EVERY science seems to have, as a science, its most rapid and brilliant growth during the earlier portions of its history. By this I do not intend to say that the mere bulk of its material increases more swiftly than at a later period, when the number of its students and investigators has become great. I mean simply that important generalizations are more readily made and more frequent, and that abstract conceptions are more speedily fertile in results. The reason for this is very obvious. At first, when any new science has but just assumed definite shape, every student has it before his mind as a unit. All parts of the field are immediately under his eye; no portion of it can easily escape notice. Thus it is studied, not less in its details, but more as a definite, consistent whole; and its growth is consistent, well-balanced, and harmonious. When, however, the field becomes larger, there is a splitting up into specialties, and, in general, each specialty is cultivated by some assiduous worker who cares but little for the character which the science may take in its entirety. In other words, the greater the mass of scientific material, the greater is the tendency among investigators to study details at the expense of generalities. Accordingly, the details multiply and become unmanageable; complexity increases, and symmetrical development comes comparatively to a stand-still.
This is emphatically true of chemistry at the present day. Only a very few chemists now study their science as a grand unit. We have technical chemists, agricultural chemists, analytical chemists, physiological chemists, and so on. Each one devotes himself to his specialty almost without reference to the others. What relation his particular branch may bear to the complete science is hardly thought of. Such questions are left to speculators and dreamers. Among those who study the abstract science, without reference to its practical applications, it is much the same. One man has all he can do to examine the derivatives of a single organic group. If he can obtain fifty new compounds in which the interlinking of the atoms may be represented in some unheard-of way, his ambition is satisfied. He chlorinates this body, and deoxidizes that; he makes numberless substitutions, all of which he knew beforehand to be possible; but what, in the end, does it amount to? In Germany, where nine-tenths of the chemists seem to be running wild over the so-called "aromatic group," this multiplication of new bodies is going on with unparalleled rapidity. And yet not one in five hundred of the substances discovered gets thoroughly described. This naphthaline derivative is a solid,