Notes. 
308 
It would seem to follow from what has been said that the instability 
of the complex molecular structure of which living organisms are made 
up, may be lessened by appropriate desiccation, but the substances 
concerned are too complex to render themselves readily accessible to 
inquiry. It appeared, however, that it might be worth while to study 
the effects of desiccation on albumin from this point of view. Albumin 
is not only a highly complex proteid, and perhaps in some respects 
akin to protoplasm itself, but it is one which gives tolerably definite 
heat reactions. It is in connexion with the last-mentioned point that 
the facts detailed in this paper are specially concerned. 
It is of course known that albumin in a watery solution is readily 
coagulated on heating to a certain temperature. This temperature, 
however, is not necessarily constant for even one type of albumin, 
doubtless owing to the readiness with which it undergoes change. 
Thus albumin obtained from different hens’ eggs will often be found 
to coagulate at different temperatures, and the differences appear, in 
part at any rate, to be connected with the age of the egg. I have 
found in the case of freshly-laid eggs, that the characteristic opal¬ 
escence which marks the early stages of coagulation may set in as low 
as 6o°C., the clotted coagulum being fully formed at 64° C. The 
heat was applied by means of a large water-bath, so as to ensure its 
being as uniform as possible. Another sample of albumin from 
a different egg tried simultaneously and under the same conditions, 
only exhibited opalescence at 65-6° C., and coagulated completely 
at 68° C. 
The albumin on which most of my experiments were made, was 
obtained from Merck, of Darmstadt, and was sent as dried egg- 
albumin. It readily dissolved in water, with the exception of a little 
flaky insoluble portion, which was filtered off. The solution had 
a low coagulation-point, the opalescence appearing at 6o° C., and the 
clot at 62° C. to 63° C. 1 Filtering off the clot and testing the filtrate 
at higher temperatures yielded no further coagulation. 
If a sample of this (dry) albumin be placed in a flask, the mouth of 
which is furnished with a cork and attached to a set of drying-tubes, 
and the temperature of the flask raised to 8o° C., a short exposure, 
of at any rate two to three hours, is enough to completely alter the 
1 It is of course known that several factors affect the coagulation-point. The 
figures given represent those obtained in my experiments, which were all kept as 
uniform as possible so as to eliminate the factor of variability. 
