232 G. H. KNIBBS. 



3. Sex-ratio.— It is a remarkable fact that in the western 

 world the frequency of suicide among men ranges from 

 double to quintuple the frequency among women, while in 

 India and Burmah the relation is reversed, that is, suicide 

 is more frequent there among women than men. 



For Australia, for the four decennia between 1871 and 

 1909 inclusive, we have (omitting West Australian suicides, 

 for which figures are not available till 1896) the following 

 results, viz: — 



Years. Males. Females. Total. Males Females 



(per 1000 of total suicides.) 



1871-1909 11,051 2,250 13,301 831 169 



1900-1909 3,992 811 4,803 831 169 



This constancy of relation of 83'lf males and 16'9'f 

 females is remarkable, and is approximately true for each 

 decennium. It shews that in the Commonwealth of Aus- 

 tralia 4*92 males commit suicide for each female who 

 commits that act, a ratio that is exceeded only by one 

 country, — Switzerland. This apparently exact constancy 

 of ratio is, however, fortuitous, since its significance 

 depends upon the constancy of the ratio of the numbers 

 at each age in the two sexes. If we assume that there is 

 no change in the distribution according to age, we can 

 correct the ratio for any change in the relative number 

 of males and females. The mean masculinity (or number 

 of males to one female) was 1*1440 for the whole period 

 1871 to 1909 inclusive and for the period 1900 to 1909 

 inclusive it was only 1*1091. The results therefore 

 require correction before comparisons are made. This 

 may be roughly given by assuming a result on an identical 

 relative number of males to females, say 110 males to 100 

 females in each case, and will then give for the periods 

 in question not quite identical results, the relative fre- 

 quency of suicide being : — 



Year 1871-1909, 825 males, 175 females per 1,000. 

 1900-1909, 830 males, 170 females per 1,000. 





