[ 447 ] 
inquiry more immediately before me. ■ The cold pro- 
duced was firft by means of ice and fnow with fal am-- 
moniac or fea-falt, and was about io° of Fahrenheit’s 
thermometer. Then ice, fo cooled, was mixed with fpi- 
rit of nitre ; but what degree of cold was thus produced I 
did not examine. This cold mixture was made in a 
tub fnrrounded with woollen cloths, and covered with 
the fame, to prevent .the effecTs of the heat of the at- 
mofphere upon the mixture itfelf, and to preferve as 
much as polfible a cold atmofphere within the veffel. 
The animal j Liices, the blood for example, freeze at 25°; 
fo that a piece of dead flelh could be frozen in fuch an 
atmofphere, 
EXPERIMENTS. 
I. The firft experiment was made on two carp. They 
were put into a glafs veftel with common river water, 
and the vefl'el put into the freezing mixture ; the water 
did not freeze faft enough; an<l therefore, to make it 
freeze fooner, we put in as much cooled fnow as to make 
the whole thick. The fnow round the carp melted; we 
put in more frefli fnow, which melted alfo ; and this was 
repeated feveral times, till we grew tired, and at laft left 
them covered up in the yard, to freeze by the joint ope- 
ration of the furrounding mixture and the natural cold 
of the atmofphere. They were frozen at laft, aftei' hav- 
ing exhaufted the whole powers of life in the produc- 
tion of heat. That this Was really the cafe, could not 
be known, till I had compleated that part of the expe~ 
- fYoL. LXV. Oo o rimentj 
