1824.] Conductors xohen transmitting the Electric Current. 279 



1,600,000; 700,000; and 1000; or 1600, 700, and 1. The 

 effect being purely mechanical, even the intensity of the motive 

 forces exerted on a molecule of one of these metals could be 

 determined, did we know the law of its action — but at least, in 

 our ignorance of this, we are sure that it must be incomparably 

 superior to gravity. A mass of mercury an inch in diameter 



alloyed with , nn „ ■ its weight of zinc, revolved with a motion so 



J 100,000 ° 



rapid as to complete the transfer of particles floating in the liquid 

 in less than a second across its surface. Now, even if we were 

 to take the supposition of a uniform acceleration of the motion 

 of a molecule from one end to the other of this transfer, the 

 intensity of gravity being taken at unity, that of the force 

 accelerating each particle of the alloy would amount to 



.r <• .' nC ,,»>. = , , c = 0-00521, and each particle of zinc being 



16 feet x (1 )" 12x16 * ° 



loaded with 100,000 times its weight of inert matter, the inten- 

 sity of the force, acting on its molecules, cannot possibly be so 

 little as 521 times their gravity. But it is in all probability 

 immensely greater. So far from being uniformly accelerated 

 along their whole course, the molecules, if narrowly watched, 

 will be evidently seen to move with less and less velocity as they 

 recede from their point of radiation ; and it is assuming little to 

 suppose their velocity at a hundredth of an inch from this point 

 double of their mean velocity with which they traverse the 

 diameter. To produce this effect, the force must (if supposed to 

 act uniformly through this small space) be increased 100 fold, 

 or to an intensity upwards of 50,000 times that of gravity. Such 

 considerations tend, if I mistake not, greatly to enlarge our 

 views of nature, and to prepare us for the admission of the most 

 extravagant numerical conclusions respecting bodies less within 

 the reach of our senses. That such minute proportions of 

 extraneous matter should be found capable of communicating 

 sensible mechanical motions, and properties of a definite 

 character, to the body they are mixed with, is perhaps the most 

 extraordinary fact that has jet appeared in chemistry. When 

 we see energies so intense exerted by the ordinary forms of 

 matter, we may very reasonably ask, what evidence we have 

 for the imponderability of any of those powerful agents to which 

 so large a part of the activity of material bodies seems to be 

 owing ? 



40. I was anxious to examine whether similar motions would 

 be produced in other metals than mercury and its alloys, when 

 in fusion. The foregoing experiments, indeed, leave little room 

 to doubt their capability to do so ; but the nature of the case 

 throws great difficulties in the way of direct experiment. I have 

 been successful hitherto only in the case of the fusible alloy of 

 lead, tin, and bismuth, no mercury being present. This, with a 



