256 



Dr. W. M. Haffkine. 



places was that the proportion of deaths to cases was not changed by 

 the treatment. 



Thus, in the observations made in a camp of coolies of the Assam- 

 Burmah Eailway Survey, out of thirty-three attacked among the 

 uninoculated portion of the camp twenty-nine died, and of four 

 attacked among the inoculated all four died. 



In the Durbhanga prison out of eleven uninoculated attacked all 

 eleven died, while five inoculated attacked lost three. 



In the Gaya gaol twenty uninoculated attacked lost ten, and eight 

 inoculated attacked lost five. 



In a group of tea plantations in Assam 154 cases in uninoculated 

 had sixty deaths, fifteen cases in inoculated had four. 



In the East Lancashire Eegiment in Lucknow 120 uninoculated 

 attacked had 79 deaths, and 18 inoculated attacked had 13. 



This circumstance, the non-reduction of the case mortality by a 

 treatment which influenced unmistakably the case incidence, appears 

 an astonishing divergence from the result of small-pox vaccination, 

 where both the number of attacks and their fatality are reduced by the 

 treatment. 



The new aspect of the problem of preventive inoculation which thus 

 presented itself in these observations on human communities consisted 

 in the possibility of a prophylactic treatment being directed separately 

 towards the reduction of the number of attacks, leaving the fatality of 

 the disease unchecked, and towards the mitigating of the character of 

 the disease and the reduction of the case mortality in those who get 

 attacked. 



Possible relation between Immunity from Attack and Resistance to actual 

 Symptoms of Disease. 



In analysing the nature of this particular result, the following two 

 facts well known in laboratory practice presented themselves to me as 

 of essential significance. 



In patients who recover from an infectious disease the pathogenic 

 microbe does not disappear from their body for a considerable time 

 after their recovery. It does not do them harm any longer, though 

 when transferred to another animal it may still cause a fatal attack. 

 Similarly, as in the case, for instance, of a guinea-pig inoculated with 

 the bacillus of chicken cholera, a naturally immune animal can breed 

 for weeks, in an abscess, microbes of an intense virulence without in 

 the least suffering in its own general health. 



A condition seems to set in in the convalescent patient, or to exist in 

 naturally immune animals, by virtue of which they do not suffer from the 

 results of activity of a pathogenic microbe, i.e., from its morbid products ; 

 and from that time the presence of the microbe in the system, even in 



