to those so long employed in studying the problems of astronomy. Although we are far from the perfect state of the science, still every advance made in it is a step toward the end. From time to time material enough is collected to enable some one to make a comprehensive generalization. These generalizations we admire, but we sometimes forget that they never could have been made had not a myriad of workers from day to day furnished the material; themselves often unconscious of the importance of the real work they were doing, but believing that every fact established, however insignificant in itself, every error of previous observers, however slight, corrected, would at some time serve a purpose in the growth of the science. Dalton's law of multiple proportions; the law of Dulong and Petit connecting the specific heat and the atomic weight of the elements; Avogadro's hypothesis relating to the connection between molecular weights and the volumes of gaseous compounds, would still have been of the future, had it not been for the efforts of a great many scientific workers, contributing their mites day by day.
Though we thus recognize a growth of the science of chemistry, entirely independent of any practical applications of its facts, it is of course true that the latter follow closely in the footsteps of the former. When, then, we rejoice in any useful application, let us remember that it could never have been made had the science itself, as a science, not advanced.
It happens in this country particularly that a man may both practise the art of chemistry and at the same time be a worker in the field of scientific chemistry. This is due to the fact that it is necessary for the men to live, and there are very few positions in the country which enable their incumbents to devote themselves to the pure science of chemistry without obliging them at the same time to look for additional means of support to that furnished by the positions themselves. This additional means of support can usually be found most readily in the practice of the art of chemistry. Too often, time that could and would be devoted to grappling with the problems of the science is given up to the art in order to keep the purse supplied. Every properly-constituted scientific man, however, who is obliged to so apply his powers as to bring himself immediate and material rewards, feels that he is doing something which he would rather not do, and that, by applying himself to his science proper, he could in the end be of much more service to the world. It is apt to be the case, too, that he who begins to slight the science and to favor the art will at last entirely sacrifice the former for the latter, and we see too many teachers of chemistry in this country at the present day who are devoting their time to the art rather than to the science of chemistry; a circumstance which has the most pernicious effect upon the growth of the science among us, for the students who are placed under the influences mentioned are not stimulated, as they should be, to con-
