296 Cholera in Relation to Certain Physical Phenomena. [part i. 



CHAPTER III. 



CONCLUSION. 



In manifesting a marked partiality for a soil of the character of the Gangetic 

 alluvium, cholera is by no means singular, for it is a well-established fact that malarious 

 fevers and kindred diseases flourish with most vigour about the deltas of large rivers 

 all over the world. 



The connection between soil and malaria, as a connection implying cause and 

 effect, is not seriously questioned, and the apparently capricious manner in which some 

 districts evolve it and others do not, is a well-recognised fact : swampy and arid soils 

 alike being capable of producing the miasm during certain seasons. 



In this malaria presents a considerable resemblance to cholera, for, although both 

 affections manifest a marked tendency to become endemic in alluvial districts, there 

 exist, nevertheless, very numerous localities, even in tropical and subtropical climates, 

 where both affections are unknown, such for example as the extensive swampy districts 

 in South Australia. That cholera also is unknown there is commonly attributed to 

 the circumstance that India is too far removed to allow of the transport of infectious 

 material, but no one has yet attempted to explain the absence of malaria on such 

 grounds. 



We would not, however, be understood to imply that the causes productive of 

 malarious fevers and cholera are identical, or that localities providing the conditions 

 necessary for the development of the one must, therefore, provide those for the other also. 



There are malarious localities of the most pronounced type where cholera has 

 never flourished, notwithstanding that cases of the affection have been brought there, 

 and fatal cases too. Of these, probably no better example could be cited than the 

 large convict settlement at the Andaman Islands, where cholera has never thriven, 

 notwithstanding the fact that it is within 3 days of India and 24 to 36 hours of Burma, 

 and that during the last twenty years steamers have constantly passed between the two 

 countries and the settlement. A steamer laden with convicts proceeds to Port Blair 

 (the only port in the islands) from Calcutta every four weeks, and cholera cases have 

 on some occasions been imported and have died after landing; but it is only 

 on rare occasions that cases of cholera have been registered as occurring in any part 

 of the settlement. 



Dr. Rean, the late Principal Medical Officer to the Settlement, however, in his 

 annual report for 1870 (quoted by Dr. C. Macnamara, op. ciL, page 336), describes cases 

 of the following character : — 



" The patients were generally admitted from some feverish locality, or had been 

 employed on works of an unhealthy character. They were taken ill somewhat suddenly, 

 the most urgent symptoms being frequent purging and vomiting with great prostration. 

 The alvine evacuations bear a resemblance to curds mixed with bloody serum, and the 



