OCR Text |
Show Experiments in diffolving Led. VI. Lea. VIL Salts in Water. Common Salt, { marked the fecond afcent of the Oy! and foundit to be 10 Inchesand 6 eighths. Repeating the Experimentin like manner with two Ounces of Nitre, I found the afcent of the Oy!to be 11 Inches and ;. Repeating it again with two Ounces of Alum, the afcent of the Oyl was 13 Inches and ath. And making it once more with Sal Armoniac, the Oyl afcended to 15 Inches: thefaid feveral afcents of the Oy! being the true fpaces which the Four abovefaid Salts take. From which, the {pace which the fame Salts take up upon Difflution, being dedutted; the remainder is the {pace gained by that Diffolution. C HAT NE Wherein, from the Experiments in the foregoing Chapter, is Jhewed, the Caufe of the Motion of the Mercury ix the BAROMETER. And fo it appears, firft, that Sal Armoniac gaineth nothing; being the onlySalt of all Ihave tryed,which caufeth the equal afcent both of the Water and the Oyl fe. jutt 15 Inches in both. Ava caufeth the afcent of the Oy/ to 13 #48 of the Water, to 11 Inches and ths: So that it gains about 1 Inch and 4 outof 13. Nytre caufeth the afcent of the Oyl, to 11 Inches and 35 of the Water, to 8 Inches and 3th So that Nitre by Diffolution gets almoft the fpaceof 3 Inches in 11. Common Salt caufeth the afcent of the Oy), to1o Inches and $ths 5 of the Water, 6 Inches and 2+ Sothat Common Salt gains by Diffolution 4 Inches in 10, which is very confiderable. 12. §. By this way the Specifick Gravity ofall kinds ofSalts may be eafily taken, and the difference betwixt them is fomewhat furprizing, For it appears by the Afcent of the Oyl, that Nitre, quantity for quantity, is abouta 22t" part lighter than Common Salt. Alum about a 6! partlighter. And Salt Armomiac, almoft a 4‘ partlighter than Common Salt. Thelike eftimate may be made of the Gravity of all other Salts. 13. §. Bythe fame Experimentit alfo appears, That according to the Specifick Gravity of Salts they are many times at leaft more or lefs Volatile 5 as in the fourlaft Salts is plain. For Common Salt which of all the four is the moft fixed, is alfo the heavyeft. Nitre whichis fomewhatlefs fixed is fomewhatlighter. But Alum whichis {till lefs fixed is muchlighter. And Sal Armoniac whichis wholly Volatile, is the lighteft of all the Salts above mentioned. gy, OR the doingofthis, it will firft be acknowledg’d, Thatnot only feveral forts of Su/phur, but alfo of » Volatile Salts, are continually fublinied from moft Bodies into the Aer. So Lightning, from thecelerity of the accenfion, appears to be made ofa Meteor, which is Nétro-Sulphureous. Snow dependeth upon Z a Mixture of Nitrous, and other Salts 3 as is evident, from the regularly and differently Figur’d Parts, which compofé the whole Body of a Svomy Cloud, before it clufters into Flakes. And one reafon, why Raiz is the beft Water for any Soyl, is becaufe it is imaes with divers Volatile and Fruitful salts. And fo from othe¥ efeors. 2. g. And next, that thefe Sais, are not always in the fame Quaz- tity, Proportion, and State, inthe Aer + but that fometimes they are more copious 3 at others, lefs: fometimes, one more copious, than an other: fometimes, more plentifully diffolved; at others; more fpareingly : and that, either as they are moreorlefs pure and diffoluble; or according to the quantity of the Vaporous Parts in the Aer, in which they are incorporated ordiffolved. 3. §. Thus much being granted, from the Experiments in the fore 4 §. And therefore it is efpecially to be obferved, That as the going Chapter compared together, we may refolve our felves about fome Phenomena in the Barometre. Which feems to vary, not fo much with the meer Weight of the Aer, which hitherto hath been fuppofed: asby the different preflure it makes, in being crowded more at one time, than at another. That is, according as certain Nétrous, or other Salize Bodies, take up le{S Space inthe Aer, when diflolved in the Watery Parts therein, than while they are undiflolved. Mercury commonly rifeth in the Cylinder for {ome days, but always for fome time, before the change of the Weather, whether for Svow or Rain : So, that thenit prefently falleth again, even before the Sow or Rain falls. Whereas, ifthe Weight of the Aer, were the only, or the chief Caufé of the afcent of the Mercury 5 than as it rifeth all the while the Weather is gathering, fo it would keepits ftanding or heighth, until the Weather breaks and falleth down: which yet it never doth, but always falls before it 5 fometimes no lefs than a whole day. The Canfe whereofis, in thatall the while the Mercury rifeth in the Cylin= der, the Aer is crowded with more and more Saline Parts, which by the |