THE CURRENTS OF THE ATLANTIC. 



407 



determined by the imperfect method of a decennial census, is 21 

 per 1000, that of England being 22. And here I cannot avoid 

 remarking, that the connexion of these facts with temperature has 

 been strangely mis-stated by the eminent French statist, M. Moreau 

 de Jonnes, by whom these vital statistics were first collected. After 

 observing that, of all the states of Europe, the British Islands are 

 the most favoured by a low mortality, he adds with evident sur- 

 prise " It is on the frozen rocks of Ireland (les rochers glaoes de 

 1'Irlande) and in the midst of the eternal mists of Scotland, that 

 man reaches the most advanced age !" 



But the season of the year, and probably even the hour of the 

 day, exert their influence upon mortality. The following numbers 

 give the relative mortality of the several months of the year in Bel- 

 gium, that of the whole year being taken as unity : 



The regularity of these numbers is very remarkable. The mortality 

 is greatest in January, the coldest month of the year, and least in 

 July, which is the warmest ; and the proportion of the former to 

 the latter is that of three to two. 



These facts are in accordance with the laws of mortality stated 

 above ; for Belgium is to the north of the neutral line, and in it, 

 therefore, the mortality should depend chiefly upon the cold of 

 winter. To the south of that line we should expect an opposite 

 result namely, that the mortality should be greatest in the hottest 

 months of the year. We do not possess the data necessary to verify, 

 or to disprove, this conjecture. It is worthy of remark, however, 

 that in Ireland, which 'is traversed by the mean isothermal of 50, 

 the periods of greatest and least mortality are neither the coldest 

 nor the hottest months, but the intermediate periods of spring and 

 autumn. It appears from the Census of 1851, that the number of 



