TRANSACTIONS OF THE SECTIONS. 



169 



The mean number of deaths per million inhabitants were as follows : — 



West Districts 367G deaths. 



Central , 4402 „ 



North „ 4670 „ 



East „ 5435 „ 



South „ 6535 „ 



It will be seen that when the southern districts are contrasted with the most 

 healthy group of districts (the west), their mortality is as 6535 to 3676 ; and when 

 compared with the districts subject to least fluctuation (the north), their mean 

 fluctuation is as 21-50 to 5'67, and their extreme fluctuation as 48 20 to 18'58. In 

 this character of fluctuation, therefore, the north and the south occupy the two 

 extremes. The only cause which seems capable of explaining a difference so re- 

 markable and so considerable is the prevalence of epidemics on the south side of the 

 Thames, and the comparative immunity from them of the inhabitants of the higher 

 districts on the north side. If sanitary improvements should be found, after a term 

 of years, to have had little effect on the rate of mortality, or the prevalence of epi- 

 demics, in these districts south of the Thames, every discouragement ought to be 

 thrown in the way of the extension of buildings in so low and unhealthy a locality. 

 The author of the paper then went on to examine the deaths from special causes, 

 beginning with the deaths from seventeen prinrApal groups of causes. These seventeen 

 groups admitted of being divided into two classes, the one characterized by a high, 

 the other by a low, or moderate, mean fluctuation. At the head of the first class 

 stands the group of zymotic diseases, followed in order by several groups of diseases 

 having a mean fluctuation varying from 31-24, in the case of zymotic diseases, down 

 to 11"26, in the case of diseases of the respiratory organs. The second class, com- 

 prising a larger number of groups, and ending with diseases of the brain, nerves, &c., 

 has a mean fluctuation from 10-71, in the case of death from old age, down to 3'50 

 in the case of diseases of the brain, nerves, &c. Of the whole seventeen groups, the 

 zymotic diseases are those which present the highest mean rate of fluctuation, and 

 the diseases of the brain, nerves, &c. the lowest. 



The group of zymotic diseases, which in the reports of the Registrar- General 

 comprises eighteen separate maladies, the author extends so as to embrace Quinsey 

 and Carbuncle. 



As the principal diseases belonging to this zymotic class are remarkable for the 

 readiness with which they may be distinguished, even by non-professional persons, 

 they are not likely to have been affected by improvements in registration or in medical 

 science ; and as they are also of great importance in their relation to the public 

 health, the more considerable of them, placed, for the most part, in the order of 

 their fluctuation, are brought together into one table : — 



