222 INTERACTION OF NATURAL FORCES. 



some time ago the industrial world of Europe in excitement. 

 The magneto-electric machines often made use of in the case 

 of rheumatic disorders are well known to the public. By 

 imparting a swift rotation to the magnet of such a machine, 

 we obtain powerful currents of electricity. If those be con- 

 ducted through water, the latter will be reduced into its two 

 components, oxygen and hydrogen. By the combustion of 

 hydrogen, water is again generated. If this combustion takes 

 place, not in atmospheric air, of which oxygen only consti- 

 tutes a fifth part, but in pure oxygen, and if a bit of chalk be 

 placed in the flame, the chalk will be raised to a white heat, 

 and give us the sun-like Drummond's light. At the same 

 time, the flame develops a considerable quantity of heat. 

 Our American proposed to utilize in this way the gases 

 obtained from electrolytic decomposition, and asserted that by 

 the combustion a sufficient amount of heat was generated to 

 keep a small steam engine in action, which again drove his 

 magneto-electric machine, decomposed the water, and thus 

 continually prepared its own fuel. This would certainly have 

 been the most splendid of all discoveries ; a perpetual motion 

 which, besides the force which kept it going, generated light 

 like the sun, and warmed all around it. The matter was by 

 no means badly cogitated. Each practical step in the affair 

 was known to be possible ; but those which at that time were 

 acquainted with the physical investigations which bear upon 

 this subject could have affirmed, on the first hearing the 

 report, that the matter was to be numbered among the numer- 

 ous stories of the fable-rich America ; and indeed, a fable it 

 remained. 



It is not necessary to multiply examples further. You 

 will infer from those given, in what immediate connection 

 heat, electricity, magnetism, light, and chemical affinity, stand 

 with mechanical forces. 



Starting from each of these different manifestations of 

 natural forces, we can set every other in motion, for the most 



