the Production of artificial Cold. 123 
Having given an account of Pr. Lo witz’s experiments, I shall 
now relate briefly the result of a series of experiments made by 
myself, which occurred to me in consequence of Pr. Lowitz’s 
discovery. 
My first object was, to repeat the foregoing experiment under 
similar circumstances ; but the thermometer (the temperature 
of the air and materials being + 32 0 ) sunk, in this instance, no 
lower than — 48°. 
The liquefaction, in the above instance, was remarkably sud- 
den ; and the full effect was produced, as it were, in an instant. 
Secondly, with a view either of producing a very extraordi- 
nary degree of cold, or ascertaining the point at which this salt 
ceases to produce further cold, I mixed the same materials, 
previously cooled by art to 40° below o, when the thermometer 
sunk to 63° below o.* 
Thirdly, some of the same salt, in a crystallized state, was 
set out to deliquesce in the open air : this liquor mixed with 
snow, each at the temperature of 32 0 , gave a cold of — 20°. 
Hence it appears, that 52 degrees of heat were absorbed, or 
rendered latent, by the liquefaction of the snow, and 28 by that 
of the salt, in the first experiment," that is, in the whole, 80 
degrees. 
The muriate of lime used in the above experiments was pre- 
pared thus. Muriatic acid 1 part, and distilled water 3 parts, 
were thoroughly mixed ; this liquor was then perfectly saturated 
with whiting, and, when clear, poured off. The mixture was 
afterwards evaporated, till it crystallized in air at -f 32 0 , 
In this instance, as I afterwards found, the proportion of snow, owing in part to a 
considerable portion of the muriate of lime remaining frozen at the bottom of the 
vessel, and not mixing, was much too great. 
R 2 
