32 DK. TYND ALL'S METHOD DEFECTIVE, 



It is difficult to see in what way Dr. Tyndall's experi- 

 ments illustrate or affect any sort of germ theory. 

 They could all have been made without a single 

 reference to germs of any kind or to a germ theory 

 or to disease. On the other hand, these last sub- 

 jects might have been rendered more intelligible to 

 the unlearned if their attention had not been diverted 

 by the brilliant illuminations and combustions. 



The method is defective. The Professor first points 

 out that he supposed that dust consisted of inorganic 

 particles. He discovers to his surprise that it con- 

 tained organic matters. Next he seems to wish that 

 his audience should regard these organic matters as 

 germs or animalcules, or at any rate look upon some 

 of the particles of dust as composed of " germinal 

 matter." But Dr. Tyndall did not demonstrate what 

 the organic particles in air were, nor did he prove that 

 dust contained anything whatever that would give 

 rise to disease. The particles might have consisted 

 entirely of harmless germs, or of disease germs or of 

 animalcules, or there might have been a few of these 

 bodies present, or there might not have been a vestige 

 of any of them, and Dr. Tyndall would not have dis- 

 covered the difference by the method of investigation 

 he employed, of the advantages of which he speaks so 

 confidently. By his discoveries, surmises, assertions, 

 and predictions published in the " Times " and other 

 journals, people have been led to suppose that dust 

 consists of germs, and that air teems with animalcules 



