26o Cholera in Relation to Certain Physical Phenomena. [part i. 



communities, and the sources of our information are mainly the same; but we have 

 in addition availed ourselves of the assistance of the compiled statistical details in 

 Dr. J. M. Cuningham's Keport on the Cholera Epidemic of 1872.* In the present 

 chapter we have, however, to deal with physical features, geological and climatic, which 

 not only differ in many districts from those observed in the endemic area, but also 

 differ among themselves. 



Taking the district of Dinapore as one which presents transitional conditions 

 between the Upper Provinces and Lower Bengal, and between the latter and the 

 Central Provinces, it will perhaps tend to simplify the subject if the physical 

 aspects and cholera-history of those parts of the country which manifest a deviation 

 from the typical cholera-producing area be taken up seriatiTn according to their 

 geographical position. 



Reviewing the geological features of the sites upon which the principal military 

 stations above Dinapore have been built. Dr. Oldham, in the memorandum already 

 referred to, states that there are in the Granges Valley Proper two very distinct deposits 

 of very different ages and probably of very different origin : one being what is 

 described as the old, the other as the Grangetic alluvium (vide page 256). 



The large city of Benares, some 125 miles higher up the Granges than Dinapore, 

 may be said to present physical features and a cholera-history closely similar to those 

 of the latter, so that it may be conveniently taken as the starting-point of our 

 description of the leading characters of the physical concomitants of the disease in 

 areas where it appears at irregular intervals. " Below Benares (speaking roughly),'' 

 writes Dr. Oldham, "the greater portion of the plain of the Granges, from the foot 

 of the hills to the north to the hills on the south, is composed of the more recent 

 alluvium, chiefly soft incoherent beds of fine sand and silt, while here and there 

 through these beds stand up parts of the older alluvium (possibly a marine deposit) 

 which for the most part consists of a strongly coherent reddish-yellow clay, 

 generally abounding in kwnkur,^ and with only occasionally irregular beds of sand 

 through it." 



It is evident therefore that, speaking generally, the soil of the Grangetic plain to 

 the westward of, say, 84° east longitude presents physical properties very diflferent 

 from what we have seen it to present from Dinapore downwards. 



Although it is quite true that on looking at a Gfeological map of India, we find 

 possibly but one tint extending from the mouths of the Granges to Lahore bounded 

 on the north by the Himalayas and on the other side by an irregular line of elevated 

 country many miles to the south of the course taken by the Granges and its 

 tributaries, with large patches of the same tint in Central India, signifying that 



* Ninth Annual Report of the Sanitary Commissioner with the Government of India — Section 1, 1873. 



t I^unhur consists of nodular calcareous concretions generally embedded in clay. Mr. W. King states that 

 it derives its origin from decomposed shells and subsequent precipitation of the carbonate of lime derived from 

 them. — Memoirs of Gfeological Survey of India, VoL IV., page 360. 



