22 



account for the seasonal variations, inasmuch as the thermic 

 chart does not indicate the same fluctuations. Although the 

 minimum deathrate coincides with the maximum temperature 

 for the quarter, that is the only correspondence — the minimum 

 temperature does not coincide with the maximum deathrate, 

 nor the falling and rising heats with increasing and decreasing 

 rates. Therefore, heat alone will not explain the variations. 



Nor will the rainfall, nor the humidity of. the atmosphere, 

 nor any combination of these, since they follow very closely 

 the thermic curves, only in a reverse direction. 



Nor will the diurnal range of temperature — the change that 

 occurs from heat to cold daily — inasmuch as the mean monthly 

 diurnal range corresponds with the ordinary temperature 

 chart, being greatest in the hottest quarter, and vice versa. 



One circumstance that I would suggest is the settled or 

 unsettled state of the season. During the summer we 

 experience a settled state of warm, dry weather. At this, 

 time we get the minimum of deaths. During the winter we 

 have a settled state of much cooler wet weather, but not 

 extremely cold. This is not so beneficial. During the autumn 

 and the spring the weather is more fluctuating, days of great 

 heat alternating with others of rain storms and much lower 

 temperature. Now it seems very possible that these milder 

 seasons, because they are so much more uncertain, may be 

 those which, in advanced phthisis, produce such an exacerbation 

 of the disease as is sufficient to cause death. 



Influence of Sex. 



Has sex any influence upon phthisis in South Australia ? 

 Yes, in more respects than one. 



1. As regards susceptibility to the disease, we find that 

 during the five years there have occurred 517 deaths among 

 males, and 450 among females. When we examine the pro- 

 portion of men and women in our community we find that 

 there are 449,633 males for every 417,859 females, or 517 men 



The estimated populations in South Australia are as under : — 



1873 .. .. 101,743 males, and 96,514 females. 



1874 .. .. 104,995 " 99,888 " 



1876 .. .. 116,503 " 107,985 " 



1877 .. .. 126,392 " 113,472 " 



449,633 417,859 



In England in 1876 there was a population of 11,801,633 males and 

 12,442,377 females, while the deaths from phthisis were 25,127 males and 

 24,668 females. But if the deaths were proportional to the populations, 

 26,491 women ought to have died instead of 24,688, or 145 women instead of 

 135. So the populations being equal, 145 men die for every 135 women ; or 

 men are more susceptible to the extent of 1-13-5 part. 



