function of the tympanum and its chain of bones by the knowledge in our possession, but we now think that this was insufficient since the physicist has discovered the intimate relation between electrical and sonorous vibrations in his micro- phone. I think I am right in saying that no piece of mechanism was ever framed in imitation of a straw of wheat or the hollow thigh bone, but when by a series of experiments the engineer dis- covered that with the least material he could gain most strength, by making his support in the form of a hollow girder or tubular bridge, then we applied his discovery to interpret the meaning of the culm of grass or the human os femoris. No contem- plation of the nerves ever excited man's imagina- tion towards the fabrication of an electric tele- graph, but, on the other hand, the insulated wire, the result of much labour and thought, was found to have its counterpart in the nerves, whose compo- nent parts it then explained. The action of salines and colloids on the human body was learned by means of parchments and tubes in the laboratory,
These facts should point out to us how fruitless it is to attempt to understand complex structures and phenomena, before we have arrived at the
