In venturing to bring this subject before the Institute to-night, I am conscious of inviting attention to a matter which has been frequently treated before and by far abler hands than mine. I at once confess that I have little original matter to bring forward; indeed, the main object of this paper is to endeavour to bring into one focus and to a common standard of criticism the various formulas for ascertaining the rate of mortality, which have already been so often discussed in this room. The expression “rate of mortality” is advisedly used here instead of “exposed to risk”, because it would seem that attention has hitherto been unduly centred in the latter.

In the course of an investigation I have lately made, into the rate of mortality that has prevailed among the female lives insured in the Scottish Equitable Life Assurance Society, I have tried various methods of arranging the facts furnisht by the books of the office; and I think it may be useful to persons engaged in similar investigations, if I describe these methods, and state the conclusions at which I have arrived as to the best course of procedure.

As stated in the foregoing paper, the number of persons to whom the observations relate was 2,205, and the total years of life 30,521. The average time for which the lives were under observation was therefore 13·84 years. The number of deaths was 668; the number of discontinuances 730; and the number of existing 807. The experience may therefore be described as an unusually mature one. The numbers at risk and the deaths in each insurance year have been calculated separately for each age at entry; but, as the numbers at individual ages are small, it is probably not worth while to publish them. The following are the figures irrespective of the age at entry.

As there is a prospect of the Scottish Insurance Companies again collecting the statistics of their mortality experience, it is desirable to consider anew the mode in which the facts should be tabulated, in order to ascertain the rate of mortality experienced among assured lives. The previous collection was drawn from theexperience of 10 offices, and consisted of the total lives assured from the beginning of the several offices, brought down to 31 December 1863. Thirty years having elapsed, it is proposed to begin with the facts then existing—tabulating the deaths arising among these; and also to tabulate new assurances, dealing with them separately. It is proposed also to discuss whole-life assurances and endowment assurances. It is also proposed to collect the experience of male and female annuitants. With so large an undertaking in prospect, it is expedient to re-consider the modes previously adopted, and in some detail to state the manner in which these experiences should be now collected.