physical properties of the elements. This work should be done with the greatest care and thoroughness. Every element should have its relations to the forces of Nature thoroughly fixed and tabulated. Even the rarest elements ought not to be neglected, since each one has its scientific importance, fills a place in some series or groups, and, for purposes of generalization, is of as great interest as any other. But, as it is to-day, the commonest substances have been very imperfectly studied. Only a few constants have been determined for some of the most familiar elements, the gases especially. Just enough is known about the commoner metals to show us how ignorant we really are. Here, then, is a great field for work, and in it some of the richest materials for both chemistry and physics are to be gathered. It is, indeed, strange that this work, obviously of such vast importance, should have been so long postponed. Of course no single individual could undertake it, but it seems as if some learned society, or even some government, might assume the burden! A twentieth part of the money expended for the determination of one astronomical constant, the earth's distance from the sun, ought to cover all the expenses of the undertaking. If we had in America a laboratory exclusively devoted to research, suitably manned and equipped, our country might carry off the glory of achieving this grand work. In default of such a laboratory, however, the labor might be accomplished through the cooperation of many individual workers, each one doing his small part, not aimlessly, but in unison with the others. One chemist might undertake to furnish certain of the elements in a perfectly pure condition; another might carefully determine under varying circumstances their densities and rates of expansion; a third could work up their specific and latent heats; a fourth their electrical relations, and so on. Failure to attain grand results would be impossible. Doubtless the labor would prove irksome and monotonous, but the reward would be sure. In five years, more would be done toward rendering chemistry an exact science, than can be accomplished in a century by means of the chemical investigations at present most in vogue.
The physical properties of the elements being established, the next thing is to do somewhat similar work for compounds. And here, before entering on experimental labors, it is necessary to know what has already been done. This knowledge is at present difficult to obtain, since the materials are scattered through many pages of many volumes of scientific transactions and periodicals, and need to be collected and systematically arranged. This work of tabulation having been finished, chemists will be able to see distinctly where experiment is most needed, what must be done entirely new, and what ought to be done over again. Then, some of the experimental details might be easily intrusted by professors to the hands of students. If, for practice, a student is taking specific gravities, let him work upon substances for which that constant has never been determined. So also with such
