44 Observations Regarding Pettenkofer s Theory. [part i. 



fermenting process taking place in the ground, which had been originated by some 

 of the poisonous material being placed in a soil adapted for its development, it would 

 follow that in India large substantial buildings would be safest by day, being cooler 

 than it is without ; but unless the flooring were made impervious to air, it would be 

 the most unfavourable at night, being warmer, consequently the native's hut, 

 approximating more closely to the temperature of the air ought to be more exempt 

 from cholera. 



Although cholera is not considered to acquire its property of infection by being 

 developed in water, still water as well as air may act as a vehicle conveying the 

 infectious matter from the ground, consequently this theory in no way affects the 

 importance to be attached to the value of obtaining water from a pure source ; indeed 

 it speaks very strongly in favour of obtaining it from places as far removed as possible 

 from human habitations. 



Particular attention has been draw^n to this subject very lately * by Dr. Buchanan, 

 one of the several distinguished sanitary officers whom Mr. Simon has gathered 

 around him at the Public Health Department of the Privy Council. While allowing 

 that there is a connection between the disease and the level of the water in the 

 wells, Dr. Buchanan maintains that the mischief -is in the luell itself; because "it is 

 precisely at the period when soil water is sinking that wells sunk in a porous soil 

 must, if ever, furnish impure supplies. A well in porous soil gets its water in two 

 ways ; water stands in it up to the level of the soil, and also drains into it from 

 every source (from rain, from slops, from cesspools) on a higher level than that of the 

 water of the soil for many yards around. In other words, besides receiving water from 

 the general waterflow through the soil, it receives the local soil water, soaking from 

 a cone of ground of which the surface of water in the well is the apex. Let 

 the level of water in the soil be high, and the base of this cone is small ; let the 

 level of the soil water be low, and the base of this cone (at the surface of the 

 ground) is large. In either case the saturated soil is comparatively impervious 

 to more water, and approaches the condition of a non-porous stratum. When the , 

 soil water is at its highest, therefore, impure slops and excrement that may be on or 

 in the ground tend to run horizontally away. When the soil water on the contrary 

 is low, such matters tend to soak downwards." 



It will be observed that Dr. Buchanan testifies to the matter-of-fact portion of 

 Pettenkofer's statement, namely, the connection of certain diseases with the level of 

 the soil water, but explains this connection in a different way. Buchanan produces 

 very remarkable illustrations in proof of his statements, which will certainly be borne 

 in mind whilst investigating this subject in India. The possibility of the foregoing 

 being the true explanation of the connection between cholera and the level of the 

 soil water had not escaped Pettenkofer, as he states that examinations have been 



Medical Tivies and Gazette, 1870. 



