SCIENCE AND MAN 365 



the Voltaic battery. The body, in other words, falls into 

 the category of machines. 



We can do with the body all that we have already 

 done with the battery heat platinum wires, decompose 

 water, magnetize iron, and deflect a magnetic needle. 

 The combustion of muscle may be made to produce all 

 these effects, as the combustion of zinc may be caused to 

 produce them. By turning the handle of a magneto- elec- 

 tric machine a ,coil of wire may be caused to rotate be- 

 tween the poles of a magnet. As long as the two ends of 

 the coil are unconnected we have simply to overcome the 

 ordinary inertia and friction of the machine in turning the 

 handle. But the moment the two ends of the coil are 

 united by a thin platinum wire a sudden addition of labor 

 is thrown upon the turning arm. When the necessary 

 labor is expended, its equivalent immediately appears. 

 The platinum wire glows. You can readily maintain it 

 at a white heat, or even fuse it. This is a very remark- 

 able result. From the muscles of the arm, with a temper- 

 ature of 100, we extract the temperature of molten plati- 

 num, which is nearly four thousand degrees. The miracle 

 here is the reverse of that of the burning bush mentioned 

 in Exodus. There the bush burned, but was not con- 

 sumed: here the body is consumed, but does not burn. 

 The similarity of the action with that of the Voltaic bat- 

 tery when it heats an external wire is too obvious to need 

 pointing out. When the machine is used to decompose 

 water, the heat of the muscle, like that of the battery, is 

 consumed in molecular work, being fully restored when 

 the gases recombine. As before, also, the transmuted heat 

 of the muscles may be bottled up, carried to the polar re- 

 gions, and there restored to its pristine form. 



