422 WHITMOKE. 



direct stimulation of the leucocytes. Wright and his assistants showed that 

 the same phenomenon was not a result of the stimulation of the leucocytes, 

 but is caused by an increase of some element in the blood which acts directly 

 on the bacteria and so alters them that the leucocytes are able to ingest them. 

 To these substances (for he showed that they were multiple) he gave the name 

 of "opsonins." Thus, as Oblmacher puts it, "it remained for Wright so to 

 modify the vaccine of Pasteur as to arouse in the serum of Buchner a substance 

 which prepared the disease producing microbe for ingestion by the phagocyte 

 of Metchnikoff ; thus bringing to practical humanitarian usefulness the laboriously 

 studied theories of these pioneers in biologic therapy." 



While Wright's work and his results have been well known for about 

 four j r ears, his method of treatment has been considered too technical 

 for the average worker, and on this account it has not received the 

 general consideration that it merits. It is not my intention to enter 

 into a discussion of the principles of opsonotherapy, but I desire to urge 

 that it is a practical method for the treatment of certain bacterial 

 diseases, and the practice is the truly valuable condition we have in 

 opsonotherapy. 



Wright enumerates "the methods, other than vaccine therapy, which 

 we have today for the treatment of bacterial diseases, as: (1) chemical 

 antiseptics; (2) extirpation of the focus of infection; (3) the de- 

 termination of lymph to the focus of infection; (4) sero- therapy ; and 

 (5) expectant treatment." 



The mere enumeration of these methods calls to the mind of every 

 one of us numerous failures, and how in any case these methods leave 

 the issue more or less to chance. 



Before proceeding to a discussion of the jjractical application of 

 vaccine therapy it will be well for us to review the methods used by the 

 body in the prevention and cure of bacterial disease. 



(a) Mechanical covering. This is of comparatively slight importance. 



(b) The main constituents are the antibacterial elements in the blood. 

 These are (1) bacterial substances, which kill bacteria; (2) bacterio- 

 lytic substances, which kill and dissolve bacteria; (3) agglutinins, which 

 agglutinate bacteria; and (4) opsonins, which alter the bacteria so that 

 they are readily ingested and digested by leucocytes. In this connection 

 the leucocytes must be considered as of great importance. 



(c) The body is able to manufacture antitoxins which do not neces- 

 sarily affect the invading bacteria, but neutralize the toxins produced by 

 these bacteria. 



The body combats bacterial invasion in two ways : The first and most 

 important, by attacking the bacteria themselves and the second by 

 neutralizing the toxin produced by the bacteria. The diphtheria bacillus 

 is the shining light among the organisms which stake their existence 

 against an antitoxic combat; while the tubercle bacillus, the pyogenic 

 cocci, including the gonococcus, the pneumococcus, the typhoid bacillus 

 and a number of others stake their existence against an opsonic combat. 



