396 Dr. Prout’s experiments on the changes which take place 
No. 2. 
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, 8cc.J 
.03 
•13 
■°9 
•25 
.12 
Animal 
.21 
2.71 
.68 
2. 12 
2.60 
Yelk 
.02 
1.23 
.06 
.03 
1.10 
A. 6 
4.O7 
.83 
2.4O 
3.82 
It may be proper to observe, that the above analyses are 
selected as the most perfect, from a variety of others made at 
each period, all of which confirm the results here given, 
though they differ, like those indeed given, in some subordi- 
nate particulars.* 
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. 
2. That an egg loses about one-sixth of its weight during 
incubation, a quantity amounting to eight times as much as it 
loses in the same time under ordinary circumstances. 
namely, the chlorine and alkaline matters. With respect to the use of these saline 
matters we know very little. Do they perform an office in the animal economy 
analogous to acid solutions in the galvanic battery ? 
* An interesting circumstance may be here mentioned, which I have never seen 
noticed by any writer on the present subject. At the end of the process of incuba- 
tion, and for some time before, the animal is so situated in the egg, as, by its superior 
weight on one side, to cause the egg to assume such a position that the beak of the 
animal shall be uppermost, and consequently fully exposed to the air when it first 
makes its way through the shell. 
