PROFESSOR PAGET ON THE FREEZING OF THE ALBUMEN OF EGGS. 223 
Many things observed in the course of these expei’inients seemed to indicate that 
the freezing of the fresh egg was retarded by some peculiarity of its mechanical con- 
struction, which was destroyed by the several means supposed to destroy its life. It 
was, therefore, desirable to ascertain whether the capability of being reduced far 
below 32° without freezing, and the consequent apparent resistance to freezing, 
could be destroyed by any means that would not at the same time prevent the egg 
from manifesting, by development in incubation, the surest evidences of vitality. In 
experiments to determine this point, I found that one might, with a bent probe, 
gently detach the whole of the albumen of an egg from its connection with the 
membrane of the shell, and that after this the chick would be developed, although, 
perhaps, not to perfection. But when eggs with the albumen thus disturbed wei’e 
exposed to cold, they did not descend below 32° without freezing; they lost heat less 
quickly, but froze sooner, than uninjured eggs did, when exposed with them to the 
same temperature ; they froze like the eggs which Mr. Huntf.r considered dead. 
Again, cracking the shell of an egg does not prevent the development of the young 
bird, although, in consequence of the excessive evaporation through the fissures, the 
development may be imperfect. But when eggs with their shells cracked in many 
places, and with slight injuries of the membrane of the shell, were exposed to cold, 
they lost heat and froze just as those did which might be reputed dead. Thus, then, 
mechanical injuries, such as could not have affected the chemical composition of the 
fresh egg, and such as did not prevent its development in incubation, were found 
sufficient to deprive it of its power of resisting freezing; and thus its power of resist- 
ance appeared to be due, not to any vital principle, but to some peculiarity of me- 
chanical construction. 
It may be very difficult to prove what this peculiarity of construction is. That it 
is a property of the albumen was proved by some experiments, in which albumen, 
gently removed from fresh eggs, exhibited the same mode of freezing as the entire 
fresh eggs did : and the following facts, as well as those already mentioned, are 
favourable to the opinion, that the property which enables fresh albumen to descend 
far below 32° without freezing, is its peculiar tenacity or viscidity, by means of 
which the water combined with it is held so steadily, that the agitation favourable, 
or even necessary, to the freezing at or near 32° cannot take place. 
1. The decay and putrefaction of an egg, the freezing and again thawing of one, 
and (as egg-preservers well know) the stirring and frequent concussion all tend to 
diminish the viscidity of the albumen to such a degree, that, instead of forming a 
consistent substance, the greater part of it will flow like a thin liquid from an aper- 
ture in the egg-shell. 
2. The albumen of eggs does not freeze like a dense solution of albumen, or of 
saline substances, in water, but like water of which the ordinary freezing is pre- 
vented. The freezing-points of aqueous solutions are, according to their densities, 
more or less below 32°; and if, in exposure to intense cold, the temperature of any 
