In order to gain the most information from the Wassermann test, more than one antigen should be used in the "set up." One of the antigens so used should undoubtedly be the
Noguchi acetone-insoluble, as it will give positive reactions with a higher percentage of syphilitic serums than the alcoholic extracts, while it is less likely to give false positive reactions than the more sensitive cholesterinized extracts. But its preparation requires so much time that this becomes quite a factor in a laboratory where considerable quantities are used. With a view of hastening the process of extraction and evaporation we tried this at higher temperatures and find that boiling temperature in no way interferes. In this way we can prepare and titrate an antigen all in one day.
To one part of finely minced beef heart, nine parts of commercial ethyl alcohol are added. (We have recently tried the