in the fixed principles of the egg during incubation. 395 
At this period all the important changes of incubation are 
completed. The albumen has now disappeared, or is re- 
duced to a few dried membranes and an earthy residuum 
(apparently consisting of the original earthy matter of the 
albumen which has remained unappropriated). The yelk is 
considerably reduced in size*, and is taken into the abdomen 
of the chick, while the animal has attained a weight nearly 
corresponding to the original weight of the albumen, added 
to that lost by the yelk, minus the total weight sustained by 
the egg during incubation. The alkaline matters and chlo- 
rine, which have been decreasing from the commencement of 
incubation, have now undergone farther diminution in quan- 
tity,^ while the earthy matters have increased in the most striking 
manner. The other principles seem to have suffered very little 
change in quantity. The following are the results of the 
analyses of the above two eggs. 
No. 1. 
Sulphuric 
Acid. 
Phospho- 
ric Acid. 
Chlorine. 
Potash, 
Soda, and 
Carb. of 
Ditto. 
Lime, Mag- 
nesia, and 
Carb. of 
Ditto. 
Resid.of albumen, \ 
Grains. 
Grains. 
Grains. 
Grains. 
Grains. 
membranes, &c ./ 
.04 
.12 
.09 
• 2 3 
.12 
Animal 
•44 
3-02 
■55 
2.2 6 
2.58 
Yelk - - - 
•O4 
1,06 
.03 
.06 
1.26 
•52 
4.20 
.67 
2-55 
3-9 6 ' 
* This has been denied or doubted by some writers, especially Haller and 
Dr. Macartney. 
f We have seen that in boiling an egg, a portion of its saline matter makes its 
way through the shell into the water. Do the saline matters, in the present instance, 
escape with the water lost during incubation ? An argument in favour of the sup- 
position is, that the loss is chiefly confined to those salts already existing in the egg. 
