SCIENTIFIC MA TEIUA LISM. 405 



You will notice that I am stating the truth strongly, as 

 at the beginning we agreed it should be stated. But I 

 must go still further, and affirm that in the eye of science 

 the animal body is just as mucli the product of molecular 

 force as the chalk and the ear of corn, or as the crystal of 

 salt or sugar. Many of the parts of the body are obviously 

 mechanical. Take the human heart, for example, with its 

 system of valves, or take the exquisite mechanism of the 

 eye or hand. Animal heat, moreover, is the same in kind 

 as the heat of a fire, being produced by the same chemical 

 process. Animal motion, too, is as certainly derived from 

 the food of the animal, as the motion of Trevethyck's 

 walking-engine from the fuel in its furnace. As regards 

 matter, the animal body creates nothing; as regards force, 

 it creates nothing. Which of you by taking thought can 

 add one cubit to his stature? All that has been said, then, 

 regarding the plant, may be restated with regard to the 

 animal. Every particle that enters into the composition 

 of a nerve, a muscle, or a bone has been placed in its posi- 

 tion by molecular force. And unless the existence of law 

 in these matters be denied, and the element of caprice in- 

 troduced, we must conclude that, given the relation of any 

 molecule of the body to its environment, its position in the 

 body might be determined mathematically. Our difficulty 

 is not with the quality of the problem, but with its com- 

 plexity; and this difficulty might be met by the simple 

 expansion of the faculties we now possess. Given this 

 expansion, with the necessary molecular data, and the chick 

 might be deduced as rigorously and as logically from the 

 egg, as the existence of Neptune from the disturbances of 

 Uranus, or as conical refraction from the undulatory theory 

 of light. 



You see I am not mincing matters, but avowing nakedly 

 what many scientific thinkers more or less distinctly believe. 

 The formation of a crystal, a plant, or an animal, is, in 

 their eyes, a purely mechanical problem, which differs from 

 the problems of ordinary mechanics, in the smallness of 

 the masses, and the complexity of the processes involved. 

 Here you have one half of our dual truth; let us now 

 glance at the other half. Associated with this wonderful 

 mechanism of the animal body we have phenomena no less 

 certain than those of physics, but between which and the 

 mechanism we discern no necessary connection. A man, 



