EEID — ON MORTALITY. 247 



As a result of this, we would anticipate a great increase of dis- 

 ease and death, and such has been the case in every instance where 

 no special means have been used to ward off the ills resulting from 

 a very large population. 



These evils are of two kinds, the social and the physical, and 

 though we do not intend to devote attention to the former, yet it 

 must be alluded to, for there can be no doubt but disease is greatly 

 modified by social conditions at either end of the scale ; at the 

 upper end by habits of fashion, ease and effeminacy, and the lower 

 by filth, squalor and poverty. 



The physical evils are those induced by an insufficient removal 

 of the gaseous, liquid and solid excreta that are necessarily the 

 result of animal life, and which are the most active agents in 

 producing disease and death in the proportion of their accumula- 

 tion. 



Hence it is not their formation that is prejudicial, but their 

 inadequate removal. By the operation of natural agencies this is 

 easily accomplished in what we may conceive as the natural mode 

 of life — the moveable scattered habitations referred to above. 



When artificial customs prevail, so in proportion must artificial 

 means be adopted to carry out the indications of nature, and since 

 we have in latter years gained much knowledge it is to be presumed, 

 if this be turned to account, there should be an amelioration of the 

 general health. Experience has proved the accuracy of this deduc- 

 tion, and the lowered death rate of some cities, notably London, is 

 the best proof, as the very high rate in others shows conversely a. 

 deficient attention to sanitary requirements. 



One law .is thoroughly established, " That the products of 

 animal life are in course of time resolved into inorganic substances 

 which become the pabulum for the growth of vegetable life. But 

 during the transformation above referred to, the compounds that 

 are formed are poisonous to the life of animals unless present in 

 extremely minute quantities. It is necessary that there should be a 

 tolerance of these poisons in the case of animals, or general disease 

 and death would result, and as different species and individuals 

 have different powers of resistance we find that the resulting dis- 



