224 PROFESSOR PAGET ON THE FREEZING OF THE ALBUMEN OF EGGS. 
such solution be reduced below its freezing-point, it will, at the instant of freezing, 
rise to that point, whatever it may be, and not to 32°. Thus, I placed in a freezing- 
mixture of which the average temperature was 10°Fahr., solutions of common salt in 
the proportions of 3, 5, 6 and 9 parts to 100 of distilled water ; they fell to from one 
to six degrees below their several freezing-points, and then, in the act of freezing, rose 
respectively to 28°, 25°, 24^°, and 23°. At these temperatures they remained till they 
were thoroughly frozen, and then they all descended to the temperature of the medium 
in which they were placed. The same is observable in the freezing of serum and 
blood, which, in their relations to heat, may be regarded as mere solutions of albu- 
men and saline matters : they freeze at from 29° to 31°, and retain these temperatures 
till they are thoroughly frozen. I found the same also in the freezing of milk and of 
thick mucilage of gum ; the former froze at 30°, the latter at 28°, but neither of them 
in freezing rose to 32°. Unlike all these substances, the albumen of fresh eggs, how- 
ever far below its freezing-point it may have descended, always in freezing rises to 
32°; it freezes therefore like water, or like a very weak saline solution, which, by 
some mechanical disposition of its particles, is prevented from freezing as soon as it 
is reduced to 32°, or a fevv degrees lower. 
3. The sudden strong agitation of fresh albumen, when its temperature is reduced 
several degrees below 32°, will often cause it to freeze at once*, as water under the 
same circumstances freezes. 
4. It is well known, that when once a portion of any given quantity of water is 
frozen, the portion in contact with the ice cannot be reduced below 32° without 
freezing. I thought, therefore, that if I could bring ice just formed into contact with 
the albumen of an egg, the water in the albumen would freeze as soon as it fell to 32°, 
and so it proved ; for in three experiments, in which the air-cavities of fresh eggs 
were filled with water before exposing them to cold, the albumen did not descend 
below 32°, but froze at that temperature. 
Whether the explanation here offered of the peculiar property of the albumen of 
fresh eggs be right or not, the property will, I think, merit consideration in reference 
to both the nature and the purpose of the substance to which it belongs. 
For, in regard to the nature of this form of albumen, its mode of freezing proves it 
to be essentially different both from all solutions of albumen and from organic tissues 
holding albuminous matter in suspension. As I have already stated, the freezing- 
* In the course of the experiments, I observed that the effect of agitation, on either albumen or a saline solu- 
tion, when its temperature is reduced below its freezing-point, depends in some measure on the temperature of 
the medium in which it is placed. Thus a saline solution, whose freezing-point was 28°, might be reduced to 
25° in a medium of 24°, and, on being now agitated, it would not freeze ; but a similar solution, reduced to 25° 
in a medium of 10°, would freeze at the instant of agitation. In a medium of which the temperature averaged 
21°, no length of exposure and no agitation would, in one of my experiments, make albumen freeze, though it 
fell to the temperature of the medium ; but in others, when albumen, in a medium averaging 10°, fell to 28°, it 
froze as soon as it was agitated. 
