THE MICROBES OF HUMAN DISEASES. 179 



the destruction of microbes is a solution of corrosive 

 sublimate (mercuric chloride), one part in 1000, which 

 can be further diluted by four parts of pure water. 



V. MICROBES OF INTERMITTENT OR MALARIOUS 

 FEVERS. 



We say microbes in the plural, since it is almost 

 certain that the different types of intermittent fever, 

 tertian, quartan fever, etc., are produced by different 

 microbes ; moreover, it is probable that these microbes 

 vary with the locality. That of intermittent fever 

 in France is probably not the same as that of the 

 malaria, or fever of the Pontine marshes in Italy ; 

 and the African fevers, again, are probably produced 

 by a different organism. 



Intermittent fevers are the first internal diseases 

 of which the vegetable parasitic nature was sus- 

 pected. Before that time we were only acquainted 

 with the parasites of the skin, and with the entozoaria 

 and epizoaria (intestinal worms, lice, acari, etc.), which 

 are animals. In 1 869, Dr. Salisbury, of Cleveland, U.S., 

 entered on researches which led him to the con- 

 clusion that intermittent fever in the marshy valleys 

 of the Ohio and the Mississippi must be ascribed to 

 the presence in the system of a filamentous alga 

 which approximates to the genus Palmella. The 

 spores of this alga are constantly found in the saliva 



