Dr. Blagden’s Experiments on 
286 
As nitre funk the freezing point of water fo little, namely, 
but 6 degrees, I had recourfe for the next fet of experiments 
to that neutral fait which, after fea fait, produces the greateft 
cold with ice; which is, the common fai ammoniac. The 
different folutions of this fait in water, being fubmitted to the 
adlion of the frigorific mixtures, froze according to the follow- 
ing table. 
Sal ammoniac. 
Proportion 
Freezing 
Freezing point 
of water to 
point by the 
by calculation. 
the fait. 
experiment. 
3 5> 7 : 1 
O 
24 l 
0 
24 ? 
The third column is calcu- 
jo : 1 
20§ 
20 
lated from the laft experi- 
9,8 : 1 
20 
I9l 
ment but one, in which the 
7 > 9 • 3 
i6f 
id| 
freezing point of a folution 
6 : 1 
12 
12 
of one part of the fal am* 
5 : 1 
8 
8 
moniac in five of water 
4 : 3 
4 
fait depofited 
proved to be 8°. 
In this table alfo the numbers of the third colum agree fuf- 
ficiently with thofe of the fecond to fhew, that fal ammoniac, 
like the two preceding falts, deprefles the freezing point in the 
fi tuple ratio of the proportion in which it is mixed with the 
water. 
The following is the account, as written at the time, of the 
experiment where the fait was to the water as 1 r 5. “ This 
“ folution cooled down to 2° at bottom, but the frigorific mix- 
“ ture being infufficient, the top remained at io°. The tum- 
“ bier was then taken out, and the frigorific mixture being 
refrefiied by fining and the addition of new materials, it 
“ was 
