EXPERIMENTS NOW RECORDED 91 



where conditions are favourable and not so re- 

 stricted as those that have been necessary in our 

 experiments. 



That there is a limit to the amount of pre- 

 liminary heating in these experiments, if living 

 organisms are to be ultimately obtained, is pro- 

 bably due to the fact of the destructive influence 

 of high temperatures upon the compound mole- 

 cules of the colloidal ingredients of the fluids used. 

 In the case of organic infusions this limit is much 

 sooner reached than where we have to do with 

 saline solutions, such as I have of late been em- 

 ploying. But it is now well known, as Graham 

 showed, that silica, obtained by dialysis from 

 sodium silicate, exists in a colloidal state, in which 

 it is represented by great compound molecules 

 (micellae) similar to, if simpler than, those of or- 

 ganic infusions. 1 It is doubtless due to this fact 

 not only that solutions containing colloidal silica 



1 Jacques Duclaux, in an article entitled " La Matiere Or- 

 ganisee " (Rev. Generate des Sciences, Feb. 28, 1910, p. 139), 

 says it has now become known that a solution of silica " con- 

 tains micellae formed of a great number of molecules of silica, 

 combined together by the same sort of bond as that which 

 unites the molecules of maltose into starch . . . and this com- 

 pound presents remarkable resemblances to natural organic 

 matter." His use of Nageli's term " micellae " for the great 

 compound molecules of colloidal solutions seems worthy of 

 adoption. 



