48 
SUMMARY AND CONCLUSIONS. 
While the use of hypnotics appeared promising for the prevention 
of anaphylaxis, it seems, from our work, that they offer little or 
no practical advantage for this purpose. We used in our experi- 
ments urethane, paraldehyde, chloral hydrate, and magnesium sul- 
phate. These substances have practically no influence upon the 
fatal outcome of anaphylaxis. 
Further work upon the specificity of anaphylaxis emphasizes the 
specific nature of this phenomenon. 
The effect of heat in modifying or destroying the sensitizing or 
poisonous properties of proteins probably depends entirely upon its 
effect in rendering the proteins insoluble, rather than by the produc- 
tion of chemical changes in the protein. 
It was found that heating dried horse serum to 130° C. for two 
hours or 150° C. for ten minutes or 170° C. for ten minutes did not 
appreciably modify its toxicity for sensitive guinea pigs. 
Dried egg white, whether whole or purified, may be heated to 130 ° C. 
for two hours or 170° C. for ten minutes without appreciably affecting 
its toxicity for sensitive guinea pigs. 
Milk when dried may be heated to 130° C. for two hours, 150° C. 
for ten minutes, or 170° C. for ten minutes, and found to be appar- 
ently more toxic than the unheated serum. Whole fluid milk may 
be heated to 170° C. for ten minutes or 130° C. for two hours without 
any apparent decrease in its toxicity. 
Dried horse serum may be heated to 130° C. for two hours, 150° C. 
for ten minutes, or 170° C. for ten minutes, without impairing to any 
appreciable degree its sensitizing properties. 
Dried milk may be heated to temperatures varying from 130° C. 
for two hours to 170° C. for ten minutes and redissolved, and found 
to be as potent for sensitizing as unheated milk. 
Fluid milk may be heated to 130° C. for fifteen minutes or 170° C. 
for ten minutes without altering its sensitizing properties. 
Dried egg white, either whole or purified, may be heated to the 
same high temperatures without apparently altering its ability to 
sensitize guinea pigs. 
The sensitizing substance in sensitive guinea pig serum, when 
dried, may be heated to at least 100° C. for ten minutes without 
destroying its power to‘ sensitize guinea pigs within forty-eight hours. 
Animals sensitized with euglobulins prepared by one-third satura- 
tion with ammonium sulphate were not sensitive when amounts 
smaller than 0.001 c. c. were used, while amounts larger than this 
sensitized guinea pigs. 
