2o8 Cholera in Relation to Certain Physical Phenomena. [part i. 



these changes could affect such portions of the community as spend the greater part 

 of their time in-doors. To this Dr. von Pettenkofer replies by instancing cases of 

 poisoning from gas which have occurred in houses unconnected directly with gas-pipes, 

 the warmer air of the house acting like a heated chimney, having drawn up the 

 soil-air through the ground on which the houses stood and thus conveyed the gas 

 which had escaped- from pipes placed in the earth outside the dwelling. Instances 

 are referred to of this haying occurred, although the gas had to travel some 20 feet 

 under the street and through the foundation and flooring of the house. 



Quite recently these statements have received marked corroboration from Dr. 

 Cobelli of Roveredo, '■'" who gives details regarding a case of the kind where a mother 

 and her two daughters, a dog and a bullfinch in its cage, were one morning found 

 poisoned in a bedroom. The two daughters were already dead and the bird also ; 

 the mother died shortly afterwards ; the dog alone recovered. The State ordered 

 an enquiry to be held, as it was scarcely conceivable that the deaths could be 

 attributed to an escape of gas, as no pipes were connected with the house. That 

 gas could get into the room, however, was shown by analysis of the air which it 

 contained^ and after minute investigation it turned out that gas was escaping 

 through an imperfectly fitting plug of one of the main pipes which had been sunk 

 about a yard below the surface (in earth of an alluvial nature), and 15 feet 7 

 inches removed from the room in which the poor people had slept. The gas had 

 been aspired into the room instead of escaping into the street, for the air of the 

 room at night had been warmer than the air outside. 



The importance of bearing observations of this kind in mind in connection with 

 attempts at tracing to their source foul emanations from covered sewers and other 

 unwholesome subsoil recesses and tracts, is too obvious to require special note. 



It is in this light that, as we understand it. Dr. von Pettenkofer suggests that 

 the relation of soil-influences should be studied, and urges that it is absolutely 

 necessary that each locality should be studied for itself at different times, seeing that 

 -constant variations take place not only in the generating power of the soil, but also 

 in its porosity, or, in other words, in its capacity for permitting any noxious elements 

 which it might contain to mingle with the upper air, A layer of asphalt beneath 

 the flooring of that gas-infected house would doubtless have prevented the occurrence 

 of poisoning, as would, possibly equally well, a layer of wet clay. 



With this brief summary of our conception of the learned Professors views, we 

 pass on to draw attention to the epitome of the Water-Level Registers [Tables I to VII 

 at the end of this paper] which liave been kept in Bengal during the last seven 

 years. Some of the returns we have been obliged to leave out of the tables, owing 

 to obvious and irremediable inaccuracies, due, probably in great part, to misconception 

 on the part of the observers as to the precise nature of the information required. 



• Zoiti^chrift filr Biologi/', Band XII, .S. 420, 



