12 



several useful considerations, immediately applicable to the knowledge 

 of man. 



The first remarkable difference between organized and inorganized 

 bodies, is to be found in the homogeneousness of the latter, and the com- 

 pound nature of the former. Let a block of marble be broken, each 

 piece will be perfectly similar to the rest, there will be no differences 

 among- them, but such as relate to size or shape. Break down the frag- 

 ments, each grain will contain particles of carbonate of lime, which will 

 be throughout the same. On the other hand, the division of a vegetable 

 or an animal, shows parts heterogeneous or dissimilar. In different 

 parts there will be found muscles, bones, arteries, blossoms, leaves, 

 bark, pith, Sec. 



Organized beings cannot live or exist in their natural condition, unless 

 solids and liquids enter at once into their composition. The co-existence 

 of these two elements is necessary; and living bodies always contain a 

 liquid mass more or less considerable, and incessantly agitated by the 

 motion of the solid and living parts. It is in fact impossible to conceive 

 life existing, without a complicated combination of solids and fluids ; and 

 xvithout admitting in the former, the faculty of being affected by impressions 

 from the latter, and the power of acting in consequence of those impres- 

 sions. The water which penetrates into mineral substances, does not 

 form a necessary part of them, and one cannot adduce in proof of the 

 existence of liquids in that class of substances, the water of crystalliza- 

 tion, though intimately combined, and rendered solid in the crystallized 

 substances. 



These inorganic and homogeneous substances, formed of particles simi- 

 lar to one another, when resolved by decomposition into their last ele- 

 ments, possess a great simplicity of inward nature. Among them are 

 ranked all the substances which do not admit of analysis; the mineral 

 compounds are often binary, as the greater part of saline substances; 

 sometimes they are ternary, but seldom quaternary; while the most sim- 

 ple vegetable contains at least three constituent principles, oxygen, hy- 

 drogen, and carbon, and no being possessed of life, consists of less than 

 four, oxygen, hydrogen, carbon and azote. In the degree of composition, 

 nature appears therefore to rise in gradations, from the mineral to the 

 vegetable, and from the latter to the animal kingdom. The complicated 

 nature of die latter, and the multiplicity of their elements account for their 

 tendency to alteration. Minerals are not subject to change, unless they 

 are acted upon by external causes. Endowed with a vis inertiae, they 

 continue in one. condition without change. The state of organized bodies 

 is incessantly varying. Their internal parts contain an active laboratory, 

 in which a number of instruments are constantly transforming into their 

 own substance, nutritious particles. Besides that tendency to alteration 

 in living animals and vegetables, when deprived of life, they become de- 

 composed, by a process of fermentation, which begins in their internal 

 parts, and by which their nature is changed in proportion to the com- 

 plication of iheir structure, and the greater number and volatility of their 

 constituent principles. 



All the parts of a living body, whether of an animal or a vegetable, 



Jlnimals Have the power of locomotion. Have azote for the base of their composi- 

 tion. Often composed of eight or ten elements. Are forced to act on their aliment to 

 fit it for nourishing 1 them. - 



