In the following essay we shall attempt the solution of a problem which has hitherto remained unsolved, though it is one of the most important problems connected with the science of life contingencies.

[Dr. Wittstein then explains the notation he uses; but we have substituted for it the usual notation, with which all our readers will be familiar; and he states that the Table B, on page 167, may serve as a specimen of a Mortality Table.]

Mortality Tables are based upon observations. We do not now propose to discuss the mode of collecting these observations. Upon this subject the author's treatise on Mathematical Statistics (Hanover, 1867), may be consulted. By whatever method the observations are made, the data resulting from them are always put in the form given in columns 1–3 of Table A, page 166. This table contains the data which Brune published in the year 1847 from the experience of the Prussian Widows' Fund, and from which he constructed his Mortality Table for Males (Table B); and we select this table in illustration of our subject, simply because it is readily accessible.