Page:Popular Science Monthly Volume 1.djvu/720

 704 the flavors and pleasing odors of food have the same effect. Hence we see their importance as means of promoting digestion.

The extract of meat belongs to the class of condiments. It first gratifies the palate, and then produces important results in the stomach. This is not due to the nutritive salts it contains, nor to any special effect it produces on absorption or nutrition. If an animal gets for food only extract of meat, it will succumb more quickly than if no food at all were given, as was demonstrated by Kemmerich in the case of a dog. We may account for this either on the supposition that the salts accelerate the transformation of albumen, or that the potash of the extract acts injuriously on the heart. Therefore, when vessels, fortresses, armies, and hospitals, are supplied with this meat-extract, they obtain what we must regard as an excellent condiment; but that will not supply the place of a single grain of the nutritive elements; and in this regard it is analogous to table-salt, coffee, tobacco, etc. Nevertheless, we cannot question the beneficial effect of a good meat-broth upon the stomach, whether in health or in sickness. Especially does it produce a good effect in the case of convalescents whose stomach is in a chronic state of debility. They cannot retain common food, except it is given to them in the shape of broth. Just as the excitation of the mucous membrane of the mouth has an effect upon the stomach, so, probably, the stomach acts upon the intestine. Thus, for instance, soon after the stomach is filled, we find the pancreas addressing itself to its function.

There are some condiments the effects of which are not at first local. They act only after having been absorbed, and their action is then perceptible in the central nervous system. This is the case, for instance, with coffee, tea, tobacco, alcoholic drinks, etc., the general action of which is well known. It has been supposed that we have here an arrest of decomposition, an economy of nutritive material. In fact, we have only another mode of arrangement or of change in the inward phenomena. The amount of work of which a man is capable depends very much upon his momentary disposition. With equal nutritive transformations, and with equal production of living force, the man who undertakes a work under favorable moral conditions will perform it more easily than another who happens to be oppressed and weighed down by some affliction. A stroke of the whip causes a horse to surmount an obstacle, before which he would have stood still without that stimulus; and yet the latter does not communicate to him any force; it only induces him to exert the force he already possessed. It is thus that condiments act upon certain determinate parts of our nervous centre, and so enable us to attain our ends. We may regard as of similar nature to this the action of opium or of musk, under the influence of which a man, who before was perfectly powerless, appears to get new life, without any demonstrable elementary change having taken place in his body. The same is to be said