Sir Sykes therefore withdrew, and for some time was seen no more; while Jasper, who had been an amused spectator of the turmoil, sauntered back to the White Room, muttering as he went: ‘Lucky, rather, that this child had so perfect an alibi, or the governor would have tried, convicted, and sentenced his only son and heir as the light-fingered captor of his lost property. A new sensation, it strikes me, that of injured innocence. And talking of that—how nicely Miss Ruth, be she who she may, played her part—not one bit overdone—it was perfect! We breathe here an atmosphere of mystery; but it will be strange if, when I am all right again, I do not make a push to get at the governor’s secret, whatever it may be.’
The letter, it need hardly be said, remained undiscovered by the volunteer searchers who undertook the quest of it; but gradually the indignant household became more calm, and the general voice confirmed the comfortable opinion, that Sir Sykes had unwittingly locked up the missing document in some desk or drawer, whence it would one day be satisfactorily extracted.
CURIOUS RESEARCHES INTO HUMAN CHARACTER.
There can be little doubt that the domain of mental science is being invaded on more than one side by the sciences which deal more especially with the material world and with the physical universe around us. When physiologists discovered that the force or impulse which travels along a nerve, which originates in the brain, and which represents the transformation of thought into action, is nearly allied to the electrical force—now one of man’s most useful and obedient ministers—one avenue to the domain of mind was opened up. And when physiologists, through the aid of delicate apparatus, were actually enabled to measure the rate at which this nerve-force travels along the nerve-fibres, it may again be said that physical science was encroaching on the domain of mind, being in a certain sense thus enabled to measure the rapidity of thought.
A study, exemplifying in a more than ordinary degree the application of the methods of physical science to the explanation of states of mind, was brought under the notice of the members of the British Association at the last meeting of that body. In the department of Anthropology, or the science investigating the physical and mental constitution of the races of man, Mr Francis Galton, as president of this section, devoted his address to an exposition of the classification or arrangement of groups of men, according to their habits of mind, and their physiognomy.
Of the curious and absorbing nature of such a study nothing need be said. Lavater’s method of pursuing the study of character through the investigation of the features of the human face has long been known. But Lavater’s system is on the whole much too loose and elementary to be regarded as satisfactory by modern scientists, whose repudiation of phrenology as a system capable of explaining the exact disposition of the brain functions, has unquestionably affected Lavater’s method also. Mr Galton refers at the outset of his address to the fact we have already alluded to—namely, that physiologists have determined the rate at which nerve-force, representing a sensation or impulse of thought and action, travels along the nerves. The common phrase ‘as quick as thought’ is found to be by no means so applicable as is generally supposed, especially when it is discovered that thought or nervous impulse, as compared with light or electricity, appears as a veritable laggard. For whilst light travels at the rate of many thousands of miles—about one hundred and eighty-six thousand miles according to the latest researches—in a second of time, nerve-force in man passes along his nerves at a rate varying from one hundred and ten or one hundred and twenty to two hundred feet per second. Or, to use Mr Galton’s words, nerve-force is ‘far from instantaneous’ in its action, and has ‘indeed no higher velocity than that of a railway express train.’
As we could naturally suppose from a consideration of this fact, small animals presenting us with a limited distance for nerve-force to travel, will avoid rapid blows and shift for themselves in the struggle for existence at a much quicker rate than large animals. Take two extreme cases in illustration of this fact. A mouse hears a suspicious or threatening sound, and at once, so to speak, accommodates its actions and movements to its protection. The ear of the mouse, as one of its ‘gateways of knowledge,’ is situated so close to the brain that the interval which elapses between the reception of the sound by the ear, or between its transmission as an impulse to the brain and the issue of a command or second impulse from the brain to the muscles of the body for the purpose of movement, is too short to be perfectly appreciated by the observer. In a whale, on the contrary, which may attain a length of eighty feet, a much longer interval will elapse before action of body follows on nervous impulse, seeing that the nerve-impulse has a longer distance to travel. Assuming that in such animals as the whales the nerve-action travels at the rate of seventy or eighty feet per second, it follows that in a large whale which has been struck near the tail by a harpoon, a second or so will elapse before the impulse is transmitted to the brain, whilst another second will pass before the second impulse is sent from the brain to put the muscles of the tail in action for the purpose of retaliating upon the harpooner. In such a case it is assumed that the brain of the animal will be the nervous centre or station at which information is received, and from which instructions are in turn telegraphed to the various organs and parts of the body. In the actual details of the case, however, it is probable that the spinal marrow of the animal or some part of it would act as the ‘head-office’ for receiving and issuing commands. We know that a headless frog will wipe off with one foot a drop of vinegar that has been placed on the other, and in the absence of the brain we thus assume that the spinal cord may act as a nerve-centre.
Doubtless the spinal marrow discharges this function naturally; and in view of this latter supposition, the interval between the reception of a blow and the muscular actions of an animal would be of less duration than in the case we have just supposed, where the brain is regarded as the central station of the nervous system. As an eminent authority in physical science has remarked, ‘the interval required for the kindling of consciousness would probably more than suffice for the destruction of the brain by lightning, or even by a rifle-bullet. Before the organ (that is, the brain) can arrange itself, it may therefore be destroyed, and in such a case we may safely conclude that death is painless.’
But confining ourselves to the domain of human thought, it seems perfectly clear that the differences between persons of different temperament are in reality referable in great part to the varying rates at which nervous impulses are transmitted through the nerves, and to or from the brain. The difference between a person of phlegmatic disposition and a person of sanguine temperament, may thus be properly enough referred to the varying rates with which sensations and feelings are appreciated and acted upon. Disposition or temperament thus becomes referred, secondarily, to the manner in which and aptitude with which nerves receive and transmit impressions. Primarily, of course, we must refer the exact causes of the quicker or slower transmission of impulses to the constitution of the individual who exhibits them.