1823.] of the Egg during Incubation. 



105 



Dr. Prout next gives the following analysis of the shell of the 

 recent egg : The egg from which the yelk had been taken, 

 which is the subject of the following experiment, had been 

 boiled hard in distilled water, and the yelk, in its moist state, 

 was found to weigh 316*5 grains. It was then partially dried by 

 exposure to the air for several weeks ; and to remove the 

 remainder of the water was reduced to powder, and exposed to 

 a temperature of somewhat more than 212°. The total loss of 

 weight was 170*2 grains, which was supposed to indicate the 

 quantity of water present. The remainder was now digested 

 repeatedly in alcohol of specific gravity *807, till that fluid came 

 off colourless. The residuum was perfectly white and pulveru- 

 lent, and possessed many of the properties of albumen ; but it 

 differed from that principle by the large proportion of phosphorus 

 it contained in some unknown state of combination. The alco- 

 holic solution was of a deep-yellow colour, and deposited crystals 

 of a sebaceous matter, and a portion of a yellow semi-fluid oil. 

 On distilling off the alcohol, the oil was obtained in a separate 

 state. On cooling, it became nearly solid, and weighed 91 grains. 

 The albuminous principle above-mentioned weighed 55*3 grains. 

 Hence this yelk consisted of 



• " Hcsides the above principles, iron is met with in almost all products of combus- 

 tion ; and the cmantity in the egg, as the process of incubation proceeds, apparently 

 increases considerably ; but it was found impossible to ascertain its quantity with any 

 degree of precision. " 



