108 Dr. Pront on the Changes in the fixed Principles [Feb. 



the 1000, and the weights of its constituent principles are as 

 follows : 



Grains. 



Unchanged albumen * 175-5 



Liquor amnii, membranes, &c 273*5 



Animal 70-0 



Yelk 250-7 



Shell and loss 230-3 



1000-0 



" At this period, the animal has attained a considerable size, 

 while the albumen has become diminished in a corresponding 

 degree. The albumen has also acquired a very firm consistence, 

 especially when coagulated by heat. 



" The liquor amnii has become more fluid, and the modified albu- 

 men, formerly mentioned, has very much diminished in quantity, 

 or disappeared.* The yelk, which at the end of the first week 

 seemed to have increased in bulk and fluidity, has now appa- 

 rently acquired its original size and consistence." 



From the results of an analysis made two days later, or on the 

 17th day of incubation, it appears that at this period the yelk 

 has yielded some of its phosphorus and sulphur to the other prin- 

 ciples of the egg ; that the chlorine has increased in the yelk, 

 and diminished in the other principles ; that the relative propor- 

 tions of alkaline bodies remain much the same as on the loth 

 day ; and that the earths have increased in quantity a little in the 

 yelk, and very considerably in the other principles. 



Experiments on the Egg at the End of the third Week, or at 

 the J ii It Period of Incubation. 



At this period an egg has lost upon an average about 160 



* « 



; About this time Harvey, and other observers, have noticed the appearance of a 

 curdy or coagulated substance in the acsophagus, crop, stomach, and intestines of the 

 animal. Is this a portion of the modified albumen above-mentioned ?" 



