26 



GENEKAL DEATH-RATE FOR ALL AGES, ETC, 



corresponding respectively with the maximuni and minimum 

 curves of temperature, thus : — 



Temperature.* 



ISTovember 



hT 



December 



60 



January 



February 



March 



63 

 60 

 69 



April 



May 

 June 



65 

 60 

 46 



July 

 August 



45 



48 



September 

 October 



62 

 63 



Mean 



54 



•5? I.. 



3 VMax. 



■8) 



•3 



•9 



•6 



•9] 



■^l 



•7j 

 •1 

 •6 

 •4 



Min, 



DEATH-RATE.t 



per centage. 



7-03 



8-97] 

 9-48 V 

 8-64 ) 

 8-28 

 7-93 

 . 8-39 



8-90 

 8-62 

 8-18 

 7-91 

 8-33 



Major 

 max. 



Minor 



These curves are best appreciated when shown in diagraphic 

 form, and comparisons in this way show the close corre- 

 spondence which exists between deaths from zymotic diseases, 

 deaths of children, the major maximum total death-rate 

 curve, and the maximum curve of temperature. 



At the same time there may be seen also a close corre- 

 spondence between the curves of deaths relating to old age, 

 deaths from diseases of the respiratory system, the minor 

 maximum seasonal death-rate curve, and the minimum curve 

 of temperature. 



It is clear, therefore, that the death-rate variation of 

 particular months is of no value in itself as an index of local 

 sanitary condition, which seldom varies to any extent within 

 the space of one year ; and therefore this form of death-rate 

 variation must, in nearly all cases, be ascribed principally to 

 seasonal influences lying beyond human control. The Typhoid 

 seasonal curve is a very remarkable one. It is at its lowest 

 point invariably from July to !N"ovember inclusive, rising 

 rapidly to its highest point in March, and from that point 

 falling as rapidly to the beginning of its minimum j)eriod in 

 July. 



This curve is not in any way disturbed by the rise and fall 

 of its death-rate in different years. A glance at the diagram 

 showing the deaths from Typhoid in Australasia shows clearly 

 a periodic rise and fall during the last twenty years, with an 

 average duration of fully four years for each period. 



The close agreement between the various widely separated 

 Colonies in theseperiodic curves teachesus caution in referring 

 the unusual rise or fall to causes altogether local. 



Local causes, no doubt, are fairly indicated by the smaller or 

 greater intensity of the rise or fall, but the actual tendency 



