THE BEGINNINGS OF IIFE. 1 9 



atmosphere were true, it might be expected that the 

 fluid in B would always rapidly change; that that in 

 A would always remain pure; and that the fluid in 

 C would, similarly, undergo no alteration. The facts, 

 however, are quite the reverse : if a properly prepared 

 turnip-infusion be employed, the fluid in A will almost 

 always remain unchanged; that in B will sometimes 

 rapidly change, and at other times will remain quite 

 pure ; whilst that in C will almost invariably become 

 turbid in from two to six da.ys. So that even if it were 

 not the case that some fluids, different from those used 

 by M. Pasteur, will almost invariably undergo change 

 in bent-neck vessels, his explanation of the cause of the 

 preservation would have been altogether upset by the 

 fact that some of the very fluids avhich remain pure in the 

 hent-neck apparatus 'will become foetid if shut up in vacuo ^. 

 If M. Pasteur's theory were true, exclusion of all air 

 from the flask should prove just as efficacious in pro- 

 tecting the fluid as any process of filtration. And the 

 fact that some of the very fluids which are protected as 

 long as they are in contact with air devoid of particles, 

 can be made to ferment and swarm with living things 

 through the mere •expulsion of this purified air% is the 

 death-blow to M. Pasteur's theory, and one of the 

 strongest proofs of the occurrence of Archebiosis. 

 The cause of the change in the latter case seems also 



^ See Appendix C, Exps. vii-ix, xiii-xv, &c. 



^ This has been done on several occasions. See Exps. ix and xv, and 

 xxxiii and xxxvi. 



C 2, 



