556 Sir John Rose Bradford [May 80, 



a " filter-passer." In both rabies and trench fever positive results 

 were rapidly obtained, and minute filter-passing viruses successfully 

 grown in the case of rabies from the brain of rabid animals, and in 

 the case of trench fever from the blood of cases of the disease in man 

 during the febrile period. They were also grown from the dejecta of 

 lice that had been infected from human cases in England. 



Positive results had now been obtained by this method from three 

 widely different diseases of men and animals — polyneuritis, rabies and 

 trench fever. The organism of the first disease was a globoid, but it 

 soon became evident that the other two organisms were not globoids, 

 as they showed no differentiation into two zones, and they did not form 

 zooglo^ja-like masses ; further, the organism of rabies was extremely 

 minute, although extraordinarily sharply defined. At this stage of 

 the work it seemed possible that the method was one generally 

 applicable for the investigation of filter-passing organisms, since the 

 virus both of rabies and of trench fever belonged definitely to this 

 group, and therefore the scope of our enquiry was still farther widened. 

 Influenza and a number of the acute specific fevers such as mumps, 

 measles, typhus, etc., were investigated. These are maladies the 

 causation of which is either unknown, uncertain, or reputed to be due 

 to filter-passers, and thus it was natural to investigate them. Two 

 other maladies in which we obtained striking results remain to be 

 mentioned, encephalitis and nephritis, and it is necessary to say a 

 few words as to the reasons for their investigation. Encephalitis 

 occurred to some extent in England last year, although at first there 

 seems to have been some uncertainty as to its nature. We did not 

 see this malady amongst the British troops in France to any 

 appreciable extent until this year, and personally I saw no cases of 

 lethargic encephalitis in France until the spring of 1919. So soon as 

 the polyneuritis results were definite, we obtained material from fatal 

 cases of encephalitis in England, and a filter-passing virus was 

 successfully grown from this material, and then when cases occurred 

 in the British Expeditionary Force similar results were obtained 

 from them. It was natural to investigate encephalitis, as it is a 

 malady possessing affinities to poliomyelitis and to polyneuritis, and 

 we have succeeded in obtaining results establishing the Koch postu- 

 lates with reference to this disease. 



As regards nephritis, there was no cogent scientific reason for 

 trying the Noguchi technique, except that all known methods had 

 failed in achieving any successful result in this malady, and there 

 were, in the opinion of many observers, reasons for looking upon 

 nephritis as due to an infection of some kind. Nephritis was known 

 to occur as a complication in certain acute infections, but in a large 

 proportion of cases of nephritis no evidence of an antecedent in- 

 fection can be obtained, and the causation of the disease was quite 

 obscure, and many had still a lingering belief that exposure to cold, 

 and especially to damp cold, was the main ^etiological factor. 



