72 DE. BASTIAK OK THE 



his method ef supporting their cogency. In the first place, it 

 may be observed that the fact of his having introduced a bundle of 

 " old hay " into the laboratory of the Eoyal Institution cannot 

 be regarded as a satisfactory explanation of the results of myself 

 and others who had been able to obtain fermentation in boiled 

 fluids long before, without the aid of any such magician's wand 

 as this which Professor Tyndall had chanced to employ. Se- 

 condly, there is the very dubious nature of the evidence by 

 which he has sought to support his interpretation, and the ab- 

 sence of any thing in what he has yet published on the subject 

 which gives any definite or independent foundation to his 

 new hypotheses. Thus, to take one illustration, in the Pro- 

 ceedings of the Eoyal Society* there is printed a note " On 

 Heat as a G-ermicide when Discontinuously Applied," in which 

 Prof. Tyndall says : — " Following up the plain suggestions of the 

 germ-theory, I have been able, even in the midst of a virulently 

 infective atmosphere, to sterilize all the infusions by a temperature 

 lower than that of boiling water. * * * Before the latent period 

 of any of the germs has been completed (say a few hours after 

 the preparation of the infusion), I subject it for a brief interval 

 to a temperature which may be under that of boiling water. Such 

 softened and vivified germs as are on the point of passing into 

 active life are thereby killed; others not yet softened remain 

 intact. I repeat this process weU within the interval necessary 

 for the most advanced of those others to finish their period of 

 latency. The number of undestroyed germs is further diminished 

 by this second heating. After a nurnber of repetitions, lohicJi varies 

 with the character of the germs, the infusion, however obstinate, is 

 completely sterilized^ 



Noting by the way that the " character of the germs " has no 

 other reality than Prof. Tyndall chooses to infer from the obsti- 

 nacy of the infusion in resisting sterilization, it is only necessary 

 further to point out that the above procedure and its results allows 

 absolutely no conclusion to be drawn in favour of the survival of 

 germs, except by ignoring the only other legitimate interpreta- 

 tion. The frequent repetitions of destructive heating might, after 

 a time, repress all tendency to fermentative change in a fluid with 

 the same facility that it might destroy germs supposed to be suc- 

 cessively awakening to life and activity. If an investigator has 

 decided beforehand that one of these possibilities is not worth 

 * No. 178, Tol. XXV. p. 669. 



