HISTORICAL REVIEW 21 



plain by the discovery of the transmission of malaria by mosquitos. 

 The latest scientific support of the theory of miasm appeared in the 

 teachings of the great sanitarian of Munich, Pettenkoffer. When he 

 began his work in the Bavarian capital, about the middle of the nine- 

 teenth century, that city was known as a hotbed of typhoid fever. 

 Fecal matter was deposited in shallow vaults and the drinking-water 

 was taken from shallow wells. The whole city was honeycombed with 

 these privies and wells, and the people were drinking strong infusions 

 of their own excrement. Pettenkoffer taught that the fecal matter 

 undergoes a ripening process in the soil and thereby becomes the cause 

 of typhoid fever. Responding to his teachings, the people of Munich 

 introduced a complete sewerage system and brought a pure drinking- 

 water from a distant mountain lake. This resulted in the eradication 

 of typhoid fever and Pettenkoffer 's theory was justified by the result. 

 We now know that the typhoid bacillus needs no ripening process 

 during the interval which elapses from its passage from the bowels 

 of one to its entrance into the alimentary canal of another. Petten- 

 koffer's theory did not assume that the noxious agent in the fecal 

 matter is a living organism, but rather held that the ripening process 

 consists of chemical changes. From this, there grew up the idea of 

 the de novo origin of typhoid fever. The fecal matter of uninfected 

 individuals was supposed to undergo ripening processes in the soil 

 and the products of these changes, finding their way into either water 

 or air, distributed the disease. This theory was not only plausible, 

 but was in accord with the then known facts. It found ready support, 

 especially among army medical officers. However healthy men 

 appeared to be when they went into camp, even in locations which 

 could not have been contaminated previously, after a few weeks, 

 typhoid fever appeared and spread in proportion to the filthiness of 

 the camp and the inefficiency of the methods of fecal disposal. Men 

 of the highest intelligence and widest experience became firm sup- 

 porters of the de novo origin of typhoid fever which they regarded 

 as a filth disease. They believed that the disease was spread by gases 

 generated in any kind of filth, but more especially by those developed 

 in fecal matter. 



The theory of miasm was applied not only to typhoid fever and 

 malaria, but to all diseases, especially those appearing in epidemic 



