GENEEAL TECHNIC 445 



the idea of specificity uppermost in their mind, adhere to the use oi the 

 latter, whereas the results of research and of practical work shows that 

 lipoids from normal organs serve equally well as antigen in making the 

 syphilitic reaction, and, indeed, may prove superior if luetic liver is 

 used that has undergone advanced fatty changes or autolysis, when 

 undesirable hemolytic and anticomplementary derivatives are extracted 

 in excess. 



Human, guinea-pig, and beef-heart muscle are usually employed. 

 The first is especially efficient and is to be preferred. 



Preparation. The organ is obtained fresh from the autopsy room. It is freed 

 from fat, and to each 10 grams of minced muscle 100 c.c. of absolute ethyl alcohol 

 are added. Extraction is conducted in exactly the same manner as was described in 

 the preparation of alcoholic extract of luetic liver. 



If guinea-pig heart is employed, as much of the fat as possible should be removed, 

 otherwise the extract may be quite anticomplementary. 



Boas prepared an extract of human heart by treating the ground muscle with 

 nine parts of absolute alcohol, shaking for an hour at room temperature, filtering, and 

 storing away in a stoppered bottle. He found that different extracts so prepared are 

 remarkably constant in their properties, although they deteriorate rapidly and should 

 be prepared freshly every few weeks. 



4. Alcoholic Extracts of Normal Organs Reenforced with Choles- 

 terin. Sachs advocated the addition of pure cholesterin to alcoholic 

 extracts of normal heart as a means of rendering these antigens more 

 delicate, without materially increasing their anticomplementary and 

 hemolytic properties. He found that such preparations possess proper- 

 ties equal to the best syphilitic extracts. This work has been confirmed 

 by Hemlein, Altman, Mclntosh and Fieldes, Desmonliere, Walker, 

 and Swift. We have studied the subject with much interest, comparing 

 the results with those secured from other antigens, as alcoholic extracts 

 of syphilitic liver and acetone-insoluble lipoids. It is true that these 

 preparations are highly sensitive so much so that I never employ them 

 alone in making diagnostic reactions, but always in conjunction with 

 other extracts as controls, in order to detect and avoid non-specific 

 reactions with non-luetic serums. We have found that they occasion- 

 ally give faint positive reactions with normal serums; on the other hand, 

 not infrequently, they react strongly positive in cases where, with other 

 extracts, the reactions are negative; in the majority of such cases 

 the serum is from a long-standing or a treated case of lues that needs 

 further treatment until the reaction with a cholesterin extract becomes 

 negative. These alcoholic extracts of normal organs have their greatest 

 value, therefore, with known syphilitic serums when the reaction is 

 conducted as a guide to treatment. In diagnostic reactions, however, it 

 is my opinion that they should not be used alone, but together with less 



