200 
FIRST EXPERIMENT. 
After having placed an egg in a cold about X'J , till it froze, I allowed it 
to thaw; by which process it was to be supposed that the preserving powers 
of the egg must be destroyed. I then put thid egg into a frigorific mix¬ 
ture/ and with it one newly laid ,, and found the difference in freezing was 
seven minutes and a half, the fresh one resisting so much longer time the 
powers of cold. 
SECOND EXPERIMENT. 
A new laid egg being put into a cold atmosphere, fluctuating between 17° 
and 15°, took above half an hour to freeze; but when thawed and put into 
an atmosphere at 25°, it froze in half the time. This experiment was repeated 
frequently with nearly the same result. 
To ascertain the comparative degree of heat between a living and a dead 
egg, and also to determine whether a living egg be subject to the same laws 
with the more imperfect animals, I made the following experiment. 
THIRD EXPERIMENT. 
A fresh egg, and one which had been frozen and thawed, were put into 
the cold mixture at 15°: the thawed one soon came to 32°, and began to 
swell and congeal; the fresh one sunk to 20° and a half, and in twenty-five 
minutes later than the dead one, it rose to 32°, and began to swell and 
freeze. 
In this experiment, the effect on the fresh egg was similar to that pro¬ 
duced on the frog, eel, snail, &c. where life allowing the heat to be dimi¬ 
nished two or three degrees below the freezing point, afterwards resisted all 
* The cold was first produced by means of ice and snow with sal ammoniac or sea-salt, to about 
the 10° of Fahrenheit’s thermometer: ice was then mixed with spirit of nitre; but what degree of 
cold was then produced I did not, says John Hunter, examine. This cold mixture was made in a tub 
surrounded with woollen cloths, and covered with the same, to prevent the effects of the heat of the 
atmosphere upon the mixtuie itself, and to preserve as much as possible a cold atmosphere within 
f xronfinl 
