POISONS AND THEIR PREVENTION 173 



influence of this special substance which has been 

 generated in the gall, the bacteria remain rooted 

 to the spot where they are first situate, and only 

 a passing and exceedingly slight local affection 

 results, which on its departure leaves the animal 

 with an immunity from rinderpest lasting some 

 four months. A number of interesting investiga- 

 tions have not unnaturally been stimulated by 

 this remarkable discovery, and researches on the 

 properties inherent in the gall of healthy animals 

 of various kinds have been recently carried out 

 by Dr. Neufeld, of the Institute for Infectious 

 Diseases in Berlin, which are, however, of a too 

 technical nature to deal with here. 



As an illustration of the practical use to which 

 Koch's gall immunisation method may be put in 

 dealing with outbreaks of rinderpest, reference to 

 a recent report furnished by the Health Officer of 

 Shanghai may be of interest. Dr. Arthur Stanley 

 describes the outbreak as follows : 



"A large herd of cattle infected with cattle-plague 

 was brought to Shanghai from the Tanyang district, 

 around the Grand Canal, for export to the allied troops 

 in the north of China. The disease spread to an 

 adjacent dairy, most of the cattle dying. On this dairy 

 becoming infected a police cordon was established 

 round it to prevent ingress and egress of cattle and 

 ingress of persons unconnected with the dairy, while 



