* * * * * THE PRESIDENT'S ANNUAL ADDRESS TO THE ROYAL MICROSCOPICAL SOCIETY.[1] [Footnote 1: Delivered by the Rev. Dr. Dallinger, F.R.S., at the annual meeting of the Royal Microscopical Society, Feb. 8, 1888.--_Nature._] Retrospect may involve regret, but can scarcely involve anxiety. To one who fully appreciates the actual, and above all the potential, importance of this society in its bearing upon the general progress of scientific research in every field of physical inquiry, the responsibilities of president will not be lightly, while they may certainly be proudly, undertaken. I think it may be now fairly taken for granted that, as this society has, from the outset, promoted and pointed to the higher scientific perfection of the microscope, so now, more than ever, it is its special function to place this in the forefront as its _raison d'etre_. The microscope has been long enough in the hands of amateur and expert alike to establish itself as an instrument having an application to every actual and conceivable department of human research; and while in the earliest days of this society it was possible for a zealous Fellow to have seen, and been more or less familiar with, all the applications to which it then had been put, it is different to-day. Specialists in the most diverse areas of research are assiduously applying the instrument to their various subjects, and with results that, if we would estimate aright, we must survey with instructed vision the whole ground which advancing science covers. From this it is manifest that this society cannot hope to infold, or at least to organically bind to itself, men whose objects of research are so diverse. But these are all none the less linked by one inseverable bond; it is the microscope; and while, amid the inconceivable diversity of its applications, it remains manifest that this society has for its primary object the constant progress of the instrument--whether in its mechanical construction or its optical appliances; whether the improvements shall bear upon the use of high powers or low powers; whether it shall be improvement that shall apply to its commercial employment, its easier professional application, or its most exalted scientific use; so long as this shall be the undoubted aim of the Royal Microscopical Society, its existence may well be the pride of Englishmen, and will commend itself more and more to men of all countries. This, and this only, can lift such a society out of what I believe has ceased to be its danger, that of forgetting that in proportion as the optical principles of the microscope are understood, and the theory of microscopical vision is made plain, the value of the instrument over every region to which it can be applied, and in all the varied hands that use it, is increased without definable limit. It is therefore by such means that the true interests of science are promoted.