SPONTANEOUS GENERATION. 571 



floating matter, and while doing so I was surprised to 

 notice that, at the ordinary rate of transfer, such matter 

 passed freely through alkalis, acids, alcohols, and ethers. 

 The eye being kept sensitive by darkness, a concentrated 

 beam of light was found to be a most searching test for 

 suspended matter both in water and in air a test indeed 

 indefinitely more searching and severe than that furnished by 

 the most powerful microscope. With the aid of such a 

 beam I examined air filtered by cotton-wool; air long kept 

 free from agitation, so as to allow the floating matter to 

 subside; calcined air, and air filtered by the deeper cells of 

 the human lungs. In all cases the correspondence between 

 my experiments and those of 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 experiment and 

 reflection, on Friday evening, January 21, 1870, I brought 

 it before the members of the Royal Institution. Two or 

 three months subsequently, for sufficient practical reasons, 

 I ventured to direct public attention to the subject in a 

 letter to the Times. Such was rny 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 honor 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 heterogeuist was far bolder than Pouchet 

 in his experiments, and far more adventurous in his con- 

 clusions. With organic infusions he obtained the results 

 of his celebrated predecessor, but he did much more the 

 atoms and molecules of inorganic liquids passing under 

 his manipulation into those more " complex chemical 

 compounds," which we dignify by calling them "living 

 organisms/' * As regards the public who take an interest 



* ' 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, Trans, of Pathological Society, vol. 

 xxvi., 258. 



