1888-89.] Haycraft and Duggan on Coagulation by Heat. 369 
(b) Diluted with one volume of water, it became opalescent at 
67° C., and coagulated at 81° C. 
( c ) Diluted with two volumes of water, it became opalescent at 
69° C., and coagulated at 86° C. 
(d) (a) Diluted with three volumes of water, it became opalescent 
at 73° C., and a few flocculi separated out at 90° C. 
Another specimen of hydrocele fluid, apparently containing less 
proteid matter, became opalescent at 70° C., and coagulated with the 
formation of flocculi at 80° *5 C. 
A third specimen became opalescent at 70° C., flocculi forming 
at 78° C. 
General Conclusions regarding Dilution. 
In the case of albumens and globulin existing in a natural con- 
dition within an animal fluid, such as white of egg, serum, or 
hydrocele fluid, the point of opalescence is gradually and almost 
uniformly raised by successive dilutions. The coagulation point, on 
the other hand, rises rapidly, and the more dilute fluids often refuse 
to form flocculi, or even to coagulate at all. 
When a globulin is dissolved in an artificially prepared saline 
solution, both the point of opalescence and coagulating point are 
uniformly raised on diluting the solution. The same appears to 
apply to serum albumen saturated with magnesium sulphate. 
The Action of Salts on the Coagulation Point of Albumen. 
It is known that the addition of many neutral salts to an 
albuminous solution has an important action on the temperature at 
which it coagulates. Some salts are stated to lower and others to 
raise the coagulation point. It is impossible to explain at present 
their action, and we have accordingly commenced a somewhat 
systematic examination of the question. Our results are far from 
complete, and will subsequently, we hope, be more fully extended. 
We have at present studied the action of two important salts, 
namely, magnesium sulphate and common salt, on the coagulation 
points of egg and serum albumen, vitellin, and globulin, and the 
action of these salts has been studied in all degrees of strength up 
to complete saturation. 
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