376 BACTERIA. 



researches on the albumoses formed by the anthrax organism 

 have opened up a new field for the chemistry of bacteriology. 

 Fowl cholera^ certain forms of septicaemia, and a number of 

 other diseases, amongst which may be mentioned hydro- 

 phobia, in which, however, the facts do not belong to quite 

 the same order, all were brought within the same zone, 

 when it was found that the introduction of the sterilized 

 products of a specific organism, first in minimal doses and 

 then in gradually increasing doses, could confer a protection 

 against the subsequent action of even the most virulent 

 organism that under ordinary circumstances gives rise to the 

 same products as those injected. Gradual " acclimatization " 

 is the ideal method though in most cases the results were 

 obtained by a single injection. It was for long supposed 

 that the products through which this immunity was con- 

 ferred were of an alkaloidal nature, and there can be little 

 doubt that in some cases, at any rate, these alkaloids may, if 

 given for a sufficiently long period of time, and in gradually 

 increasing doses, have some effect in " acclimatizing " the 

 tissues to the action of the poison. As pointed out by 

 Sewall, who carefully studied the substances contained in 

 snake poison, the albumose contained in such poison, given 

 in very minute doses to pigeons, confers upon them the 

 power of withstanding seven times the ordinary deadly dose 

 of snake poison, even three months after the inoculation 

 has been made. A single dose of the ordinary hemi- 

 albumose of proteid digestion confers a similar immunity 

 against the action of this same albumose for a period of twelve 

 hours. Hankin, working on this analogy, concluded that 

 the albumose that he was able to separate from anthrax 

 bacilli was really the substance that conferred the immunity 

 against attacks of the bacillus itself, and he found that, 

 although he could kill rabbits with doses of the five 

 millionth of the body weight, a dose of one-ten milUonth 

 of the body weight rendered the animal immune to the 

 action of virulent anthrax. He found that he had obtained 

 an instrument of such delicacy, although of so great power, 

 that he was able to protect even mice against anthrax, which 

 had only been done once before — by Hueppe and Wood. It 

 would appear, however, that it was necessary to allow a certain 

 interval to come between the inoculation with the albumose 

 and the injection of the virulent anthrax organism. This is 



