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as it so often is with other organisms (mixed infections), still 

 requires much investigation ; and the effect of these associated 

 micro-organisms on the blood also requires detailed study before 

 much success is to be expected from the use of tuberculin in 

 the treatment of acute pulmonary tuberculosis. 



Class 3. — The acute bacterial infections, such as septicaemia, 

 ulcerative endocarditis, etc., seemed to offer few possibilities 

 for the exploitation of vaccine treatment. It does not, however, 

 appear in the light of recent events that their exhibition in these 

 cases will be given up without a struggle. The all-important 

 thing is that frequent, even daily, examinations of the blood 

 must be instituted during treatment. It is only by these means 

 that we can follow what is going on ; that is to say, know to 

 what extent the patient is inoculating himself. Next in 

 importance is the administration of such small doses of vaccine 

 that the negative phase may be made as slight as possible, or 

 may, if possible, be avoided altogether. 



It is difficult, without an intimate knowledge of the subject, 

 to conceive how the injection of dead bacteria into a patient 

 who is already inoculating himself to an excessive degree can 

 be expected to be of advantage to that patient. Wright 

 suggests the following as an explanation of the mechanism : 

 " In the case where bacteria are, as in the septicaemic conditions, 

 found in the blood-stream, or in organs standing in direct 

 relation with this, the bacterial derivatives are of necessity 

 diluted by the whole volume of the blood and lymph before 

 they can come into application upon the tissues in which, we 

 may take it, the machinery for the elaboration of protective 

 substances is located. In conformity with this great dilution 

 of the bacterial derivatives, a comparatively speaking ineffective 

 immunising stimulus will here be administered. In contrast 

 with this, where a bacterial vaccine is inoculated directly into 

 the tissues the bacterial products will come into application 

 upon these in very concentrated form, calling forth a 

 correspondingly larger production of protective substances." 



Cancer. — One group of diseases remains for consideration, 

 though it is only in the light of very recent work that it is 

 necessary to mention it in connection with bacterial disease. 

 Every attempt has been made to trace cancer to a microbic 

 origin, but no reliable work has, as yet, succeeded in proving 

 this. It may be said that to-day the research into the origin of 



