276 APPENDIX. [No. XVIII. 



the mind, being one of the functions of the body, is of varying power in 

 different individuals. 



68. The obsei-vations which apply to different individuals, apply with 

 greater force to different races. 



No. XVIII. 



ON THE PEODUOTION OF CHOLERA BY INSUFFICIENT 

 DRAINAGE. With Remarks on the Hypothesis op abt 



ALTEBED ElECTEICAL StATE OP THE AtMOSPHEEE. By AlPEEd' 



Smee, F.R.S., Surgeon to the Bank of England, &c. (From the 

 'Lancet,' September 1st, 1849.) 



When pestilence passes over the land, and consigns to a premature grave 

 alike the old and the young, it behoves each in his respective depart- 

 ment to endeavour to trace out the proximate cause, and strive to dis- 

 cover some antidote to so direful a calamity. 



The experience of all the world proves that the lowest districts, the 

 banks of rivers, and natural watercourses are the situations in which the 

 malady chiefly resides. Two physical hypotheses may be f r'amed upon this 

 fact : firstly, that the cholera is' caused by a poison which gravitates to 

 those situations ; secondly, that in those situations poison is generated. 



If, however, cholera be produced by a heavy poison subsiding from 

 the atmosphere to low situations, we should have cholera exhibitiug itseK 

 in all low districts, and the weight of the air would be absolutely greater 

 in such localities. This fact has not been proved, otherwise the Board of 

 Health could always determine, by weighing the atmosphere, where cholera 

 was likely tp appear, and, when existing, when it was likely to depart. 

 The hypothesis of a heavy poison being the cause of cholera is a generaliza- 

 tion embracing many facts, but not based upon any direct proof. 



In low situations, however, drainage is manifestly more or less imper- 

 fect. The effete materials of the human frame are not quickly removed 

 from the sphere of human residences, and thus can act more detrimentally 

 than ia higher and drier localities. Nothiug is more hurtful to animal 

 life than the effete matter of the same animal, and disease more or less 

 serious is sure to occur when any creature is exposed to the influence of 

 the worn-out materials of its own frame. 



Nature has provided that ordinarily the most rapid diffusion of 

 gaseous emanations should take place throughout the atmosphere; and 

 with such force does this diffusion occur, that Professor Graham has 

 beautifully observed, that it would be as easy to stop the mountain tor- 

 rent as to impede the equable diffusion of different gases. 



Every person must have observed that sometimes this diffusion is 

 qxiicker than at others, and that the same source will sometimes exhale 

 the most pestiferous stench, whilst at others no offensive odour will be 

 discoverable. This difference is clearly attributable to the exhalation 

 passing more rapidly into the atmosphere at one time than another. 



Now all cholera cases appear in situations where the victims have 



