brief résumé will be necessary. A genera] address on the work of the congress will be followed by discourses on the inner unity of seven greal divisions of knowledge. These seven meetings will be followed by others in twenty-four departments in each of which will be set forth the fundamental conceptions of the various branches, and the progress of each during the nineteenth century. The remaining days of the congress will be occupied with meetings, each lasting three hours, for discussions of the present problems of each science and of its relations to cognate branches.
A necessary condition to success, which was had in view from the beginning, was that the leading addresses should be given by the most eminent representatives of every branch of science whose attendance at the congress could be secured. This must be regarded as one of the novelties of the scheme, calculated to heighten its interest. But the problem of realizing it was no easy one. To invite all eminent investigators of various countries was not a difficult matter—no doubt it has been clone in the case of many a congress—but it would obviously be impossible to bring together even one representative of every branch of science by merely extending this invitation. The difficulty was heightened by the fact that two principal addresses were to be delivered in each of the great branches. Only three hours being allotted to each branch, the number of addresses could not be increased. After a careful consideration of the exigencies of the situation it was found impracticable to extend the number of individual branches that could be treated in a single week beyond a limit which might approximate to 130. By frequent additions and exclusions as the development of the scheme was worked out the maximum was found to be 128. It seemed that the most satisfactory result would be reached by having sixteen simultaneous meetings, each for the discussion of a single branch, on each half-day. The number of available days being four, it would thus be possible to arrange for 128 meetings of three hours each. The limitations thus imposed rendered necessary the exclusion of many important branches of science from the list of subjects to be specially treated. The best that could be done w r as in each case to give preference to branches of such interest or so widely cultivated that it was not difficult to find speakers to treat them.
Much having been written on the adopted scheme of classification and its defects, a word on this subject may not be out of place. I do not suppose that any one concerned would for a moment claim that the field of knowledge could be separated into exactly seven divisions, neither more nor less—or that there are twenty-four separate departments of knowledge, and 128 branches of sciences of sufficient importance to be separately treated. Nor is it important whether the scheme of classification is or is not ideally a good one. The main object was