Experiments on the freezing of Acids . 1 79 
N° 
Strength 
before 
fent. 
Decanted part. 
Undecanted part. 
Strength 
of whole 
mafs. 
Quantity. 
Strength. 
Quantity. 
Strength. 
1 
*977 
I 37 S 
>967 
3460 
’9^3 
>964 
2 
i 9 l8 
39 1 5 
>919 
1876 
,905 
,850 
> 9 l 4 
3 
,846 
88 
*777 
49*5 
,849 
4 
>758 
3 8 9 
,71° 
f 3795 
i 547 
*753 
,803 
*755 
The undecanted part of N° 4. was divided into two parts ; 
namely, the lefs and the more congealable part ; and it is die 
latter whofe quantity and ftrength is given in the la ft line. 
It is well known, that oil of vitriol attradls moifture with 
great avidity; and fome of thefe acids were much expofed to 
the air during the experiments made with them, and may 
therefore be fuppofed to have attra&ed fo much moifture from 
the air, as might fenfibly diminifli their ftrength ; and this 
feems aflually to have been the cafe with fome of them. But 
as the bottles were well ftopped, and as, except in one acid 
which was the moft expofed to the air, the ftrength of the 
whole mafs comes out not much lefs than that determined be- 
fore the liquors were fent to Hudfon’s Bay, I imagine their 
ftrength could not fenfibly alter during their voyage home ; 
and confequently their ftrength, at the time the laft obferva- 
tions were made with them, could not differ much from that 
here fet down. 
It would be tedious to give the experiments for determining 
their freezing points in detail ; but the refult is as follows. The 
freezing point of N° 1. tried in the firft method, was fomewhat 
above -f 1°, but it is uncertain how much ; that tried in the 
fecond manner feemed -6°f. But the freezing point of the 
undecanted part, after having been intirely melted, and again 
A a 2 expofed 
