44 



DR. BASTIAN ON THE 



be observed that this interpretation renders no explanation of the 

 initial higher fermentability of the unheated neutral infusion. 



It was to test the validity of this partial interpretation of the 

 facts that my experiments were undertaken. If M. Pasteur's 

 views were correct, the addition of no quantity of sterilized potash 

 after the acid fluid had been boiled (and therefore also sterilized) 

 should suffice to induce fermentation and the appearance of or- 

 ganisms. But, as we have seen, such results do follow. What 

 explanation, then, can be given of these experiments ? There is 

 only one which is at all compatible with the above-mentioned 

 view of M. Pasteur ; and this shall be first referred to. 



1. Ihe Fertilizing Agent contains living Germs. — As I have 

 already stated, this was very soon affirmed in a positive manner, by 

 more than one experimenter, to be the explanation of my results. 



In previous experiments recorded by other investigators in 

 which barren fluids had been fertilized by the addition of fresh 

 matter from without, such matter, being unheated, had always 

 been assumed to produce this eff'ect by reason of its containing 

 living germs*. The explanation of my experiments being, there- 

 fore, facile and ready to hand, they were on this account speedily 

 condemned, both before the French Academy and the Eoyal So- 

 ciety of London. Yet this particular interpretation had been 

 fully considered, and its disproof had been set forth, when my re- 

 sults were first announcedt. 



It had been proved that neither the liquor potassse nor the 

 air within the little tube heated to 100° C. acts merely as a 

 germ-containiug medium, since the addition in the same manner 

 of only one or two drops or of a slight excess of potash did not 

 suffice to contaminate several ounces of boiled urine. But if the 

 action of the contents of the liquor-potassse tubes had been due 

 to their containing living germs, a single drop of liquor potassaD, 

 together with the air from such a boiled tube, should have always 

 sufficed rapidly to initiate fermentation even in a gallon or more 

 of urine. The fact that it did not, proved conclusively that neither 

 the liquor potassae nor the air of the tube was the bearer of living 

 germs. 



* See Pasteur's chapter headed " Ensemencement des poussieres qui existent 

 en suspension dans Vair, dans des liqueurs jpropres au dSveloppement des orga- 

 nismes infirieurs," Ann. de Chim. et de Phys. 1862, t. Ixiv. p. 40; Burdon San- 

 derson in Brit. Med. Journ. Mar. 27, 1875, p. 403 ; and Tyndall in Phil. Trans. 

 (1876), vol. clxvi. p. 47. 



t Proceedings of Boyal Soc, vol. xxv. 1876, p. 154. 



