5 66 THE POPULAR SCIENCE MONTHLY. 



lated, equilibrated influences which constitute its real wealth, its 

 source of power, its store of potential energy, whence all its perform- 

 ances emanate. 



In the execution of vital motion matter is to some extent " con- 

 sumed." During expansion it is consumed taken up by the expand- 

 ing substance at the cost of the medium. During contraction it is 

 consumed taken up by the medium at the cost of the contracting sub- 

 stance. 



Now, in conformity with the prevailing one-sided view of motility, 

 which attributes the entire phenomenon to so-called contractility, it is 

 generally supposed that the force displayed during living motion is 

 derived exclusively from the consumption of matter on the part of the 

 medium ; and it is also generally supposed that this consumption con- 

 sists in a process of oxidation. Oxidation, it is said, generates a cer- 

 tain amount of heat ; this heat is the real motor power in the case. 



It does not much affect the bearings of this view whether the oxi- 

 dizing material be derived, as some maintain, from the contracting 

 substance itself, or whether, as others think, it be derived from food- 

 ingredients. The combustion of matter, with accompanying evolution 

 of heat, is deemed to be the true source of power; and the contracting 

 substance the muscular fibres in higher animals are stated to be 

 playing merely the part of machinery. 



Thus viewed, the problem of life may be considered altogether hope- 

 less. The organism then represents nothing but a force-directing en- 

 gine, in which the combustion of compounds previously put together 

 in vegetables constitutes the actual driving force. Vital manifesta- 

 tions, accordingly, can be only due to the action of the force liberated 

 from vegetable compounds and applied to the organic machinery. 

 Poor Science, of all-powerful vitality, thou art very young yet, and 

 amazingly unconscious withal ! 



The moving substance, the protoplasm, plays just so much or just 

 so little the part of machinery as the steam does in the steam-engine. 

 The substance H 2 in a calorific medium from about 32 to 212 Fahr., 

 under ordinary atmospheric pressure, occupies a certain space. In a 

 calorific medium above 212, under the same pressure, it occupies an 

 enormously larger space. This specific property of filling such different 

 spaces, under these different thermal conditions, is the very source of its 

 power of that motor power which sets the engine going. Whoever 

 wishes to become fully convinced of the fact that it is not the heat of 

 combustion, but the specific expansibility and contractility of H 2 0, by 

 which the engine is driven, may just throw, instead of so much H 2 0, a 

 proportionate weight of Au into the boiler. 



If this remark should happen to appear far too commonplace for 

 the purposes of scientific illustration, I can merely state in defense of 

 it that, perhaps, in pondering over its meaning, the reader will find 

 himself initiated into a deeper view of force than is usually accepted. 



