Page:Popular Science Monthly Volume 2.djvu/423

Rh from increasing, in all possible ways, the amount of meat used in laborers' meals. Quite recently, at a manufacturing establishment of the Tarn, M. Talabot has improved the strength and sanitary condition of his workmen by giving them meat in abundance. Under the influence of a diet almost wholly vegetable, each laborer lost on an average fifteen days work a year through fatigue or sickness. As soon as the use of meat was adopted, the average loss for each man per year was not over three days. Often enough, it must be owned, alcohol is only the workman's means of remedying the want of heat-producing elements in his food; a deceitful remedy, which buoys up the system for a time, only to sap it afterward with alarming subtlety. One of the best preventives of the abuse of alcohol would certainly be the lessening of the cost of meat.

From the point of view of the relation between heat and motion, the living being may thus be compared to an inanimate motor, as a steam-engine. In both cases, heat is engendered by combustion, and transformed into mechanical work by a system of organs more or less complex. In both cases it is at first in a state of tension, and yields motion in proportion as it is demanded for the performance of certain work. Only the living being is the far more perfect machine. While the best-made steam-engines only utilize $12/100$ of the disposable force, the muscular system of man, according to Hirn, accounts for $18/100$. On the other hand, the animated motor has this peculiarity, that its sources of heat and its mechanical arrangements are intimately commingled, that its heat is produced by organs in motion with a sort of general diffusion, and that the machine itself becomes in turn transformed within itself into heat; an incredible complication, of which science has succeeded in unravelling the simple laws only by dint of the united efforts and resources of physics, chemistry, and biology.

As some physiologists hold, heat must not only be the source of motion in the system, but must also undergo transformation into nervous activity. The functional action of the brain must be a labor, exactly like that of the biceps. Mind itself should be regarded as engendered by heat. Late experiments by Valentin, Lombard, Byasson, and especially Schiff, would seem to prove, it is thought, that there is a proportional and constant relation between the energy of nervous functions and the heat of the parts in which they are effected. Gavarret boldly concludes, from his researches, that heat has the same relations to the nervous system that it has to the muscular system; only, in the case of the muscles, the force produced exhibits itself externally by visible phenomena, while in that of the nerves it is exhausted internally in profound molecular action, which eludes any exact measurement. A given sum of heat developed in the system would thus be on one side a mechanical equivalent, and on the other a psychological equivalent. Gavarret, who is a cautious savant and true to experimental methods, doubtless does not go so far as to maintain that