124 A MANUAL OF BACTERIOLOGY 



methylene blue. In another case of the same 

 disease, Watson Cheyne found that certain bacilli 

 plugged the vessels and gave rise to haemorrhages. 

 Concerning this disease, he remarks that ' we may 

 have to do with an infective disease of which the 

 essence is the entrance of certain specific organisms 

 into the blood, and their growth in it. It may, 

 however, be that in these two cases, and in others, 

 the primary affection is something quite distinct 

 from microbes, resulting, however, in such an altered 

 constitution of the fluids of the body, that of the 

 innumerable organisms present in the mouth and 

 intestinal tract, certain of them may be able to 

 penetrate into and live in the blood, form emboli, 

 and thus lead to the haemorrhages which are so 

 marked a feature of these diseases.' 



Micrococcus variolce et vaccinice. Micrococci (0'5 

 p in diameter) have been found in the lymphatics 

 of the skin (in small-pox, 1 cow-pox, and sheep-pox 2 ) 

 in the vicinity of the pocks. The microbes were 

 found by Cohn 3 in the lymph of vaccina and 

 variola. No doubt they are the active agent in 

 small-pox and cow-pox, for if the lymph is filtered 

 through a Chamberland filter, the filtrate loses its 

 infectious properties. 



The author * has shown that a solution of salicylic 

 acid acts upon vaccine lymph, and deprives it of 

 the power of inoculation. 



1 Weigert in Med. Centralblatt, 1871. 



2 Klein in Philosophical Transactions of Royal Society, 1874. 



3 Virchow's Archiv, vol. Iv. 



4 Griffiths in Proc. Roy. Soc. Edinburgh, vol. xiv. p. 97. 



