348 ■ Tranfmijion of Galvanic EkBricity through Charcoal. 



conceive why fuch a length of time was required for the produftion of the inflammable gaSi 

 When I introduced charcoal conne£ted with the izinc fide, and fiiver wire conneded with 

 the filver fide, into boiled water, gas was almoft immediately given out from the wire ; 

 though when I conne£ted filver with the zinc fide, and charcoal with the filver fide, no 

 gas was liberated for many minutes. 



4. A flip of charcoal was connedted with the zinc end, and a filver wire with the 

 filver end, and both plunged into a veflel of lime water. Gas was immediately given out 

 from the filver wire; a few globules only formed round the charcoal: they were ap- 

 parently covered with a white cruft. As the procefs advanced, white clouds fell from the 

 charcoal, and difFufcd themfelves through the fluid. 



5. Two pieces of charcoal were connefted with the ends of the jhIc, and plunged into 

 a ftrong folution of cauftic pot-afli. During two hours no gas was given out from either 

 of the pieces, and no change of colour was perceived in the fluid, though the com- 

 munication was perfe£b. When a filver wire was connefted with the zinc, and charcoal 

 with the filver, gas was produced from the wire, but none from the charcoal. When charcoal 

 was connefted with the zinc, and filver wire with the filver, gas was very rapidly pro- 

 duced round the point of the wire; but not an atom formed round the charcoal. 



6. When the- flips of charcoal connected with the pile were introduced into folution of 

 ammoniac, gas was given out from the zinc charcoal ; but none from the filver charcoal. 

 When filver wire was connefted with the filver fide, the charcoal being Hill connedled 

 with the zinc fide, gas was given out from both, but moft rapidly from the wire. Thefe 

 gafes were caught and examined. That from the charcoal gave no diminution with 

 nitrous gas. An accident prevented me from examining it by other tefts ; the gas from 

 tfee filver equalled twenty times the volume of the other gas, and appeared to be pure 

 hydrogen. 



I {hall, at prefent, ofl^cr no theoretical conjeGures concerning thefe experiments. The 

 two laft will probably lead to interefting conclufions. I am, at this moment, engaged 

 in examining fmall quantities of folution of pot-afli and ammoniac which have been 

 long galvanifed in contact with charcoal: the refuk of this examination, if at all im- 

 portant, I (hall take the liberty of communicating to you at fome future time. 

 * I remain, 



SIR, 



Very refpeftfully, 



Your's, &c. 



HUMPHRY DAVY. 

 Detury Square, Hetivells, Sept. 22, 1800. 



SCIENTIFIC 



