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the Production of artificial Cold. 
The result of Mr. Lowitz’s experiments are, in his Memoir,* 
given according to the scale of Reaumur; but, in this, are 
throughout reduced to that of Fahrenheit. 
Mr. Lowitz, Professor of chemistry in Petersburgh, having 
found, by an experiment made in the Winter of 1792, that 
caustic vegetable alkali, in a solid state, produced a degree of 
cold far exceeding any other substance before mixed with 
snow, viz. 8 g degrees, determined to prosecute the subject; 
and, upon reflection, considering that the deliquescent salts were 
likely to be fittest for his purpose, fixed chiefly upon the class 
of muriatic salts, or those which have their base neutralized by 
the muriatic acid. The result of his experiments was the dis- 
covery, that crystallized muriate of lime sunk the thermometer 
82 degrees ; and that the other neutral salts of this class, though 
much inferior to that salt, exhibited nevertheless remarkable 
powers of the same kind.'f 
Professor Lowitz, in the Memoir alluded to, observes that 
he has repeated my experiments with chemical salts and snow , 
but could not produce a degree of cold below -f- 2 0 . Here is 
evidently some mistake ; for it is sufficiently known, that the 
novelty of my experiments depends on the production of cold, 
without the use of ice in any form.J 
Pr. Lowitz, having found by experiment that, at the tem- 
perature of 27 °,four parts of muriate of lime to three of snow 
produced a temperature of — 55 0 , and that an increase of the 
* See a translation from Crell’s Chemical Annals for 1796, by Mons. Van Moks, 
Vol. XXII. p. 297, of the Annales de Chimie. 
f Professor Lowitz no sooner discovered the great efficacy of the muriate of lime 
for this purpose, than he gladly rejected the caustic vegetable alkali, on account of 
its burning quality ; the difference being one degree only. 
J See the table of frigorific mixtures. Phil. Trans, for 1795, p. 279. 
mdccci. R 
