330 



Prof. H. C. Bastian on the Heat 



which the experiments of series A show to be eminently favourable for 

 their growth and reproduction. Being certain, therefore, that the ■living 

 units are killed in the drops with which the fluids of series C were inocu- 

 lated (because they were drops of the same fluid as was employed in 

 series B), we may be equally certain that the turbidity and putrefaction 

 which did ensue in the turnip-solutions of series were due to the in- 

 fluence of the mere dead constituents of these drops of the turbid saline 

 fluid; whilst, seeing that the behaviour of the fluids of series D was 

 precisely similar to those of series C, we have a perfect right to infer that 

 this series of fluids (D) was as devoid of living units as those of C are 

 known to be — that is, that Bacteria, Vibriones, and their supposed germs 

 are killed by the temperature of 140° P. in organic fluids, just as they are 

 in saline fluids, although, as shown by the experiments of series E, they 

 do not succumb to a heat of 131° F. These experiments of series C and 

 D further illustrate the different degrees of amenability of different 

 organic fluids to the same dead ferments ; whilst the comparison of the 

 results with the hay-infusions of series C and D with those previously 

 cited (in which the inoculating compound was a drop of an organic infusion 

 heated to the same temperature of 140° F.) will illustrate the different 

 influence of dissimilar dead ferments upon infusions of the same kind. 



The evidence now in our possession shows, therefore, that whilst the 

 temperature at which living ferments cease to be operative varies within 

 very narrow limits (131°-140° F.) *, that which destroys the virtues of 

 not-living ferments varies within much wider limits, and depends not 

 only upon the amount of heat employed, but also upon the nature of the 

 putrescible or fermentable liquid to which such ferment is added, in con- 

 junction with the degree of heat and other conditions to which the mix- 

 ture is subsequently exposed f. Here, therefore, we have evidence as to 

 the existence of a most important difference between living and not- 

 living ferments, which has always been either unrecognized or more or 

 less deliberately ignored by M. Pasteur and his followers This differ- 



* Liebig has proved that a temperature of 140° F. kills Torulce, and always suffices to 

 arrest a process of fermentation taking place under their influence in a sugar solution. 

 Toridce heated in water to 140° F. also fail to initiate fermentation in a sugar solution. 

 I have also found that an exposure to a temperature of 131° P. for five minutes always 

 suffices to destroy the life of Desmids, Euglenae, Amoeba?, Monads, Ciliated Infusoria, 

 Rotifers, Nematoids, and other organisms contained in specimens of pond-water. All 

 these lower organisms seem to be destroyed at about the same temperature, as might 

 have been expected from the fundamental relationship which must exist between these 

 several varieties of the one substance — living matter. 



f See ' The Beginnings of Life,' vol. i. p. 437. 



% See, for instance, all M. Pasteur's celebrated experiments in which he had recourse 

 to an "ensemen cement des poussieres qui existent en suspension dans l'air," as re- 

 corded in chaps, iv. & v. of his memoir in 'Ann. de Chimie et de Physique,' 1862. 

 M. Pasteur was engaged in an investigation one of the avowed objects of which was to 

 determine whether fermentation could or could not take place without the intervention of 



