fae al 
two degrees between 60° and 70°; and 0,0017 by every two 
degrees between 50° and 60%, Whence it appears that the 
ftronger acid is lefs altered by variation of temperature than 
the weaker, which formerly appeared to me an irregularity, but 
now feems to proceed from the increafe of the accrued denfity, 
when larger proportions of water are mixed with the ftronger 
acid. 
Thirdly, vitriolic acid, whofe denfity at any degree between 
50° and 70° refembles the correfponding at the fame degree in 
‘the column C, gains or lofes, 0,00086 for every two degrees between 
602 and ¥o° inclufively, and, 0,00076 between 50° and 60°. Be- 
tween 45° and so” I could perceive no difference. 
Of the Nitrous Acid. 
THE fpecific gravity of the moft concentrated nitrous acid I 
could produce was 1,5543 in the temperature of 60°: It was of a 
yellowith red colour, and fo highly phlogifticated and volatile, that 
it was impoflible to make accurate experiments upon it, when 
mixed with {mall proportions of water; but when mixed with an 
equal weight I found its encreafe of denfity to be about ~; of the 
whole. Hence I formed the firft fifty numbers of the fubfequent 
table by calculation, according to Mr. Pouget’s formula, and the 
remainder by experiments, conducted, as already mentioned in 
treating of the vitriolic acid. The temperature at which the den- 
fities were examined was always between 59,5° and 60°, feldom 
60,5°. The acid I ufed was the pale yellow acid, whofe fpecific 
gravity was 1,4099, but the firft I confidered as the ftandard. 
Table 
