192 MICROBES, FERMENTS, AND MOULDS. 



conditions more apparent. Want of air and cleanli- 

 ness is one of the principal factors of these cruel 

 epidemics. In the confined lodgings of the artisans 

 of large cities, the dead, the sick, and the healthy 

 man may be found sharing the same room and even 

 the same bed; linen impregnated with typhoid ex- 

 cretions may remain for days in the same chamber. 

 The walls and floors of our barracks, too rarely cleansed, 

 disinfected, or whitewashed, harbour myriads of mi- 

 crobes ; and the water of adjoining wells likewise con- 

 tains them in great numbers. 



Nor can it be said that hygienic conditions are 

 more carefully observed in the rural habitations of 

 villages and detached farms. The peasant is as 

 ignorant of the laws of health and cleanliness as the 

 artisan; the neglect of the builder, often a mere 

 mason, of the landlord and the tenant, is still more 

 striking in country districts. For this reason epi- 

 demics are generally more fatal in the country than 

 in towns ; but they are less frequent, of shorter dura- 

 tion, and more easily localized in a village or detached 

 farm, since in this case there is a large supply of 

 oxygen, which is the great destroyer of microbes. 



With respect to typhoid fever, one of the most 

 common diseases in this country, the lesions by which 

 it is always characterized show that the microbe pro- 

 ducing it is chiefly found in the mucous membrane of 

 the intestines, in Peyer's glands, and in the isolated 

 follicles which cover this membrane, and which are 



