166 
From these numbers it is evident that in unhealthy years 
the increase of mortality is relatively greater between the 
ages of 25 and 76 than at any other age, and that very 
young and very old lives are relatively much less affected 
than in years when the general rate of mortality is below 
the average ; thus confirming the view I have taken that 
the excess of deaths in unfavourable years is principally due 
to meteorological causes. 
It has long been admitted that the state of the public 
health is affected by changes in the state of the weather ; 
and for many years the Registrar General has regularly 
included in his reports statements of the weekly, quarterly, 
and annual mean and extreme values of the various 
meteorological elements as observed at Greenwich; but 
these statements as usually given are of little value to sani- 
tary science. To be of use, the results of meteorological 
observations ought to be regularly grouped and discussed 
with reference to the various questions which arise in connec- 
tion with the origin and development of diseases ; but this 
obvious and very important course of proceeding appears to 
be entirely neglected by boards of health, health committees, 
and officers of health, and as a natural consequence, their 
misdirected efforts, made without a due regard to the true 
principles of sanitary science, have hitherto failed entirely to 
effect any improvement in the state of the public health, or 
any reduction in the general rate of mortality, as is clearly 
shown in the mortality returns. Thus during the 15 years, 
1838-52, the average annual rate of mortality for the whole 
of England was 22*35 to 1,000 persons living ; and during 
the succeeding 15 years, 1853-67, it was 22*47. It is there- 
fore evident that notwithstanding the so-called sanitary 
improvements, made, at great cost, in almost every town and 
district irs the kingdom during the latter period, the public 
health remained in the same unsatisfactory state in which it 
had been during the previous 1 5 years ; and the death rate 
still showed a tendency to increase. 
From a table at page xlii of the 30 th Annual Report of 
the Registrar General, it appears that during the six years? 
