How anxious and agitated we are when we enter upon a new field of science; when, at every step, the doubt arises whether some important phenomenon may not have escaped us! How we are tormented by the fear of not being able to face the most vital questions, nor to find out those phenomena most fruitful in results and most subtile! What trepidation overcomes one before one writes down even a few lines in the book of science! Even amongst physicians it is not easy to find any who are able to write down the history of any fact or observation. The majority of them only know how to relate things in the same dogmatic words with which they are described in treatises, and only a few take the trouble to examine the development of an idea. And yet, in the study of human nature there is nothing more interesting than to follow the different phases of a problem, to see whence a thought arose, to know the first means by which nature was interrogated, then the sudden changes of method, the incidents, the errors and corrections, and at last the victory which crowns our labour and wins a fact for science. I believe if it could be seen near at hand how a research develops in the laboratories, the followers of the experimental sciences would be greater in number. It is a work of patience. The only difficulty consists in gradually learning the language of Nature, in finding out the way to interrogate her and compel her to reply. In this struggle, in which we, humble pygmies, fight continually in order to wrest from Life its secret, there are moments of intoxicating emotion, rays of light amongst the shadows, which excite the imagination of the scholar and the artist. IV The second case, which I studied in company with Dr. Albertotti, was that of a boy eleven years of age, with an agreeable physiognomy and very beautiful physical proportions. He had scarcely reached his second year when he fell from a terrace, fracturing his skull and causing a severe concussion of the brain. After two years and a half he began to suffer from epileptic fits, and later, signs of insanity appeared which obliged his relatives to send him to the lunatic asylum in Turin. When I saw him in February 1877, he had a large opening in the skull, a little above the right eye, and covered with skin; it was as big as the palm of his hand, and in the pit of it one could feel the pulsing of the brain. The terrible fall had for ever arrested his intellectual development. He was gay, smiling, and lively, like a big baby, but he could not speak. It was a saddening circumstance that in the midst of this ruin of his mind one single higher idea had remained, a remnant of his earlier intellectual life, a motto which he constantly repeated: 'I want to go to school.’