116 CLINICAL BACTERIOLOGY AND 



we have obtained good results from the early injection of 

 a stock B. coli vaccine, usually beginning with a dose of 

 25,000,000 in young calves. It is advisable, where an autog- 

 enous vaccine is not used, a polyvalent one should take its 

 place. 



A second injection of 50,000,000 should be given three 

 or four days later, and the conditions noted. 



In addition to vaccines, in many bacterial intestinal in- 

 vasions we have had excellent results from the early use 

 and repeated administration of boric acid. 



Johne's Disease in Cattle. 



It may not be out of place here to mention a rather 

 common bacterial invasion of the intestines of (usually) 

 adult cattle in certain districts by an acid-fast bacterium 

 resembling in many ways the bacillus of tubercle, and 

 named, after the discoverer, Johne's bacillus. 



Practitioners in days gone by considered Johne's disease, 

 as seen in cattle, to be a form of enteric tuberculosis. 



The specific bacillus can be easily isolated, stained, and 

 demonstrated under the microscope, T V oil immersion, from 

 scrapings made from the intestines. It is, however, a very 

 shy microbe to cultivate artificially in the laboratory upon 

 the usual media ; but, thanks to the well-known research 

 work of Twort and Ingram, a medium has been prepared 

 to suit the growing tastes of this bacterium. These two 

 workers found by cultivating and killing the Timothy- 

 grass bacillus (B. phlei), and mixing the result with the 

 nutrient media, the bacillus of Johne grew most success- 

 fully, the reason they give being that probably the 

 Timothy -grass bacillus is the "wild ancestor" of the 

 Johne bacillus. 



They have made a vaccine, as above indicated, which 

 they assert has a diagnostic value towards Johne's disease 

 equal to that which tuberculin has to tuberculosis, and 

 mallein has to glanders ; and they are careful to point 

 out that the maximum rise of temperature is expected 



