ALBUMINOLYSINS 99 



Antilipoids. Still more recent studies have brought to light another 

 interesting class of antibodies which are not "tuned" to any par- 

 ticular cell, so far as our present knowledge goes, but which have the 

 power of reacting with substances belonging to the group of lipoids. 

 Such antibodies have been discovered in patients suffering from 

 syphilis, yaws, frambesia, trypanosomiasis, cancer, leprosy, etc., and 

 may, for the present, be spoken of as antilipoids. Their reaction 

 with the corresponding lipoids is characterized by the fact that if 

 complement be present at the time this is fixed to a greater or less 

 degree, so that upon the subsequent addition to the mixture of 

 lipoid, antilipoid, and complement, of washed red corpuscles and a 

 suitable hemolytic amboceptor, hemolysis either does not occur at 

 all, or is more or less impeded. This remarkable phenomenon is 

 the basis of the so-called Wassermann test for syphilis, and as such 

 constitutes one of the most important discoveries of medicine (see 

 Wassermann reaction). 



Albuminolysins. I have pointed out above that upon injecting 

 albumins, either of vegetable or animal origin, into an animal of an 

 alien species, antibodies are formed which are known as precipitins, 

 and are characterized by their ability to form a precipitate, when 

 brought together with the corresponding antigenic substances. 

 The allergic state which develops as the result of the injection of 

 foreign albumins can manifest itself in still other ways, however. 

 If a guinea-pig is thus injected with normal horse serum, for 

 example, and an interval of from ten to thirteen days is allowed to 

 elapse, it will be noted that the second injection is followed by most 

 threatening symptoms intense dyspnea and marked drop of temper- 

 ature ( Theobald Smith phenomenon) which frequently end in death. 

 Corresponding symptoms occur in other animals and may follow 

 the introduction of almost any foreign albumin by parenteral chan- 

 nels. Evidently the first injection sensitizes the animal to subse- 

 quent injections and the thought naturally suggested itself that here 

 also antibodies may play a role. What these antibodies are is still 

 a matter of surmise. Some investigators have attempted to identify 

 them with the precipitins, while others look upon them as a peculiar 

 type of lysins, which we may accordingly term albuminolysins, and 

 suppose that during the interaction between the lysin and its anti- 

 gen, at the time of the second injection, highly poisonous inter- 



