, I will fet the lofs 
 of elaftick air at nine cubick inches, which 
 is but tir P art °f t ^ e whole air refpired, 
 which will amount to 353 cubick inches in 
 one hour, or 100 grains, at the rate of 84000 
 cubick inches infpired in an hour, or five 
 ounces 216 grains, in 24 hours. 
 
 By pouring the like quantity of air to and 
 fro under water, I found that little or none 
 of it was loft; (o it was not abibrbed by the 
 water : To make this trial accurately, the 
 air muft be detained fome time under water, 
 to bring it firft to the fame temperature with 
 the water. Care alio muft be taken in make- 
 jng this Experiment, that the lungs be in the 
 lame decree of contraction at the laft breath- 
 ixig, as at the firft 5 eife a confiderable error 
 may arife from thence. 
 
 But tho' this be not an exact eftimate, yet 
 it is evident from the foregoing Experiments 
 on rcfpirati on, that fome of the elafticity of 
 the air which is infpired is deftroyed; and 
 that chiefly among the veficles, where it is 
 moil loaded v/ith vapours 3 whence probably 
 
 fome 
 
Analyfis of the Air. 247 
 fome of it, together with the acid fpirks, 
 with which the air abounds, are conveyed 
 to the blood, which we fee is by an admi- 
 rable contrivance there fpread into a vaft 
 expanfe, commenfurate to a very large fur- 
 face of air, from which it is parted by very 
 thin partitions ; fo very thin, as thereby pro- 
 bably to admit the blood and air-particles 
 (which are there continually changing from 
 an elaftick to a ftrongly attracting ftate) with- 
 in the reach of each other's attraction, where- 
 by a continued fucceffion of frefh air may be 
 abforbed by the blood. 
 
 And in the Analyfis of the blood, either 
 by fire or fermentation in Exper. 49. and 80, 
 we find good plenty of particles ready to re- 
 fume the elaftick quality of air : But whe- 
 ther any of thefe air -particles enter the 
 blood by the lungs, is not eafy to deter- 
 mine ; becaufe there is certainly great ftore 
 of air in the food of animals, whether it be 
 vegetable or animal food. Yet, when we 
 confider how much air continually lofes its 
 elafticity in the lungs, which feem purpofely 
 framed into innumerable minute meanders, 
 that they may thereby the better feize and 
 bind that volatile Hermes : It makes it very 
 probable, that thofe particles which are now 
 
 R 4 changed 
 
2 4 3 Analyjis of the Air. 
 
 changed from an elaftick, repulfive, to a 
 ftrongly attracting ftate, may eafily be at- 
 tracted thro' the thin partition of the veficles, 
 by the fulphureous particles which abound in 
 the blood. 
 
 And nature feems to make ufe of the like 
 artifices in vegetables, where we find that 
 air is freely drawn in; not only with the 
 principal fund of nourishment at the root, 
 but alfo thro' feveral parts of the body of 
 the vegetable above ground ; which air was 
 feen to afcend in an elaftick ftate moft freely 
 and vifibly through the larger trachea of the 
 Vine; and is thence doublefs carried with 
 the fap into minuter verTels, where being in- 
 timately united with the fulphureous, faline, 
 and other particles, it forms the nutritive 
 ductile matter, out of which all the parts of 
 vegetables do grow. 
 
 Experiment CXI. 
 
 It is plain from thefe effects of the fumes 
 of burning Brim/lone, lighted Candle, and 
 the breath of Animals, on the eiafticity of 
 the air, that its eiafticity in the veficles of 
 the lungs muft be continually decreafing, by 
 reafon of the vapours it is there loaded with ; 
 fo that thofe veficles would in a little time 
 
 fubfide 
 
Analyjis of the Air. 249 
 
 lubfide and fall flat, if they were not fre- 
 quently replen ifhed with frefh elaftick air at 
 every infpiration, thro* which the inferior 
 heated vapour and air afcends, and leaves 
 room for the freih air to defcend into the 
 veficles, where the heat of the lungs makes it 
 expand about § part ; which degree of ex- 
 panfion of a temperate air, I found by in- 
 verting a fmall glafs bubble in water, a little 
 warmer than a Thermometer is, by having its 
 ball held fome time in the mouth, which 
 may reafonably be taken for the degree of 
 warmth in the cavity of the lungs. When 
 the bubble was cool, the quantity of water 
 imbibed by it was equal to -$ of the cavity of 
 the whole bubble. 
 
 But when, inflead of thefe frequent recruits 
 of fiefh air, there is infpired an air, fur- 
 charged with acid fumes and vapours, which 
 not only by their acidity contract the exqui- 
 fitely fenfible veficles, but alfo by their groff- 
 nefs much retard the free ingrefs of the air 
 into the veficles, many of which are exceed- 
 ing fmall, fo as not to be viiible without a 
 microfcope ; which fames are alfo continu- 
 ally rebating the elafticity of tha: air; then 
 the air in the veficles will, by Exper. 107, 
 and 108, loie its elafticity very fall; and 
 
 con- 
 
250 Analyfn of the Air. 
 
 confequently the veficles will fall flat, not- 
 withstanding the endeavours of the extend- 
 ing Thorax to dilate them as ufual ; whereby 
 the motion of the blood thro' the lungs being 
 flopped, inftant death enfues. 
 
 Which fudden and fatal effect of thefe 
 noxious vapours, has hitherto been fuppofed 
 to be wholly owing to the lofs and wafte of 
 the "chifying fpirit of air ; but may not 
 unreaibnably be alfo attributed to the lofs 
 of a conliderable part of the air's elafticity, 
 and the groffhefs and denfity of the vapours, 
 which the air is charged with ; for mutually 
 attaching particles, when floating in fo thin a 
 medium as the air, will readily coalefce into 
 groffer combinations : which effect of thefe 
 vapours having not been duly obferved be- 
 fore, it was concluded, that they did not 
 ^ffedt the air's elafticity ; and that confe- 
 quently the lungs muft needs be as much 
 dilated in infpiration by this, as by a clear 
 air. 
 
 But that the lungs will not rife and dilate 
 as ufual, when they draw in fuch noxious 
 air, which decreafes faft in its elafticity, I 
 was affured by the Experiment I made on 
 myfelf, in Exper. 108. for when towards the 
 latter end of the minute, the fuffocating qua- 
 lity 
 
Analyjis of the Air. 251 
 
 lity of the air in the bladder was greateft, it 
 was with much difficulty that I could dilate 
 my lungs a very little. 
 
 From this property in the vapours arife- 
 ing from animal bodies, to rebate and de- 
 ftroy part of the elaflicity of the air, a pro- 
 bable account may be given of what be- 
 comes of a redundant quantity of air, which 
 may at any time have gotten into the cavity 
 of the T'horaXy either by a wound, or by 
 fome defect in the fubftance of the lungs, 
 or by very violent exerclfe. Which, if it 
 was to continue always in that expanded 
 ftate, would very much incommode refpi- 
 ration, by hindering the dilatation of the 
 lungs in infpiration. But if the vapours, 
 which do continually arife in the cavity of 
 the thorax, deftroy fome part of the elafli- 
 city of the air, then there will be room for 
 the lungs to heave : And probably, it is in 
 the fame manner that the winds are reforb- 
 ed, which, in their elaftick ftate, fly from 
 one part of the body or limbs to another, 
 caufing by their di Ltention of the veiTels much 
 pain. 
 
 Expe- 
 
1 5 z j4nalyjis of the Air. 
 
 Experiment CXII. 
 
 I have by the following Experiment found, 
 that the air will pafs here and there thro* the 
 fubftance of the lungs, with a very fmall 
 force, viz. 
 
 I cut afunder the bodies of feveral young 
 and fmall animals juft below the Diaphragm, 
 and then taking care not to cut any veffel 
 belonging to the lungs, I laid the Thorax 
 open, by taking away the Diaphragm, and 
 fo much of the ribs, as was needful to ex- 
 pofe the lungs to full view, when blown up. 
 And having cut off the head, I fattened the 
 wind-pipe to a very fhort inverted leg of a 
 glafs fyphon; and then placed the inverted 
 lungs and fyphon in a large and deep glafs 
 veffel x full of water, (Fig. 32.) under the 
 air-pump receiver />/>; and paffing the longer 
 leg of the fyphon through the top of the 
 receiver, where it was cemented faft at z, as 
 I drew the air out of the receiver, the lungs 
 dilated, having a free communication with 
 the outward air, by means of the glafs fy- 
 phon ; fome of which air would here and 
 there pafs in a few places thro' the fubftance 
 of the lungs, and rife in fmall ftreams thro* 
 the water, when the receiver was exhaufted 
 
 no 
 
Analyfn of the Air. 255 
 
 no more than to make the Mercury in the 
 gage rife lefs than two inches. When I ex- 
 haufted the receiver, fo as to raife the Mer- 
 cury feven or eight inches, though it made 
 the air rufli with much more violence thro* 
 thofe fmall apertures in the furface of the 
 lungs, yet I did not perceive that the num- 
 ber of thofe apertures was increafed, or at 
 leaft very little. An argument that thofe 
 apertures were not forcibly made by exhauil- 
 ing the receiver lefs than two inches, but 
 were originally in the live animal. And 
 that the lungs of living animals are fome- 
 times raifed with the like force, efpecially in 
 violent exercife, I found by the following 
 Experiment; viz* 
 
 Experiment CXIII. 
 I tied down a live Dog on his back, near 
 the edge of a table, and then made a fmall 
 hole through the intercoftal mufcles into his 
 Thorax, near the Diaphragm. I cemented 
 faft into this hole the incurvated end of a 
 glafs tube, whofe orifice was covered with a 
 little cap full of holes, that the dilatation 
 of the lungs might not at once flop the ori- 
 fice of the tube. A fmall phial full of fpiric 
 of Wine was tied to the bottom of the per- 
 
 pendicular 
 
2^4 Analyjis of the Air. 
 
 pendicular tube, by which means the tube 
 and vial could eafily yield to the motion of 
 the Dog's body, without danger of breaking 
 the tube, which was 36 inches long. The 
 event was, that in ordinary infpirations, the 
 fpirit rofe about fix inches in the tube ; but 
 in great and laborious infpirations, it would 
 rife 24 and 30 inches, viz. when I flopped 
 the Dog's noftrils and mouth, fo that he 
 could not breathe : This Experiment fhews 
 the force with which the lungs are raifed 
 by the dilatation of the Thorax, either in 
 ordinary or extraordinary and laborious in- 
 fpirations. When I blew air with fome force 
 into the Thorax, the Dog was juft ready to 
 expire. 
 
 By means of another (hort tube, which 
 had a communication with that which was 
 fixed to the Thorax, near its infertion into 
 the Tldorax y I could draw the air out of the 
 Thorax, the height of the Mercury, inftead 
 of fpirit in the tube, (hewing to what degree 
 the Thorax was exhaufted of air : The Mer- 
 cury was hereby raifed nine inches, which 
 would gradually fubfide as the air got into 
 the Thorax thro* the lungs. 
 
 I then laid bare the wind-pipe, and having 
 cut it off a little below the Larynx, I affixed 
 
 to 
 
Analyjis of the Air. 255 
 
 to it a bladder full of air, and then conti- 
 nued fucking air out of the Thorax, with a 
 force fufficient to keep the lungs pretty much 
 dilated. As the Mercury fubfided in the 
 gage, I repeated the fuction for a quarter of 
 an hour, till a good part of the air in the 
 bladder was either drawn thro* the fubftance 
 of the lungs into the Thorax, or had loft its 
 elafticity. When I preffed the bladder, the 
 Mercury fubfided the fafter ; the Dog was all 
 the while alive, and would probably have 
 lived much longer, if the Experiment had 
 been continued ; as is likely from the follow- 
 ing Experiment, viz. 
 
 Experiment CXIV. 
 
 I tied a middle-fized Dog down alive on 
 a table, and having laid bare his wind-pipe, 
 I cut it afunder juft below the Larynx, and 
 fixed faft to it the fmall end of a common 
 foflet ; the other end of the foflet had a large 
 bladder tied to it, which contained 162 cu- 
 bick inches -, and to the other end of the 
 bladder was tied the great end of another 
 folTet, whofe orifice was covered with a valve, 
 which opened inward, fo as to admit any air 
 that was blown into the bladder, but none 
 could return that way ; yet for further fecu- 
 
 rity, 
 
156 Analyjis of the Air. 
 
 rity, that paffage was alfo flopped with a 
 
 fpigot. 
 
 As foon as the firft foffet was tied faft to 
 the wind- pipe, the bladder was blown full of 
 air thro' the other foffet ; when the Dog had 
 breathed the air in the bladder to and fro 
 for a minute or two, he then breathed very 
 faft, and {hewed great uneafinefs, as being 
 almoft fuffocated. 
 
 Then with my hand I preffed the bladder 
 hard, fo as to drive the air into his lungs with 
 fome force -, and thereby make his Abdomen 
 rife by the preffure of the Diaphragm^ as in 
 natural breathings : Then taking alternately 
 my hand off the bladder, the lungs with the 
 Abdomen fubfided ; I continued in this man- 
 ner to make the Dog breathe for an hour > 
 during which time I was obliged to blow 
 frefti air into the bladder every five minutes, 
 three parts in four of that air being either 
 abforbed by the vapours of the lungs, or 
 efcaping thro' the ligatures, upon my pref- 
 fmg hard on the bladder. 
 
 During this hour, the Dog was frequently 
 near expiring, whenever I preffed the air 
 but weakly into his lungs ; as I found by 
 his pulfe, which was very plain to be felt 
 in the great crural artery near the groin, 
 
 which 
 4 
 
Analy/is of the Air. 257 
 
 which place an afliftant held his finger on 
 moft part of the time; but the languid pulfe 
 was quickly accelerated, fo as to beat fail -, 
 foon after I dilated the lungs much, by pref- 
 fing hard upon the bladder, efpecially when 
 the motion of the lungs was promoted by 
 pre fling alternately the Abdomen and the blad- 
 der, whereby both the contraction and dila- 
 tation of the lungs was increaled. 
 
 And I could by this means roufe the lan- 
 guid pulfe whenever I pleafed, not only at 
 the end of every five minutes, when more air 
 was blown into the bladder from a man's 
 lungs, but alfo towards the end of the five 
 minutes, when the air was fulleft of fumes. 
 
 At the end of the hour, I intended to try 
 whether I could by the fame means have kept 
 the Dog alive fome time longer, when the 
 bladder was filled with the fumes of burning 
 Brimjlone : But being obliged to ceafe for a 
 little time from prefling the air into his lungs, 
 while matters were preparing for this addi- 
 tional Experiment, in the mean time the Dog 
 died, which might otherwife have lived lon- 
 ger, if I had continued to force the air into 
 his lungs. 
 
 Now, though this Experiment was fo fre- 
 quently difturbed, by being obliged to blow 
 
 S more 
 
258 dnalyjis of the Air. 
 
 more air into the bladder twelve times du- 
 ring the hour ; yet fince he was almoft fuf- 
 focated in lefs than two minutes, by breath- 
 ing of himfelf to and fro the firfl air in the 
 bladder, he would, by Experiment 106. on 
 Candles, have died in lefs than two minutes, 
 when one fourth of the old air remained in 
 the bladder, immediately to taint die new 
 admitted air from a man's lungs; fo that his 
 continuing to live through the whole hour, 
 muft be owing to the forcible dilatation of 
 the lungs, by compreffing the bladder, and 
 not to the vivifying fpirit of air. For with- 
 out that forcible dilatation, he had, after the 
 firfl five or ten minutes, been certainly dead 
 in lefs than a minute, when his pulfe was fo 
 very low and weak, which I did not find to be 
 revived barely by blowing three parts in four 
 of new air from the lungs of a man into the 
 bladder : But it was conftantly roufed and 
 quickned, whenever I increafed the dilata- 
 tions of the lungs, by comprefllng the bladder 
 more vigoroufly ; and that whether it was at 
 the beginning or end of each five minutes, 
 yet it was more eafily quickned, when the 
 bladder was at any time newly filled, than 
 when it was near empty. 
 
 From 
 
 !! 
 
dnalyfis of the Ah. 2 5 9 
 
 From thefe violent and fatal effe&s of very 
 noxious vapours on the refpiration and life 
 of animals, we may fee how the refpiration 
 is proportionately incommoded, when the air 
 is loaded with lefTer degrees of vapours, which 
 vapours do, in fome meafure, clog and lower 
 the air's elaflicity ; which ic bed regains by 
 having thefe vapours difpelled by the venti- 
 lating motion of the free open air, which 
 is rendered wholefome by the agitation of 
 winds : Thus, what we call a clofe warm 
 air, fuch as has been long confined in a room, 
 without having the vapours in it carried off 
 by communicating with the open air, is ape 
 to give us more or lefs uneafinefs, in pro- 
 portion to the quantity of vapours which 
 are floating in it. For which rcafon the 
 German ftoves, which heat the air in a room 
 without a free admittance of frefh air to 
 carry off the vapours thac are raifed, as alfo 
 the modern invention to convey heated air 
 into rooms through hot flues, feem not fo 
 well contrived, to favour a free refpiration, 
 as our common method of fires in open 
 chimneys, which fires are continually car- 
 rying a large ftream of heated air out of the 
 rooms up the chimney, which ftream mufl 
 neceflarily be fupplied with equal quantities 
 
 S 2 of 
 
260 Jnal)fis of the Air. 
 
 of frelh air, through the doors and windows, 
 or the cranies of them. 
 
 And thus many of thofe who have weak 
 lungs, but can breathe well enough in the 
 freih country air, are greatly incommoded 
 in their breathing, when they come into 
 large cities, where the air is full of fuligi- 
 nous vapours, arifing from innumerable coal 
 fires, and ftenches from filthy lay-ftalls and 
 fewers : And even the mofl robuft and heal- 
 thy, in changing from a city to a country 
 air, find an exhilarating pleafure, arifing from 
 a more free and kindly infpiration, whereby 
 the lungs being lefs loaded with condenfing 
 air and vapours, and thereby the veficles 
 more dilated, with a clearer and more ela- 
 ftick air, a freer courfe is thereby given to 
 the blood, and probably a purer air mixed 
 with ic ; and this is one reafon why in the 
 country a ierene dry conflitution of the air 
 is more exhilarating than a moift thick air. 
 
 And for the lame reafon, it is no wonder, 
 that peffilentral and other noxious epidemi- 
 cal infections are conveyed by the breath to 
 the blood (when we confider v/hat a great 
 quantity of the airy vehicle lofes its elafti- 
 eity among the veficles, whereby the infe- 
 ctious Mia/ma- is lodged in the lungs). 
 
 When 
 
Andyfis of the Air. 2 6 1 
 •When I reflecl on the great quantities of 
 claftick air, which are deftroyed by fulphu- 
 reous fumes ; it feems ro me not improba- 
 ble, that when an animal is killed by light- 
 ning without any vifible wound, or imrnc-' 
 diate ftroke, that it may be done by the air's 
 elasticity, being inftantly deftroyed by the 
 fulphureous lightning near the animal; 
 whereby the lungs will fall flat, and caufe 
 fudden death; which is further confirmed' 
 by the flatnefs of the lungs of animals thus 
 killed by lightning, their veficles being found 
 upon diffedion to be fallen flat, and to have 
 no air in them : The burfting alio of glafs- 
 windows outwards, feems to be from the 
 fame effeft of lightning on the air's elafti- 
 city. 
 
 It is likewife by destroying the air's elafti- 
 city in fermented liquors, that lightning ren- 
 ders them flat and vapid: For fince fulphu- 
 reous fleams held near or under veffels will 
 check redundant fermentation, as well as the 
 putting of fulphureous mixtures into the li- 
 quor, it is plain, thofe fleams can eafily pe- 
 netrate the wood of the containing veffels. 
 No wonder then, that the more fubtile 
 lightnings mould have the like effects. I 
 
 S 3 know 
 
i6t Analyjis of the Ah. 
 
 know not whether the common practice of 
 laying a bar of iron on a veiTel, be a good 
 prefervative againft the ill effects of lightning 
 on liquors. I mould think, that the cover- 
 ing a veffel with a large cloth dipped in a 
 ftrong brine, would be a better prefervative • 
 for falts are known to be ftrong attracters of 
 fulphur. 
 
 The certain death which comes on the 
 explofion of Mines, feems to be effected in 
 the fame manner : For though at firft there 
 J s a great expanfion of the air, which muft 
 dilate the lungs, yet that air is no fooner 
 filled with fuliginous vapours, but a good 
 deal of its elaflicity is immediately deftroyed : 
 As in the cafe of burning Matches in Expe- 
 riment 103. the heat of the flame at firft 
 expanded the air ; but notwithftanding the 
 flame continued burning, it immediately con- 
 tracted, and loft much of its elaflicity, as 
 foon as fome quantity of fulphureous fleams 
 afcended in it. 
 
 Which fleams have doubtlefs the fame 
 effect on the air, in the lungs of animals held 
 over them, as in the Grotto di cani, or when 
 a clofe room is filled with them,, where they 
 certainly fuffocate, 
 
 I 
 
Anahjis of the Ah. 265 
 
 It is found by Experiments 103, 106, and 
 107, that an air greatly charged with vapours 
 lofes much of its elafticity, which is the rea- 
 fon why fubterraneous damps fuffocate ani- 
 mals, and extinguiih the flame of candles- 
 And by Experiment 106, we fee that the 
 fooner a Candle goes out, the fafter the air 
 lofes its elafticity. 
 
 Experiment CXV. 
 
 This put me upon attempting to find fome 
 means to qualify and rebate the deadly noxi- 
 ous quality of thefe vapours: And in order 
 to it, I put thro' the hole, in the top of the 
 air-pump receiver, (Fig. 3 2.) which contained 
 two quarts, one leg of an iron fyphon made 
 3f a gun-barrel, which reached near to the 
 bottom of the receiver: It was cemented fail 
 at z. I tied three folds of woollen cloth over 
 he orifice of the fyphon, which was in the 
 eceiver. The candle went out in lefs than 
 wo minutes, tho' I continued pumping all 
 he while, and the air pafled fo freely thro* 
 he folds of cloth into the receiver, that the 
 lercury in the gage did not rile above an 
 ich. 
 
 When I put the other end of the fyphon 
 ito a hot iron pot, with burning Brim/lone 
 
 S 4 in 
 
» 1 
 
 264 Analyfis of the Air. 
 
 in it 5 upon pumping, the candle went out 
 in 15 feconds of a minute; but when I took 
 away the three folds of cloth, and drew the 
 fulphureous fleams thro' the open fyphon, 
 the light of the candle was inftantly extin- 
 guiihed ; whence we fee the 3 folds of cloth 
 •preferved the candle alight 15". And where 
 the deadly quality of vapours in mines is not 
 fo ftrong as theie fulphureous ones were, the 
 drawing the breath through many folds of 
 woollen cloth may be a means to prefervelife 
 a little longer, in proportion to the more or 
 ■lefs noxious quality of the damps. 
 
 When, inftead of the three folds of cloth, I 
 immerfed the end of the fyphon three inches 
 deep in water in the veffel x y (Fig. 32.) tho' 
 upon pumping the fulphureous fumes did 
 afcend vifibly through the water, yet tte 
 candle continued burning half a minute, i. e 
 double the time that it did when fumes paffec 
 thro' folds of woollen cloth. 
 
 E X P E R I M E N T CX VI. 
 
 I bored a hole in the fide of a large woodei 
 foflet ab y (Fig. 3^ ) and glewed into it th 
 great end of another foffet i /', covering th 
 prince with a bladder valve r : Then I fit 
 ted a valve .b i 7 to the orifice of the iro 
 
 fypho 
 
 
Jnalyfis of the Ah. 165 
 
 fyphon S S y fixing the end of the fyphon faft 
 at b into the foffet a b : Then by means of 
 narrow hoops I placed four Diaphragms of 
 flannel at half an inch diftance from each 
 other, into the broad rim of a fieve, which 
 was about feven inches diameter. The fieve 
 was fixed to, and had a free communication 
 with, both orifices of the fyphon, by means 
 of two large bladders i i n n 0. 
 
 Linen would probably be more proper to 
 make thefe Diaphragms of than flannel, be- 
 caufe oil or greafe is ufed in the making of 
 flannel : And as I have heard, it is whitened 
 by the fumes of burning Brimjtone; which I 
 was not aware of, when I made uie of flannel 
 in thefe Experiments. 
 
 The inftrument being thus prepared, 
 pinching my noftrils clofe, when I drew in 
 breath with my mouth at ft the valve i b 
 being thereby lifted up, the air pafled freely 
 through the fyphon from the bladders, 
 which then fubfided, and fhrunk confider- 
 ably: But when I breathed air out of my 
 lungs, then the valve i b clofing the orifice 
 of the fyphon, the air pafled thro' the valve 
 r into the bladders, and thereby dilated 
 them j by which artifice the air which I ex- 
 pired muft neceffarily pafsthro' all the Dia- 
 phragms, 
 
2 66 Analyjis of the Air. 
 
 phragms, before it could be infpired into my 
 lungs again. The whole capacity of the 
 bladders and fyphon was 4 or 5 quarts. 
 
 Common fea-falt, and Sal Tartar, being 
 ftrong imbibers of fulphureous fleams, 1 dip- 
 ped the four Diaphragms in ftrong folutions 
 of thofe falts, as alfo in white- wine vinegar, 
 which is looked upon as a good anti-pefti- 
 lential : Taking care after each of thefe Ex- 
 periments to cleanfe the fyphon and bladder 
 well from the foul air, by filling them with 
 water. 
 
 I could breathe to and fro the air inclofed 
 in this inftrument for a minute and half, 
 when there were no Diaphragms in it \ when 
 the four Diaphragms were dipped in vinegar, 
 three minutes ; when dipped in a ftrong folu- 
 tion of fea-falr, three minutes and an half. 
 In a Lixivium of Sal Tartar, three minutes ; 
 when the Diaphragms were dipped in the 
 like Lixivium, and then well dried, five mi- 
 nutes ; and once 8 -f- \ minutes, with very 
 highly calcined Sal Tartar -, but whether 
 this was owing to the Tartar s being greatly 
 calcined, whereby it might more ftrongly 
 attract fulphureous grofs vapours, or whe- 
 ther it was owing to the bladder and fyphon's 
 being intirely dry, or whether it was occa- 
 
 fioned 
 
AnaJyJis of the Air. 2^7 
 
 fioned by fome unheeded paiLge for the air 
 thro' the ligatures, I am uncertain ; neither 
 did I care to afcertain the matter by repeated 
 Experiments, fearing I might thereby fome 
 way injure my lungs, by frequently breathing 
 in fuch grofs vapours. 
 
 Hence Sal Tartar mould be the beft pre- 
 fervative againft noxious vapours, as being a 
 very ftrong imbiber of fulphureous, acid and 
 watry vapours, as is fea-falt alfo : For having 
 carefully weighed the four Diaphragms be- 
 fore I fixed them in the inftrument, I found 
 that they had increased in weight 30 grains 
 in five minutes ; and it was the fame in two 
 different trials ; Co they increafed in weight 
 at the rate of j 9 ounces in 24 hours. From 
 which deducting £ part of the quantity of 
 moifture, which 1 found thofe Diaphragms 
 attracted in 5 minutes in the open air ; there 
 remain 15 -j- -| ounces, for the weight of 
 the moifture from the breath in 24 hours : 
 But this is probably too great an allowance, 
 confidering that the Diaphragms might at- 
 tract more than £ part from the moifture of 
 the bladders and of the fyphon. See Exper. 6. 
 Vol. II. Appen. p. 323. 
 
 I have found, that when the Diaphragms 
 had fome fmall degree of dampnefs, they 
 
 increafed 
 
I 6 8 Analyjis of the • Alt. 
 
 increafed in weight fix grains in three minutes <, 
 but they made no increafe in weight in the 
 fame time, when in the open air : which fix 
 grains in three minutes is at the rate of about 
 6 -flounces in 24 hours; and this is nearly 
 the fame proportion of moifture that I ob- 
 tained by breathing into a large receiver full 
 of fpunges. But the fix grains imbibed by 
 the four Diaphragms in three minutes, was 
 not near all the vapours which were in that 
 bulk of inclofed air ; for at the end of the 
 three minutes, the often refpired air was fo 
 loaded with vapours, which in that floating 
 ftate were eafily, by their mutual attraction, 
 formed into combinations of particles, too 
 grofs to enter the minute veficles of the 
 lungs, and was therefore unfit for refpira- 
 tion ; fo that it is not eafy to determine what 
 proportion is carried off by refpiration, efpe- 
 cially confidering that fome of the infpired 
 air, which has loft its elafticity in the lungs, 
 is mingled with it. But fuppofing 6 + jl 
 ounces to be the quantity of moifture car- 
 ried off by refpiration in twenty-four hours, 
 then the furface of the lungs being found, 
 as above, 41635 fquare inches, only y^- part 
 of an inch depth will be evaporated off 
 their inward furface in that time, which 
 
 is 
 
Analyjis of the Jir. 269 
 
 is but y ' T part of the depth of what is per- 
 fpired off the furface of a man's body in that 
 time. 
 
 If then life can by this means be fupported 
 for five minutes with four Diaphragms and 
 a gallon of air, then doubtlefs, with double 
 that quantity of air and eight Diaphragms, 
 we might well expect: to live at lead ten mi- 
 nutes. It was a confiderable difadvantage, 
 that I was obliged to make ufe of bladders, 
 which had been often wetted and dried, fo 
 that the unfavoury fumes from them muft 
 needs have contributed much to the unfitting 
 the included air for refpiration : Yet there 
 is a necefiity for making ufe of either blad- 
 der or leather in thefe cafes ; for we cannot 
 breathe to and fro the air of a veffel, whofe 
 fides will not dilate and contract in confor- 
 mity with the expirations and infpirations, 
 unlefs the vefTel be very large, and too big 
 to be conveniently portable. 
 
 Having flopped up the wide fucking ori- 
 fice of a large pair of kitchen bellows, they 
 being firft dilated, I could breathe to and fro 
 at their nofe, the air contained in them for 
 more than three minutes, without much in- 
 convenience, they heaving and falling very 
 ealily by the action of refpiration. Some 
 
 fuch- 
 
17 o Analysis of the Air. 
 
 fuch-like inftrument might be of ufe in any 
 cafe, where a room was filled with fuffoea- 
 ting vapours, where it might be necelTary to 
 enter for a few minutes, in order to remove 
 the caufe of them, or to fetch any perfon or 
 thing out; as in the cafe when houfes are 
 firft beginning to fire, in the Chymifts ela- 
 boratories ; and in many other cafes, where 
 places were filled with noxious deadly va- 
 pours, as in the cafe of ftink-pots thrown 
 into (hips, in mines, &c. And might it not 
 alfo be ferviceable to Divers ? 
 
 But in every apparatus of this kind great 
 care muft always be taken, that the infpira- 
 tion be as free as poffible, by making large 
 paffages and valves to play moft eafily. For 
 tho' a man by a peculiar action of his mouth 
 and tongue may fuck Mercury 22 inches, 
 and fome men 27 or 28 high ; yet I have 
 found by experience, that by the bare infpi- 
 ring action of the Diaphragm, and dilating 
 c Thorax y I could fcarcely raife the Mercury 
 two inches. At which time the Diaphragm 
 muft act with a force equal to the weigh c of 
 a Cylinder of Mercury, whofe bafe is com- 
 menfurate to the area of the Diaphragm, and 
 its height two inches, whereby the Dia- 
 phragm muft at that time fuftain a weight 
 
 - equal 
 
Analyjis of the AW. \y\ 
 
 equal to many pounds. Neither are its 
 counter-acting mufcles, thofe of the Abdomen, 
 able to exert a greater force. 
 
 For notwithstanding a man, by ftrongly 
 compreffing a quantity of air included in his 
 mouth, may raife a column of Mercury in 
 an inverted fyphon, to five or {even inches 
 height, yet he cannot, with his utmoft /train- 
 ings, raife it above two inches, by the con- 
 tracting force of the mufcles of the Abdomen, 
 whence we fee that our loudeft vociferations 
 are made with a force of air no greater than 
 this. So that any fmall impediment in breathe- 
 ing will haften the fuffocation, which con- 
 fifts chiefly in the falling flat of the lungs, 
 occafioned by the groflhcfs of the particles 
 of a thick noxious air, they being in that 
 floating ftate moft cafily attracted by each 
 other : As we find in the foregoing Experi- 
 ments that fulphur and the elaftick repelling 
 particles of air do : And confequently unela- 
 ftick, fulphureous, faline, and other floating 
 particles will moft eafily coalefce; whereby 
 they are rendered too grofs to enter the mi- 
 nute veficles; which are alfo much con- 
 tracted, as well by the lofs of the elafticity 
 of the contained air, as by the contraction 
 occafioned by the ftimulating, acid, fulphu- 
 reous 
 
27 * Analyjis of the Ah. 
 
 reous vapours. And it is not improbable, 
 that one great defign of nature, in the ftru- 
 cture of this important and wonderful vifcus, 
 was to frame its veficles fo very minute, 
 thereby effectually to hinder the ingrefs of 
 grofs feculent particles, which might be inju- 
 rious to the animal ceconomy. 
 
 This quality offalts ftrongly to attract ful- 
 phureous, acid, and other noxious particles, 
 might make them very beneficial to man- 
 kind in many other refpects. Thus in feve- 
 ral unwholefome trades, as the fmelters of 
 metals, the cerufs-makers, the plumbers, &c* 
 it might not unlikely be of good fervice to 
 them, in preferving them, in fome meafure 
 at leaft, from the noxious fumes of the ma*- 
 terials they deal in, which by many of the 
 foregoing Experiments we are affured mufl 
 needs coalefce with the elaftick air in the 
 lungs, and be lodged there ; to prevent which 
 inconvenience the workmen might, while 
 they are at work, make ufe of pretty broad 
 mufflers, tilled with two, four, or more 
 Diaphragms of flannel or cloth dipped in a 
 folution of Sal Tartar or Pot-afi\ or Sea-Salf, 
 and then dried. 
 
 The like mufflers might alfo be of fervice 
 
 in many cafes where perfons may have urgent 
 
 occafion 
 
Analyjls of the Air. 275 
 
 occafion to go for a fhort time into an in- 
 fectious air : Which mufflers might, by an 
 eafy contrivance, be fo made as to draw in 
 breath thro' the Diaphragms, and to breathe 
 it out by another vent. 
 
 In thefe and the like cafes this kind of 
 mufflers may be very ferviceable ; but in the 
 cafe of the damps of mines they are by no 
 means to be depended on, becaufe they are 
 not a fufficient fcreen from fo very noxious 
 vapours. 
 
 Experiment CXVII. 
 
 We have from the following Experiment 
 a good hint, to make thefe Salts of fervice to 
 us in fome other refpects, &c. 
 
 I fet a lighted Candle under a large receiver 
 (Fig. 35) which contained about four gal- 
 lons 5 it continued burning for 3 + JL mi- 
 nutes, in which time it had abforbed about 
 a quart of air. I then filled the receiver with 
 frefli air, by pouring it full of water, and 
 then emptying of it ; when having wiped it 
 dry, I lined all the infide with a piece of 
 flannel dipped in a Lixivium of Sal c tartar y 
 and then dried ; the flannel was extended 
 with little hoops made of pliant twigs. The 
 Candle continued burning under the receiver 
 
 T thus 
 
274 Analyjis of the 'Air. 
 
 thus prepared 3 + \ minutes ; yet it abforbed 
 but two thirds of the quantity of air which 
 it abforbed when there was no flannel in the 
 receiver. 
 
 The reafon of which difference in the 
 quantities of elaflick air abforbed, appears 
 from Experiment 106, where leaft air was 
 always abforbed in leaft receivers, which was 
 the prefent cafe: For the flannel lining, be- 
 fides the fpace it took up, could not be fo 
 clofely adapted, but that there was left a full 
 third of the capacity of the receiver, between 
 the lining and the receiver : So that the Candle 
 burnt in a bulk of air lefs by one third than 
 the whole capacity of the receiver j for which 
 reafon lefs air alfo was abforbed. 
 
 And we may further obferve, that lince the 
 Candle continued burning as long in a quan- 
 tity of air, equal but to two thirds of the re- 
 ceiver, as in the whole air of the receiver 5 
 this muft be owing to the Sal Tartar in the 
 flannel lining, which muft needs have abforbed 
 one third of the fuliginous vapours, which 
 arofe from the burning candle. Hence we may 
 not unreafonably conclude, that the pernicious 
 quality of noxious vapours in the air might, 
 in many cafes, be much rebated and qualified 
 by the ftrongly abforbing power of Salts. 
 
 Whe- 
 
Analyfis of the Ah. 275 
 
 Whether Salts will have a good effedt in 
 all, or any of thefe cafes, experience will 
 beft inform us. There is certainly fufficienc 
 ground, from many of the foregoing Expe- 
 riments, to encourage us to make the trial, 
 and they may at leail: be hints for further im- 
 provements. 
 
 We fee that Candles and burning Brim- 
 ftone do in a much greater degree deflroy 
 the elafticity of the air, than the breath of 
 Animals 5 becaufe their vapours are more 
 plentiful, and abound more wi^h acid ful- 
 phureous particles, and are alio lefs diluted 
 with watry vapours, than the breath of Ani- 
 mals is: In which alfo there are fulphureous 
 particles, tho' In lerTer degrees; for the ani- 
 mal fluids, as well as folids, are ftored with 
 them : And therefore the Candle and Matches 
 ceafing to burn, foon after they are confined 
 in a fmall quantity of air, feems not to be 
 owing to their having rendred that air effete, 
 by having confumed its vivifying fpir it \ but 
 mould rather be owing to the great quantity 
 of acid fuliginous vapours, with which that 
 air is charged, which deflroy a good deal of 
 its elafticity, and very much clog and retard 
 the elaftick motion of the remainder. 
 
 T 2 And 
 
2?6 Analyfis of the Air. 
 
 And the effect; the half exhaufting of a 
 receiver has upon the elafticity of the remain- 
 ing half of the air, feems to be the reafon 
 why the flame of a Candle does not con- 
 tinue burning, till it has filled the receiver 
 it ftands in with fumes s but goes out the 
 quicker,, the fooner the air is drawn out to 
 that degree ; which feems therefore to be 
 owing to this, that an air rarefied to double 
 its fpace, will not expand fo briskly with the 
 warmth of flame, as a more condenfed air 
 will do : And confequently action and re- 
 action being reciprocal, will not give fo brisk 
 a motion to the flame, which fubfifts by a 
 eonftant fucceflion of frefh air, to fupply the 
 place of the either abforbed, or much dilated 
 air, which is continually flying off. And the 
 quicker the fucceflion of this frefh air is, by 
 blowing, the more vigorously does a fire 
 burn. 
 
 If the continuance of the burning of the 
 Candle be wholly owing to the vivifying 
 jpirit^ then fuppofmg in the cafe of a re- 
 ceiver, capacious enough for a Candle to burn 
 a minute in it, that half the vivifying fpirit 
 be drawn out with half the air, in ten feconds 
 of time j then the Candle fhould not go out 
 at ihe end of thofe ten feconds, but burn 
 
 twenty 
 
Analyjis of the Axr. 177 
 
 twenty feconds more, which it does not ; 
 therefore the burning of the candle is not 
 wholly owing to the vilifying fpirit, but to 
 certain degrees of the air's elafticity. When 
 a wholly exhaufted receiver was by means of 
 a burning-glafs firft filled with the fumes of 
 brown paper with Nitre, and then filled 
 with frefh air, the nitrous paper, upon ap- 
 plying the burning-glafs, did freely detonize; 
 and a Candle put into a like air, burnt for 28"$ 
 which in a frefh air, in the fame receiver 
 burnt but 43 ; but when the fame receiver, 
 with air in ir, was filled full of fumes of 
 detonized Nitre, and a Candle placed in that 
 thick vapour, it went out inftanrly ; for a 
 Candle will not burn, nor the Nitre deto- 
 nize in a very rare, nor a very thick air ; 
 whence the reafon why the Nitre detonized, 
 and the Candle burnt, when placed in the 
 receiver, afcer frefli air was let in upon 
 the fumes which were made in vacuo, was, 
 that thofe fumes w r ere much difperfed and 
 condenfed on the fides of the glafs, upon 
 the milling in of the frefh air: for the fumes 
 were then much more rare and tranfparent, 
 than before the air was let in. 
 
 That a Fire which is fupplied with a hot 
 air will not burn fo briskly as a Fire which 
 
 T 3 is 
 
2 7 8 Jnalyjis of the Ah. 
 
 is fed by a cool air, is evident from hence y 
 that when the Sun ihines on a Fire, and 
 thereby too much rarefies the ambient air, 
 that Fire will not burn well; nor will a 
 fmall Fire burn fo well near a large one, as 
 at fbme diftance from it. And e contra, it 
 is a common obfervation, that in very cold 
 frofty weather, Fires burn moft briskly ; the 
 reafon of which feems to be this, that the 
 elaflick expanfion of the cold condenfed air 
 to a rarefied ftate, when it enters the Fire, is 
 much brisker than that of an air already 
 rarefied in a good meafure by heat, before it 
 enters the Fire; and confequently a conti- 
 nued fuccefiion of cold air mud give a brisker 
 motion to the Fire, than the like fucceffion 
 of hot air : And fuch colder and more con- 
 denfed air will alfo (as Sir Ifaac Newton ob- 
 ferves qu. 11) by its greater weight check 
 the afcent of the vapours and exhalations of 
 the Fire, more than a warmer lighter air. 
 So that between the action and re-action of 
 the air and fulphur of the fuel, and of the 
 colder and denfer circumambient air, which 
 rarefies much upon entring the Fire, the heat 
 of the Fire is greatly increafed. See Vol. II, 
 
 /•3 2 9- 
 
 This 
 
dvaly/is of the Air. 279 
 
 This continual fjpply of frefh air to the 
 fuel, feems hence alfo very neceiTary for keep- 
 ing a Fire alive 3 becaufe it is found, that a 
 Brimftone Match will not take fire in a va- 
 cuum, but only boil and fmoke -, nor will 
 Nitre incorporated into Broun Paper then 
 detonize, except here and there a fingle grain, 
 that part only of the Paper turning black, on 
 which the focus of the burning-glafs falls ; 
 nor would they burn when a half-exhaufted 
 receiver with fumes in it was filled with frefii 
 air added to thofe fumes : In which cafe it 
 is plain, that a good quantity of the fup- 
 pofed vivifying jpirit of air mufl enter 
 the receiver with the frefh air, and confe- 
 quently thofe fubftances mould take fire, and 
 burn for a fhort time at leaft, which yet they 
 did not. 
 
 And that the air's elafticity conduces much 
 to the intenfe burning of Fires, feems evident 
 from hence -, that Spirit of Nitre (which, by 
 Experiment 75, has but little elaftick air in 
 it) when poured upon live Coals, extinguishes 
 inftead of invigorating them : But Spirit of 
 Nitre, when by being mixt with Sar Tartar 
 it is reduced to Nitre, will then flame, when 
 thrown into the Fire, viz. becaufe Sal Tartar 
 abounds with elaftick aereal particle?, as ap- 
 
 T 4 pears 
 
2 8 o Jnalyjts of the Ah. 
 
 pears by Experiment 74, where 224 times 
 its bulk of air arofe from a quantity of Sal 
 Tartar. And for the fame reafon it is that 
 common Nitre y when thrown into the Fire, 
 flames, tho' its Spirit will not, viz. becaufe 
 there is much elaftick air in it, as appears 
 from Experiment 72, as well as from the 
 great quantity of it, generated in the firing 
 of Gun-powder. 
 
 The reafon why Sal Tartar, when thrown 
 on live Coals, does not detonize and flame 
 like Nitre, (notwithstanding, by Experiment 
 74, plenty of elaftick particles did arife from 
 it) is this, viz. becaufe by the fame Experi- 
 ment, compared with Experiment 72, it is 
 found, that a much more intenfe degree of 
 heat was required to extricate the elaftick air 
 from Sal Tartar, the more fix'd body, than 
 from Nitre ; the great degree of Fire with 
 which Sal Tartar is made, rendering the 
 cohefion of its parts more firm ; For it is 
 well known that Fire, inftead of difuniting, 
 does in many cafes inseparably unite the parts 
 of bodies : And hence it is that Puhis Ful- 
 minans, which is a mixture of Sal Tartar, 
 Nitre and fulphur, gives a greater explofion 
 than Gun-powder : Becaufe the particles of 
 ihe Sal Tartar cohering more firmly in a 
 
 fix'd 
 
Analyfis of the jiir. 8 1 x 
 
 fix'd ftate than thofe of Nitre, they are there- 
 fore thrown off with a greater repulfive force, 
 by the united action and re- action of all thofe 
 ingredients armed each with its acid Spirit. 
 
 Experiment CXVIII. 
 
 Which acid Spirits, confirming of a volatile 
 acid Salt diluted in phlegm, do contribute 
 much to the force of explofion > for when 
 heated to a certain degree, they make a great 
 explofion, like water heated to the fame de- 
 gree, as I found by dropping a few drops of 
 Spirit of Nitre, oil of Vitriol, water, and 
 fpittle, on an Anvil; and then holding over 
 thofe drops a piece of Iron, which had a 
 white heat given it ; upon finking down the 
 hot Iron with a large Hammer, there was a 
 very great explofion made by each of thofe 
 liquors: But frothy fpittle, which had air in 
 it, made a louder explofion than water; which 
 fhews that the vaft explofion of the Nitre and 
 Sal Tartar, which are compofed of elaftick 
 air-particles, included in an acid Spirit, is 
 owing to their united force. 
 
 We may therefore, from what has been 
 faid, with good reafon conclude, that Fire is 
 chiefly invigorated by the action and re- action 
 
 of 
 
28 x Analyjis of the Air. 
 
 of the acid fulphureous particles of the fuel, 
 and the elaftick ones, which arife and enter 
 the Fire, either from the fuel in which they 
 abound, or from the circumambient air : For 
 by Experiment 103, and many others, acid 
 fulphureous particles adl vigoroufly on air ; 
 and fince a&ion and re-a&ion are reciprocal, 
 fo muft air on fulphur ; and there is, we fee, 
 plenty of both, as well in mineral as vege- 
 table fuel, as alfo in animal fubftances, for 
 which reafon they will burn. 
 
 But when the acid fulphur, which we fee 
 afts vigoroufly on air, is taken out of any 
 fuel, the remaining Salt, water and earth, are 
 not inflammable, but on the contrary, quench 
 and retard fire; and as air cannot produce 
 fire without fulphur, fo neither can fulphur 
 burn without air : Thus Charcoal heated to 
 an intenfe degree for many hours in a clofe 
 veflel, will not burn as in the open air 5 it 
 will only be red-hot all the time, like a mafs 
 of Gold, without wafting : But no fooner is 
 it expofed to the free air, but the fulphur, 
 by the violent aftion and re-a&ion between 
 that and the elaftick air, is foon feparated and 
 carried off from the Salt and Earth, which 
 are thereby reduced from a folid and hard, to 
 a foft impalpable Calx. 
 
 And 
 
Analyjis of the Ah. 285 
 
 And when a Brimjione Match, which was 
 placed in an exhaufted receiver, was heated 
 by the focus of a burning-glafs fo as to melt 
 the Brim/lone, yet it did not kindle into fire, 
 nor confume, notwithstanding the ftrength 
 and vigour of the action and re-a&ion that is 
 obferved between light and fulphureous bo- 
 dies. Which is affigned by the illuftrious Sir 
 Ifaac Newton, as cc one reafon why fulphu- 
 " reous bodies take fire more readily, and 
 " burn more vehemently than other bodies 
 <c do, Qu. 7." What his notion of fire and 
 flame is, he gives us in Qu. 9. and 10. Q11.9. 
 cc Is not Fire a body heated fo hot as to emit 
 " light copioufly ? For what elfe is a red-hot 
 " Iron than Fire ? And what elfe is a burn- 
 < c ing Coal, than red-hot Wood?" Qu. 10. 
 <c Is not Flame a vapour, fume or exhalation, 
 <c heated red-hot, that is, fo hot as to flame? 
 ci For bodies do not flame without emitting 
 " a copious fume, and this fume burns in 
 
 <c the flame. — Some bodies heated bv 
 
 ic motion or fermentation, if the heat grow 
 " intenfe, fume copioufly -, and if the heat be 
 <{ great enough, the fames will fhine, and 
 * become flame: Metals in fufion do noc 
 " flame for want of a copious fume, except 
 <c fpelter, which fumes copioufly, and thcre- 
 
 <( 
 
 bv 
 
<£ 
 
 «C 
 
 % 84 Analyfis of the Air. 
 
 (C by flames : All flaming bodies, as Oil, 
 « Tallow, Wax, Wood, foffil Coals, Pitch, 
 <c Sulphur, by flaming wafte and vanifh into 
 u burning fmoak ; which fmoak, if the flame 
 < c be put out, is very thick and vifible, and 
 c< fometimes fmells ftrongly, but in flame 
 " lofes its fmell by burning ; and according 
 <c to the nature of the fmoak the flame is 
 
 of feveral colours, as that of fulphur, blue ; 
 
 that of copper opened with fublimate, 
 
 green; that of tallow, yellow; that of 
 <c camphire, white; fmoak paffing through 
 " flame cannot but grow red-hot ; and red- 
 <c hot fmoak can have no other appearance 
 <c than that of flame." 
 
 But Mr. Lemery the younger fays, cc That 
 " the matter of light produces fulphur, be- 
 cc ing mixt with compofitions of fait, earth, 
 " and water, and that all inflammable mat- 
 « c ters are fuch only in virtue of the parti- 
 <c cles of fire which they contain. For in 
 " the Analyfis, fuch inflammable bodies pro- 
 " duce fait, earth, water, and a certain fubtle 
 " matter, which paries through the clofeft 
 " veflfels ; fo that what pains foever the artift 
 " ufes, not to lofe any thing, he ftill finds a 
 €C confiderable diminution of weight. 
 
 <c 
 
 Novr 
 
Analyjis of the Air. 285 
 
 " Now thefe principles of fait, earth and 
 water, are inactive bodies, and of no ufe, 
 in the compofition of inflammable bodies, 
 but to detain and arreft the particles of lire, 
 which are the real and only matter of 
 <c flame. 
 
 " It appears therefore to be the matter of 
 <c flame that the artift lofes in decompound- 
 <c ing inflammable bodies, Mem. de VAcad. 
 " anno 171 3." 
 
 But by many of the preceding Experiments 
 it is evident, that the matter loft in the Ana- 
 lyfis of thefe bodies was elaftick air, a very 
 active principle in fire, but not an elemental 
 fire, as he fuppofes. 
 
 Mr. Geoffrey compounded fulphur of 
 acid Salt, Bitumen, a little Earth, and Oil 
 o£ Tartar." Mem. de V Acad, anno 1703. 
 In which Oil of Tartar there is much air by 
 Experiment 74, which air was doubtlefs by 
 its elafticity very inftrumental in the inflam- 
 mability of this artificial fulphur. 
 
 If Fire was a particular diftincl: kind of 
 body inherent in fulphur, as Mr. Homberg % 
 Mr. Lemery, and feme others imagine, then 
 fuch fulphureous bodies, when ignited, mould 
 rarefy and dilate all the circumambient air; 
 whereas it is found by many of the precede- 
 
 ing 
 
 cc 
 
2% 6 Analyfis of the Air. 
 
 ing Experiments, that acid fulphureous fuel 
 conftantly attracts and condemns a confider- 
 able part of the circumambient elaftick air $ 
 An argument, that there is no fire endued 
 with peculiar properties inherent in fulphur $ 
 and alio, that the heat of fire confifts princi- 
 pally in the brisk vibrating action and re- 
 action, between the elaftick repelling air, and 
 the ftrongly attracting acid fulphur, which 
 fulphur in its Analyfis is found to conrain an 
 inflammable oil, and acid fait, a very fix'd 
 earth, and a little metal. 
 
 Now fulphur and air are fuppofed to be 
 acted by that ethereal medium, li by which 
 " ( the great Sir Ifaac Newton fuppofes ) 
 <c light is refracted and reflected, and by 
 <c whofe vibrations light communicates heat 
 <c to bodies, and is put into fits of eafy re- 
 ff flection, and eafy tranfmiffion : And do 
 <c not the vibrations of this medium in hot 
 <c bodies contribute to the intenfenefs and 
 fC duration of their heat? And do not hot 
 cc bodies communicate their heat to conti- 
 ic guous cold ones, by the vibrations of this 
 * c medium, propagated from them into cold 
 <c ones ? And is not this medium exceed- 
 " ingly more rare and fubtle than the air, 
 " and exceedingly more elaftick and active? 
 
 " And 
 
Analyfis of the Air. 187 
 
 iC And does it not readily pervade all bodies, 
 <c Optic, qu. 18. The elaftick force of this 
 " medium, in proportion to its denfity, muft 
 11 be above 490,000,000,000 times greater 
 w than the elaftick force of the air is, in pro- 
 " portion to its denfity, ibid.qu. 21." A force 
 fufficient to give an intenfe degree of heat, 
 efpecially when its elafticity is much increafed 
 by the brisk action and re-action of particles 
 of the fuel and ambient air. 
 
 From this manifeft attraction, action and 
 re-action, that there is between the acid ful- 
 phureous and elaftick aereal particles, we 
 may not unreafonably conclude, that what 
 we call the fire-particles in Lime, and feve- 
 ral other bodies, which have undergone the 
 fire, are the fulphureous and elaftick parti- 
 cles of the fire fix'd in the Lime ; which par- 
 ticles, while the Lime was hot, were in a 
 very a&ive, attracting and repelling flare; 
 and being, as the Lime cooled, detained in 
 the folid body of the Lime, at the feveral at- 
 tracting and repelling diftances they then hap- 
 pended to be at, they muft neceffarily con- 
 tinue in that fix'd ftate, notwithstanding the 
 ethereal medium, which is fuppofed freely 
 to pervade all bodies, be continually follicit- 
 ing them to action : But when the folid fub- 
 
 ftance 
 
1 8 8 Analyjis of the Air. 
 
 fiance of the Lime is difTolved, by the affix- 
 fion of fome liquid, being thereby emanci- 
 pated, they are again at liberty to be influ- 
 enced and agitated by each other's attraction 
 and repulfion ; upon which a violent ebul- 
 lition enfues, from the adtion and re-adlion 
 of thefe particles ; which ebullition ceafes 
 not, till one part of the elaftick particles are 
 fubdued and fix'd by the ftrong attraction 
 of the fulphur, and the other part is got 
 beyond the fphere of its attraction, and 
 thereby thrown off into true permanent air: 
 And that this is a probable folution of the 
 matter, there is good reafon to conclude, 
 from the frequent inftances we have in many 
 of the foregoing Experiments, that plenty 
 of elaftick air is at the fame time borii gene- 
 rated and abforbed by the fame fermenting 
 mixture ; fome of which were obferved 
 to generate more air than they abforbed, 
 and others, e contra y abforbed more than 
 they generated, which was the cafe of 
 Lime. 
 
 Experiment CXIX. 
 
 And that the fulphureous and aereal par- 
 ticles of the fire are lodged in many of thofe 
 
 bodies 
 
Analyfis of the Air. 289 
 
 bodies which ic acts upon, and thereby con- 
 iiderably augments their weight, is very evi- 
 dent in Minium or Red Lead, which is ob- 
 ferved to increaie in weight about JL part in 
 undergoing the action of the fire ; the ac- 
 quired rednefs of the Minium, indicating the 
 addition of plenty of fulphur in the opera- 
 tion : For fulphur, as it is found to act moil 
 vigouroufly on lighr, fo it is apt to reflect, 
 the flrongeft, viz. the red rays. And that 
 there is good ftore of air added to the Mi- 
 nium, I found by diftilling firfl 1922 grains 
 of Lead, from whence I obtained only icwen 
 cubick inches of air ; but from 1922 grains, 
 which was a cubick inch of Red Lead, 
 there arofe in the like fpace of time thirty- 
 four cubick inches of air ; a great part of 
 which air was doubtlefs abforbed by the 
 fulphureous particles of the fuel, in the 
 reverberatory furnace, in which the Mi- 
 nium was made; for by Experiment 106. 
 the more the fumes of a fare are confined, 
 the greater quantity of elaftick air they ab- 
 forb. 
 
 It was therefore doubtlefs this quantity 
 1 air in the Minium, which burft the her- 
 metically fealed glafles cf the excellent Mr. 
 Boyle, when he heated the Minium contain'd 
 
 U in 
 
290 Analyjis of the Ah. 
 
 in them by a burning-glafs 3 but the pious 
 and learned Dr. Nieuiventyt attributes this 
 effect wholly to the expanfion of the fire- 
 particles lodged in the Minium, u he fup- 
 " poling fire to be a particular fluid mat- 
 " ter, which maintains its own eflence and 
 " figure, remaining always fire, though not 
 cc always burning. Religious Pbilojbpber, p. 
 
 " 3 IO « 
 
 To the fame caufe alfo, exclufive of the 
 
 air, he attributes the vaft expanfion of a 
 mixture of compound Aqua-fort is and Oil of 
 Carraways, whereas by Experiment 62. there 
 is a great quantity of air in all Oils. And by 
 pouring fome compound Aqua-fort is on Oil 
 of Cloves, the mixture expanded into a fpace 
 equal to 720 times the bulk of the oil, that 
 part of the expanfion, which was owing to 
 the watry part of the oil and fpirit 3 was foon 
 contracted ; whereas the other part of the 
 expanfion, which was owing to the elaftick 
 air of the oil, was not all contracted till the 
 next day, by which time the fulphureous 
 fumes had reforbed it. 
 
 It has been the opinion of fome, that pu- 
 trefaction is the effect of inherent fire : that 
 Vegetables alone are the fubject of Fermen- 
 tation, but both Vegetables and Animals or. 
 
 putre- 
 
Anal)fis of the Air. 2 9 1 
 
 putrefaction ; which operations they attri- 
 bute to very different caufes. The immediate 
 caufe of fermentation is (they fay) the mo- 
 tion of the air intercepted between the fluid 
 and vifcous parts of the fermenting liquor; 
 but the caufe of putrefaction they would 
 have to be, fire itfelf, collected or included 
 within the putrefying fubject. But I do not 
 fee why thefe may not reafonably enough 
 be looked upon as the effects of different 
 degrees of fermentation 5 nutrition being the 
 genuine effect of that degree of it, in which 
 the fum of the attracting action of the par- 
 ticles is much fuperior to the fum of their 
 repulfive power : But when their repelling 
 force far exxeeds their attractive, then the 
 component parts of Vegetables are diffolved. 
 Which diffolving fubftances, when they are 
 diluted with much liquor, do not acquire a 
 great heat in the diffolution, the brisknefs of 
 the inteftine motion being checked by the 
 liquor: But when they are only moift, like 
 green and damp Hay, in a large heap, then 
 they acquire a violent heat fo as to fcorch, 
 burn and flame 5 whereby the union of their 
 conftituent parts being more throughly dif- 
 folved, they will neither produce a vinous, 
 nor an acid fpirit : Which great degree of 
 
 U 2 folution 
 
1 9 1 Analyfis of the Air. 
 
 folution may well be effected by this means, 
 without the action of a fire, fuppofed to be 
 included within the putrefying fubjecl. Where- 
 fore, according to the old Axiom, Entia non 
 funt temere neque abfque neceffitate multipli- 
 canda. 
 
 If the notion of fermentation be restrained 
 to the greater repelling degrees of fermen- 
 tation, in which fenfe it has commonly been 
 understood; then it is as certain, that the 
 juices of Vegetables and Animals do not fer- 
 ment in a healthy ftate, as it is, that they do 
 not at the lame time coalefce and difunite : 
 But if fermentation be taken in a larger fenfe, 
 for any the fmalleft to the greateil: degree 
 of inteftine motion of the particles of a fluid, 
 then all vegetable and animal fluids are in a 
 natural ftate, in lb me degree of ferment; for 
 they abound both with elaftick and fulphu- 
 reous particles: And it may with as much 
 reafon be argued, that there is no degree 
 of warmth in Animals and Vegetables, be- 
 caufe a great degree of heat will caufe a 
 folution of continuity, as to fay, there is no 
 decree of ferment in the fluids of thofe bo- 
 dies, becaufe a great repelling degree of fer- 
 ment will moil certainly diflblve them. 
 
 That 
 
Analyfis of the Axr. 293 
 
 That illuftrious Philofopher, Sir Ifaac New- 
 ton, to his thoughts about the nature of acids, 
 gives this rational account of the nature of 
 
 fermentation. " The particles of acids 
 
 " are endued with a great attractive force, 
 " in which force their activitv confifts — 
 " By this attractive force they get about the 
 " particles of bodies, whether they be of a 
 " metallick or ftony nature, 2nd adhere to 
 ic them moil: clofely on all fides, fo that they 
 <c can fcarce be feparated from them by diftil- 
 c< lation or fublimation ; wjien they are at- 
 u traded and gathered together about the 
 <c particles of bodies, they raife, disjoin, and 
 " make them one from another, that is, they 
 " diffolve thofe bodies. 
 
 " Bv their attractive force alfo. bv which 
 they rufh towards the particles of bodies, 
 they move the fluid, and excite heat, and 
 they make afunder fome particles, fo much 
 as to turn them into air, and generate bub- 
 " bles: And this is the reafon of diflblution, 
 " and all violent fermentation. Harris's 
 u Lexicon Tech. Vol. II. Introduction." 
 
 Thus we have from thefe Experiments 
 many manifeft proofs of confiderable quan- 
 tities of true permanent air, which are by 
 means of fire and fermentation railed from, 
 
 U 3 and 
 
1 94 Jnalyfis of the Air. 
 
 and abforbed by animal, vegetable and mine- 
 ral fubftances. 
 
 That this air confifts of particles which are 
 in a very active ftate, repelling each other 
 with force, and thereby conftituting the fame 
 kind of elaftick fluid with common air, is 
 plain from its raifing the Mercury in Expe- 
 riment 88 and 89, and from its continuing 
 in that elaftick ftate for many months and 
 years, tho' cool'd by fevere frofts ; whereas 
 watry vapours, tho* they expand much with 
 heat, yet are found immediately to condenfe 
 into their firft dimenfions when cold. 
 
 The air generated by fire was not, in many 
 inftances, feparated without great violence 
 from the fix'd bodies, in which it was incor- 
 porated ; as in the cafe of Nitre, Tartar, Sal 
 Tartar and Copperas ; whence it mould leem, 
 that the air generated from thefe Salts, may 
 probably be very inftrumental in the union 
 ot Sq!:s, as well as that central, denfer, and 
 compacter particle of earth, which Sir IJaac 
 Newton obferves, does by its attraction make 
 the watry acid flow round it, for compoiing 
 the particles of Salt, qu. 3 1. For fince, upon 
 thedifiblution of the condiment parts of Salt 
 by fire, it is found, that upon feparating and 
 
 .ciiizing the acid fpirir, the air-particles do 
 
 in 
 
Anvlyfis of the Air. 295 
 
 in great abundance rufh forth from a fixt to 
 a repelling elaftick ftate ; it mufl needs be, 
 that theie particles did, in their fixt ftate, 
 ftrongly attract the acid fpirits, as well as the 
 fulphureous earthy parts of the Salt; for the 
 moft ftrongly repelling and elaftick particles 
 are obferv'd, in a fixt ftate, to be the moft 
 ftrongly attracting. 
 
 But the watry acid, which, when fepa- 
 rated from Salt by the action of fire, makes 
 a very corrofive fuming fpirit, will not make 
 elaftick air, though its parts were put into a 
 brisk motion by fire in Experiment 75. And 
 the event was the fame with feveral other 
 volatile fubftances, as volatile Salt of Sal 
 Ammoniac > Camphire and Brandy-, which, 
 though diftilled over with a confiderable hear, 
 yet generated no elaftick air, in Experiment 
 52, 61, 66. Whence it is plain, the acid 
 vapours in the air only float in it like the 
 watry vapours ; and when ftrongly attra- 
 cted by the elaftick particles of the air, 
 they firmly adhere to them, and make 
 Salts. 
 
 Thus in Experiment 73. we fee, by the 
 vaft quantity of air there is found in Tartar, 
 that tho' it contains the other principles of 
 vegetables, yet air, with feme volatile Salt, 
 
 U 4 feems 
 
i 9 6 Analyfis of the Air. 
 
 feems to make up a confiderable part of its 
 compofition ; which air, when by the action 
 of fire it is more firmly united with the earth, 
 and acid fulphureous particles, requires a more 
 intenfe degree of heat, to extricate it from 
 thofe adhering fubftances, as we find in the 
 diftillation of Sal Tartar, Exper. 74. which 
 Air and volatile Salt are moft readily fepa- 
 rated by fermentation. 
 
 And by Experiment 72. plenty of air arifes 
 alio from Nitre, at the fame time that the 
 acid fpirit is feparated from it by the action 
 of fire. 
 
 We find alfo by Experiment 71. that fome 
 air is by the fame means obtained from com- 
 mon Sea-falt, tho' not in fo great plenty, nor 
 {0 eafily, as from Tartar and Nitre \ it being 
 a more fixt body, by reafon of the fulphur 
 which abounds in it; neither is it io eafily 
 changed in animal bodies, as other Salts are; 
 yet, fince it fertilizes ground, it muft needs be 
 changed by vegetables. 
 
 There is good reafon alio to iufpecl, that 
 thefe acid (pints are not wholly free from 
 air-particles, notwithftanding there were no 
 elaflick ones produced, when they were put 
 into a brisk motion, by the action of fire in 
 Experiment 75. which might be cccafioned 
 
 * b Y 
 
dnalyfis of the Air. 1 97 
 
 by the great quantity of acid fpirit, in which 
 they were involved. For we fee in Experi- 
 ment 90. that when the acid fpirit of Aqua 
 Regia was more ftrongly attracted by the 
 diflblving gold, than by the air-particles, 
 then plenty of air-particles, which were thus 
 freed from the acid fpirit, did continually 
 arife from the Aqua Regia, and not from the 
 gold, at lead not from the metallick particles 
 of the gold, for that lofes nothing of its 
 weight in the folution ; fo that if any does 
 arife from the gold, it muft be what may 
 be latent in the pores of the gold. Whence 
 it is probable, that the air which is obtained 
 by the fermenting mixture of acid and alka- 
 line fubftances, may not arife wholly from 
 the diflblved alkaline body, but in part alio 
 from the acid. Thus the great quantity of 
 elailick air, which in Experiment 83. is gene- 
 rated from the mixture of Vinegar and Oyfter- 
 fhell, may as well arife in part from the Tar- 
 tar, to which Vinegar owes its acidity, as 
 from the diflblved Oyfterfhell. And what 
 makes it further probable is, that the Vine- 
 gar lofes its aciditv in the ferment, than is, 
 its Tartar: for diflblving menftruums are 
 generally obferved to be changed in fermen- 
 tation, as well as the diflblved body. 
 
 Have 
 
198 Analyjts of the' Air. 
 
 Have we not reafon alfo hence to conclude, 
 that the energy of acid fpirits may, in fome 
 meafure, be owing to the ftrongly attracting 
 air-particles in them; which active princi- 
 ples may give an impetus to the acid fpicu/tf, 
 as well as the earthy oily matter, which is 
 found in thefe acid fpirits? 
 
 There are, we fee, alfo great ftore of air- 
 particles found in the Analyfis of the blood, 
 which arifes doubtlefs as well from the ferum 
 as from the cra[f anient um^ for all the animal 
 fluids and folids have air and fulphur in them : 
 Which ftrongly attracting principles feem 
 to be more intimately united together in the 
 more perfect and elaborate part of it, its red 
 globules; fo that we may not unreafonably 
 conclude, that air is a band of union here as 
 well as in Salts : And accordingly we find the 
 greateft plenty of air in the moft folid parts 
 of the body, where the cohefion of the parts 
 is the ftrongeft ; for by comparing Experi- 
 ment 49. and 51. we fee that much more air 
 was found in the diftillation of horn, than of 
 blood. And the cohefion of animal fubftances 
 was nor, as we find by the fame Experiment, 
 diflblved even in the blood, without confi- 
 derable violence of fire ; tho' it is fometimes 
 dene to a fatal degree in our blood, by that 
 
 more 
 
Annlyji~> of the Air. 299 
 
 more fubtile diflblvent fermentation: But we 
 
 may obferve, that * :olent Sales, Spirits, and 
 fulphureous Oil, which are at the fame time 
 feparated from thefe fubftances, will not make 
 elaftick air. 
 
 Experiment CXX. 
 
 As elaftick air is thus generated by the force 
 of fire from thefe and many other fubftances, 
 to is the elafticity of the air greatly deftroyed 
 by fulphureous bodies. Sir Ifaac Newton 
 obferves, " That as light acts upon fulphur, 
 " fo, fince all action is mutual, fulphurs ought 
 " to act moft upon light/' And the fame 
 may be obferved of air and fulphur ; for by 
 Experiment 103. it is found that burning 
 fulphur, which is a very ftrongly attravting 
 fubftance, powerfully attracts and fixes the 
 elaftick panicles of air; fo that there muft 
 needs be a good quantity of unelaftick air- 
 particles in oil and flour of fulphur : The 
 firft of which is made by burning fulphur 
 under a bell, the other by fublimation: In 
 further confirmation of this it is obferved, 
 that Oleum Snlphuris per Campanam is with 
 more difficulty made in a dry than a moift 
 air j and I have found by Experiment pur- 
 
 pofely 
 
300 Analyjis of the Air. 
 
 pofely made, that a Candle, which burnt jo'' 
 in a very dry receiver, burnt but 64" in the 
 fame receiver, when filled with the fumes of 
 hot water j and yet abforbed one-fifth part 
 more air, than when it burnt longer in the 
 dry air. 
 
 Sulphur not only abforbs the air when 
 burning in a homogeneal mafs, but alfo in 
 many fermenting mixtures ; and as Sir Ifaac 
 Newton obferved the attractive and refractive 
 power of bodies to be greater or lefs, as they 
 partook more or lefs of fulphureous oily par- 
 ticles j fo there is good reafon from thefe Ex- 
 periments to attribute the fixing of the ela- 
 ftick particles of the air to the ftrong attra- 
 ction of the fulphureous particles, with which 
 he fays it is probable that all bodies abound 
 more or lefs. Electrical bodies are alfo ob- 
 ferved to attract more ftrongly, in proportion 
 to the greater quantity of fulphur which they 
 contain. 
 
 That great plenty of air is united with 
 fulphur in the oil of vegetables, is evident, 
 from the quantity of air that arofe from the 
 diflillation of oils of Anniieeds and Olives, in 
 Exper. 62. When by fermentation the con- 
 ttituent parts of a Vegetable are feparated, 
 part of the air flies off in fermentation into 
 
 an 
 
Analyfis of the Air. 3 o 1 
 
 an elaftick ftate; part unites with the eflen- 
 tial Salt, Water, Oil and Earth, which con- 
 ftitute the Tartar which adheres to the fides 
 of the veffel ; the remainder, which continues 
 in the fermented liquor, is there, fome of it 
 in a fix'd, and fome in an elaftick ftate, which 
 gives brisknefs to the liquor; their expanding 
 bubbles rifing of a very vifible fize, when the 
 weight of the incumbent air is taken off the 
 liquor in a- vacuum. 
 
 And as there was found a greater quantity 
 of air in the deer's horn than in blood, we 
 may alfo obferve it to be in a much greater 
 proportion in the more folid parts of Vege- 
 tables, than in their fluid : For we find in 
 Experiment 55. $j. and 60. that near one- 
 third part of the fubftance of the Peafe, heart 
 of Oak, and Tobacco, were, by the action of 
 fire, changed from an unelaftick ftate to an 
 elaftick air : And fince a much greater pro- 
 portion of air is found in the folid than the 
 fluid parts of bodies, may we not with good 
 reafon conclude, that it is very inftrumental, 
 as a band of union in thofe bodies? " Thofe 
 " particles (as Sir Ifaac Newton oblerves) 
 <£ receding from one another with the great- 
 " eft repulfive force, and being moft dirri- 
 " cultly brought together, which upon con- 
 
 " tact 
 
goi AnaJyJis of the Air. 
 
 ", tact cohere mod ftrongly. Qu. 3 1." And 
 if the attraction of cohefion of an unelaftick 
 air-particle be proportionable to its repulfive 
 force in an elaftick ftate ; then, fince its ela- 
 ftick force is found to be fo vaftly great, fo 
 mull: that of its cohefion be alfo. Sir -Ifaac 
 Newton calculates from the inflection of the 
 rays of light, that the attracting force of par- 
 ticles, near the point of contact, is 10000, 
 0000, 0000, 0000 greater than the force of 
 
 gravity. 
 
 Sulphur in a quiefoent fix'd ftate in a large 
 body, does not abforb the elaftick air ; for a 
 hard roll of Brimftone does not abforb air : 
 But when fome of that Brimftone, by being 
 powdered and mix'd with filings of Iron, is 
 fet a fermenting, and thereby reduced into 
 very minute particles, whofe attraction in- 
 creafes as their fize decreafes ; then it abforbs 
 elaftick air vigoroufly : As may be ken in 
 many inftances under Experiment 95. The 
 Walton Mineral, in which there is a good 
 quantity of fulphur, did, when compound 
 Aqua-fortis was poured on it, in Experiment 
 96. make a confiderable fermentation, and 
 abforb a great quantity of elaftick air : But 
 when the ferment was much increafed, by 
 adding an equal quantity of water to the like 
 
 mix- 
 
 , 
 
Analyjis of the Air. 305 
 
 mixture, then inflead of abforbing 85 cubick 
 inches, as before, it generated 80 cubick 
 inches of air: So that fermenting mixtures, 
 which have fulphur in them, do not always 
 abforb, but fometimes ''generate air : The 
 reafon of which in the Experiment now under 
 confideration feems to be this, viz. in the firft 
 cafe a good quantity of elaftick air was gene- 
 rated by the inteftine motion of the ferment- 
 ing ingredients 5 but there ariiing thence a 
 thick, acid, fulphureous fume, this fume ab- 
 forbed a greater quantity of elaftick air than 
 was before generated : And we find by Expe- 
 riment 103, that the fulphureous particles 
 which fly off in the air, do by their attraction 
 deftroy its elafticity ; for in that Experiment 
 burning Brimftone greatly deftroyed the air'^ 
 elafticity ; which muft be done by the flame, 
 and afcending fumes ; becaufe in the burning 
 of any quantity of Brimftone the whole mafs 
 is in a manner wafted, there remaining only a 
 very little dry earth : And therefore the ab- 
 forbed air cannot remain there, but muft be 
 abforbed by the afcending fumes, which then 
 attract moft ftrongly, when reduced ad mi- 
 nima : And it is well known, that a Candle in 
 burning flies all off into flame and vapour, fo 
 that what air it abforbs, muft be by thole fumes. 
 
 Expe- 
 
304 Analyjis of the Air. 
 
 Exp e rime n't CXXL 
 
 And further, I have found that thefe fumes 
 deftroy the air's elafticity for many hours after 
 the Brimftone Match, which made them, 
 was taken out of the vcffel z z a a: (Fig. 35.) 
 Thofe fumes being firft cooled by immerfing 
 that veffel and its ciftern x x y (or an inverted 
 wine flask, full of the fumes) under cold wa- 
 ter for fome time ; then marking the furface 
 of the water z z y I immerfed the vefTels in 
 warm water: And when all was cold again 
 the following day, I found a good quantity 
 of the air's elafticity was deftroy ed by the 
 water's afcending above z z. And the event 
 was the fame upon frequent repetitions of the 
 fame Experiment. 
 
 But if, inftead of the fumes of burning 
 Brimftone, I filled a flask full of fumes from 
 the fmoak of wood, after it had done flame- 
 ino- then there was but half as much air 
 abfbrbed by thole fumes, as there was by 
 the fumes of Brimftone ; viz. becaufe the 
 fmoak of wood was much diluted with the 
 watry vapour which afcended with it out 
 of the wood. And this is doublefs the rea- 
 fon why the fmoak of wood, though it in- 
 commodes 
 
Analyjis of the Air. 305 
 
 commodes the lungs, yet it will not fuffbcate 
 like that of Charcoal, which is withal more 
 fulphureous, without any mixture of watry 
 vapours. 
 
 And that new generated elaftick air is re- 
 forbed by thefe fumes, I found by attempting 
 to fire a Match of Brimftone with a burning- 
 glafs, by means of a pretty large piece of 
 Brown Paper, which had been dipped in a 
 flrong folution of Nitre, and then dried ; 
 which Nitre in detonizing generated near two 
 quarts of air; which quantity of air, and a 
 great deal more, was abforbed, when the 
 Brimftone took fire, and flamed vigoroufly. 
 
 So that the 85 cubick inches of air, Exper. 
 96. which I found upon meafuring, was ab- 
 foibed by the Walton Mineral and compound 
 Aqua-fortis, was the excefs of what was ab- 
 forbed by thole fumes above what was gene- 
 rated by the fermenting mixture. 
 
 And the reafon is the fame in Filings of 
 Iron, and Spirit of Nitre, Exper. 94. which 
 alio abforbed more than they generated, whe- 
 ther with or without water. 
 
 Hence alio we fee the reafon why Filings 
 of Iron and compound Aqua-fortis y in the 
 fame 94th Experiment, abforbed air ; and why, 
 when mix\l with an equal quantity of water, 
 
 X it 
 
306 Analyjis of the Afa. 
 
 it moftly abforbed, but did fometimes gene- 
 rate, and then abforb again : And it was the 
 fame with oil of Vitriol, filings of Iron and 
 Water, and Newcaftle Coal, and compound 
 Aqua-fortis, and others : viz. At firft, when 
 the ferment was brisk, the abforbing fumes 
 role fiftefr, whereby more air was abforbed 
 than generated ; but as the ferment abated, to 
 fuch a degree as to be able ftill to generate 
 elaftick air, but not to fend forth a propor- 
 tionable quantity of fumes, in that cafe more 
 air would be generated than abforbed. 
 
 And in Experiment 95. there are feveral 
 inftances of the air's being in like manner ab- 
 forbed in leffer degrees, by other fermenting 
 mixtures : As in the mixture of fpirit of Harts- 
 horn with filings of Iron, and with filings of 
 Copper : And fpirit of Sal Ammoniac with 
 filings of Copper ; and alfo filings of Iron 
 and Water ; powdered Flint, and compound 
 Aqua-fortis ; powdered Briftol Diamond with 
 the fame liquor. 
 
 It is probable from Experiment 103 and 
 106. where it was found that the thicker 
 the fuliginous vapours were, the farter they 
 abforbed the air, that if the above-mentioned 
 fermenting mixtures had not been confined 
 
 in ciofe veiTels, but in the open air, where 
 
 the 
 
Analyfis of the Ah. ^07 
 
 the vapours would have been Jefs denfe, that 
 in that cafe much leis air would have been 
 abforbed, perhaps a great deal lefs than was 
 generated. 
 
 In the fecond cafe of the IV alien Mineral, 
 Experiment 96. when inftead of abforbing, 
 it generated air, the parts of the compound 
 Aqua- forth were then more at liberty to act 
 by being diluted with an equal quantity of 
 water j whereby the ferment being more 
 violent, the particles which conftituted the 
 new elaftick air were thereby thrown oft in 
 greater plenty, and perhaps with a greater 
 degree of elafticity, which might carry them 
 beyond the fphere of attraction of the ful- 
 phureous particles. 
 
 This is further illuftrated by Experiment 
 94. where filings of Iron and oil of Vitriol 
 alone generated very little, but the like quan- 
 tities of filings of Iron, with an equal quan- 
 tity of water, generated 43 cubick inches of 
 air \ and the like ingredients, with three times 
 that quantity cf water, generated 108 cubick 
 inches. 
 
 And though the quantity of the afcending 
 fumes (which was in this cafe of the JValton 
 Mineral very great) mud needs in their afcent 
 abforb a good deal of elaftick air, (for they 
 
 X 2 will 
 
3 o 8 Analyfis of the Air. 
 
 will abforb air) yet if, where the ferment was 
 fo much greater, more elaftick air was gene- 
 rated by the fermenting mixture, than was 
 abforbed by the afcending fumes, then the 
 quantity of new generated air, which I found 
 between zz and aa, (Fig. 35.) when I mea- 
 fured it, was equal to the excefs of what was 
 generated above what was abforbed. 
 
 And probably in this cafe the air was not 
 abforbed fo much in proportion to the den- 
 fity of the fames, as in the firft cafe ; becaufe 
 here the fulphureous fumes were much 
 blended with watry vapours : for we find in 
 Experiment 97. that fix times more was 
 wafted in fumes in this cafe, than in the 
 other ; and therefore probably a good part 
 of the cubick inch of water afcended with 
 the vapour, and might thereby weaken its 
 abforbing power : For watry vapours do not 
 abfoib elaftick air as the fulphureous ones do ; 
 tho' by Experiment 120. a Candle abforbed 
 more in a damp than in a dry air. 
 
 And it is from thefe diluting watry vapours, 
 that filings of Iron, with fpirit of Nitre and 
 Water, abforbed lefs than with fpirit of Nitre 
 alone 3 for in both cafes it abforbs more than 
 
 it generates. 
 
 Thus 
 
Analyjis of the Ait. 309 
 
 Thus alfo oil of Vitriol and Chalk gene- 
 rate air, their fume being fmall, and that 
 much diluted with the watry vapours in the 
 Chalk. 
 
 But Lime, with oil of Vitriol, or White- 
 Wine Vinegar or Water, make a confiderable 
 fume, and abforb good quantities of air: 
 Lime alone left to flaken gradually, as it 
 makes no fume, fo it abforbs no a jr. 
 
 We fee in Experiment 92. where the fer- 
 ment was not very fudden nor violent, nor 
 the quantity of abforbing fumes large, that 
 the Antimony and Aqua- fort is generated a 
 quantity of air equal to 520 times the bulk 
 of the Antimony. Thus alfo in the mixture of 
 Aqua Regia and Antimony, in Experiment 
 91. while at firft the ferment was fmall, then 
 air was generated ; but when with the in- 
 creasing ferment plenty of fumes arofe, then 
 there was a change from a generating to an 
 abforbing ftate. See Vol. II. p. 292. 
 
 Since we find fuch great quantities of ela- 
 flick air generated in the folution of animal 
 and vegetable fubfrances, it muft needs be, 
 that a good deal does conftantly arife from 
 the diflblving of thefe aliments in the ftomach 
 and bowels, which diflblution it greatly pro- 
 motes: Some of which may very probably 
 
 X 3 
 
3 i o Jnalyjis of the Ah. 
 
 be reforbed again, by the fumes which arife 
 with them ; for we fee in Experiment 83. 
 that Oyfter-fhell and Vinegar, Oyfter-fhell 
 and Rennet, Oyfter-fhell and Orange-juice, 
 Rennet alone, Rennet and Bread, firft gene- 
 rated, and then abforbed air ; but Oyfter-fhell 
 withfome of the liquor of a Calf's ftomach, 
 which had fed much upon Hay, did not gene- 
 rate air; and it was the fame with Oyfter-fhell 
 and Ox-gall, and Spittle and Urine - y Oyfter- 
 fhell and Milk generated a little air, but Li- 
 mon-juice and Milk did at the fame time ab- 
 forb a little : Thus we fee, that the variety of 
 mixtures in the ftomach appear fometimesto 
 generate, and fometimes to abforb air ; that 
 is, there is fometimes more generated than 
 abforbed, and fometimes an equal quantity, 
 and fometimes lefs, according to the propor- 
 tion the generating power of the diflblving 
 ailments bears to the abforbing power of the 
 fumes which arife from them. In a true 
 kindly digeftion, the generating power exceeds 
 the abforbing power but a little : But when- 
 ever the digeftiori deviates in fome degree 
 from this natural irate, to generate a greater 
 proportion of elaftick air, then are we trou- 
 bled more or lets with diftending Flatus's. I 
 had ii . ] to make thtfe, and many more, 
 
 Expe- 
 
 
Analyfis of the Aiv. 3 1 1 
 
 Experiments, relating to the nature of dige- 
 ftion, in a warmth equal to that of the fto- 
 mach; but have been hitherto prevented by 
 purfuing other Experiments. 
 
 Thus we fee that all thefe mixtures do in 
 fermentation generate elaftick air; but thofe 
 which emit thick fumes, charg'd with ful- 
 phur, reforb more than was generated, in pro- 
 portion to the fulphureoufnefs and thicknefs 
 of thofe fumes. 
 
 I have alfo fhewn in many of the forego- 
 ing Experiments, that plenty of true perma- 
 nent elaftick air is generated from the fer- 
 menting mixtures of acid and alkaline fub- 
 ftances, and efpecially from the fermentation 
 and diflblution of animal and vegetable bo- 
 dies, into whofe fubftances we fee it is in a 
 great proportion intimately and firmly incor- 
 porated; and confequcntly great quantities of 
 elaftick air muft be continually expended in 
 their production ; part of which does, we fee, 
 relume its elaftick quality, when briskly 
 thrown off from thofe bodies by fermentation 
 in the diflblution of their texture. But part 
 may probably never regain its elafticity, or at 
 leaft not in many centuries, that efpecially 
 which is incorporated into the more durable 
 parts of Animals and Vegetables. However, 
 
 X 4 we 
 
% \ i Analyfn of tide Air. 
 
 we may with pleafure fee what immenfe trea- 
 fures of this noble and important element, 
 endued with a moft active principle, the all- 
 wife Providence of the great Author of na- 
 ture has provided, the conftant wafte of it 
 being abundantly fupplied by heat and fer- 
 mentation from innumerable denfe bodies ; 
 and that probably from many of thofe bodies, 
 which, when they had their afcending fumes 
 confined in my glaffes, abforbed more air 
 than they generated -, frut would, in a more 
 free, open fpace, generate more than they ab- 
 forbed. 
 
 - I made fome attempts both by fire, and 
 alfo by fermenting and abforbing mixtures, 
 to try if I could deprive all the particles of 
 any quantity of elaltick air of their elafticity; 
 but I could not effect it : There is therefore 
 no direct proof fiom any of thefe Experi- 
 ments, that all the elaftick air may be ab- 
 forbed, tho* 'tis very probable it may, fince 
 we find it is in fuch great plenty generated 
 and abforbed -, it may well therefore be all 
 abforbed and changed from an elaftick to a 
 fixt ftate : For, as Sir Isaac Newton 
 obferves of light, cc That nothing; more is re- 
 * c quifite for producing all the variety of co- 
 « lours, and degrees of refrangibilny, than 
 
 tc that 
 
Artalyfis of the Air. 3 1 3 
 
 " that the rays of light be bodies of different 
 " fizes, the lead of which may make the 
 " weakeft and darkeft of the colours, and be 
 more eafily diverted, by refra&ing furfaces 
 from the right courfe; and the reft, as 
 they are bigger and bigger, may make the 
 
 ftronger and more lucid colours and be 
 
 more and more difficultly diverted, <%u. 29." 
 So £>u. 30. he obferves of air, " That denfe 
 f£ bodies, by fermentation, rarefy into feveral 
 " forts of air, and this air, by fermentation, 
 cc and fometimes without, returns into denfe 
 11 bodies. " And fince we find in fact from 
 thefe Experiments, that air arifes from a 
 great variety of denfe bodies, both by fire 
 and fermentation, it is probable that they 
 may have very different degrees of elafticity, 
 in proportion to the different fize and denfity 
 of its particles, and the different force with 
 which they were thrown offinco an elaftick 
 ftate. " Thofe particles (as Sir Isaac New- 
 ' c ton obferves) receding from one another, 
 " with the greateft repulfive force, and bein^ 
 u molt difficultly brought together, which 
 " upon contact cohere mofl ftroncrly. " 
 Whence thofe of the weakeft elasticity will 
 be leaft able to refill: a counter-acting power, 
 and will therefore be fooneft changed from 
 
 an 
 
5 1 4 Analyjls of the Air. 
 
 an elaftick to a fixt ftate. And 'tis confonant 
 to reafon to think, that the air may confift 
 of infinite degrees of thefe, from the mod 
 elaftick and repelling, till we come to the 
 more fluggim, watry, and other particles, 
 which float in the air; yet the repelling force 
 of the leafl elaftick particle, near the furface 
 of the earth, while it continues in that ela- 
 ftick ftate, muft be fuperior to the incumbent 
 preffure of a column of air, whofe height is 
 equal to that of the atmofphere, and its bafe 
 to the furface of the fphere of its elaftick 
 activity. 
 
 Thus, upon the whole, we fee that air 
 abounds in animal, vegetable, and mineral 
 fubftancesj in all which it bears a confider- 
 able part : if all the parts of matter were 
 only endued with a ftrongly attracting power, 
 whole nature would then immediately be- 
 come one unactive cohering lump > where- 
 fore it was abfolutely neceflary, in order to 
 the actuating and enlivening this vaft mafs of 
 attracting matter, that there mould be every 
 where intermix'd with it a due proportion 
 of ftrongly repelling elaftick particles, which 
 might enliven the whole mafs, by the incef- 
 fant action between them and the attracting 
 particles : And fince thefe elaftick particles 
 
 are 
 
Analyjis of the Air. 3 1 5 
 
 are continually in great abundance reduced 
 by the power of the ftrong attraCters, from an 
 elaftick to a fixt ftate ; it was therefore ne- 
 cefTary, that thefe particles fhould be endued 
 with a property of refuming their elaftick 
 ftate, whenever they were difengaged from 
 that mafs in which they were fixt, that thereby 
 this beautiful frame of things might be main- 
 tained in a continual round of the produ- 
 ction and diffolution of animal and vegetable 
 bodies. 
 
 The air is very inftrumental in the pro- 
 duction and growth of animals and vegeta- 
 bles, both by invigorating their feveral juices 
 while in an elaftick aCtive ftate, and alfo by 
 greatly contributing in a fix'd ftate to the 
 union and firm connection of the feveral con- 
 ftituent parts of thofe bodies, viz, their wa- 
 ter, fait, fulphur, and earth. This band of 
 union, in conjunction with the external air, 
 is alfo a very powerful agent in the diffolu- 
 ticn and corruption of the fame bodies; for 
 it makes one in every fermenting mixture ; 
 the aCtion and re-aCtion of the aereal and fal- 
 phureous particles is, in many fermenting 
 mixtures, fo great, as to excite a burning 
 heat, and in others a fudden flame : And it 
 is, we fee, by the like aCtion and re-aCtion 
 
 of 
 
3 1 6 Anatyjis of the Air. 
 
 of the fame principles, in fuel and the am- 
 bient air, that common culinary fires are pro- 
 duced and maintained. 
 
 Tho* the force of its elafticity is fo great 
 as to be able to bear a prodigious preflure, 
 without lofing that elafticity, yet we have, 
 from the foregoing Experiments, evident 
 proof, that its elafticity is eafily, and in great 
 abundance deftroyed ; and is thereby reduced 
 to a fixt ftate, by the ftrong attraction of the 
 acid fulphureous particles, which arife either 
 from fire or from fermentation : And there- 
 fore elajlicity is not an ejfential immutable 
 property of air-particles j but they are, we fee, 
 eafily changed from an elaftick to a fixt ftate, 
 by the ftrong attraction of the acid, fulphu- 
 reous, and faline particles, which abound in 
 the air. Whence it is reafonable to conclude, 
 that our atmofphere is a Chaos, confifting 
 not only of elaftick, but alfo of unelaftick 
 air- particles, which in great plenty float in it, 
 as well as the fulphureous, faline, watry and 
 earthy particles, which are no ways capable 
 of being thrown off into a permanently ela- 
 ftick ftate, like thofe particles which confti- 
 ftute true permanent air. 
 
 Since then air is found fo manifeftly to 
 abound in almoft all natural bodies -, fince we 
 
 find 
 
dnalyjis of the Air. 3 17 
 
 find it fo operative and aftive a * principle in 
 every chymical operation ; fince its conftituenc 
 parts are of fo durable a # nature, that the 
 moft violent adlion of fire or fermentation 
 cannot induce fuch an alteration of its texture, 
 as thereby to difqualify it from refuming, 
 either by the means of fire, or fermentation, 
 its former elaftick ftate 5 unlefs in the cafe of 
 vitrification, when, with the vegetable Salt 
 and Nitre, in which it is incorporated, it 
 may perhaps fome of it, with other chymical 
 principles, be immutably fixt : Since then 
 this is the cafe, may we not with good reafon 
 adopt this now fixt, now volatile Proteus, 
 among the chymical principles, and that a 
 very a&ive one, as well as acid fulphur ; not- 
 withftanding it has hitherto been overlooked 
 and reje&ed by Chymifts, as no way intitled 
 to that denomination ? 
 
 If thofe who unhappily fpent their time 
 and fubltance in fearch after an imaginary 
 production, that was to reduce all things to 
 gold, had, inftead of that fruitlefs purfuit, be- 
 llowed their labour in fearching after this 
 much negleded volatile Hermes, who has fo 
 often efcaped thro' their burft receivers, in 
 
 * Jov'n omnia plena. Virgil. 
 
 the 
 
2 1 8 Of Vegetation. 
 
 the difguife of a fubtile fpirit, a mere flatu- 
 lent explofive matter; they would then, in- 
 ftead of reaping vanity, have found their 
 refearches rewarded with very confiderable 
 and ufeful difcoveries. 
 
 
 CHAP. VII. 
 
 Of Vegetation. 
 
 WE are but too fenfible, that our rea- 
 fonings about the wonderful and in- 
 tricate operations of nature are fo full of un- 
 certainty, that, as the Wife- man truly ob- 
 ferves, hardly do we guefs aright at the things 
 that are upon earthy and with labour do we 
 find the things that are before us, Wifdom, 
 Chap. ix. ver. 16. And this obfervation we 
 find fufficiently verified in vegetable nature, 
 whofe abundant productions, tho' they are 
 moft viiible and obvious to us, yet are we 
 much in the dark about the nature of them ; 
 becaufe the texture of the veffels of plants is 
 fo intricate and fine, that we can trace but 
 few of them, though affifted with the beft 
 microfcopes. We have however good reafon 
 
 to 
 
Of Vegetation. 3 19 
 
 to be diligent in making farther and farther 
 refearches ; for tho' we can never hope to 
 come to the bottom and firft principles of 
 things, yet in fo inexhauftible a fubject, where 
 every the fmalleft part of this wonderful fa- 
 brick is wrought in the mod curious and 
 beautiful manner, we need not doubt of have- 
 ing our inquiries rewarded, with fome fur- 
 ther pleafing difcovery ; but if this fhould 
 not be the reward of our diligence, we are 
 however fure of entertaining; our minds after 
 the moft agreeable manner, by feeing in every 
 thing, with furprizing delight, fuch plain 
 fignatures of the wonderful hand of the Di- 
 vine Architect, as muft neceflarily difpofe and 
 carry our thoughts to an act of adoration, the 
 bed: and nobleft employment and entertain- 
 ment of the mind. 
 
 What I (hall here fay, will be chiefly found- 
 ed on the following Experiments; and on 
 feveral of the preceding ones, without repeat- 
 ing what has already been occafionally ob- 
 ferved on the fubjecl: of Vegetation. 
 
 We find by the chymical Analyfis of Vege- 
 tables, that their fubftance is compofed of 
 fulphur, volatile fait, water and earth ; which 
 principles are all endued with mutually at- 
 tracting powers, and alfo of a large portion 
 
 of 
 
2 2 o Of Vegetation. 
 
 of air, which has a wonderful property of 
 ftrongly attracting in a fixt ftate, or of re- 
 pelling in an elaftick ftate, with a power 
 which is fuperior to vaft compreffing forces ; 
 and it is by the infinite combinations, action 
 and re-action of thefe principles, that all the 
 operations in animal and vegetable bodies are 
 effected. 
 
 Thefe active aereal particles are very fer- 
 viceable in carrying on the work of Vege- 
 tation to its perfection and maturity $ not 
 only in helping by their elafticity to diftend 
 each ductile part, but alfo by enlivening and 
 invigorating their fap, where, mixing with 
 the other mutually attracting principles, they 
 are by gentle heat and motion fet at liberty 
 to affimilate into the nourifhment of the re_ 
 fpective parts : " The foft and moift nourim- 
 ment eafily changing its texture by gentle 
 heat and motion, which congregates homo- 
 geneal bodies, and feparates heterogeneal 
 " ones." Ne<wto?is Opticks, qu. 31. The 
 fum of the attracting power of thefe mutu- 
 ally acting and re-acting principles being, 
 while in this nutritive ftate, fuperior to the 
 fum of their repelling power 5 whereby the 
 work of nutrition is gradually advanced 
 by the nearer and nearer union of thefe 
 
 prin- 
 
 <: 
 
 <c 
 
Of Vegetation. 3 2 1 
 
 principles, from a leffer to a greater degree 
 of confiftency, till they are advanced to that 
 vifcid ductile ftate, whence the feveral parts 
 of Vegetables are formed -, and are at length 
 firmly compacted into hard fubftances, by 
 the flying off of the watry diluting vehicle, 
 fooner or later, according to the different de- 
 grees of cohefion of thefe thus compacted 
 principles. 
 
 But when the watry particles do again foak 
 into and difunite them, and their repelling 
 power is thereby become fuperior to their 
 attracting power; then is the union of the 
 parts of Vegetables thereby fo thoroughly dif- 
 folved, that this ftate of putrefaction does, 
 by a wife order of Providence, fit them to re- 
 fufcitate again in new vegetable productions, 
 whereby the nutritive fund of nature can ne- 
 ver be exhaufted ; which being the fame both 
 in Animals and Vegetables, it is thereby ad- 
 mirably fitted, by a little alteration of its tex- 
 ture, to nourim either. 
 
 Now, tho' all the principles of Vegetables 
 are, in their due proportion, neceffary to the 
 production and perfection of them ; yet we 
 generally find greater proportions cf oil in 
 the more elaborate and exalted parts of Vege- 
 tables : And thus feeds are found to abound 
 
 Y with 
 
322 Of Vegetation. 
 
 with oil, and confequently with fulphur and 
 air, as we fee by Experiment 56. 57. 58. 
 Which feeds containing the rudiments of 
 future Vegetables, it was neceffary that they 
 mould be well ftored with principles that 
 would both preferve the feed from putre- 
 faction, and alfo be very active in promoting 
 Germination and Vegetation. Thus alfo by 
 the grateful odours of flowers we are affured, 
 that they are ftored with a very fubtile, highly 
 fublimed oil, which perfumes the ambient 
 air ; and the fame may be obferv'd from the 
 high taftes of fruits. 
 
 And as Oil is an excellent prefervative 
 againft the injuries of cold, fo it is found 
 to abound in the fap of the more northern 
 trees; and it is this which in Ever-greens 
 keeps their leaves from falling. 
 
 But plants of a lefs durable texture, as 
 they abound with a greater proportion of 
 fait and water, which is not fo ftrongly at- 
 tracting as fulphur and air, fo are they lefs 
 able to endure the cold; and as plants are 
 obferved to have a greater proportion of fait 
 and water in them in the fpring, than in 
 the autumn, fo are they more eafily injured 
 
 by cold in the fpring, than in a more ad- 
 vanced 
 
Of Vegetation. 325 
 
 Vanced age, when their quantity of oil is in- 
 creafed with their greater maturity. 
 
 Whence we find that Nature's chief bufi- 
 nefs in bringing the parts of a Vegetable, efpe- 
 cially its fruit and feed, to maturity, is to com- 
 bine together in a due proportion, the more 
 adlive and noble principles of fulphur and air, 
 that chiefly conftitute oil, which in its moft 
 refined ftate is never found without fome de- 
 gree of earth and fait in it. 
 
 And the more perfect this maturity is, the 
 more firmly are thefe noble principles united, 
 Thus Rhenifh Wines, which grow in a more 
 northern climate, are found to yield their 
 Tartar, /. c. by Exper. 73. their incorporated 
 air and fulphur, in greater plenty, than the 
 ftronger Wines of hotter countries, in which 
 thefe generous principles are more firmly 
 united: And particularly in Madeira Wine, 
 they are fixt to fuch a degree, that that Wine 
 requires a confiderable degree of warmth, 
 fuch as would deftroy the more delicate tex- 
 ture of many other Wines, to keep it in order, 
 and give it a generous tafte ; and 'tis from 
 the fame reafon, that fmall French Wines are 
 found to yield more fpirit in diftillation, than 
 ftrong Spanifi Wines. 
 
 Y 2 But 
 
324 Of Vegetation. 
 
 But when, on the other hand, the crude 
 watry part of the nutriment bears too great a 
 proportion to the more noble principles either 
 in a too luxuriant ftate of a plant, or when 
 its roots are planted too deep, or it ftands in 
 too fhady a pofition, or in a very cold and wet 
 fummer; then it is found, that either no 
 fruit is produced, or if there be any, yet it 
 continues in a crude watry ftate; and never 
 comes to that degree of maturity, which a 
 due proportion of the more noble principles 
 would bring it to. 
 
 Thus we find in this and every other part 
 of this beautiful fcene of things, when we 
 attentively confider them, that the great Au- 
 thor of nature has admirably tempered the 
 conftituent principles of natural bodies, in 
 fuch due proportions as might beft fit them 
 for the ftate and purpofes they were intended 
 for. 
 
 It is very plain from many of the foregoing 
 Experiments and Obfervations, that the leaves 
 are very ferviceable in this work of Vegeta- 
 tion, by being inftrumental in bringing nou- 
 rifhment from the lower parts, within the 
 reach of the attraction of the growing fruit; 
 which, like young animals, is furnimed with 
 proper inftruments to fuck it thence. But 
 
 the 
 
Of Vegetation. 325 
 
 the leaves feem alfo defigned for many other 
 noble and important fervices ; for Nature 
 admirably adapts her iufrruments fo as to 
 be at the fame time ferviceable to many 
 good purpoies. Thus the leaves, in which 
 are the main excretory duels in Vegetables, 
 feparate and carry off the redundant watry 
 fluid, which by being long detained, would 
 turn rancid and prejudicious to the plant, 
 leaving the more nutritive parts to coalefce ; 
 part of which nourishment, we have good 
 reafon to think, is conveyed into Vegetables 
 through the leaves, which do plentifully im- 
 bibe the dew and rain, which contain fait, 
 fulphur, &c. For the air is full of acid 
 and fulphureous particles, which when they 
 abound much, do, by the action and. re-action 
 between them and the elaftick air, caufe that 
 fultry heat, which ulually ends in lightning 
 and thunder : And thefe new combinations 
 of air, fulphur, and acid fpirit, which are 
 conftantly forming in the air, are doubtlefs 
 very ferviceable in promoting the work of 
 Vegetation ; when being imbibed by the 
 leaves, they may not improbably be the 
 materials out of which the more fubtile and 
 refined principles of Vegetables are formed : 
 For fo fine a fluid as the air feems to be a 
 
 Y 3 more 
 

 716 Of Vegetation. 
 
 more proper medium, wherein to prepare 
 and combine the more exalted principles of 
 Vegetables, than the groffer watry fluid of 
 the fap; and for the fame reafon, 'tis likely, 
 that the mod refined and active principles 
 of Animals are alfo prepared in the air, and 
 thence conveyed through the lungs into the 
 blood ; and that there is plenty of thefe 
 fulphureo-aereai particles in the leaves, is 
 evident from the fulphureous exudations, 
 which are found at the edges of leaves, 
 which Bees are obferved to make their waxen 
 cells of, as w T ell as of the duft of flowers: 
 And that wax abounds with fulphur is plain, 
 from its burning freely, &c. 
 
 We may therefore reafonably conclude, 
 that one great ufe of leaves is what has been 
 long fufpected by many, viz. to perform in 
 fome rneafure the fame office for the fup- 
 port of the vegetable life, that the lungs of 
 Animals do, for the fupport of the animal 
 life ; Plants very probably drawing through 
 their leaves fome part of their nourifhment 
 from the air. 
 
 But as plants have not a dilating and con- 
 tracting Thorax, their infpirations and expi- 
 rations will not be fo frequent as thofe of 
 jftnimals. but depend wholly on {he alter- 
 nate 
 
Of Vegetation. 327 
 
 nate changes from hot to cold for infpira- 
 tion, and vice verfa for expiration ; and 'tis 
 not improbable, that plants of more rich and 
 racy juices m-iy imbibe and affimilate more 
 of this aereal food into their conftitutions, 
 than others, which have more watry vapid 
 Juices. We may look upon the Vine as a 
 good inftance of this, which in Experiment 
 3. perfpired lefs than the Apple-tree. For 
 as it delights not in drawing much watry 
 nourimmenr from the earth by its roots, fo 
 it mud therefore neceffarily be brought to a 
 more ftrongly imbibing ftate at night, than 
 other trees, which abound more with watry 
 nourifhment ; and it will therefore confe- 
 quently imbibe more from the air. And 
 likely this may be the reafon, why plants in 
 hoc countries abound more with fine aro- 
 matick principles, than the more northern 
 plants; for they do undoubtedly imbibe more 
 dew. 
 
 And if this conjecture be right, then it 
 gives us a farther reafon, why trees which 
 abound with moifture, cither from too 
 (haded a pofuion, or a too luxurious ftatc, 
 are unfruitful, viz. becaufe, being in thefe 
 cafes more replete with moifture, they can- 
 not imbibe fo ftrongly from the air, as 
 
 Y 4 O&ers 
 
328 Of Vegetation. 
 
 others do, that] great bleffing, the dew of 
 Heaven. 
 
 And as the moft racy generous taftes of 
 fruits, and the grateful odours of flowers, 
 do not improbably arife from thefe refined 
 aereal principles, fo may the beautiful colours 
 of flowers be owing, in a good meafure, to 
 the fame original -, for it is a known obfer- 
 vation, that a dry foil contributes much more 
 to their variegation, than a ftrong moift one 
 does. 
 
 And may not Light alfo, by freely entring 
 the expanded furfaces of leaves and flowers^ 
 contribute much to the ennobling the prin- 
 ciples of Vegetables ? For Sir Ifaac Newton 
 puts it as a very probable query, " Are not 
 " grofs bodies and Light convertible into 
 €C one another ? And may not bodies receive 
 ic much of their activity from the particles 
 « of Light, which enter their compofition ? 
 <l The change of bodies into light, and of 
 < c light into bodies, is very conformable to 
 u the courfe of nature, w T hich feems delighted 
 
 u*ith tranfmutations. Opt, ^'.30." 
 
 E x p E- 
 
Of Vegetation. 319 
 
 Experiment CXXII. 
 
 That the Leaves and Stems of Plants do 
 imbibe elaftick air, there is fome reafon to 
 iuipeft, from the following Experiment, 
 which, in the firft Edition of this Book, I 
 mentioned as not made with accuracy enough; 
 but I have iince repeated it with greater ac- 
 curacy, viz. June 29. I fet a well-rooted 
 plant of Pepper-mint in a glafs-ciftern full of 
 earth, and then poured in as much water as 
 it would contain ; over this glafs-ciftern I 
 placed an inverted glafs z z y a a> as in Fig. 
 2$. the water being drawn up by means of 
 a fyphon to a a. At the fame time alfo I 
 placed in the fame manner another inverted 
 glafs z z y a a, of equal fize with the former, 
 but without any plant under it: the capacity 
 of thefe veflels above the water a a was equ.al 
 to 49 cubick inches. In a month's time the 
 Mint had made feveral weak (lender moots, 
 and many fmall hairy roots (hot out at i:he 
 joints that were above water, occasioned pro- 
 bably by the great moifture of the air, in 
 which the plant flood ; half the leaves of the 
 old item were now dead ; but the leaves and 
 item of the young (hoots continued green 
 
 mod 
 
33 o Of Vegetation. 
 
 moft part of the following winter: The wa- 
 ter in the two inverted glaffes rofe and fell, 
 as it was either affeded by the different 
 weight of the Atmofphere, or by the dila- 
 tation and contraction of the air above a a. 
 But the water in the velfel in which the 
 Pepper-mint flood, rofe fo much above a a, 
 and above the furface of the water in the 
 other veffcl, that one-feventh part of that 
 air muft have been reduced to a fixt ftate, 
 either by being imbibed into the fubftance 
 of the plant, or by the vapours which arofe 
 from the plant. This was chiefly done in 
 the two or three fummer month b ; for after 
 that no more air was abforbed. The begin- 
 ning of April in the following fpring, I took 
 out the old mint, and put a frefh plant in 
 its place, to try if it would abibrb any 
 more of the air, but it faded in four or five 
 days. Yet a frefh plant put into the other 
 glafs, whofe air had been confined for nine 
 months, lived near a month, almoft as long 
 as another plant did in frefh confined air; 
 for I have found that a tender plant confined 
 in this manner in April, would not live fo 
 long as a ftronger grown plant, put in in 
 "June, 
 
 The 
 
Of Vegetation. 351 
 
 The like plants placed in the fams man- 
 ner feparately, in the diftilled airs of Tartar 
 and Newcajlle Coal, foon faded ; yet a like 
 plant confined in three pints of air, a quart 
 of which was diftilled from an Ox's tooth, 
 grew about two inches in height, and had 
 fome green leaves on it, after fix or feven 
 weeks confinement. 
 
 Finding that a frefti plant could not live 
 in the air, which had been for feveral months 
 infected by the mint which was placed in it 
 the 19th otjune ; inftead of a plant, I placed 
 in that air a mixture of powdered Brimftone 
 and filings of Iron moiftened with water ; this 
 mixture abforbed four cubick inches of this 
 air. 
 
 Experiment CXXIII. 
 
 In order to find out the manner of the 
 growth of young {hoots, I firft prepared the 
 following inftrument ; viz. I took a fmall 
 flick a> (Fig. 40.) and at a quarter of an inch 
 diftance from each other, I run the points of 
 five pins, 1, 2, 3, 4, 5, thro' the ftick, fo far 
 as to ftand-^ of an inch from the ftick ; then 
 bending down the great ends of the pins, I 
 jDOund them all faft with waxed thread ; I 
 provided alio fome red-lead mixed with oil. 
 f In 
 
3$z Of Vegetation. 
 
 In the fpring, when the Vines had made 
 fhort (hoots, I dipped the points of the pins 
 in the paint, and then pricked the young 
 fhoot of a Vine (Fig. 41.) with the five 
 points at once, from t top: I then took 
 off the marking inftrument, and placing the 
 loweft point of it in the hole p y the upper- 
 moft mark, I again pricked freili holes from 
 p to /, and then marked the two other points 
 i h > thus the whole fhoot was marked every 
 i. inch, the red paint making every point 
 remain vifible. 
 
 (Fig. 42.) (hews the true proportion of 
 the fame (hoot, when it was full grown, 
 the September following ; where every cor- 
 refponding point is noted with the fame 
 letter. 
 
 The diftance from t to s was not en- 
 larged above 3— part of an inch ; from s to q, 
 the -£ of an inch ; from q to p, f ; from p 
 to 0, f j from to /z, 7-5-; from n to m, k |; 
 from m to /, 1 -j- T ^ of an inch ; from / to /, 
 1 + to inch nearly '> an ^ from i to b t three 
 inches. 
 
 In this Experiment we fee, that the firft 
 joint to r extended very little, it being al- 
 moft hardened, and come near to its full 
 growth, when I marked it: The next joint, 
 
 from 
 
Of Vegetation. 335 
 
 from r to ;/, being younger, extended fome- 
 thing more ; and the third joint, from n to k, 
 extended from \ of an inch, to 3 + jl inches; 
 but from k to b y the very tender joint, which 
 was but £ inch long, when I marked it, was, 
 when full grown, three inches long. 
 
 We may obferve, that Nature, in order 
 to fupply thefe young growing (hoots witk 
 plenty of ductile matter, is very careful to 
 furnifh, at fmall diftances, the young (hoots of 
 all forts of trees with many leaves throughout 
 their whole length, which ferve as fo many 
 jointly acting powers placed at different (la- 
 tions, thereby to draw with more eafe plenty 
 of fap to the extending fhoot. 
 
 The like provifion has Nature made in 
 the Corn, Grafs, Cane, and Reed-kind j the 
 leafy fpires, which draw the nourifliment to 
 each joint, being provided long before the 
 (lem (hoots; which (lender ftem, in its ten- 
 der ductile (late, would mod: eafily break, 
 and dry up too foon, fo as to prevent its due 
 growth, had not Nature, to prevent both 
 thefe inconveniencies, provided (Irong Thecas 
 or Scabbards, which both fupport and keep 
 long, in a fupple ductile (late, the tender 
 extending (lem. 
 
334 Of Vegetation. 
 
 I marked in the fame manner as the Vine, 
 at the proper feafons, young Honeyfuckle 
 {hoots, young Afparagus y and young Sun- 
 Jlowers - y and I found in them all a gradual 
 fcale of unequal extenfions, thofe parts ex- 
 tending moft which were tendereft. The 
 white pare of the Afparagus % which was 
 under-ground, extended very little in length, 
 and accordingly we find the fibres of the 
 white part very tough and ftringy : But the 
 greateft extenfion of the tender green part, 
 which was about four inches above the 
 ground when I marked it, feparated the marks 
 from a quarter of an inch to twelve inches 
 diftance > the greateft diftention of the Sun- 
 flower was from -i inch to four inches di- 
 ftance. 
 
 From thefe Experiments it is evident, that 
 the growth of a young bud to a {hoot con- 
 fifts in the gradual dilatation and extenfion 
 of every part, the knots of a fhoot being 
 very near each other in the bud, as may 
 plainly and diftindlly be feen in the flit bud 
 of the Vine and Fig-tree , but by this gra- 
 dual diftenfion of every part, they are ex- 
 tended to their full length. And we may 
 eafily conceive how the longitudinal capil- 
 lary tubes ftill retain their hollownefs, not- 
 
 with- 
 
Of Vegetation. 33 ^ 
 
 withftanding their being diftended, from the 
 like effect in melted glafs-tubes, which retain 
 a hollownefs, tho' drawn out to the fineft 
 thread. 
 
 The whole progrefs of the firft joint r is 
 very fhort in comparifon of the other joints, 
 becaufe at firft fetting out its leaves being 
 very fmall, and the feafon yet cooler than 
 afterwards, 'tis probable that but little fan 
 is conveyed to it ; and therefore it extending 
 but flowly, its fibres are in the mean time 
 grown tough and hard, before it can arrive 
 to any confiderable length. But as the feafon 
 advances, and the leaves inlarge, greater 
 plenty of nourishment being thereby con- 
 veyed, the fecond joint grows longer than the 
 firft, and the third and fourth ftill on gra- 
 dually longer than the preceding 5 thefe do 
 therefore, in equal times, make greater ad- 
 vances than the former. 
 
 The wetter the feafon, the longer and 
 larger (hoots do Vegetables ufually make -, 
 becaufe their fofc ductile parts do then con- 
 tinue longer in a moift, tender ftate: but in 
 a dry feafon the fibres fooner harden, and 
 ftop the further growth of the fhoot 5 and 
 this may probably be one reafon why the 
 two or three laft joints of every (hoot are 
 
 ufually 
 
i}6 Of Vegetation. 
 
 ufually ihorter than the middle joints, viz* 
 becaufe they mooting out in the more ad- 
 vanced hot dry fummer feafon, their fibres 
 are foon hardened and dried, and are withal 
 checked in their growth by the cool autum- 
 nal nights : I had a Vine-moot of one year's 
 growth, which was 14 feet long, and had 39 
 joints, all pretty nearly of an equal length, 
 except fome of the firft and laft. 
 
 And for the fame reafon, Beans and many 
 other plants, which (land where they are 
 much (haded, being thereby kept continually 
 moift:, do grow to unufual heights, and are 
 drawn up, as they call it, by the cver-fhadow- 
 ing trees, their parts being kept long, foft 
 and dudlile : j But this very moift (haded (fate 
 is ufually attended with fterility; very long 
 joints of Vines are alio obferved to be un- 
 fruitful. 
 
 This Experiment, which (hews the man- 
 ner of the growth of (hoots, confirms Bore Hi's 
 opinion, who, in his Book De mctu Ani- 
 malium, Pare fecond, Chap. 13. fuppofes 
 the tender growing (hoot to be diftended, 
 like fofc wax, by the expanfion of the moi- 
 fture in the fpongy pith ; which dilating 
 moifturc, he with good reafon concludes, 
 is hindered from returning back, (while it 
 
 expands) 
 
Of Vegetation. ^f 
 
 expands) by the fponginefs of the pith, with- 
 out the help of valves. For 'tis very pro- 
 bable, that the particles of water, which im- 
 mediately adhere to, and are ftrongly im- 
 bibed into, and attracted by every fibre of 
 the fpongy pith, will fuffer fome degree of 
 expanfion, before they can be detach'd by the 
 fun's warmth from each attracting fibre ; and 
 confequently the mafs of fpongy fibres, of 
 which the pith confifts, muft thereby be 
 extended. 
 
 And that the pith may be the more fer- 
 viceable for this purpofe, Nature has pro- 
 vided, in moft (hoots, a ftrong partition at 
 every knot ; which partitions ferve not only 
 as plinths or abutments for the dilating pith 
 to exert its force on, but alfo to prevent the 
 rarefied fap's too free retreat from the pith, 
 as well as for the ihooting forth of branches, 
 leaves and fruit. 
 
 But a dilating fpongy fubftance, by equally 
 expanding itfelf every way, would not pro- 
 duce an oblong fhoot, but rather a globofe 
 one, like an Apple ; to prevent which incon- 
 venience we may obferve, that Nature has 
 provided feveral Diaphragms, befides thofe 
 at each knot, which are placed at fmall di- 
 ftances acrofs the pith, thereby preventing 
 
 Z its 
 
338 Of Vegetation. 
 
 its too great lateral dilatation. Thefe are very 
 plain to be feen in Walnut-tree (hoots : And 
 the fame we may obferve in the pith of the 
 branches of the Sun-flower, and of feveral 
 other plants ; where, tho* thefe Diaphragms 
 are not to be diftinguifhed, while the pith is 
 full and replete with moifture, yet when it 
 dries up, they are often plain to be feen : and 
 it is further obferved, that where the pith 
 confifts of diftinct veficles, the fibres of thofe 
 veficles are often found to run horizontally, 
 whereby they can the better refift the too 
 great lateral dilatation of the moot. 
 
 We may obferve, that Nature makes ufe of 
 the fame artifice in the growth of the feathers 
 of Birds, which is very vifible in the great pi- 
 nion feathers of the wing, the fmaller and 
 upper part of which is extended by a fpongy 
 pith, but the lower and bigger quill-part by a 
 feries of large veficles, which, when replete 
 with dilating moifture, do extend the quill, 
 and keep it in a fupple ductile flate 5 but when 
 the quill is full grown, thefe veficles are always 
 dry : in which ftate we may plainly obferve 
 every veficle to be contracted at each end by 
 a Diaphragm or Sphincter, whereby its too 
 great lateral dilatation is prevented, but not 
 its diftenfion lengthwife.. 
 
 And 
 
Of Vegetation. 3 ? 9 
 
 And as this pith in the quill grows dry and 
 ufelefs after the quill is full-grown, we mav 
 obfcrve the fame in the pith of tree?, which 
 is always fucculcnt, and full of moifture, while 
 the '{hoot is growing, by the expanfion of 
 which the tender ductile (hoot is diftended in 
 every part, its fibres being at the fame time 
 kept fupple by this moifture ; but when each 
 year's moot is full grown, then the pith gra- 
 dually dries up, and continues for the future 
 dry and kecfey, its veficles being ever after 
 empty, Nature always carefully providing for 
 the fucceeding year's growth, by preferving 
 a tender ductile part in the bud replete with 
 fucculent pith. 
 
 And as in Vegetables, fo doubtlefs in Ani- 
 mals, the tender ductile bones of young Ani- 
 mals are gradually increafed in every part, 
 that is not hardened and oiTified 5 but fince it 
 was inconfiftent with the motion of the joints 
 to have the ends of the bones (oft and ductile, 
 as in Vegetables, therefore Nature makes a 
 wonderful provifion for this at the glutinous 
 ferrated joining of the heads to the fhanks of 
 the bones ; which joining, while it continues 
 ductile, the Animal grows ; but when it ofllfies, 
 then the Animal can no longer grow: As I 
 Was affured by the following Experiment, *ui& 
 
 Z 2 I 
 
340 Of Vegetation. 
 
 I took a half-grown Chick, vvhofe leg-bone 
 was then two inches long ; and with a fharp- 
 pointed iron, at half an inch diftance, I pierced 
 two fmall holes thro' the middle of the fcaly 
 covering of the leg and fhin-bone ; two months 
 after I killed the Chick, and upon laying the 
 bone bare, I found on it obfcure remains of 
 the two marks I had made at the fame diftance 
 of half an inch : So that that part of the bone 
 had not at all diftended lengthwife, fince the 
 time that I marked it 3 notwithstanding the 
 bone was in that time grown an inch more 
 in length, which growth was moftly at the 
 upper end of the bone, where a wonderful 
 provifion is made for its growth at the join- 
 ing of its head to the fhank, called by Anato- 
 mifts Sympbyjis. 
 
 And as the bones grow in length and fize, 
 fo mud the membranous, the mufcular, the 
 nervous, the cartilaginous and vafcular fibres 
 of the animal body necefTarily extend and ex- 
 pand, from the ductile nutriment which Na- 
 ture furnifhes every part withal ; in which 
 refpects animal bodies do as truly vegetate as 
 do the growing Vegetables : Whence it muft 
 needs be of the greateft confequence, that the 
 growing Animal be fupplied with proper nou- 
 rifhment for that purpoie, in order to form a 
 
 flrong 
 
Of Vegetation. 341 
 
 llrong athletick conftitution ; for when grow- 
 ing Nature is deprived of proper materials for 
 this purpofe, then is me under a neceffity of 
 drawing out very flender threads of life, as is 
 too often the cafe of young growing perfons, 
 who, by indulging in fpirituous liquors, or 
 other excefles, do thereby greatly deprave the 
 nutritive ductile matter, whence all the dif- 
 tending fibres of the body are fupplied. 
 
 Since we are by thefe Experiments afTured, 
 that the longitudinal fibres and fap-veflels of 
 wood in its firft year's growth, do thus diftend 
 in length by the extenfion of every part $ and 
 iince Nature in fimilar productions makes ufe 
 of the fame, or nearly the fame methods, thefe 
 confiderations make it not unreafonable to 
 think, that the fecond and following years 
 additional ringlets of v/ood are not formed 
 by a merely horizontal dilatation of the vef- 
 fels ; for it is not eafy to conceive, how lon- 
 gitudinal fibres and tubular fap-veffels mould 
 thus be formed, but rather by the fhooting 
 of the longitudinal tubes and fibres length- 
 ways from thofe of the lail year's wood, 
 whereby there is a free communication main- 
 tained between thefe and the fap-veffels of all 
 the preceding year's growth. The obferva- 
 tions on the manner of the growth of the 
 
 Z 3 ringlets 
 
34* Of Vegetation. 
 
 ringlets of wood in Experiment 46. (Fig, 30.) 
 do further confirm this. 
 
 But whether it be by an horizontal or lon- 
 gitudinal mooting, we may obferve that Na- 
 ture has taken great care to keep the parts 
 between the bark and wood always very fup- 
 pie with flimy maifrure ; from which ductile 
 matter the woody fibres, veficles and buds are 
 formed. 
 
 Thus we fee that Nature, in order to the 
 production and growth of all the parts of 
 Animals and Vegetables, prepares her ductile 
 matter ; in doing of which (lie felects and 
 combines particles of very different degrees 
 of mutual attraction, curioufly proportioning 
 the mixture according to the many different 
 purpofes file defigns it for 3 either for bony or 
 more lax fibres of very different degrees in 
 Animals, or whether it be for the forming 
 of woody or more fofc fibres of various kinds 
 in Vegetables. 
 
 The gx r eat variety of which different fub- 
 ftances in the fame Vegetable prove, that 
 there are appropriated veffels for conveying 
 very different forts of nutriment. And in 
 many Vegetables ibme of thofe appropriate 
 veffels are plainly to be ken replete either 
 with milky, ydlow, or red nutriment. 
 
 Dr- 
 
Of Vegetation. 34? 
 
 Dr. Keil/ y in his account of animal fecre- 
 tion, page 49. obferves, that where Nature 
 intends to feparate a vifcid matter from the 
 blood, (he contrives very much to retard its 
 motion; whereby the inteftine motion of the 
 blood being allayed, its particles can the bet* 
 ter coalefce, in order to form the vifcid fecre- 
 tion. And Dr. Grew, before him, obferved 
 an inftance of the fame contrivance in Veire- 
 tables, where a fecretion is intended, that is 
 to cornpofe a hard fubftance, viz. in the ker- 
 nel or feed of hard ftone fruits, which does 
 not immediately adhere to, and grow from 
 the upper part of the ftone, which would be 
 the fhorteft and neareft way to convey nou- 
 rifhment to it ; but the fingle umbilical vef- 
 fel, by which the kernel is nourished, fetches 
 a compafs round the concave of the ftone, 
 and then enters the kernel near its cone; by 
 which artifice this vefTel being much pro- 
 longed, the motion of the fap is thereby re- 
 tarded, and a vifcid nutriment conveyed to 
 the feed, which turns to hard fubftance. 
 
 The like artifice of Nature we may obferve 
 in the long capillary fibrous veiTels, which lie 
 between the green hull and the hard (hell of 
 the Walnut, which are analogous to the 
 fibrous Mace of Nutmegs, the ends of whofe 
 
 Z 4. hairy 
 
344 Of Vegetation. 
 
 hairy fibres are inferted into the angles of the 
 furrows in the Walnut-fhell : Their ufe is 
 therefore doubtlefs to carry in thofe long di- 
 flin<ft veffels the very vifcous matter, which 
 turns, when dry, to a hard (hell ; whereas, 
 were the fhell immediately nourifhed from 
 the foft pulpous hull that furrounds it, it 
 would certainly be of the fame foft conftitu- 
 tion, the ufe of the hull being only to keep 
 the fhell in a foft ductile ftate, till the Nut has 
 done growing. 
 
 We may obferve the like effect of a flower 
 motion of the fap in Ever-greens, which per- 
 fpiring little, their fap moves much more 
 flowly than in more perfpiring trees, and is 
 therefore much more vifcid, whereby they 
 are better enabled to out-live the winter's 
 cold. It is obferved, that the fap of Ever- 
 greens in hot countries is not fo vifcous as the 
 fap of more northern Ever-greens, as the Fir, 
 &c. for the fap in hotter countries muft have 
 a brisker motion, by means of its greater per- 
 fpiration. 
 
 Experiment CXXIV. 
 
 In order to inquire into the manner of the 
 expanfion of leaves, I provided a little oaken 
 board or fpatula, a b c d y of this fhape and 
 
 fize 
 
Of Vegetation. 34 j 
 
 fize (Fig. 43.) ; through the broad part, at a 
 quarter of an inch diftance from each other, 
 I run the points of 25 pins x x y which flood 
 ^ inch thro', and divided a fquare inch into 
 16 equal parts. 
 
 With this inftrument in the proper feafon, 
 when leaves were very young, I pricked feve- 
 ral of them thro' at once with the points of 
 all thefe pins, dipping them firft in the red- 
 lead, which made lafting marks. 
 
 (Fig. 44.) reprefents the fhape and fize of 
 a young Fig-leaf, when firft marked with red 
 points, 4- inch diftance from each other. 
 
 (Fig. 45.) reprefents the fame full-grown 
 leaf, and the numbers anfwer to the corre- 
 fponding numbers in the young leaf; whereby 
 may be feen how the feveral points of the 
 growing leaf were feparated from each other, 
 and in what proportion, viz. from a quarter 
 of an inch to about three quarters of an inch 
 diftance. 
 
 In this Experiment we may obferve, that 
 the growth and expaniion of the leaves is 
 owing to the dilatation of the veficles in every 
 part, as the growth of a young fhcot was 
 fhewn to be owing to the fame caufe in the 
 foregoing Experiment, and doubtlefs the cafe 
 is the fame in all fruits. 
 
 If 
 
3 4*> Of Vegetation. 
 
 If thefe Experiments on leaves were further 
 purfued, there might probably be many curi- 
 ous obfervations made in relation to the fhape 
 of leaves, by obferving the difference of the 
 progreffive and lateral motions of thefe points 
 in different leaves, that were of very different 
 lengths in proportion to their breadths. 
 
 That the force of dilating fap and air, in- 
 cluded in the innumerable little veficles of 
 young tender fhoots and leaves, is abundantly 
 fufficientfor the extending of fhoots, and ex- 
 panding of leaves j we have evident proof 
 from the great force we find in the fap of the 
 Vine, chap. 3. and from the vaft force with 
 which infinuating moifture expanded the 
 Peas. Experiment 3 2. we fee the great power 
 of expanding water, when heated in the 
 engine to raife water by fire -, and water with 
 air and other active particles inxapillary tubes, 
 and innumerable fmall veficles, do doubtlefs 
 ad with a great force, tho' expanded with 
 no more heat than what the fun's warmth 
 gives them. 
 
 And thus we fee that Nature exerts a con- 
 fiderable, tho' fecret and filent power, in car- 
 rying on all her productions; which demon- 
 ftrates the wifdom of the Author of nature, 
 in giving fuch due proportion and direction 
 
 to 
 
Of Vegetation. 347 
 
 to thefe powers, that they uniformly concur 
 to the production and perfection of natural 
 Beings ; whereas, were fuch powers under no 
 guidance, they mud necefTarily produce a 
 Chaos, inftead of that regular and beautiful 
 Syftem of nature which we fee. 
 
 We may plainly fee the influence of the 
 fun's warmth in expanding the fap in all the 
 parts of Vegetables, as well in the roots as 
 the body that is above-ground, by the influ- 
 ence it has on the fix Thermometers, defcribed 
 under Experiment 20. five of which were 
 fixed at different depths, from two inches to 
 two feet under-ground, the other being ex- 
 pofed to the open air. 
 
 When, in the greateft noon-tide heat, the 
 fpirit of that which was expofed to the fun 
 was rifen, fince the early morning, from 2 1 
 to 48 degrees, then the fpirit in the fecond 
 Thermometer, whofe ball was two inches 
 under-ground, was at 45 degrees; and the 
 3d, 4th, and 5th Thermometers were gradu- 
 ally of lefs and lefs degrees of heat, as they 
 were placed lower in the ground to the fixth 
 Thermometer, which was two feet under- 
 ground, fa which the fpirit was 3 1 degrees 
 high. In this ftate of heat on all the parts 
 of the Vegetable, we fee the fun mult have 
 
 a very 
 
34^ Of Vegetation. 
 
 a very confiderable influence in expanding 
 the fap in all its parts. The warmth was 
 much greater on the body above-ground, than 
 on the roots which were two feet deep ; thofe 
 roots, and parts of roots, which are deepeft, 
 as they feel much lefs of the fun's warmth, 
 fo are they not fo foon, nor fo much affedled 
 by the alternacies of day and night, warm 
 and cold : but that part of Vegetables which 
 is above-ground, mull have its fap con fid er- 
 ably rarefied, when the heat increafed from 
 morning to two o' clock afternoon, fo much 
 as to raife the fpirit in the ift Thermometer 
 from 21 to 48 degrees above the freezing 
 point. 
 
 When in the coldeft days of the winter 
 1724, the froft was fo intenfe as to freeze the 
 furface of ftagnant water near an inch thick, 
 then the fpirit in the Thermometer , which was 
 expofed to the open air, was fallen four de- 
 grees below the freezing point; the fpirit of 
 that whofe ball was two inches under-ground, 
 was four degrees above the freezing point; 
 the 3d, 4th and 5th "Thermometers were pro- 
 portionably fallen lefs and lefs, as they were 
 deeper, to the 6th Thermometer ; which being 
 two feet under-ground, the fpirit was ten 
 degrees above the freezing point. In this 
 
 ftate 
 
Of Vegetation. 349 
 
 Hate of things the work of Vegetation feemed 
 to be wholly at a ftand, at lead within the 
 reach of the froft. 
 
 But when the cold was fo far relaxed, as 
 to have the fpirit in the firft Thermometer 
 but five degrees above the freezing point, the 
 fecond 8 degrees, and the fixth 13 degrees, 
 tho' it was ftill very cold, yet this being fome 
 advance from freezing towards warm, and 
 there being confequently fome expanfion of 
 the fap, feveral of the hardy Vegetables grew, 
 viz. fome Ever-greens, Snow-drops, Crocus's, 
 &c. which forward hardy plants do proba- 
 bly partake much of the nature of Ever- 
 greens in perfpiring little ; and the motion 
 of their fap being confequently very flow, it 
 will become more vifcous, as in Ever-greefts, 
 and thereby the better able to refift the win- 
 ter's cold ; and the fmall expanfive force 
 which this fap acquires in the winter, is 
 moftly exerted in extending the plant, little 
 of it being wafted in proportion to the fum- 
 mer's perfpiration. 
 
 Supported by the evidence of many of the 
 foregoing Experiments, I will now trace the 
 Vegetation of a Tree from its firft feminal 
 plant in the Seed to its full maturity and pro- 
 duction of other Seeds, without entring into 
 
 a par- 
 
150 Of Vegetation. 
 
 a particular defcription of the ftru&ure of the 
 parts of Vegetables, which has already been 
 accurately done by Dr. Grew and Malpighi. 
 
 We fee by Experiment 56. 57. 58. on di- 
 ftilled Wheat, Peas, and Muftard-feed, what 
 a wonderful provifion Nature has made, that 
 the Seeds of Plants mould be well ftored with 
 very active principles, which principles are 
 there compacted together by Him, who curi- 
 oufly adapts all things to the purpofes for 
 which they are intended, with fuch a juft 
 degree of cohefion, as retains them in that 
 ftate till the proper feafon of germination : 
 for if they were of a more lax conftitution, 
 they would too loon diffolve, like the other 
 tender annual parts of plants ; and if they 
 were more firmly connected, as in the hearc 
 of Oak, they muft neceffarily have been many 
 years in germinating, though fuppled with 
 moifture and warmth. 
 
 When a Seed is fown in the ground, in 
 a few days it imbibes fo much moifture, as 
 to fwell with very great force 5 as we fee in 
 the Experiment on Peas in an iron pot, 
 this forcible fwelling of the lobes of the 
 Seed ar> a r y (Fig. 46.) does probably pro- 
 trude moifture and nourishment from the 
 capillary vefTels r r 7 which are called the 
 
 Seed- 
 
Of Vegetation. 3 5 t 
 
 Seed-roots, into the radicle c z d- y which 
 radicle, when it has fhot fome length into 
 the ground, does then imbibe nourifhment 
 from thence ; and after it has acquired fuf- 
 ficient ftrength, as this tender ductile root 
 is extending from z to r, it muft necefla- 
 rily carry the expanding Seed-lobes upwards, 
 at the fame time that the dilating from z to 
 d makes it fhoot downwards ; and when 
 the root is thus far grown, it fupplies the 
 Plume b with nourifhment, which thereby 
 fwelling and extending, opens the lobes a r, 
 a r, which are at the fame time railed 
 above-ground with the Plume; where they, 
 by expanding and growing thinner, turn to 
 green leaves (except the Seeds of the Pulfe 
 kind); which leaves are of fuch importance 
 to the yet tender Plume, that it perifhes, or 
 will not thrive if they are pulled off; which 
 makes it probable, that they do the fame 
 office to the Plume, that the leaves adjoining 
 to Apples, Quinces, and other fruits, do to 
 them, viz. they draw fap within the reach 
 of their attraction; fee Exper. 8. and 30. 
 But when the Plume is fo far advanced ia 
 growth, as to have branches and expanded 
 leaves to draw up nourifhment ; then thefe 
 fupplemental feminal leaves, a r, a r, being of 
 
 no 
 
3 5 i 0/ Vegetation. 
 
 no farther ufe, do periflij not only becaufe 
 the now grown and more expanded leaves 
 of the young plant or tree do fo over-fhadow 
 the fupplemental leaves, that their former 
 more plentiful perfpiration is much abated, 
 and thereby alfo their power of attracting fap 
 fails ; but alfo, becaufe the fap is drawn from 
 them by the leaves, and they being thus de- 
 prived of nourimment, do perifh. 
 
 As the tree advances in ftature, the firft, 
 fecond, third, and fourth order of lateral 
 branches {hoot our, each lower order being 
 longer than thofe immediately above them ; 
 not only on account of primogeniture, but 
 alfo, becaufe being inferted in larger parts of 
 the trunk, and nearer the root, they have the 
 advantage of being ferved with greater plenty 
 of fap, whence arifes the beautiful parabo- 
 lical figure of trees. 
 
 But when trees ftand thick together in 
 Woods or Groves, this their natural fhape is 
 altered, becaufe the lower lateral branches 
 being much fhaded, they can perfpire little ; 
 and therefore drawing little nourifhment, 
 they perifh ; but the top branches being ex- 
 pofed to a free drying air, they perfpire plen- 
 tifully, and thereby drawing the fap to the 
 top, they advance much in height : But vice 
 
 versa, 
 5 
 
Of Vegetation. jyj 
 
 versa, if, when fuch a Grove of tall trees is 
 cut down, there be left here and there a fingle 
 tree, that tree will then (hoot out lateral 
 branches $ the leaves of which branches now 
 perfpiring freely, will attract plenty of fap, 
 on which account the top being deprived of 
 its nourishment, it ufually dies. 
 
 And as trees in a Grove or Wood grow 
 only in length, becaufe all the nourifhmenc 
 is by the leaves drawn to the top, moft of 
 the fmall lateral (haded branches in the mean 
 time perifhing for want of perfpiration and 
 nutrition ; fo the cafe is the very fame in the 
 branches of a tree, which ufually making an 
 angle of about 45 degrees with the item of 
 the tree, do thereby beautifully fill up, at equal 
 and proper diftances, the fpace between the 
 lower branches and the top of the tree, form- 
 ing thereby, as it were, a parabolical Grove or 
 Thicket, which (hading the arms, the fmall 
 lateral moots of thofe arms ufually perifh for 
 want of due perfpiration ; and therefore the 
 arms continue naked like the bodies of trees 
 in a grove, all the nourishment being drawn 
 up to the tops of the feveral branches by the 
 leaves which are there expofed to the warm 
 fun, and free drying air, whereby the branches 
 of trees expand much. 
 
 A a And 
 
5 54 Of Vegetation. 
 
 And where the lateral branches are very 
 vigorous, fo as to make ftrong moots, and 
 attract the nourimment plentifully, there the 
 tree ufually abates in its height : But where 
 the tree prevails in height, as in groves, there 
 commonly its lateral branches are fmalleft. 
 So that we may look upon a tree as a com- 
 plicated Engine, which has as many different 
 powers as it has arms and branches, each 
 drawing from their common fountain of life 
 the root : and the whole of each yearly growth 
 of the tree will be proportionable to the fum 
 of their attracting powers, and the quantity 
 of nourimment the root affords : But this at- 
 tracting power and nourimment will be more 
 or lefs, according to the different ages of the 
 tree, and the more or lefs kindly feafons of 
 the year. 
 
 And the proportional growth of their late- 
 ral and top branches, in relation to each other, 
 will much depend on the difference of their 
 feveral attracting powers. If the peripiration 
 and attraction of the lateral brances is little 
 or nothing, as in woods and groves, then the 
 top branches will mightily prevail -, but when 
 in a free open air the perfpiration and attra- 
 ction of the lateral branches comes nearer to 
 an equality with that of the top, then are the 
 
 afpi- 
 
Of Vegetation. 355 
 
 afpirings of the top branches greatly checked. 
 And the cafe is the fame in moft other Vege- 
 tables, which, when they ftand thick toge- 
 ther, grow much in length with very weak 
 lateral moots. 
 
 And as the leaves are thus ferviceable in 
 promoting the growth of a tree, we may ob- 
 ferve that Nature has placed the petals of the 
 leaves-ftalks where moft nourifhment is want- 
 ing, to produce leaves, moots and fruit ; and 
 fome fuch thin leafy expanfion is fo neceffary 
 for this purpofe, that Nature provides fmall 
 thin expanfions, which may be called pri- 
 mary leaves, that ferve to protect and draw 
 nourifhment to the young moot and leaf-buds, 
 before the leaf itfelf is expanded. 
 
 And herein we fee the admirable contri- 
 vance of the Author of nature in adapting 
 her different ways of conveying nourifhment 
 to the different circumftances of her produ- 
 ctions. For in this embryo ftate of the buds 
 a fuitable proviiion is made to bring nou;ifh- 
 ment to them in a quantity fufficient for their 
 then fmall demands : But when they are in 
 fome degree increafed and formed, a much 
 greater quantity of nourifhment is neceifarv, 
 in proportion to their greater incteafe : Na- 
 ture, that fhe may then no longer fupply with 
 
 A a 2 a 
 
35^ Of Vegetation. 
 
 a fcanty hand, immediately changes her me- 
 thod, in order to convey nourifhment with 
 a more liberal hand to her produ&ions > 
 which fupply daily increafes by the greater 
 expanfion of the leaves, and confequently the 
 more plentiful attraction and fupply of fap, 
 as the greater growth and demand for it in- 
 creafes. 
 
 We find a much more elaborate and beau- 
 tiful apparatus, for the like purpofe, in the 
 curious expanfions of bloflbms and flowers, 
 which feem to be appointed by Nature not 
 only to protedt, but alfo to draw and convey 
 nourifhment to the embryo fruit and feeds. 
 But as foon as the Calix is formed into a 
 fmall fruit, now impregnated with its minute 
 feminal tree, furnimed with its Secondine, 
 Corion and Amnion, (which new-fet fruit 
 may, in that ftate, be looked upon as a com- 
 plete egg of the tree, containing its young 
 unhatched tree, yet in embryo) then the blol- 
 fom falls off, leaving this new-formed egg, 
 or firft-fet fruit, in this infant ftate, to im- 
 bibe nourifhment fufficient for itfelf, and the 
 F&tus with which it is impregnated : Which 
 nourifhment is brought within the reach 
 and power of its fudlion by the adjoining 
 leaves. 
 
 If 
 
Of Vegetation. 357 
 
 If I may be allowed to indulge conjecture 
 in a cafe in which the mod diligent inquirers 
 are as yet, after all their laudable refearches, 
 advanced but little farther than mere con- 
 jecture, I would propofe it to their confidera- 
 tion, whether from the manifeft proof we 
 have that fulphur ftrongly attracts air, a hint 
 may not be taken, to confider whether this 
 may not be the primary ufe of the Farina 
 fcecundans, to attract and unite with itfelf 
 elaftick or other refined active particles. That 
 this Farina abounds with fulphur, and that 
 a very refined fort, is probable, from the 
 fubtle oil which Chymifts obtain from Saf- 
 fron. And if this be the ufe of it, was it 
 poflible that it could be more aptly placed 
 for the purpofe, than on very moveable Apices 
 fixt on the flender points of the Stamina, 
 whereby it might eafily, wich the leaft breath 
 of wind, be difperfed in the air, thereby fur- 
 rounding the plant, as it were, with an Ac- 
 mofphere of fublimed fulphureous pounce ? 
 (for many trees and plants abound with it) 
 which uniting with the air-particles, they, 
 or a very fublimed fpirit from them, may, 
 perhaps, be infpired or imbibed at feveral 
 parts of the plant, and efpecially at the Pijiil- 
 lum, and be thence conveyed to the Capfula 
 
 A a 3 Jem* 
 
3 5 8 Hoe Conchfion. 
 
 feminalis, efpecially towards evening, and ia 
 the night, when the beautiful Petala of the 
 flowers are clofed up, and they, with all the 
 other parts of the Vegetable, are in a ftrongly 
 imbibing ftate. And if to thefe united ful- 
 phureous and aereal particles, we fuppofe 
 fome particles of light to be joined, (for Sir 
 Ijaac Newton has found, that fulphur attracts 
 light ftrongly) then the refult of thefe three, 
 by far the mofl active principles in Nature, 
 will be a PunBum S aliens, to invigorate the 
 feminal plant : And thus we are at laft con- 
 dueled, by the regular Analyfis of vegetable 
 Nature, to the firft enlivening principle of 
 their minuteft Origin. 
 
 The Conchjion. 
 
 V| T E have, from the foregoing Experi- 
 V ments, many proofs of the very great 
 and different quantities of moifture imbibed 
 and perfpired by different kinds of Trees, 
 and alfo of the influence the feveral ftates of 
 the air, as to warm or cold, wet or dry, have 
 on that perfpiration. We fee alfo what ftores 
 of moifture Nature has provided in the Earth 
 againft a dry feafon, to anfwer this great ex- 
 pence of it in the production and fupport of 
 Vegetables j how far the Dew can contribute 
 
 to 
 
The Conclujion. 359 
 
 to this fupply, and how infufficient its fmall 
 quantity is towards making good the great 
 demands of perforation : And that plants can 
 plentifully imbibe moifture thro' their items 
 and leaves, as well as perfpire it. 
 
 We fee with what degrees of warmth the 
 Sun, that kindly natural genius of Vegetation, 
 acts on the feveral parts of Vegetables, from 
 their tops down to their roots two feet under 
 ground. 
 
 We have alfo many proofs of the great 
 force with which plants, and their feveral 
 branches and leaves, imbibe moiflure up their 
 capillary fap-veflels : The great influence the 
 perfpiring leaves have in this work, and the 
 care Nature has taken to place them in fuch 
 order, and at fuch proper diftances, as may 
 render them moft ferviceable to this purpofe, 
 efpecially in bringing plenty of nourimment 
 to the young growing moots and fruit, whofe 
 ftem is ufually furrounded with them near 
 the fruit's infertion into the twig. 
 
 We fee here too, that the growth of moots, 
 leaves and fruit, co:i lifts in the extenfion of 
 every part ; for the effecting of which, Nature 
 has provided innumerable little veficles, which 
 being replete with dilating moifture, it does 
 thereby powerfully extend, and draw out every 
 ductile part. A a 4 V.'e 
 
3<Jo The Conclufion. 
 
 We have here alfo many inftances of the 
 great force of the afcending fap in the Vine in 
 the bleeding feafon ; as alfo of the fap's freely 
 either afcending or defcending, as it fhall hap- 
 pen to be drawn by the perfpiring leaves ; and 
 alfo of its ready lateral motion thro* the late- 
 rally communicating fap-veflels ; together 
 with many proofs of the great plenty of air 
 drawn in and mixt with the fap, and incor- 
 porated into the fubftance of Vegetables. 
 
 If therefore thefe Experiments and Obfer- 
 vations give us any farther infight into the 
 nature of plants, they will then doubtlefs be 
 of fome ufe in Agriculture and Gardening, 
 either by ferving to redtify fome miftaken 
 notions, or by helping farther to explain the 
 reafons of many kinds of culture, which long 
 repeated experience has found to be good, and 
 perhaps by leading us to make fome advances 
 therein : But as it requires a long feries and 
 great variety of frequently repeated Experi- 
 ments and Obfervations to make a very finall 
 advance in the knowledge of the nature of 
 Vegetables, fo proportionably we are from 
 thence only to expedt fome gradual improve- 
 ments in the culture of them. 
 
 The fpecifick differences of Vegetables, 
 
 which are all fuftained and grow from the 
 
 fame 
 
The Conchjion. ^61 
 
 fame nourifhment, is doubtlefs owing to the 
 very different formation of their minute vef- 
 fels, whereby an almoft infinite variety of 
 combinations of the common principles of 
 Vegetables is made ; whence fome abound 
 more with fome principles, and fome with 
 others. Hence fome are of a warmer and 
 more fulphureous, others of a more watry, 
 faline, and therefore colder nature 5 fome of a 
 more firm and lafling, others of a more lax 
 and perifhable conftitution. Hence alio it is 
 that fome plants flourish befl in one climate, 
 and others in another ; that much moifture is 
 kindly to fome, and hurtful to others ; that 
 fome require a ftrong, rich, and others a poor, 
 fandy foil ; fome do bell: in the (hade, and 
 others in the fun, &c. And could our eyes 
 attain to a fight of the admirable texture of 
 the parts on which the fpecifick differences in 
 plants depend, what an amazing and beautiful 
 fcene of inimitable embroidery fhould we be- 
 hold ? what a variety of mafterly ftrokes of 
 machinery? what evident marks of confum- 
 mate wifdom fhould we be entertained with ? 
 
 We may oblerve, that the conftitution of 
 plants is curioufly adapted to the prefent fiate 
 of things, fo as to be mod flourifhing and 
 vigorous in a middle (rate of the air, viz. 
 
 when 
 
$6i The Conchjion. 
 
 when there is a due mixture and proportion 
 of warm and cold, wet and dry 5 but when 
 thefeafons deviate far to any extreme of thefe, 
 then are they lefs or more injurious to the 
 feveral forts of Vegetables, according to the 
 very different degrees of hardinefs, or healthy 
 latitude they enjoy. 
 
 The different feafons in which plants thrive 
 beft, feem to depend, among other caufes, on 
 the very different quantities imbibed and per- 
 fpired by different kinds of plants. Thus 
 the Ever-greens perfpiring little, and having 
 thereby a thick, vifcid, oily fap, they can the 
 better endure the winter's cold, and fubfifl 
 with little frem nourifhment : They feem 
 many of them to flourifh mod in the tem- 
 perate feafons of the year, but not fo well in 
 the hotteft part of fummer, becaufe their per- 
 foration is then fomewhat too great, in pro- 
 portion to the flow afcent of the fap, which 
 makes fome of them at that feafon to abate of 
 their vigour : Thus fome plants, which grow 
 and thrive with the flow perfpiration of Ja- 
 7iuary and February, perirfi as the fpring ad- 
 vances, and the warmth and perfpiration is 
 too great for them. And thus Garden Peas 
 and Beans, which are fown in what is found 
 to be their proper feafon, viz. in November, 
 
 Janu- 
 
T'he Conchjion. 365 
 
 January, or February, tho* they make but a 
 ilow progrefs in their growth upwards, du- 
 ring the cold feafon, yet their roots, as alfo 
 thofe of winter Corn, do in the mean time 
 fhoot well into the warmer earth, fo as to be 
 able to afford plenty of nourifhment when 
 the feafon advances, and there is a greater 
 demand of it both for nutrition and perfpira- 
 tion. But when Peas are fown in June, in. 
 order for a crop in September, they rarely 
 thrive well, unlefs in a cool moift fummer, 
 by reafon of the too great perfpiration caufed 
 by the fummer's heat, which dries and har- 
 dens their fibres before they are full grown. 
 
 Tho' we have from thefe Experiments, 
 and from common obfervation, many proofs 
 of the great expanfive force, with which the 
 fibrous roots of plants fhoot, yet the lefs re- 
 finance thefe tender fhoots meet with, the 
 greater progrefs they will certainly make in 
 equal times : And therefore one confiderable 
 ufe of fallowing and trenching ground, and 
 of mixing therewith feveral forts of compofr, 
 as Chalk, Lime, Marie, Mould, &c. is not 
 only thereby to repleniih it with rich manure, 
 but alio to loofen and mellow the foil, not 
 only that the air may the more eafily pene- 
 trate to the roots, but alfo that the roots may 
 
 the 
 
364 y^tf Conch/ion. 
 
 the more readily make vigorous (hoots. And 
 the greater proportion the furface of the roots 
 bears to the furface of the plants above- 
 ground, fo much the greater quantity of 
 nourifhment they will afford; and confe- 
 quently the plants will be the more vigorous, 
 and better able to weather it out, againft 
 unkindly feafons, than thofe plants whofe 
 roots have made much (horter fhoots. Herein 
 therefore confifts the great care and skill of 
 the Husbandman, to adapt his different forts 
 of Husbandry to the very different foils, feafons 
 and kinds of grain ; that the feveral forts of 
 earth, from the very ftiff and ftrong ground, 
 to the loofe light earths, may be wrought to 
 the beft temper they are capable of, for the 
 kindly {hooting and nourishing of the roots. 
 And probably the Husbandman might get 
 many ufeful hints, to dired: him in adapt- 
 ing the feveral kinds of manure, and dif- 
 ferent forts and feafons of culture, to his 
 different foils and grains, if in the feveral 
 ftages and growth of his Corn he would 
 not only make his obfervations on what 
 appears above-ground, but would alfo fre- 
 quently dig up, compare and examine the 
 roots of plants of each fort, efpecially of 
 thofe which grew in different foilsj and were 
 
 any 
 
7*he Conchjion. 365 
 
 any how cultivated in a different manner from 
 each other ; this would inform them alfo, 
 whether they fowed their Corn too thick or 
 too thin, by comparing the branchings and 
 extent of each root, with the fpace of ground 
 allotted it to grow in. 
 
 And fince we find fo great a quantity of 
 air infpired and mixt with the fap, and 
 wrought into the fubftance of Vegetables, 
 the advantage of ploughing and fallowing 
 ground feems to arife not only from the 
 killing the weeds, and making it more mel- 
 low, for the (hooting of the roots of Corn ; 
 but it is thereby alfo the better expofed to 
 have the fertilizing, fulphureous, aereal, and 
 acid particles of the air mixt with ir, which 
 make land fruitful, as is evident from the 
 fertility which the fword or furface of land 
 acquires, by being long expofed to the air, 
 without any culture or manure whatever. 
 
 We have ken many proofs of the great 
 quantities of liquor imbibed and perfpired 
 by plants, and the very fenfible influence 
 which different flates of the air had on their 
 more or lefs free perfpiration : A main in- 
 tention therefore to be attended to in the 
 culture of them, is to take due care, that 
 they be fown or planted in proper feafons 
 
 and 
 
i66 The Conchjion. 
 
 and foils, fuch as will afford them their due 
 proportion of nourifhment ; which foils, as 
 they are exhaufted, muft, as 'tis well known, 
 from time to time, be replenifhed with frefh 
 compoft, fuch as is full of faline, fulphu- 
 reous and aereal particles, with which com- 
 mon dung, lime, afhes, fvvord, or burn- 
 bated turf abound ; as alfo fuch manures, 
 as have nitrous and other falts in them : for 
 tho' neither nitre nor common fait be found 
 in Vegetables, yet fince they are obferved to 
 promote fertility, it is reafonable to con- 
 clude, that their texture is greatly altered 
 in Vegetation, by having their acid volatile 
 falts feparated from the attracting central 
 air and earthy particles, and thereby make- 
 ing new combinations with the nutritive 
 juice; and the probability of this is further 
 confirmed, from the great plenty of air and 
 volatile fait, which is found in another com- 
 bination of them, vfa in the Tartar of 
 fermenting liquors : For it is the opinion of 
 Chymifts, that there is but one volatile Salt 
 in nature, out of which all other kinds of 
 falts are formed by very different combina- 
 tions; all which nutritive principles do, by 
 various combinations of the cultivated earth, 
 compofe that nutritive ductile matter, out 
 
 of 
 
tfhe Conchtfion. ^67 
 
 of which the parts of Vegetables are formed, 
 and without which the watry vehicle alone 
 cannot render a barren foil fruitful. 
 
 Nor is this the only care : The thriving 
 and fertility of plants and trees depends 
 much upon the happy influence and con- 
 currence of a great variety of other cir- 
 cumftances. Thus many trees are unfruit- 
 ful by being planted too deep, whereby 
 their roots being in too moid: a ftate, and 
 too far from the proper influence of the 
 Sun, whofe power greatly decreafes, the 
 deeper we go, as we fee in Experiment 20. 
 they imbibe too much crude moifture, which, 
 tho' productive of wood, is yet unkindly for 
 fruit. 
 
 Or if, when not planted too deep, they 
 are full of crude fap, either by being too 
 luxurious, or too much fhaded ; or are 
 planted in a moift, when they delight in a 
 dry foil, then the flip is not ib fufficiently 
 digefted by the Sun's warmth, as to be in 
 that ductile ftate, which is proper for the 
 producing of fruit. 
 
 And thus the Vine, which is known to 
 thrive well in a dry, gravelly, rocky foil, 
 will not be fo fruitful in a moid:, ft iff, clay 
 ground: And accordingly we may obferve 
 
 in 
 
3<58 The Conclufion. 
 
 in Experiment 3. that the/ the Vine imbibed 
 and perfpired more than the Ever-green, yet 
 it perfpired lefs than the Apple-tree, which 
 delights in, and bears bed in a ftrong brick- 
 earth clay 5 for tho' the Vine bleeds moil 
 freely in its feafon, produces many long 
 fucculent (hoots, and bears great plenty of 
 a very juicy fruit, yet from that Experiment 
 it is plain, that it is not a great perfpirer, 
 and therefore thrives beft in a dry, rocky, or 
 gravelly foil. 
 
 The confiderable quantity of moifture, 
 which by Experiment 16. is perfpired from 
 the branches of trees, during the cold winter 
 feafon, plainly {hews the reafon why, in a 
 long feries of cold North-eafterly winds, the 
 bloflbms, and tender young-fet fruit and 
 leaves, are in the early fpring fo frequently 
 blafted, viz. by having the moifture exhaled 
 fafter than it can be fupplied from the trees : 
 for doubtlefs that moifture rifes the flower 
 from the root, the colder the feafon is, tho' it 
 rifes in fome degree all the winter, as is evi- 
 dent from the fame Experiment. 
 
 And from the fame caufe it is, that the 
 Jeafy fpires of Corn are, by thefe cold dry- 
 ing winds, often faded and turned yellow ; 
 which makes the Husbandman, on thefe oc- 
 
 cafions, 
 
 5 
 
The Concltijion. 369 
 
 crXions, wifh for fnow ; which, tho' it be very 
 cold, yet it not only defends the root from 
 being frozen, but alio fcreens the Corn from 
 thefe drying winds, and keeps it in a moiit, 
 florid, fupple ftate. 
 
 It feems therefore to be a very reafonable 
 direction, which is given by fome of the 
 Authors, who write on Agriculture and Gar- 
 dening, viz, during thefe cold drying wind?, 
 when little dew falls, to water the trees in 
 dry foils, in the bloffoming feafon, and while 
 the young-fet fruit is tender ; and provided 
 there is no immediate danger of a froft, or in 
 cafe of continued froft, to take care to cover 
 the trees well, and at the fame time to fprinkle 
 them with water, which is imitating Nature's 
 method of watering every part : But if the 
 fuccefs of this practice in cold weather may 
 be thought a little doubtful, yet the fprin- 
 kling the bodies and leaves of trees, in a very 
 hot and dry fummer feafon, feems moil rea- 
 fonable$ for by Exper. 42. they will imbibe 
 much moiflure. 
 
 As to Hoping fhelters over Wall-trees, I 
 have often found, that when they are fo broad 
 a^s to prevent any rain or dew coming at the 
 trees, they do more harm than good, in thefe 
 long eafterly drying winds, becaufe they pre- 
 
 B b vent 
 
\7 o The Conclufion. 
 
 vent the rain and dews falling on them, which 
 would not only refrefh and fupple them, but 
 alfo convey nourifhment to them : But in the 
 cafe of fharp frofts after fhowers of rain, thefe 
 fhelters, and other fences, mull needs be of 
 excellent ufe to prevent the almoft total de- 
 ftruction which is occafioned by the freezing 
 of the tender parts of Vegetables, when they 
 are full faturate with rain. 
 
 The full proof we have from thefe Expe- 
 riments, of the ferviceablenefs of the leaves in 
 drawing up the fap, and the care we fee Na- 
 ture takes in furnifhing the twigs with plenty 
 of them, principally near the fruit, may in- 
 ftrudl us on the one hand, not to be too lavifh 
 in pruning them off, and to be ever mindful 
 to leave fome on the branch beyond the fruit; 
 and on the other hand, to be as careful to 
 cut off all fupernuous fhoots, which we are 
 affured to draw off in wafte great quantity of 
 nourifhment. And might it not be advife- 
 able, among many other ways which are 
 prefcribed, to try whether the too great luxu- 
 riancy of a tree or branch could not be much 
 checked by pulling off fome of its leaves ? 
 How many, Experience will beft teach us ; 
 the pulling all off, will endanger the killing 
 the branch or tree. 
 
 There 
 
The Conchjion. 371 
 
 There is another very confiderable ufe of 
 the leaves, viz. to keep the growing fruit in 
 a fupple ductile ftate, by defending it from 
 the fun and drying winds, which by tough- 
 ning and hardening its fibres fpoils its growth, 
 when too much expofed to them ; but when 
 full grown, or near it, a little more fun is 
 often very needful to ripen it. In hotter 
 climates fruits want more fhade than in this 
 country ; and here too more fhade is needful 
 in a hot dry fummer, than in a wet cool one. 
 
 The confideration of the ftrong imbibing 
 power of the branches of trees, and the rea- 
 dinefs with which we fee the fap paries to and 
 fro to follow the ftrongeft attraction, may per- 
 haps give fome ufeful hints to the Gardener, 
 in the pruning and fhaping of his trees, in 
 checking the too luxuriant, and helping and 
 encouraging the unthriving parts of trees. 
 
 It is a conftant rule among Gardeners, 
 founded on long experience, to prune weak 
 trees early in the w T inter, becaufe they find 
 that late pruning checks them ; and for the 
 fame reafon to prune luxuriant trees late in 
 the fpring, in order to check their luxuriancy. 
 Now it is evident, that this check does not 
 proceed from any confiderable lots of fap at 
 the wounds of the pruned tree, (excepting 
 
 B b 2 the 
 
3?i The Conch/ion. 
 
 the cafe of a few bleeding trees when cut in 
 that feafon, but muft arife from fome other 
 caufe ; for by Experiment 12. and 37. where 
 mercurial gages were fixt to the ftems of frefh- 
 cut trees, thofe wounds were conftantly in a 
 ftrongly imbibing ftate, except the Vine in 
 the bleeding feafon. 
 
 When a weak tree is pruned early in the 
 beginning of the winter, the orifices of the 
 fap-veffels are clofed up long before the fpring, 
 as is evident from many Experiments in the 
 1 ft, 2d, and 3d chapters : and confequently, 
 when in the fpring and fummer the warm 
 weather advances, the attracting force of the 
 perfpiring leaves is not then weakened by 
 many inlets from frefh wounds, but is wholly 
 exerted in drawing fap from the root. Whereas 
 on the other hand, when a luxuriant tree is 
 pruned late in the fpring, the force of its leaves 
 to attraft fap from the root will be much fpent 
 and loft at the leveral frefli-cut inlets. 
 
 Befides, the early pruned tree being eafed 
 of feveral of its twigs or branches, has thereby 
 the advantage of ftanding through the whole 
 winter, with a head better proportioned to its 
 weak root. And fince by Exper. 16. the fap 
 is found to afcend in the winter, lefs of that 
 i han cold etude juice is drawn thro' the roots 
 
 and 
 
The Conchjion. 37$ 
 
 and ftem, to fupply the perfpiration of the 
 remaining boughs, whereby the fap of the 
 tree is probably lefs depauperated than it 
 would have been, if all the boughs had re- 
 mained on. For thefe reafons early pruning 
 mould, in the main, and excepting fome 
 cafes, be better than late. 
 
 And the reafonablenefs of this practice is 
 further confirmed by the experience of fome, 
 who have found, that by pruning Vines, and 
 pulling all the leaves off them in September, 
 as foon as the fruit was off, they have borne 
 greater plenty of Grapes than other Vines, 
 particularly in the year J726. when, by reafon 
 of the extreme wetnefs and coldnefs of the 
 preceding fummer, the unripe moots produe'd 
 generally very little fruit. But early pruning 
 feems to be the more preferable, becaufe pull- 
 ing off the leaves may poffibly both wound 
 the adjoining bud, and injure it, by depriving 
 it of the nourilhment which the leaf would 
 have brought to it. 
 
 From many Experiments in the fecond 
 Chapter, the Gardener will fee with what 
 force his grafts imbibe fap from the flock, 
 efpecially that ductile nourishment from be- 
 tween the bark and wood -, which correfpond- 
 ing parts he well knows, by conftant expe- 
 rience, 
 
^74 ^h* Conclufion. 
 
 rience, muft be carefully adapted to each 
 other in grafting, thofe grafts being always 
 beft, whofe buds are not far afunder, viz. 
 becaufe their expanding leaves can therefore 
 draw up fap the more vigorously. 
 
 The great quantities of moiflure, which 
 we find by Experiment 12. are imbibed at 
 wounds where branches are cut off, fhews 
 the reafonablenefs of the caution ufed by many 
 who are defirous to preferve their trees, viz. 
 either by plaiftering or covering with Sheet- 
 lead the very large wounds of trees, to defend 
 their trunks from being rotted by the foaking 
 in of rain. 
 
 And from the fame 12th Experiment a 
 hint may be taken to make fome attempts to 
 give an artificial tafte to fruits, by making 
 trees imbibe in the fame manner fome flrongly 
 tinged or perfumed liquor, which is not fpi- 
 rituous : for that, we fee, will kill the tree. I 
 have made the ftem of a branch of a tree im- 
 bibe two quarts of water without killing it : 
 If any are defirous to make this Experiment, 
 they mould take care to cut the flump which 
 is to imbibe the liquor as long as they can, 
 that there may be the more room, from time 
 to time, to cut off an inch or two of the top, 
 when it is grown fo faturate with liquor, that 
 more will not pafs, Tho' 
 
The Conchifion. 375 
 
 Tho* Ever-greens are found to imbibe and 
 perfpire much Iefs than other trees, yet is the 
 quantity they perfpire fo considerable, that it 
 has always been one of the greateft difficulties 
 in the ordering of a Green-houfe, to let in 
 frefh air enough without expofing the plants 
 to too much cold. For iince the perfpiration 
 of trees will not be free and kindly in a clofe 
 damp air, the fap will be apt to ftagnate, 
 which will make the plants grow mouldy, 
 or they will be fickly, by imbibing fuch damp 
 rancid vapours : For by Mr. Millers curious 
 obfervations on the perfpiration of the Plan- 
 tain tree of the Weft-Indies, and of the Aloe 
 under Experiment 5. plants will often imbibe 
 moifture in the night, as well in Stoves as 
 common Green-houfe, without fire; it is cer- 
 tainly of as great importance to the life of 
 the plants to difcharge that infected rancid 
 air, by the admittance of frefh, as it is to 
 defend them from the extreme cold of the 
 outward air, which will deftroy them, if let 
 in immediately upon them. It feems there- 
 fore to be a very reafonablc method which 
 fome ufe, viz. to cover fome of the inlets of 
 their Green-houfes on all fides with canvas, 
 and in extreme cold weather with fhutters 
 made of reed or ftraw, thro' which the air can 
 
 only 
 
376 The ConchJionJ 
 
 only pafs in little ftreams : The like contri- 
 vance would probably alfo be of good fervice 
 to purify gradually the thick rancid fumes 
 which arife from the dung of hot beds, and 
 are often very deftructive of the tender plants: 
 This is to imitate Nature, which, while (he 
 provides for the defence of living creatures 
 againft the cold, by a good covering of Hair, 
 Wool, or Feathers, at the fame time (he takes 
 care that the air may have admittance thro' 
 innumerable narrow meanders, in fuch quan- 
 tities, as may be fufficient to carry off the 
 perfpiring matter. 
 
 I have here, and as occafion offered, under 
 feveral of the foregoing Experiments, only 
 touch'd upon a few of the moft obvious in- 
 ftances, wherein thefe kind of refearches may 
 poffibly be of fervice in giving us ufeful hints 
 in the culture of plants : Tho' I am very fen- 
 fible, that it is from long experience chiefly 
 that we are to expect the moft certain rules of 
 practice $ yet it is withal to be remembred, that 
 the likelieft method to enable us to make the 
 moft judicious obfervatiohs, and to put us upon 
 the moft probable means of improving any. art, 
 is to get the beft infight we can into the nature 
 and properties of thofe things which we are 
 defirous to cultivate and improve, ' 
 FINIS. 
 
S.G. 
 
S.G. 
 
r-