206 ACTIVE IMMUNIZATION 



being used for each oese of the culture. The emulsion is kept for 

 30 minutes at 60 C., treated with carbolic acid to the extent of 0.5 per 

 cent., and allowed to stand for twenty-four hours before being used. 

 During epidemics Shiga recommends that still larger doses of the 

 vaccine be used, or to vaccinate three times with increasing quantities. 



DYSENTERY. 



Protective vaccination against bacillary dysentery has likewise 

 been attempted, but has not as yet led to results which are compar- 

 able in value to what we see in the case of plague and cholera. Shiga 

 himself inoculated some 10,000 individuals between 1898 and 1900, 

 and thought that he could note a decrease in the mortality, while 

 the morbidity and the severity of the symptoms were apparently 

 uninfluenced. The dead cultures, however, are so highly toxic that 

 this element in itself is an obstacle to the more general use of such 

 a vaccine. Whether further investigations in this direction will lead 

 to more practical results time only can tell, but it would not seem to 

 be out of the question, particularly when coupled with the use of a 

 corresponding antitoxic serum. 



OTHER DISEASES. 



In the other infectious maladies to which the human being is sub- 

 ject protective vaccination has either not yet been attempted or has 

 not yielded encouraging results. There are a number of infectious 

 diseases, however, occurring in the domesticated animals against which 

 vaccination may be successfully employed. This is notably the case 

 with anthrax, swine plague (Schweinerotlauf), cattle plague (Rinder- 

 pest), sympathetic anthrax (Rauschbrand), and within certain limi- 

 tations also with cattle tuberculosis. For a consideration of the 

 methods employed and the results which have been reached in these 

 diseases which so closely affect the human being the reader is referred 

 to special works. 



(5) ACTIVE IMMUNIZATION FOR THERAPEUTIC PURPOSES. 



While in the diseases which have thus far been considered, active 

 immunization will only furnish results of value when carried out for 

 prophylactic purposes, whereas the same measures have no influence, 



