necessary steps for their solution. This is emi- Dently true of the nervous system, where we are endeavouring to understand its most intricate phenomena by the application of laws derived only from our present limited knowledge. The remark- able observations of late, with respect to anos- thesia in hysterical women, states of somnambulism and costasy, and very similar conditions found through all animal life, should make us feel that we have still to learn the meaning of nerve force. With our present imperfect knowledge, the attempt to understand it is like taking a child, ignorant of the very first laws in physics, before a steam engine and endeavouring to explain its action. We cannot solve a problem until we know the meaning of the terms in which it is framed. Thus we see our greatest men, like Faraday, endeavouring to master the simplest facts and phenomena, taking for their maxim "tota in minimis," all nature exists in the least. Harvey made use of all the known laws of his time, and hence the grandeur and fruitfulness of his dis- covery.
I might here remark that this gradual growth of knowledge is another example of the progression
