THE BEGINNINGS OF LIFE. 341 



says 1 : c je n'ai jamais vu se former dans le lait ainsi 

 traite autre chose que des Vibrions, et des Bacteriums, 

 aucune Mucedinee aucune Torulacee aucun ferment 

 vegetal. II n'y a pas de doute que cela tient a ce que 

 les germes de ces dernieres productions ne peuvent 

 resister a 100 au sein de Feau, ce que j'ai d'ailleurs 

 constate par des experiences directes. Et de meme 

 nous aliens reconnaitre que, si le lait se putrefe dans 

 les clrconstances precedentes^ c*est que les germes des 

 Infusoires dont nous venous de parler peuvent resister a 

 la temperature hum'ide de ioo c , lorsque le liquide oil on 

 les chauffe joult de certains proprletes? But the passage 

 which I have placed in italics has not been demon- 

 strated by any direct evidence: it is in fact entirely 

 opposed to all such evidence 2 . 



1 Loc. cit., p. 60. 



2 Prof. Jeffries Wyman very aptly says (American Jour, of Science and 

 Arts, vol. xliv. Sept. 1867) : ' The study of organisms living in thermal 

 springs is of great importance in connection with the investigation of 

 the limits of vital resistance. Having become adapted through a long 

 series of years to their surroundings, such organisms may be supposed 

 to live under circumstances the most favourable possible for sustaining 

 life at a high temperature. It is a well-known physiological fact that 

 living beings may be slowly transferred to new and widely different con- 

 ditions without injury ; but if the same change is suddenly made they 

 perish.' Even in these most favourable cases, however, no living things 

 have ever been found in springs at the temperature of boiling water, 

 though certain Conferva were found by M. Descloizeaux in a hot spring 

 in Iceland which was registered at 208 F. No more extreme case than 

 this can, I believe, be quoted. As Prof. Wyman points out, however, 

 the question which it concerns us to settle is, at what temperature the 

 organisms met with in our infusions perish these being accustomed to 

 live at ordinary atmospheric temperatures, and not being steeled against 

 the action of heat by long custom and habit. 



