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.

    38/660
    of the skin; for, when the latter is suppressed, the former becomes more abundant. The skin exercises a power of absorption very much resembling that possessed by the intestines. The whole length of the intestinal canal is much greater in herbivorous than in carnivorous animals. It is only in the very lowest tribes of animals that the same orifice is applied to the double purpose of receiving fresh supplies of aliment, and of ejecting the sub- stances unfitted for nutrition. Their intestines assume the appearance of a sack with only one entrance. But in a far greater number of animals, having the intestinal canal supplied with two orifices, the nutritive juice [or chyle] is absorbed through the coats of the intestines, and immediately diffused [by the lacteals] through all the pores of the body. This arrangement appears to belong to the entire class of insects. If we commence from the arachnides [or spiders] and the worms, and then examine all animals higher in the scale of creation, it Avill be found that the nutritive fluid circulates through a system of cylindrical vessels; and that it only supplies the several parts requiring nourishment by means of their ramified extremities [or lacteals], through which the nutriment is deposited in the places requiring sustenance. These vessels, which distribute the nutritive fluid or blood to all parts of the body, receive the name of arteries. Those, on the contrary, are called reins, which restore the blood to the centre of the circulating system. This motion of the nutritive fluid is sometimes performed simply in one circle; often there are two circular motions, and even three, if we include that of the rena-portce [which collects the blood of the intestines, and conveys it to the liver]. The velocity of its motion is frequently assisted by certain fleshy organs called hearts, which are placed at some one centre ot circulation, often at both. In the vertebrated and red-blooded animals, the nutritive fluid, or chyle, leaves the intestines either white or transparent; and is conveyed into the venous system, by means of particular vessels called lacteals, where it mixes with the blood. Other vessels similar to the lacteals, and composing with them one arrangement, called the lymphatic system, convey into the venous system those nutritive particles which have either escaped the lacteals, or have been absorbed through the cuticle or outer skin. Before the blood is fitted to renovate the substance of the several parts of the body, it must receive, from the surrounding element, through the medium of respira- tion, that modification which we have already noticed. One part of the vessels belonging to those animals, which possess a circulating system, is destined to convey the blood to certain organs, where it is distributed over a large extent of surface, in order that the action of the surrounding element may be the more energetic. When the animal is adapted for breathing the air, this organ is holloAV, and called lungs. But when the animal only breathes [the air dissolved] in water, the organ projects, and is called branchioe, or gills. Certain organs of motion are always arranged so as to draw the surrounding element either within or upon the organ of respiration. In animals which do not possess a circulating system, the air penetrates into every part of the body, through elastic vessels called tracheae; or else water acts upon them, either by penetrating, in a similar manner, through vessels, or simply by being absorbed through the surface of the skin. In Man, respiration is performed by means of the pressure and elastic force of the air, which rushes into the lungs, where a vacuum would otherwise have been formed by the elevation of the ribs, and the depression of the diaphragm. Muscular force then expels the air, after the necessary purification of the blood existing in the lungs has been performed ; and the same actions are again repeated. The blood, which was of a dark purple colour, while slowly travelling from all parts of the body to the heart, has no sooner been purified by yielding its excess of carbonic acid to the surrounding air, and by absorbing oxygen, than its colour changes into a bright vermilion. In Birds, it was necessary to combine lungs of small bulk with an extensive aeration of the blood ; and, accordingly, the blood not only passes into the lungs, but through them into capacious air cells; from which, by the action of the chest, it is again expelled. The lungs thus act twice upon the same portion of air. The change of the tadpole into the frog is accompanied by extraordinary alterations in its respira-