332 



Prof. H. C. Bastiau on the Heat 



the germs of some Bacteria and Vibriones are capable of resisting the 

 influence of a heat of 212° P. when in the moist state, though they are 

 killed by a temperature of 230° F., was a conclusion altogether unwar- 

 ranted by the evidence which he adduced. Finding that certain fluids 

 treated after the manner introduced by Schwann always remained quite 

 devoid of living organisms, M. Pasteur very legitimately concluded that 

 preexisting organisms and germs had been killed during the boiling of the 

 liquid ; but findiug that when a little powdered chalk was added to fluids 

 of the same kind (which in all other respects were treated in a similar 

 manner) living organisms were after a time invariably found to appear, 

 although they as invariably failed to appear when the same fluids were 

 heated to a temperature of 230° P. (110° C), two equally legitimate pro- 

 visional conclusions were open to M. Pasteur in explanation of these 

 facts. What did M. Pasteur do ? Following the same method as he 

 had formerly employed*, he again ignored one of the equally possible 

 interpretations, and unsuccessfully attempted to prove, by a repe- 

 tition of similar reasoning t, that the different results in the two 

 series of experiments were due to the fact that the germs of Bacteria 

 and Vibriones which had been killed by the temperature of 212° P. in the 

 first series, were not killed by this temperature in the second series (in 

 which a slightly alkaline fluid had been employed), although they were 

 destroyed by the higher temperature of 230° P. Thus results which were 

 due to the action of not-liviug ferments were ascribed to living ferments, 

 and the possible action of not-living ferments was ignored, although, as 

 I have said before, the ostensible object of M. Pasteur's researches was 

 to inquire into the relative' importance of not-living and living ferments, 

 or whether, in fact, " dead " substances (in the ordinary acceptation of 

 the word) could act as ferments. 



"When viewed from the stand-point of the physico-chemical theory of 

 fermentation, the apparently contradictory results arrived at by the same 

 experimenter at different times or by different experimenters, in this line 

 of research, cease to be the inexplicable puzzle which they must alwa} r s 

 appear to those who place implicit faith in the narrower and too exclusive 

 " vital " theory of fermentation advocated by M. Pasteur and his followers. 



My investigations have convinced me that, with regard to degree of 

 fermentability, the various fermentable fluids and mixtures are divisible 

 into three distinct subclasses : — 



I. There are what may be called self-fermentable fluids or mixtures — 

 that is, fluids or mixtures which, after exposure to a temperature of 

 212° P. or higher, are still capable of undergoing fermentative changes 

 without the addition of less-heated matter, either not-living or living. 

 The changes occurring in these self-fermentable fluids (in which preexist- 

 ing living things have been killed), when strictly protected from contact 

 with adventitious particles, vary in rapidity and in intensity from the 

 * See note \ on page 330. 



t See Ann. de China, et de Pbys. 1862, pp. 60-65. 



