I might submit these two examples, the one as a young and comparatively weak population, the other as a comparatively mature and strong population. The adult mining population of 30 years of age is not, I apprehend, a population advancing to a further stage of maturity, but one kept down by noxious agencies and premature mortality to that limit of age, with no chance for them or for other generations to pass beyond it whilst in this employment, except through the operation of sanitary measures in removing the causes of depression. The difference in the proportions of ages between a depressed and unhealthy and a comparatively long-lived and strong population, is shown in the following comparative view of the ages of the miners and of the 1033 non-mining labourers who were living and working:— ┌──────────────┬───────┬─────┬──────┬─────┬──────┬─────┬─────┬────────┐ │ │ 30 │ 40 │ 45 │ 50 │ 55 │ 60 │ 70 │80 Years│ │ │ Years │Years│Years │Years│Years │Years│Years│ and │ │ │of Age │ and │ and │ and │ and │ and │ and │upwards.│ │ │ and │under│under │under│under │under│under│ │ │ │ under │ 45. │ 50. │ 55. │ 60. │ 70. │ 80. │ │ │ │ 40. │ │ │ │ │ │ │ │ ├──────────────┼───────┼─────┼──────┼─────┼──────┼─────┼─────┼────────┤ │Miners 1651│ 772│ 377│ 239│ 125│ 56│ 29│ 1│ │ │Labourers 1033│ 695│ 422│ Not │ 284│ Not │ 144│ 48│ 7│ │ │ │ │given.│ │given.│ │ │ │ │ │ Per │ Per │ Per │ Per │ Per │ Per │ Per │ Per │ │ │ cent. │cent.│cent. │cent.│cent. │cent.│cent.│ cent. │ │Miners │ 47│ 23│ 14│ 7½│ 3½│ 1½│ │ │ │Labourers │ 67│ 41│ │ 27│ │ 14│ 4½│ ½│ └──────────────┴───────┴─────┴──────┴─────┴──────┴─────┴─────┴────────┘ So that whilst in every 100 men of the younger population of workpeople there would not be 2 men of the experience beyond sixty years of age, not 8 above fifty, or not a fourth passed forty; in the older population there would be 14 beyond sixty, 27 beyond fifty, or a clear majority of mature age, and, it may be presumed, of the comparatively staid habits given by age. Dr. Scott Allison found that the average age of the living male heads of families of the _collier_ population at Tranent whose condition he has contrasted with that of the agricultural population, and whose ages he could ascertain, was 34 years; whilst the average age of the living male heads of the agricultural families was 51 years and 10 months. He considers that the like proportions would be found to be more extensively prevalent, and would serve as fair indications of the relative condition of the different populations.