and attractive Powers of various f aline Sub/lances. 2 j 
gravities betwixt which that fought for muft lie, and a propor- 
tionate excefs or defect. 
I have added a column of attraction of the nitrous acid to 
water as far as it keeps pace with the increafe of denfity, but 
no farther, as I am unacquainted with the law of its further 
increafe. 
The fpecific gravity of the ftrongeft fpirit of nitre yet made 
is, according to Mr. baume, 1,500; and according to Mr. 
BERGMAN, 1,586. 
I next proceeded to examine the proportion of acid, water, 
and fixed alkali in nitre, in the fame manner as I had before 
done that in digeftive fait, and found that 100 gr. of perfeftly 
dry nitre contain 28,48 gr. acid, 5,2 of water, and 66,32 of 
fixed alkali. 
I fhall now compare the refult of thefe experiments with 
thofe of Mr. homberg. 
The fpecific gravity of the fpirit of nitre which Mr. hom- 
berg made ufe of was 1,349 ; and of this, he fays, 1 oz. 2 dr. 
and 36 gr. that is, 621 Troy, are requisite to faturate 1 French 
(oz. 472,5 Troy) of dry fait of tartar; according to my com- 
putation 613 gr. are fufficient ; for this fpecific gravity lies be- 
tween the tabular fpecific gravities by obfervation 1,362 and 
1, 337, and is nearly an arithmetical mean between them. The 
correfponding mathematical fpecific gravity lies betwixt the ta- 
bular quantities 1,315 and 1,286, and is nearly 1,300. Now, 
the proportion of acid and water in this is, 2,629 ac i c h and 
8 > 7 6 5 
7,465 of water; for — 1,300 8,765 x .300 
= 7,465 water and = 2,629, of acid; 
and the fum of both is 10,044. Now, fince 10,5 gr. mild ve- 
getable fixed alkali require 3,55 gr. of acid for their faturation, 
472,5 
