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 inapregnated 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 
