



vital powers are distinct and strong, and differ from those of the more 

 perfect animals and of man, by very slight shades: thehean and the ves- 

 sels of the fish feel and act with him, without his consciousness. Further, 

 he has senses, nerves, and a brain, from which he has intimation of what- 

 ever can affect him; muscles and hard parts, by the action of which he 

 moves, and changes his place, adapting himself to the relations that 

 subsist between the substances around him and his own peculiar mode of 

 existence. 



We are come, ai last, to the red and warm-blooded animals, at the head 

 of which are the manuiiiferse and man. They are entirely alike, save 

 some slight differences in the less essential organs. There is none that 

 has not the vertebral column, four limbs, a brain which fills, exactly, the 

 cavity of the skull, a spinal marrow, nerves of two sorts, five senses, mus- 

 cles, partly obedient to the will, partly independent in their action; add 

 to these a long digestive tube coiled upon itself, furnished at its mouth 

 with agents of saliva and mastication : vessels and lymphatic glands, ar- 

 teries and veins, a heart with two auricles, and two ventricles, tabular 

 lungs, which must act incessantly in impregnating the blood, that passes 

 through them, with the vital part of the atmosphere*, which if it fail, life 

 is suspended or gone. None of their organs live, but while they partake 

 in the general action of system, and while they are under the influ- 

 ence of the heart. All die, irrecoverably, when they are parted from the 

 body of the animal, and are in no way replaced ; whatever some physio- 

 logists may have said on pretended regeneration of the nerves and some 

 other pans. 



Every thing that is important to life, is to be found in these animals; 

 and as the most essential organs are within, and concealed in deep cavi- 

 ties, a celebrated naturalist was correct in saying, that all animals are es- 

 sentially the same, and that their differences are in their external parts, 

 and chiefly to be observed in their coverings and in their extremities. 



The human body, consisting of a collection of liquids and solids, con- 

 tains of the former, about five-sixths of its weight. This proportion of 

 the liquids to the solids, may, at first sight, appear to you beyond the 

 the truth; but consider the excessive decrease of size of a dried limb; 

 the glutseus maxinnfs, for example, becomes, by drying, no thicker than 

 a sheet of paper. The liquids which constitute the greatest weight of 

 the body, exist before the solids; for the embryo, which is at first in a 

 gelatinous state, may be considered as fluid ; besides, it is from a liquid 

 that all the organs receive their nourishment and repair their wastes. 

 The solids, formed from the liquids, return to their former state, when, 

 having for a sufficient length of time, formed a part of the animal, they 

 become decomposed by the nutritive process. Even from this slight 

 view of the subject, fluidity is seen to be essential to living matter, since 

 the solids are uniformly formed from the fluids, and eventually return to 

 their former state. Solidity is then only a transient condition and an ac- 

 cidental state of organized and living matter, and this circumstance 

 affords to the humoral pa,thologists ample opportunities of embarrassing 

 their opponents with many objections not easily answered. Water forms 

 the principal part and the principal vehicle of all the animal fluids, it con- 



* Late experiments have shown that a different process takes place in the lungs. See 

 CHAPTER or RESPIRATION. 



