430 THE BEGINNINGS OF LIFE. 



2 1 2 F, even for one or two hours. This result is now so 

 easily and surely obtainable, as to make it come within 

 the domain of natural law 1 . All pre-existing living 

 matter and organisms having been killed within the 

 closed flasks, how can new living things appear therein 

 save by a process of Archebiosis or new origination 

 of living compounds ? The explanations which are ad- 

 duced may be criticized, the phraseology employed may 

 be objected to, but the great fact remains that the new 

 living matter must have originated by the occurrence 

 of some combinations similar in kind to those which 



1 In a very large number of trials I have never had a single failure 

 when an infusion of turnip has been employed, and from what I have 

 more recently seen of the effects produced by the addition of a very 

 minute fragment of cheese to such an infusion (see Appendix C, 

 pp. xxxiv xxxviii), I fully believe that in 999 cases out of 1000, if not 

 in every case, a positive result could be obtained. Having made use of 

 this infusion most frequently, I am able to speak more positively con- 

 cerning it than about others, many of which would, I doubt not, if 

 sufficient care were taken, yield equally unmistakeable results. It must 

 indeed never be forgotten, that the obtaining of positive results or not, 

 in such experiments, depends not a little upon the strength of the 

 solutions employed. A weak infusion will often yield no trace of living 

 things, whilst a stronger infusion prepared at the same time, and 

 treated in the same manner will, after a similar period, be found to 

 swarm with living organisms. The original access of germs having been 

 equally possible in each case, and the destructive influences to which 

 they had been submitted being similar, the subsequent presence of living 

 organisms in the one solution and their absence from the other, seems 

 only consistent with the supposition, that an increased quantity of or- 

 ganic matter in a solution acts in the same way as the addition of a 

 very fermentable fragment (cheese), and suffices to produce an increased 

 tendency towards the occurrence of those fermentative changes during 

 which there is a correlative production of new-born living matter. 



