Scientific men must often experience a feeling not far removed from alarm, when we contemplate the flood of new knowledge which each year brings with it. New societies spring into existence, with their Proceedings and Transactions, laden with the latest discoveries, and new journals continually appear in response to the growing demand for popular science. Every year the additions to the common stock of knowledge become more bulky, if not more valuable; and one is impelled to ask, Where is this to end? Most students of science who desire something more than a general knowledge, feel that their powers of acquisition and retention are already severely taxed. It would seem that any considerable addition to the burden of existing information would make it almost intolerable.

It may be answered that the tendency of real science is ever towards simplicity; and that those departments which suffer seriously from masses of undigested material are also those which least deserve the name of science. Happily, there is much truth in this. A new method, or a new mode of conception, easily grasped when once presented to the mind, may supersede at a stroke the results of years of labour, making clear what was before obscure, and binding what was fragmentary into a coherent whole. True progress consists quite as much in the more complete assimilation of the old, as in the accumulation of new facts and inferences which in many cases ought to be regarded rather as the raw materials of science than as science itself.