226 THE POPULAR SCIENCE MONTHLY. 



familiar chemical methods, and that conferred the power of re- 

 sisting the living micro-organism. 



During the epidemic in Spain, Ferran's inoculations were prac- 

 ticed in more than thirty thousand persons. In the province of 

 Valencia there were 62'33 cases per thousand of population, and 

 31*11 per thousand died of cholera. Where inoculation was gen- 

 erally practiced the cholera affected 76*95 per thousand, with a mor- 

 tality of 33*58, of the total uninoculated ; while among the inocu- 

 lated 12*69 per thousand were attacked, and only 3*41 per thousand 

 died. In other words, in the latter class 6*06 times fewer people 

 were attacked, with a mortality 9*84 times less than that of the 

 uninoculated. 



Ferran's methods were investigated by commissions from sev- 

 eral of the European scientific societies ; and by several, notably 

 that from France, he was condemned for having made claims that 

 could not be demonstrated. 



In 1888 Dr. Gamaleia published the results of experiments he 

 had made with the cholera spirillum. He found that the cultures 

 of this organism, as obtained from the human body, lose their 

 virulence in the laboratory. In order to restore this virulence, 

 and possibly to enhance it, Dr. Gamaleia first inoculated a 

 guinea-pig with the cholera spirillum, and when the disease 

 was apparent in that animal made an inoculation from it into 

 a carrier-pigeon. This was on the principle employed by Pas- 

 teur to increase or attenuate the virus of chicken-cholera, rouget, 

 anthrax, and rabies by inoculating different animals with the re- 

 spective virus of those diseases. So toxic does the cholera spi- 

 rillum become in the pigeon, that a few drops of its blood rapidly 

 kill an animal susceptible to cholera. He also found that in a 

 sterilized culture of the spirillum there was a principle that, ad- 

 ministered in non-toxic doses to an animal, would afford subse- 

 quent protection from cholera. The phenomena produced by 

 these inoculations were similar to those observed by Ferran in 

 his own experiments, though no inoculations were made in man 

 by Gamaleia. G. Klemperer has reported this year experiments 

 that verify those made by Ferran and Gamaleia. He discovered 

 that a guinea-pig could be protected against cholera by inoculat- 

 ing it with the serum of the blood of a rabbit that had been pro- 

 tected by inoculation of mild cultures of the spirillum ; and in 

 one rabbit that had been rendered immune to pneumonia as well 

 as to cholera, its serum afforded protection from cholera to 

 guinea-pigs, and from pneumonia to mice. He considered that 

 these results corresponded with the immunity observed in human 

 beings after an attack of Asiatic cholera. 



During this year Haffkine has reported to the Paris Biologi- 

 cal Society experiments that he has made with the spirillum. 



