60 



ANIMAL CHEMISTRY. 



PART III. 



THE PHENOMENA OF MOTION IN THE ANIMAL ORGANISM. 



I. IT might appear an unprofitable task to 

 add one more to the innumerable forms 

 under which the human intellect has viewed 

 the nature and essence of that peculiar cause 

 which must be considered as the ultimate 

 source of the phenomena which characterize 

 vegetable and animal life, were it not that 

 certain conceptions present themselves as 

 necessary, deductions from the views on this 

 subject developed in the introduction to the 

 first part of this work. The following pages 

 will be devoted to a more detailed examina- 

 tion of these deductions. It must be ad- 

 mitted here, that all these conclusions will 

 lose their force and significance, if it can be 

 proved that the cause of vital activity has 

 in its manifestations nothing in common with 

 other known causes which produce motion 

 or change of form and structure in matter. 



But a comparison of its peculiarities with 

 the modus operand i of these other causes, 

 cannot, at all events, fail to be advantageous, 

 inasmuch as the nature and essence of 

 natural phenomena are recognizable, not by 

 abstraction, but only by comparative obser- 

 vations. 



If the vital phenomena be considered as 

 manifestations of a peculiar force, then the 

 effects of this force must be regulated by 

 certain laws, which laws may be investi- 

 gated ; and these laws must be in harmony 

 with the universal laws of resistance and 

 motion, which preserve in their courses the 

 worlds of our own and other systems, and 

 which also determine changes of form and 

 structure in material bodies ; altogether in- 

 dependently of the matter in which vital 

 activity appears to reside or of the form in 

 which vitality is manifested. 



The vital force in a living animal tissue 

 appears as a cause of growth in the mass, 

 and of resistance to those external agencies 

 which tend to alter the form, structure, and 

 composition of the substance of the tissue 

 in which the vital energy resides. 



This force further manifests itself as a 

 cause of motion and of change in the form 

 and structure of material substances, by the 

 disturbance and abolition of the state of rest 

 in which those chemical forces exist, by 

 which the elements of the compounds con- 

 veyed to the living tissues, in the form of 

 food, are held together. 



The vital force causes a decomposition of 

 the constituents of food, and destroys the 

 force of -attraction which is continually ex- 

 erted between their molecules ; it alters the 

 direction of the chemical forces in such wise, 

 that the elements of the constituents of food 

 arrange themselves in another form, and 

 combine to produce new compounds, either } 

 identi ial in composition with the living tis- 

 sues, or differing from them ; it further 



changes the direction and force of the at 

 traction of cohesion, destroys the cohesion 

 of the nutritious compounds, and forces the 

 new compounds to assume forms altogether 

 different from those which are the result of 

 the attraction of cohesion when acting freely, 

 that is, without resistance. 



The vital force is also manifested as a 

 force of attraction, inasmuch as the new 

 compound produced by the change of form 

 and structure in the food, when it has a 

 composition identical with that of the living 

 tissue, becomes a part of that tissue. 



Those newly-formed compounds, whose 

 composition differs from that of the living 

 tissue, are removed from the situation in 

 which they are formed, and, in the shape 

 of certain secretions, being carried to other 

 parts of the body, undergo in contact with 

 these a series of analogous changes. 



The vital force is manifested in the form 

 of resistance, inasmuch as by its presence 

 in the living tissues, their elements acquire 

 the power of withstanding the disturbance 

 and change in their form and composition, 

 which external agencies tend to produce; a 

 power which, simply as chemical com- 

 pounds, they do not possess. 



As in the case of other forces, the con 

 ception of an unequal intensity of the vita] 

 force comprehends not only an unequal 

 capacity for growth in the mass and an 

 unequal power of overcoming chemical re- 

 sistance, but also an inequality in the amount 

 of that resistance which the parts or con- 

 stituents of the living tissue oppose to a 

 change in their form and composition, from 

 the action of new external active causes of 

 change; just as the force of cohesion or of 

 affinity is in direct proportion to the resist- 

 ance which these forces oppose to any ex- 

 ternal cause, mechanical or chemical, tend- 

 ing to separate the molecules, or the elements 

 of an existing compound. 



The manifestations of the vital force are 

 dependent on a certain form of the tissue in 

 which it resides, as well as on a fixed com- 

 position in the substance of the living tissue. 



The capacity of growth in a living tissue 

 is determined by the immediate contact with 

 matters adapted to a certain decomposition, 

 or the elements of which are capable of be- 

 coming component parts of the tissue in 

 which vitality resides. 



The phenomenon of growth, or increase 

 in the mass, presupposes that the acting 

 vital force is more powerful that the resis' 

 ance which the chemical force opposes to 

 the decomposition or transformation of the 

 elements of the food. 



The manifestations of the vital force are 

 dependent, on a certain temperature. Neither 

 in a plant nor in an animal do vital phe 



