34 PHILOSOPHY OF ZOOLOGY. 
commencement of life, and to the exercise of its func- 
tions, let us now attend to some of the phenomena present- 
ed by organized bodies during the continuance thereof. 
When all the organs are in such a degree of perfection as 
to be able, easily and durably, to perform the functions of 
life, the body is said to be in a state of Health. The an- 
cients recognized a Goddess, who was supposed to preside 
over this condition, whom the Greeks termed ‘Yyee, and the 
Romans Salus. 
When we consider the situation in which orgamzed bo- 
- dies are placed on the surface of the globe, the changes 
which take place in the quantity and nature of their food, | 
the variations in the temperature of the surrounding ele- 
ments, besides the occurrence of an infinite variety of acci- 
dents,—all calculated to retard or derange their motions, 
we may expect to find many individuals, in which the har- 
mony between:the different parts is interrupted, and the 
functions of particular organs suspended,—producing a con- 
dition the opposite of health, termed Disease. 'The unin- 
terrupted influence, indeed, of external objects, acting 
either directly or indirectly, precludes the possibility of an 
organized body enjoying perfect health for any length of 
time. These obstacles, however, are in part removed, by 
the power which each individual possesses of accommoda- 
ting itself to circumstances; of varying, within a certain 
range, its form, structure, and actions; of repairmg imju- 
ries ; and of continuing to live, though in part mutilated. 
Such displays of the vital power are familiar to the Phy- 
sician, and constitute the very basis of the healing art. 
Besides the destructive influence of external objects, we 
may refer many of the diseases which assail organized. bo- 
dies, to some imperfection or derangement of the vital 
principle itself. This is obviously the case, when an. organ 
