In the following pages we give a description of the method pursued in an investigation into the Mortality Rates of the combined populations of New South Wales and Victoria, also tabular statements of the results at which we arrived. We offer no apology for trespassing on the courtesy of the Institute and asking their attention to a paper on such a well-worn subject as mortality rates, inasmuch as the rates of mortality being experienced by persons living in different parts of the world, are in themselves of more than passing interest. Moreover, where the population under consideration has been largely transplanted from a home on one side of the globe to a new land on the other, amidst new surroundings, experiencing a new climate, and cultivating almost virgin soil, its progress in the social scale will probably attract more than usual attention. The Australian Colonies afford an excellent example of such a new nation, and their rapid development makes their experience in mortality a subject of more than usual moment, both to themselves and to the mother country. Not only is there the desire to compare their present mortality rates with those prevailing in the mother land but there is the additional incentive to enquiry as to whether their own present experience is varying from that of their earlier days. To those engaged in the conduct of Industrial Business, rates of mortality, derived from the statistics of the general population, are an absolute necessity; and as industrial assurance is now making rapid strides in the Australian Colonies, a paper dealing with Australian mortality should be welcomed by those most closely associated with that class of business.