132 MICROBES AND THE MICROBE-KILLER. 



and form, appropriating oxygen and exhaling carbonic 

 acid. The older chemists thought that it was a mere 

 effect of contact, but that idea must be laid aside in view 

 of the certainty that a chemical decomposition takes 

 place, and that the destruction of the properties of the 

 blood is really due to that cause. 



The extreme minuteness of these micro-organisms is 

 a feature that must always be borne in mind. Not only 

 are they small, often beyond reach of any but the 

 highest microscopic powers, but their tissues are ex- 

 tremely dehcate, so as to render them imperceptible 

 sometimes to all but the most practised eyes. For this 

 reason it is extremely difficult to meet with them when 

 they do not afford a sufficient resistance to light to en- 

 able us to obtain photographs or any natural delineation. 



And it was this difficulty which I had to overcome in 

 producing most of the plates that appear in this work. 

 No attempt had ever before been made to convey by 

 means of such illustrations to the general public an idea 

 of what microbes are, and, when it is remembered that 

 they are so minute and so translucent as scarcely to cast 

 a shadow, the reason may be understood. So-called 

 engravings of microbes of la grippe, for instance, and 

 other diseases, which have appeared in the papers, are 

 purely the work of somebody's imagination. They bear 

 no resemblance whatever to the reality. 



This peculiarity does not affect the vitality of mi- 

 crobes. Minute and delicate though they are, they are 

 extremely tenacious of life. They cannot be destroyed 

 readily. When my factories were first established I had 

 abundant opportunity to make a collection of numerous 

 forms of microbes. My patients brought me bottles of 

 matter, for examination, in a state of fermentation, and 

 sometimes I discovered in one of them as many as from 

 six to ten varieties, showing to me conclusively that 

 that person had as many forms of disease, while the pa- 

 tient may have been treated for but one ailment by his 

 doctor. Sometimes I received matter from the stomach 

 of a patient immediately after he had taken his medi- 



