246 POPULAR SCIENCE MONTHLY. 



The inoculation was first .to be made on volunteers among the 

 physicians on probation at Netley; then on volunteers among the 

 young officers of the army on the eve of their departure for the tropics; 

 and then, with the approval of the military authorities, on volunteers 

 among private soldiers. At the end of 1895, during my visit to Eng- 

 land, I obtained from Sir William Mackinnon, then Director-General 

 of the Army Medical Department, permission for Professor Wright to 

 start the work upon the plan above detailed; and the first inoculations, 

 in the way described above, were done in the middle of 1896. Soon 

 after that, Pfeiffer and Kolle, recognizing the same similarity between 

 the cholera and typhoid microbes, and pointing out that the results 

 obtained by us in India were likely to be repeated when applying the 

 method to typhoid, proposed and started a similar series of inoculations. 



When the inoculation against plague was begun, and observation 

 showed that dead vaccines alone were apparently sufficient to produce 

 satisfactory results, a second inoculation with living virus appeared 

 less urgently necessary; and as the effect of such an inoculation, which 

 Professor Wright very courageously tried first on himself, seemed 

 troublesome, it was decided to do for the time being the second 

 inoculation also with the carbolized virus. Similarly, the plan which 

 was adopted for the plague inoculation, of cultivating the vaccine in a 

 liquid, instead of a solid medium, and of using cultures of several 

 weeks' duration, has been subsequently adopted in the typhoid inocu- 

 lation also. 



Many thousands of British soldiers and civilians have already un- 

 dergone the inoculation in question. The latter was done partly with 

 vaccines cultivated on a solid medium, according to the older plan, 

 and partly with vaccines prepared according to the plague inoculation 

 method. The results so far observed are encouraging, and, I hope, 

 will shortly be improved considerably. At the last Harveian dinner 

 in London, Surgeon-General Jameson, Director-General of the Army 

 Medical Department, summarized the results of the observations in 

 India, where, among several thousands of young soldiers, the most 

 prone to the disease, the incidence of typhoid since their inoculation 

 was 0.7 per mille, while among the older, more resistant, not inoculated 

 soldiers, the incidence was during the same period just double that. 

 A large proportion of the force now on service in the South African 

 campaign have been inoculated, some before embarking and others 

 on their way out. 



Such is the position of preventive inoculation, as applied, so far, 

 to human communities. The very success of these operations is now 

 apt to create some sort of feigned or earnest alarm, and one meets 

 at present with the question, What is going to happen to our poor 



