1886.] NEW YORK ACADEMY OF SCIENCES. 207 



Add to this tluit an infusion of the tissues of ;in uniniul, ufter 

 inocuhxtion (which lias recovered and enjoys immunity from a 

 disease, and from whicli, on Pasteur's theory, the pabulum 

 necessary for that disease germ has been exhausted), forms a 

 suitable culture medium for the germs of that disease, and we 

 have a very strong case against this theory. 



The exhaustion of chicken bouillon, so that it will not support 

 the new cultivation of fowl-cholera microbe, simply means that 

 too much of the proteid constituents in solution have been re- 

 moved in thelife processes of the jirevious cultivation to allow the 

 fluid to act as suitable pabulum for the new crop. 



Let us now examine the second of the theories jiroposed, the 

 " antidote theory " of Klein, enlarged upon in the twentieth chap- 

 ter of his book previously mentioned, where he thus defines and ex- 

 plains it: "According to this (theory), the organisms growing and 

 multiplying in the body during the first attack produce, directly or 

 indirectly, some substance which acts as a sort of poison against a 

 second immigration of the same organism. . . . According to 

 this theory, we can well understand that — just as in the case of an 

 animal, say a pig, unsusceptible to anthrax, the unsusceptibility 

 being due to the presence in the blood and tissues of a particular 

 chemical substance inimical to the growth of the bacillus anthra- 

 cis — so also in the case of a sheep or ox which has once passed, 

 through anthrax, there is now present in the blood and tissues 

 a chemical substance inimical to the growth and multiplication 

 of the bacillus anthracis, whereby these animals become pos- 

 sessed of immunity against a second attack of anthrax. Whether 

 this chemical substance has been elaborated directly by the ba- 

 cilli, or whether it is a result of the chemical processes induced 

 in the body by the bacilli during the first illness, matters not at 

 all; it is only necessary to assume that the blood and tissues of 

 the living animal contain this chemical substance." So much 

 for Klein in behalf of this theory, concerning which he says: 

 "I am inclined to think that this theory is in harmony with the 

 facts." Let us examine upon what foundation it rests. 



In the beginning we remark that, while rendering neces- 

 sary a certain number of hypothetical substances to act as anti- 

 dotes against subsequent invasions of germs of the same character, 

 it is, if I may so call it, '•quantitatively" superior to Pasteur's 

 theory, inasmuch as we can conceive of smaller quantities of 

 these chemical poisons being capable of prohibiting the growth 

 of micro-organisms than the amount of substance necessary to 

 sustain them; and where a substance is hypothetical, the smaller 

 the amount the better defence has it from the question, "Why 

 has it not been found ? " 



Still, in common with Pasteur's, it his the defect of neces- 



