I.—It is well known that the very different death-rates obtaining in different asylums depend much more on the different classes of patients they contain, than on any differences in the hygiene, or other conditions of the asylums themselves. Very little has, however, been done to obtain any accurate measure of the mortality rates that obtain amongst different classes of patients. The statistical tables of this association, which have now been used in the annual reports of asylums for a dozen years, contain much material that may be used for elucidating the matter. It is somewhat surprising that the valuable statistics contained in these tables have not been made use of to any extent either for this or any other purpose; the impediment, probably, is the considerable labour involved in any extensive analysis of their numerous data.