462 Miscellaneous Intelligence, 



hole throui^h the side of the generator, which was accordingly done. 

 After getting the steam up to a proper temperature, I took out the 

 plug, and although we were working the engine at thirty atmos- 

 pheres, nothing was seen or heard to issue from the plug-hole ; all 

 was perfectly quiet : I next lowered the temperature by shutting 

 the damper, and opening the furnace door; a singing from the 

 aperture was soon observable, and when a coal was, held before it, 

 rapid combustion ensued; nothing, however, was yet visible : but as 

 the temperature decreased, the steam became more and more visi- 

 ble, the noise at the same increasing, until finally the roar was tre- 

 mendous, and might have been heard the distance of half a mile. 

 This was conclusive. I should mention that, at the aperture, the 

 iron was red-hot." " The hole was one quarter of an inch in dia- 

 meter." 



"The experiment affords some data towards answering the ques- 

 tion, at what distance from the heated metal the water remained, 

 when under the pressure of thirty atmospheres ; we may safely aver 

 that it exceeded one-eighth of an inch." — Silliman's Journal, \iu. 46. 



2. On the Use of feeble Electric Currents, for effecting the Com- 

 hifiation of numerous Bodies, by M. Becquerel. — A highly interest- 

 ing memoir on this subject is inserted in the thirty-fifth volume of the 

 Annates de Chimie, the intention of M. Becquerel being to show 

 that electro-chemical powers may be used not only for the decom- 

 position and analysis of bodies, but also for the production of new 

 compounds. * 



The facts described in the paper are commenced by one in- 

 tended to illustrate future reasoning, by shewing what takes place 

 when a very feeble electric current traverses a metallic circuit, in- 

 terrupted in one part by a neutral solution, into which the two ex- 

 tremities of the wires forming the circuit are immersed. Two 

 small copper wires were connected together by loops, and the two 

 free ends joined to the ends of a galvanometer wire; the circuit 

 was then cut in one place, and th« extremities immersed in a solu- 

 tion of chloride of sodium. Then, if one of the loops be raised to a 

 red heat by a spirit lamp, an electric current is produced, the heated 

 loop furnishing negative electricity. Now if the ends plunged 

 in the saline solution are terminated by platina or gold wires, 

 710 current of electricity is observed; with silver terminations, 

 the current is very feeble ; but with wires of zinc, lead, iron or tin, 

 the current is very energetic. These remarkable effects, highly 

 important in the phenomena hereafter to be considered, are no way 

 connected with the conductibility of the metals ; for lead and zinc, 

 which are the worst conductors, are those which, with the copper, 

 produce the most powerful effects. The current ceases altogether 

 as soon as the lamp is removed. 



As the zinc, copper, lead, and iron, belong to the class of oxida- 

 ble metals, M. Becquerel concludes, from this experiment, that 



