80 THE GERM THEORY OF DISEASE. 



vital energies; or, the physiological processes of digestion, 

 nutrition and the formation of waste products. 



These considerations suggest an extended examination of 

 the physiological phenomena of life, in its varied forms, as 

 related to matter, as the best means of gaining a clear concep- 

 tion of the teachings of the facts developed by experiment. 

 It will be seen by any one who reviews this whole subject 

 closely that, while the experimentation that has been had fur- 

 nishes the strongest evidence that disease results from the 

 presence of micro-organisms (is brought about in some way 

 through the life and growth of these lowly forms), the modus 

 operandi by which they induce disease has not been explained, 

 or such explanation has been but partial. 



Indeed, thus far, the principal effort has been to show that 

 micro-organisms are regularly connected with certain pro- 

 cesses of disease, and that these in no case occur without this 

 accompaniment, rather than to show how they induce disease. 

 This was necessary, in the beginning of this work, for the 

 collection and collation of sufficient data upon which to con- 

 struct theories, and found a basis of truth, from which inquiry 

 might proceed to the more perfect unfolding of the mysteries of 

 this important subject. The Germ Theory of Disease, as it 

 stands to-day, is essentially a mass of unexplained facts, devel- 

 oped by direct experiment of the most subtle nature; so subtle, 

 indeed, that there are but few men who have the natural endow- 

 ments and rigid training necessary to verify them in a manner, 

 and with the certainty, that the thought of the times demands. 



Under these circumstances, and with the plain fact before 

 us that the mere presence of the organisms is not a sufficient 

 cause of the diseases that experiment teaches us are induced by 

 them, we naturally turn to the well demonstrated fact that 

 micro-organisms do give rise to poisons, for an explanation of 

 these phenomena. It is our purpose now to make an effort 



