The title _Horæ Subsecivæ_, borrowed by Dr. John from the title-pages of some old volumes of the minor English literature of the seventeenth century, indicates, and was intended to indicate, the nature of his writings. They are all “Leisure Hours,” little things done at times snatched from business. There are between forty and fifty of them in all, none of them long, and most of them very short. It is vain in his case to repeat the regret, so common in similar cases, that the author did not throw his whole strength into some one or two suitable subjects, and produce one or two important works. By constitution, I believe, no less than by circumstances, Dr. John Brown was unfitted for large and continuous works, and was at home only in short occasional papers. One compensation is the spontaneity of his writings, the sense of immediate throb and impulse in each. Every paper he wrote was, as it were, a moment of himself, and we can read his own character in the collected series. A considerable proportion of his papers, represented most directly by his _Plain Lectures on Health addressed to Working People_, his little essay entitled _Art and Science_, and his other little essays called _Excursus Ethicus_ and _Education through the Senses_, but also by his _Locke and Sydenham_ and others of his sketches of eminent physicians, are in a didactic vein. Moreover, they are all mainly didactic on one string. When these papers are read, it is found that they all propound and illustrate one idea, which had taken such strong hold of the author that it may be called one of his characteristics. It is the idea of the distinction or contrast between the speculative, theoretical, or scientific habit of mind, and the practical or active habit. In medical practice and medical education, more particularly, Dr. John Brown thought there had come to be too much attention to mere science, too much faith in mere increase of knowledge and in exquisiteness of research and apparatus, and too little regard for that solid breadth of mind, that soundness of practical observation and power of decision in emergencies, that instinctive or acquired sagacity, which had been conspicuous among the best of the older physicians. As usual, he has put this idea into the form of humorous apologue:— A DIALOGUE. SCENE.—Clinical wards of Royal Infirmary. The Physician and his Clerk _loquuntur_. John Murdoch, in the clinical ward with thoracic aneurism of the aorta, had at his bedside a liniment of aconite, etc. Under the stress of a paroxysm of pain, he drank it off, and was soon dead. _Physician._—Well, Sir, what about Murdoch? Did you see him alive? _Clerk._—Yes, Sir. _Physician._—Did you feel his pulse? _Clerk._—No, Sir. _Physician._—Did you examine his eyes? _Clerk._—No, Sir. _Physician._—Did you observe any frothing at the mouth and nose? _Clerk._—No, Sir. _Physician._—Did you count his respirations? _Clerk._—No, Sir.