36 JOURNAL OP THE TRINIDAD 



most frequently occurs in certain manufacturing centres where 

 the hides of animals are treated after being imported from abroad, 

 or brought up from the country, such as Bermondsey in the south of 

 London, and Bradford in Yorkshire. It is commonly known as 

 woolsorter's disease. The stringent regulations now in force in 

 England, as to cattle infected with splenic fever will doubtless 

 diminish the frequency of the disease, but there is still a serious 

 danger to be apprehended from hides imported from abroad. 

 In the British Medical Journal of January '20, 1891, I see that 

 a case of malignant pustule occurred in Paris recently, the source 

 of infection being goat-skins imported from China. The skins 

 were found to contain the dermestes vulpinus in two stages of 

 development. The bodies of these insects and their excrement 

 contained the bacillus anthracis, and guinea pigs inoculated with 

 these insects or their excrement reduced to powder, died of 

 charbon. 



Pasteur by cultivating the anthrax bacillus succeeded in 

 producing a protective vaccine for animals. This protection, 

 however, only lasts for a time. 



If the bacillus is passed through different species of animals 

 its virulence is altered. Bacilli from sheep or cattle are fatal if 

 re-inoculated into these animals, but if inoculated into mice, the 

 bacilli thus obtained lose their virulence for sheep or cattle, and 

 the latter are protected for a time against virulent anthrax. 

 Also a culture that is vaccine for sheep kills a guinea pig and 

 then yields bacilli fatal to sheep. 



The Bacillus tuberculosis is another member of this genus 

 which has been constantly in evidence since its discovery by 

 Koch in 1882. Much attention has been given to its life histor}^, 

 though not with the same success as in the case of the anthrax 

 bacillus, for spore formation though described by some observers 

 has not been satisfactorily made out. Koch's four postulates are 

 fulfilled in the case of animals, though it is obvious that the last 

 experiment of the chain cannot be applied in the case of man. 

 There is, however, little doubt that tubercle bacilli blown about 

 with dust constitute a real danger to the community. In the 

 British Medical Journal of January 13, 1894, Dr. Miller records 

 the discovery of tubercle bacilli in dust from a house in which 

 three people had died of phthisis at varying intervals, and two 

 others had shown ph}^sical signs of the disease. 



The Bacillus lepra? is very closely allied to the bacillus 

 tuberculosis in size and form, but especially in its behaviour to 

 staining reagents. These two bacilli are separated from all others 

 by the fact that they retain certain aniline dyes when treated 

 with nitric or sulphuric acid, while other bacilli are decolorized. 

 We have, however", advanced very little in our knowledge of the 



