BY E. M. JOHlSrSTOlSr, F.L.S. 23 



The truer index of the relative health and sanitary 

 condition, as computed by the Health Standard, would place 

 Hobart far before the others. .It is not always possible, 

 however, to make a close estimate of the ages living under 60 

 in cities, but if we measure deaths under 60 by the estimated 

 total population, we get a close approximation to relative value 

 of the condition affecting health and sanitation in the cities 

 compared, thus : — 



Deaths under 60 years per 1,000 persons living" 



1. Hobart, 1885 13-97 



2. Adelaide, 1885 15-42 



3. London, 1885 17-16 

 4 Sydney, 1884 19-52 

 5. Brisbane, 1885 19*79 



Thus it is evident that the true index to health and 

 sanitary condition of different places can only be obtained by 

 eliminating the old age group, as in the method of the 

 Health Standard. Comparisons by the usual mode are widely 

 misleading. The very remarkable circumstance that Hobart 

 shows 43-46 per cent, of the total deaths, as being 60 years 

 and over, with a mean age at death of 74-30 years, is of itself 

 sufficient as to prove the reasonableness of these conclusions. 



The Influence of Migeation 



The death-rate for all ages is also greatly affected by 

 Migration, as it invariably disturbs the proportion of the 

 principal age groups. 



The bulk of Immigrants to cities and young Colonies 

 consists of persons between the ages of 5 and 50. This is the 

 period of life, as already explained, when deaths are at a 

 minimum, relative to the same age group living. In most of 

 the Australasian Colonies the death-rate for this group ranges 

 between 5-60 and 7-72 persons per 1,000 living. 



Where Immigration is large in proportion to the original 

 population, there will certainly be a very great fall in the 

 total death-rate, without any change in the proportional 

 yields for each age group, and without any material change 

 in the conditions affecting health. 



Thus if a stream of Immigration equal to 10,000 ]3er year of 

 ages between 5 and 50 were absorbed by a young Colony 

 whose original normal population was 200,000, with a total 

 death-rate of 15-40 per 1,000 ; then if the death-rate 

 for ages 5-60 was only 6-17 per 1,000, it follows that in 

 ten years the total death-rate would be reduced to 12-32 

 per 1,000— that is a fall of 3-08 per 1,000 in the total 

 death-rate without any alteration whatever as regards 

 death-rate yield for particular ages, and with no material 



