H. Helmholtz on the Interaction of Natural Forces. 197 



ter, 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 oxj^gen only constitutes 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 Drum- 

 mond's light. At the same time the flame develops a considera- 

 ble quantity of heat. Out American proposed to utili^^e in this 

 way the gases obtained from electrolytic decomposition, and as- 

 serted, 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 mo- 

 tion which, besides the force that 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 who at that time were ac- 

 quainted with the physical investigations which bear upon this 

 subject, could have affirmed, on first hearing the report, that the 

 matter was to be numbered among the numerous 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 connexion heat, elec- 

 tricity, magnetism, light, and chemical a£B.nity, stand, with me- 

 chanical forces. 



Starting from each of these different manifestations of natural 

 forces, we can set every other in motion, for the most part not 

 in one way merely, but in many ways. It is here as with the 

 weaver's web, 



Where a step stirs a thousand threads, 



The shuttles shoot from side to side, 



The fibres flow unseen, 



Antl one shock strikes a thousand combinations * 



Now it is elear that if by any means we could succeed, through 

 mechanical forces, as the above American professed to have done, 

 to excite chemical, electrical, or other natural processes, which, 

 by any circuit whatever, and without altering permanently the 

 active masses in the machine, could produce mechanical force in 

 greater quantity than that at first applied, a portion of the work 

 thus gained might be made use of to keep the machine in mo- 

 tion, wliile the rest of the work might be applied to any other 

 purpose whatever. The problem was to find, in the complicated 



* " Wo ein Tritt tausend FaJea regt, 



Die Schifflein heriiber liiniiber schiessen, 



Die Fiiden ungesehen fliessen, 



Em Sclilag tausend Verbindungen sclilagt.'* 



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