24 eresidext's addeess. 



devoted himself to his task — whatever the defects of his book a 

 knowledge of its elaborate details is essential to a student of the 

 subject, even though he may be predisposed to regard it in the 

 same light as the bulk of the world received the summing up 

 of the case for "the Claimant." 



It is well known to all present here that if a vegetable infu- 

 sion, say of hay or other such substance be allowed to stand for 

 some days, under favourable conditions, it will be found to con- 

 tain enormous numbers of minute living organisms, such as have 

 been known hitherto under the general term "infusoria." This 

 experiment varied in numberless ways, and modified to embrace 

 collateral issues, is the groundwork on which the present phases 

 of the controversy rest — the vexed questions being, whence came 

 active life into the infusion ? did it originate in infinitely minute 

 germs either existing in the fluid or carried into it from the air ? 

 or was it developed spontaneously (de novo) without the agency 

 of previously existing beings? It is generally admitted that 

 germs do exist in the air and in aqueous fluids in infinite num- 

 bers, and it is also generally admitted that prolonged exposure 

 to a heat of 100° cent, is sufficient to destroy their vitality. 

 Thus it is manifest that to determine any single fact in con- 

 nection with the subject, the most elaborate precautions are ne- 

 cessary, firstly, to destroy all existing germs, and secondly, to 

 preclude the admission of fresh germs from the external air. I 

 need not enter into details, but I may say, that it is precisely on 

 these points that Dr. Bastian's successive papers leave an unsa- 

 tisfactory impression on the mind, and hence to myself, and I 

 believe to many others, one series of his experiments in particular 

 has assumed a new significance since its repetition with confir- 

 matory results by so accomplished an observer as Dr. Burdon 

 Sanderson. It may certainly now be accepted as a fact, that an 

 infusion of turnip to which a small particle of cheese has been 

 added, or an infusion of hay, after long boiling in a tube, subse- 

 quently hermetically sealed, will within a few days be crowded 

 with those obscure elementary organisms Bacteria and Leptothrix 

 It is perfectly open to the opponents of abiogenesis to hold that 

 even accepting these results, they only put back the explanation 



