370 MARSHALL AND TEAGTJE. 



Bruck(l7) found that his strong immune serum alone would cause delleetion 

 in the amount of 0.05 cubic centimeters, and Uhlenhuth(20) gives us a long list 

 of substances of diverse nature which will produce non-specific deflection. Selig- 

 mann(21) concluded that absorption of complement is brought about by altering 

 the molecular condition of the colloids in solution, even without causing precipi- 

 tation. He states that his experiments do not explain the specific immunity 

 reaction, but serve to show that there are other non-specific reactions of a 

 similar nature. 



Landsteiner(22) noted deflection when the syphilitic serum was used with 

 extracts from the organs of normal animals, for instance, guinea-pigs' livers, or 

 with alcoholic extracts of organs. We will describe below in more detail the 

 nature of this process as well as the deflection with sodium oleate and lecithin. 



However, the positive reactions which are not specific are of such a 

 nature that they do not prevent a careful worker from employing the 

 deflection method with a degree of certainty that is at least comparable 

 to that attaching to many generally accepted clinical methods. 



Although a positive fixation reaction with suitable controls give us 

 certain evidence of the existence of syphilis, a negative reaction does not 

 give the same proof of its non-existence. There are various possible 

 sources of error wdiich must be borne in mind in the interpretation of 

 negative results. 



According to llichaelis and others, the syphilitic extract of liver is occasionally 

 hemolytic itself. This function may more than compensate for any possible 

 deflection; aqueous or alcoholic extracts of the liver are very unstable and it is 

 not infrequent that a preparation which has proved satisfactory one day is per-. 

 fectly useless on the next, and almost all extracts deteriorate on standing. 

 There are also other possible causes which may lead to a negative reaction. 

 They may be summarized as follows: (a) the- patient has no syphilis and has 

 never had it ; ( 6 ) the patient has been completely cured of previous disease ; 

 (c) the serum is obtained from a patient during a temporary absence of the 

 specific complement-binding substances from the blood of the patient; (d) there 

 are certain refractory individuals whose serum always fails to deflect; (e) under 

 energetic mercurial treatment it occasionally happens that the deflecting power 

 disappears. It has also been observed that the reaction is less constant in the 

 early stages and increases in regularity with the age of the disease. 



The preceding discussion shows that the particular value of the 

 deflection methods in clinical medicine at present is in the diagnosis of 

 syphilitic diseases. 



As Wassermann remarked(19) in December, 1907: "It is, up to the present 

 time, more valuable than the Widal test was after an equal trial * * *. 

 Probably as with the Widal test, some cases will' be found which give a positive 

 reaction, although there is conclusive reason to believe that syphilis is not 

 present, but no such eases have been observed so far." He summarizes about 

 1,500 cases in which the serum diagnosis of syphilis has been attempted, in the 

 great majority of which results were eminently satisfactory. Citron notes that 

 in the primary stages 90 per cent were positive, in the secondary stage between 

 98 and 100 per cent, in the late cases where the process is active the reaction is 

 practically universal. 



