Volume 1

A history of the earth, and animated nature / By Oliver Goldsmith. With an introductory view of the animal kingdom, tr. from the French by Baron Cuvier. And copious notes embracing accounts of new discoveries in natural history: And a life of the author by Washington Irving. And a carefully prepared index to the whole work.

  • Oliver Goldsmith
Date:
1847
Catalogue details

Licence: Public Domain Mark

Credit: A history of the earth, and animated nature / By Oliver Goldsmith. With an introductory view of the animal kingdom, tr. from the French by Baron Cuvier. And copious notes embracing accounts of new discoveries in natural history: And a life of the author by Washington Irving. And a carefully prepared index to the whole work. Source: Wellcome Collection.

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    arrangement also permits the accumulation of force upon one point; for a great number of muscular fibres are employed to contract one tendon, in the same manner several horses may be employed to draw the same rope. The peculiar shape observable in the articulated surfaces of the hard parts confine the motions of the tendons within certain limits, and they are still further restrained by cords or envelops, usually called ligaments, attached to the sides of the articula- tions. Animals become enabled to execute the innumerable motions involved in the exercise of walking or leaping, flying or swimming, according as the bony and mus- cular appendages are adapted for these various motions; and also, according to the relative forms and proportions which the limbs, in consequence, bear among them- selves. Nutrition, which we shall now explain, forms the first of the vegetative functions. The muscular fibres connected with digestion and circulation are not influenced by the will, but, on the contrary, as we have already explained, their principal arrangements and subdivisions appear to be specially intended to render the animal completely unconscious of their exercise. It is only when the mind is disturbed by violent passions, or paroxysms, that its influence is extended beyond the ordinary limits, and that it agitates these functions common to vegetable life. Sometimes, when the organs are diseased, their exercise is accompanied by sensation; but, in ordinary cases, digestion and circulation are performed without the consciousness of the animal. The aliment is first masticated, that is, minutely divided by the jaws and teeth, or sucked in, when taken by the animal in a liquid form. It is then swallowed en- tirely by the muscular action of the back parts of the mouth and throat, and deposited in the first portions of the alimentary canal, Avhich are usually expanded into one or more stomachs, where the food is penetrated and dissolved by corrosive juices. This gastric juice possesses the very remarkable property of dissolving most animal and vegetable matters, when deprived of life, and some mineral substances. It more especially acts upon such as yield nutriment to the animal, and are adapted to its general habits and formation. When recently procured from the stomach of a healthy animal, it appears as a clear mucilaginous fluid, slightly salt to the taste. Substances, when undergoing fermentation or putrefaction, are immediately checked in their action by the gastric juice, and are formed by its corrosive influence into a new fluid, possessed of entirely difierent properties, called chyme. But most mineral substances are indigestible. Certain tribes of savages, as the Otomacs, will, however, swallow daily large quantities of earth to allay the cravings of hunger. But this substance does not appear to be dissolved; it merely acts mechanically in distending the stomach. The higher region of the alimentary canal is occupied by the stomach, which receives the food conveyed to it through the oesophagus or gullet. The form and structure of the stomach bear a constant relation to the nature of the food. In herbivorous animals, it is composed of a complicated system of reservoirs, where, by a slow and intricate process, the small quantity of nutriment con- tained in vegetable matter is abstracted and conveyed into the system. In carnivorous animals, the stomach is comparatively simple; and a supply of abundant nourishment is readily procured from animal food. After passing through the stomach, the food is received into the remaining part of the canal, where it is acted upon by other juices destined to complete its preparation. The chyme formed in the stomach having passed into the intestine, comes in contact with the bile and the pancreatic juice. An immediate change takes place. The chyme acquires the yellow colour and bitter taste of bile, and at length divides into two portions; the one, a white tenacious liquid called chyle, and the other, a yellow pulp. The coats of the intestinal canal are supplied with pores, which imbibe that portion of the alimentary mass adapted for the nutrition of the body [being the chyle], while the useless residue is finally conveyed away and ejected. The canal in which this first function of nutrition is performed, appears to be a continuation of the skin, and it is composed, in a similar manner, of laminjB. Even the surrounding fibres are analogous to those adhering to the internal surface of the skin, and called the fleshy pannicle. A mucous secretion takes place throughout this canal, which seems to have some connexion with the perspiration from the surface