the- Congelation of Vitriolic Acid . 273 
1804 
17 94 
1790 
1770 
1 75 9 
*75° 
The acids which remained, and which would not freeze 
either in melting fnovv, or in the mixture of fnow, fait, and 
water, were found on examination to 
cific gravities. 1846 
1 839 
1815 
1 745 
1720 
1 700 
1610 
1 55 1 
It appears, from the firft table of fpecific gravities, that the 
medium denfity of the acids which did freeze with the cold of 
melting fnow was 1780 ; and from the fecond table it appears, 
that, at the denfities of 1790 and 1770, the acid had been 
incapable of freezing with that degree of cold. Hence it fol- 
lows, that 1780 is nearly the ftrength or denfity of eafieft 
freezing; and that an increal'e or diminution of that denfity, 
equal to T ^. T th part, renders the acid incapable of freezing 
with the cold of melting fnow, notwithftanding this cold is 
fome degrees above the freezing point of the moft congelable 
acid. From the fecond table of fpecific gravities it appears, 
that by applying a more intenfe cold, namely, that produced 
by a mixture of fnow, fait, and water, the limits of the den- 
fity of the acids capable of congelation were extended to about 
_l_j. above or below the point of eafieft freezing : and there 
fee ms 
have the following fpe- 
