CONDITIONS FAYOUEING rERMENTATION. 



40 



For. 



1. All certain knowledge, based 

 upon direct experiment, tends to 

 show that no form of living matter 

 can, in the moist state, resist an ex- 

 posure even for one minute to a tem- 

 perature of 212° F.(100°C.). 



2. The appearance of ferment- 

 organisms in suitable fluids within 

 closed vessels which have been heated 

 for periods ranging from 5 minutes 

 to 8 hours to a temperature of 212° F. 



Against. 



1. The possibility that some germs 

 of ferment-organisms can survive 

 long periods of desiccation, and that 

 in this condition they are not killed 

 by a brief exposure in fluids or vapour 

 to a temperature of 212° F. 



2. The possibility that some germs 

 of ferment-organisms can remain for 

 2, 4, 6, or even 8 hours either in 

 fluids at 212° F. or in a medium sa- 

 turated with vapour at 212° F., 

 and yet not be rendered moist and 

 killed. 



3. The 'possibility that natural 

 conditions no longer permit the de 

 novo formation of living matter either 

 in experimental vessels or elsewhere 

 — though this is a view supported 

 by no independent evidence. 



4. The possibility that the spon- 

 taneous origin of ferment-organisms 

 will be disproved, simply because it 

 is now admitted that the doctrine of 

 " spontaneous generation " has been 

 disproved in regard to higher organ- 

 isms to which it was erroneously 

 applied by our predecessors. 



3. The well-grounded belief that a 

 de novo origin of living matter must 

 have occiu-red in at least one period 

 of the earth's history, and the ab- 

 sence of any sufficient reason for 

 now questioning the continuity and 

 potency of natural phenomena. 



4. The consideration that if any 

 such new birth now occurs, we might 

 expect that it would be by the growth 

 of invisible into visible particles ; 

 and that this is the ordinary mode 

 of appearance of such organisms as 

 are found in the boiled fluids witliin 

 sealed vessels — that is, of ferment- 

 organisms. 



It seems to me that the facts and considerations of the left- 

 hand column, to say the least, carry most weight with them, and 

 that the exclusive doctrine of Biogenesis is compelled to assume a 

 rather desperately defensive attitude. 



Further evidence will be brought forward in the next and suc- 

 ceeding sections of this communication in regard to the general 

 question ; meanwhile it is evident that by my experiments with 

 urine and potash, in addition to the disproof of a false hypothesis, 

 I have unquestionably done one or other of two things : either («) 

 I have proved that living matter may be now evolved de novo, or 

 (h) I have succeeded in bringing back to life germs which hitherto 

 were so powerless and latent as to have been regarded by other 

 experimenters as hopelessly dead. Even the latter is no mean 

 result for the physician and the science of medicine, since, as I shall 

 subsequently point out, the question of the truth or the reverse of 



LINN. JOUEN. — ZOOLOGY, VOL. XIT. 4 



