requires the co-operation of minds of various orders, quite akin
in their relations to those necessary in a mine or great
manufacturing establishment. Laborers whose duties are in a large
measure matters of routine must be guided by the skill of a class
higher in quality and smaller in number than their own, and these
again by the technical knowledge of leaders in research. Between
these extremes we have a great variety of systems of co-operation.

There is another feature of modern research the apprehension of
which is necessary to the completeness of our view. A cursory
survey of the field of science conveys the impression that it
embraces only a constantly increasing number of disconnected
specialties, in which each cultivator knows little or nothing of
what is being done by others. Measured by its bulk, the published
mass of scientific research is increasing in a more than
geometrical ratio. Not only do the publications of nearly every
scientific society increase in number and volume, but new and
vigorous societies are constantly organized to add to the sum
total. The stately quartos issued from the presses of the leading
academies of Europe are, in most cases, to be counted by hundreds.
The Philosophical Transactions of the Royal Society already number
about two hundred volumes, and the time when the Memoirs of the
French Academy of Sciences shall reach the thousand mark does not
belong to the very remote future. Besides such large volumes,
these and other societies publish smaller ones in a constantly
growing number. In addition to the publications of learned
societies, there are journals devoted to each scientific
specialty, which seem to propagate their species by subdivision in
much the same way as some of the lower orders of animal life.
Every new publication of the kind is suggested by the wants of a