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May 24. The mercury was nineteen May 26. 'Twas 38 inches high. PNEUMATICS 27. There was no change.

inches and a half high.

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December 14. The mercury continued at the fame height; and this day opening the receiver, I found the dough had a very acid smell.

From this experiment it seems to follow, that fpirit of wine, even in dough kneaded with leaven, hinders the production of air.

(11.) Angust 29. I included pears, with a mercurial gage, in a receiver In pears. full of water, and then intruded air into it, till the mercury refted twentyfix inches higher than ufual; within a quarter of an hour, one of the pears was broken, and afterwards, almost all of it reduced to pulp.

Aug. 30. In twenty-four hours space, the pears feem'd to have afforded no air; but on the contrary, the mercury in the gage was depressed an inch and a half.

Aug. 31. I found no change in the height of the mercury.

Sept. 1. The pears began to produce air, and the mercury was almost twenty-feven inches high.

Sept. 2. In twenty-four hours time, the mercury afcended more than eight inches; and now 'twas thirty-five inches high.

Sept. 3. The height of the mercury was increafed feventeen inches; fo that now it was about fifty-two inches high.

Sept. 4. Within twenty-four hours, the mercury rofe feven inches higher, and then refted at fifty-nine.

Sept. 5. It was fixty-four inches high; and a pear being broken, was become black.

Sept. 6. Three inches and more, being added to the height of the mercury, it came now to fixty-feven inches, and one fourth, beyond what it was accuftom'd.

Sept. 7. It defcended three inches, and refted again at fixty-four.

Sept. 8. The mercury was depreffed to fifty-eight inches; and fome of the water having broke out, I fet the receiver with a fcrew.

Sept. 9. The mercury afcended full three inches, and was now fufpended above fixty-feven.

Sept. 10. In twenty-four hours it mounted one and a half, and stopp'd almoft at fixty-nine.

Sept. 11. Now it began to defcend again, and stood no higher than fixty-feven inches; yet I am certain, nothing had efcaped out of the receiver; but it was a fharp cold night.

Sept. 12. No change happen'd.

Sept. 13. The height of the mercury again decreased, and it was not above fixty-four inches. The cold increased.

Sept. 14. In twenty-four hours it became higher by fix inches, reaching to seventy.

Sept. 16. It was about fixty-nine | Sept. 2o. It again afcended to 71. 23. The mercury was again depreffed to fixty-nine.

inches high.

19. It remained the fame.

Octob. 1. It came to the height of feventy-five inches.

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Octob.

PNEUNATICS

Octob. 3. Yesterday I found no change at all in the mercury; but to-day it rested at seventy; and the cold was very fevere.

Octob. 5. Yesterday the mercury remained in the fame place; but this day it reach'd to feventy-five. It was a rainy day.

Octob. 7. It continu'd rainy; and the mercury continu'd at the fame. height.

Octob. 10. Hitherto the mercury was not changed; but this day I found it had defcended to fixty-nine inches; tho' the rain ceas'd not.

Octob. 12. Yesterday the mercury ftood ftill; but this day it was deprefs'd to fixty-five inches; and the cold weather return'd.

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From this experiment we may learn, that fruits, in a great compreffure of the air, cannot produce fo great a quantity of air; for when I made an eftimate of the quantity of the fruits, and of the small space to be fill'd with air; I found that quantity of air was not one eighth part of what had been produced in a large empty receiver: tho' the coldness of the water might alfo, hinder the generation thereof, as the following experiment will fhew.

'Tis farther manifeft, that the air is produced by starts, and as it were, by reciprocations; as all bodies in motion, by the force of their gravity, or of their fpring, are carried beyond their point of reft, and fo make many vibrations, or returnings. And tho' cold and heat are not the fole causes of fuch reciprocations, yet they feem to contribute much thereto.

In pafle again. (12.) Feb. 22. 1677. I included ten ounces of paste in a receiver, that would hold twenty-two ounces of water; and afterwards, I thrust as much air into it, as fufficed to faftain feventy-three inches of mercury befides the wonted preffure. In two hours fpace I perceived no fenfible change.

Febr. 23. In eighteen hours time, the mercury rofe feven inches only, its height being eighty.

In fix hours it afcended three; and its height was eighty-three.

And water feem'd to be exprefs'd

Febr. 24. 25.

90
97

out of the mafs.

26.

Its height 101

March 2.7

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3. Its height was

45. It remain❜d at 121.

120

121

March 8. During these two or three laft days, the froft breaking, the PNEUMATICS mercury ran up 4 inches; and the height thereof was 125.

March 10. Yefterday the mercury remain'd at the fame height, but

this day mounting 6 inches, it refted at 131.

March 21. The cold continuing long, no air was produc'd; but in the three last days the mercury afcended 7 inches, and remain'd at 138.

April 4. Yesterday the mercury had afcended, but I deferr'd measuring the quantity till to-day; in the night one of the iron wyres, that straiten'd the receiver, was broken, and the receiver thrown to the distance. of 4 or 5 foot.

Hence we may conjecture, that the compreffion of the air very much. hinder'd the production thereof; for that is ufually perform'd in paste, in 2 or 3 days time. Cold alfo much hinders its production.

(13.) March 1. 1677. I included 2 ounces of bruised raisins of the sun, In raisins and with 6 ounces of vinegar, in a receiver; upon which numerous bubbles vinegar. broke out.

March 2. The mercury, in 24 hours fpace, afcended not to the height of half an inch; yet fome bubbles ftill appear'd.

March 25. The vinegar always appear'd interfpers'd amongst some of the bubbles, yet the mercury afcended not to the height of one inch. Hence it appears, that vinegar hinders the production of air and fermentation; for raifins of themselves afford much air.

(14) April 7. I included 10 ounces of pafte, in a receiver capable of In pale. holding 22 ounces of water; afterwards I intruded as much air into it, as fuffic'd to fuftain 128 inches of mercury, befides its accuftom'd height.

In 6 hours time the mercury rofe 4 inches, and refted at 132.
April 8. In 16 hours the mercury ran up 9 inches higher, and stay'd at

141.

Nine hours after, the mercury manifefted no change.

April 9. In the morning I perceiv'd some air had broke forth, and the mercury was deprefs'd to 130 inches; therefore I fcrew'd the receiver tighter, and thruft in 11 inches of new air; the height was 141.

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April 27. For eight whole days the mercury kept its ftation; but on the two last it afcended 7 inches, and continu'd at 198, above its wonted height.

April 30. The mercury perfifting at the fame height, I eafed the fcrew, fo that fome air might break out; and when the mercury had fo far de

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fcended,

PNEUNATICS

Octob. 3. Yesterday I found no change at all in the mercury; but to-day it refted at feventy; and the cold was very fevere.

Octob. 5. Yesterday the mercury remained in the fame place; but this day it reach'd to feventy-five. It was a rainy day.

Octob. 7. It continu'd rainy; and the mercury continu'd at the fame height.

Octob. 10. Hitherto the mercury was not changed; but this day I found it had defcended to fixty-nine inches; tho' the rain ceas'd not.

Octob. 12. Yesterday the mercury ftood ftill; but this day it was deprefs'd to fixty-five inches; and the cold weather return'd.

Octob. 13. The height of the

mercury was fixty four.
14.The heights fixty-nine.
15.3 Was feventy-four.

24. The height was fixty-eight.
It was a cold fea-

fon.

Nov. 2. The height was fixty-four.

The cold increas'd.

Nov. 5. The height was eighty and

a half. The cold abated. 22. The height was fixty-five. It was a hard froft.

27. The height was fixty-eight. It thaw'd.

Decemb.6. The height was fixty-one. It was a very fevere froft.

From this experiment we may learn, that fruits, in a great compreffure of the air, cannot produce fo great a quantity of air; for when I made an estimate of the quantity of the fruits, and of the small space to be fill'd with air; I found that quantity of air was not one eighth part of what had been produced in a large empty receiver: tho' the coldness of the water might alfo, hinder the generation thereof, as the following experiment will fhew.

'Tis farther manifeft, that the air is produced by starts, and as it were, by reciprocations; as all bodies in motion, by the force of their gravity, or of their fpring, are carried beyond their point of reft, and fo make many vibrations, or returnings. And tho' cold and heat are not the fole causes of such reciprocations, yet they feem to contribute much thereto.

In pafle again. (12.) Feb. 22. 1677. I included ten ounces of pafte in a receiver, that would hold twenty-two ounces of water; and afterwards, I thruft as much air into it, as fufficed to fuftain feventy-three inches of mercury befides the wonted preffure. In two hours fpace I perceived no fenfible change.

Febr. 23. In eighteen hours time, the mercury rofe feven inches only, its height being eighty.

In fix hours it afcended three; and its height was eighty-three.

Febr. 24.

90

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And water feem'd to be exprefs'd

out of the mafs.

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March 8. During these two or three laft days, the froft breaking, the PNEUMATICS mercury ran up 4 inches; and the height thereof was 125.

March 10. Yesterday the mercury remain'd at the fame height, but

this day mounting 6 inches, it refted at 131.

March 21. The cold continuing long, no air was produc'd; but in the three last days the mercury afcended 7 inches, and remain'd at 138.

April 4. Yefterday the mercury had afcended, but I deferr'd measuring the quantity till to-day; in the night one of the iron wyres, that straiten'd the receiver, was broken, and the receiver thrown to the distance. of 4 or 5 foot.

Hence we may conjecture, that the compreffion of the air very much. hinder'd the production thereof; for that is ufually perform'd in paste, in 2 or 3 days time. Cold alfo much hinders its production.

(13.) March 1. 1677. I included 2 ounces of bruifed raifins of the fun, In raifins and with 6 ounces of vinegar, in a receiver; upon which numerous bubbles vinegar. broke out.

March 2. The mercury, in 24 hours fpace, afcended not to the height of half an inch; yet fome bubbles ftill appear'd.

March 25. The vinegar always appear'd interfpers'd amongst some of the bubbles, yet the mercury afcended not to the height of one inch. Hence it appears, that vinegar hinders the production of air and fermentation; for raifins of themfelves afford much air.

(14.) April 7. I included 10 ounces of paste, in a receiver capable of In paste. holding 22 ounces of water; afterwards I intruded as much air into it, as fuffic'd to fuftain 128 inches of mercury, befides its accuftom'd height.

In 6 hours time the mercury rofe 4 inches, and rested at 132.
April 8. In 16 hours the mercury ran up 9 inches higher, and stay'd at

141.

Nine hours after, the mercury manifefted no change.

April 9. In the morning I perceiv'd fome air had broke forth, and the mercury was deprefs'd to 130 inches; therefore I fcrew'd the receiver tighter, and thruft in 11 inches of new air; the height was 141.

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April 27. For eight whole days the mercury kept its station; but on the two laft it afcended 7 inches, and continu'd at 198, above its wonted height.

April 30. The mercury perfifting at the fame height, I eafed the fcrew, fo that fome air might break out; and when the mercury had fo far de

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fcended,

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