Charles Sedgwick Minot

“ Others believe that mind is a thing of its own kind. When the sunlight of discovery shall dispel the mists of the unknown, that conceal the true nature of the mind, then that image, now so dim, will become distinct, and its real character evident. ”

“ In brief, an almost endless variety of circumstances affect the circulation of a given part, as shown by the changes of its volume; but, among these circumstances, the condition of the brain is especially influential.
Mosso, however, has not confined his investigations to the waking condition, but has extended them also to men asleep, thus discovering a very great increase in the volume of the forearm as a person gradually falls asleep. The large size of the forearm during sleep may be diminished by a dream, or by any cause that renders the sleep less profound. ”

“ Just as the ornithologist may study the habits of a bird, its mode of hopping, flying, feeding, singing, and so forth, and make himself thoroughly familiar with its natural history, without learning anything of its anatomy, the laws of muscular contraction or digestion, so also the philosopher may investigate the actions of the mind, the succession and relations of ideas, or may formulate the principles of logic, in entire ignorance of the processes which occur in the brain. ”

“ The slow but unmistakable gravitation of psychology toward physiology does not forecast, it seems to me, the demise of the former, but indicates rather that psychologists, having now gathered and arranged a great mass of data concerning the mind, are making an inevitable step in progress in seeking deeper than ever before for explanations. During the new phase, into which psychology has apparently entered, the principal problems will probably concern the relation of mind to the substratum of matter in which it displays itself. ”

“ Pursuing his researches in other directions, Professor Mosso has succeeded in demonstrating that, when the brain acts, not only does the arm receive less blood, but the brain actually does receive more. ”

“ Mosso experimented in the laboratory of Professor Ludwig, at Leipsic, upon the circulation of the blood through the kidney. He took advantage of the fact that death is a double process: 1. The death of the animal as a whole, or that which we ordinarily call death; and, 2. The subsequent and gradual death of the tissues, to which is due the curious phenomenon that an organ survives the animal of which it has formed a part. ”

“ For example, if the paper moves an inch per minute, then, if we measure up a horizontal line the number of inches along which the tracing continues to rise, we can fix the points corresponding to a given time, and measure the height to which the pen had risen at any given instant, and also the rate at which it rose.
The vertical motion of the pen depends on the rise and fall of the test-tube M, which in its turn is caused by the out- and in-flow of the water surrounding the arm. Hence, a rise in the curve corresponds to an expansion, a fall to a contraction of the forearm. ”

“ In animals thus operated upon, the same changes of volume can be seen to occur in the brain, and closer observation shows that the variations are due to contraction or expansion of the blood-vessels.
These investigations demonstrate that one of the physiological conditions of increased mental action is an increased supply of blood, which is produced principally by a dilatation of the cerebral blood-vessels, accompanied by a contraction of the blood-vessels of other parts of the body. ”

“ Through such an opening it can be observed that the soft brain is smaller during sleep than during waking, because during the former state it draws back from the opening, and during the latter it may swell so much as even to protrude through the opening. ”

“ Now, the mind derives its material through the senses. The sensations arise from physical causes. The final results of mental performances are various actions of the body, physical events such as motion and speech. ”

“ Physics, therefore, are the alpha and omega of our mental history. Concerning what occurs between the physical cause of sensation and the physical result of mental action, two extreme opinions stand opposed. On the one hand, mind is defined as a succession of purely physical phenomena ”

“ These have a difficult office to perform, for they must register the changes in the volume of the limb. The forearm is placed in the cylinder A B, which is then filled with water; when the arm swells, the water is driven out through the rubber tube F; when the arm shrinks, the water is sucked back. ”