SPONTANEOUS GENEEATION. 289 



air filtered by cotton-wool ; air long kept free from agita- 

 tion, so as to allow the floating matter to subside ; cal- 

 cined air, and air filtered by the deeper cells of the human 

 lungs. In all cases the correspondence between my ex- 

 periments and those of Schwann, Schroeder, Pasteur, and 

 Lister in regard to spontaneous generation was perfect. 

 The air which they found inoperative was proved by 

 the luminous beam to be optically pure and therefore 

 germless. Having worked at the subject both by expe- 

 riment and reflection, on Friday evening, January 21, 

 1870, I brought it before the members of the Eoyal 

 Institution. Two or three months subsequently, for 

 suflScient practical reasons, I ventured to direct public 

 attention to the subject in a letter to the Times. 

 Such was my first contact with this important question. 

 This letter, I believe, gave occasion for the first 

 public utterance of Dr. Bastian in relation to this 

 subject. He did me the honour to inform me, as others 

 had informed Pasteur, that the subject 'pertains to the 

 biologist and physician.' He expressed 'amazement' 

 at my reasoning, and warned me that before what I had 

 done could be undone ' much irreparable mischief might 

 be occasioned.' With far less preliminary experience to 

 guide and warn him, the English heterogenist was far 

 bolder than Pouchet in his experiments, and far more 

 adventurous in his conclusions. With organic infusions 

 he obtained the results of his celebrated predecessor, 

 but he did much more — the atoms and molecules of in- 

 organic liquids passing under his manipulation into 

 those more ' complex chemical compounds,' which we 

 dignify by calling them ' living organisms.'' As re- 



' ' It is further held that bacteria or allied organisms are prone 

 to be engendered as correlative products, coming into existence in 

 the several fermentations, just as independently as other less 

 complex chemical compounds.' — Bastian, Tram, of Pathological 

 Society, vol. xxvi. 258. 



