in the Fixed Principles of the Egg dur ing Incubation. 73 
Grains. 
Grains. 
Residuum of albumen, membranes, &c. 
29.5 
38.1 
Animal, - 
555.1 
553.6 
Yolk, - 
167.7 
151.3 
Shell and loss, ... 
247.7 
257.0 
1000.0 
1 000.0 
At this period, all the important changes of incubation are 
completed. The albumen has now disappeared, or is reduced 
to a few dried membranes and an earthy residuum. The yolk 
is considerably reduced in size, and is taken into the abdomen 
of the chick, while the animal has attained a weight nearly cor- 
responding to the original weight of the albumen, added to 
that lost by the yolk, minus the total loss of 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 quantity, 
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 analy- 
ses of the above two eggs : 
No. I. 
No.II. 
Sulphuric 
Acid. 
Phospho- 
ric Acid. 
Chlorine. 
Potash, 
Soda,5< 
Carb. of 
ditto. 
Lime, 
Magne. 
s<-Carb. 
of do. 
Sulphuric 
Acid. 
Phospho- 
ric Acid. 
Chlorine, 
Potash, 
Soda,&. 
Carb. of 
ditto. 
Lime, 
Magne. 
^.Carb. 
of do. 
R 
.esid. of albu- 1 
Gr. 
Gr. 
Gr. 
Gr. 
Gr. 
Gr. 
Gr. 
Gr. 
Gr. 
Gr. 
men, mem- > 
hranes. 1 
.04 
.12 
.09 
.23 
.12 
.03 
.13 
.09 
.25 
.12 
Animal, 
.44 
3.02 
.55 
2.26 
2.58 
.21 
2.71 
.68 
2.12 
2.60 
Yolk, 
.04 
1.06 
.03 
.06 
1.26 
.02 
1.23 
.06 
.03 
1.10 
.52 
4.20 
.67 
2.55 
3.96 
.26 
4,07 
.83 
2.40 
3.82 
These experiments, then, demonstrate, or render probable, 
the following circumstances. 
1. That the relative weights of the constituent principles of 
different eggs vary very considerably. 
£. That an egg loses about one-sixth of its weight during in- 
cubation, a quantity amounting to eight times as much as it 
loses in the same time under ordinary circumstances. 
