Computation of a charged Surface equivalent to the Pile; •^5 



of the condcnfer, which was the fame as that of the pile itfelf, was, therefore, fo many 

 times* lefs than that of the cledrometcrj that is to fay, its fpark was I'y x -j-ss-s 

 — rri^'s of an inch. 



Our jar of one foot furfaee, with its fpark of ^'^ of an inch, having produced the fame 

 fliock as the pile with this fpark of ttIss of an inch, the furfaee of coated glafs of the 

 fame thicknefs as the jar, and equivalent in capacity to the galvanic pile, muft be as the 

 fquare of ^V to the fquare of -y-rio^j that is as i to 3^ millions nearly. Such 

 therefore, according to this method of computing, appears to be the capacity of the 

 galvanic pile, fo prodigioufly exceeding the largeft batteries ever yet conftrufted. But 

 on the other hand, its intenCty being fo very low, the (hock may be confidered as if pro» 

 duced much more by the mafs or quantity of ele£lricity,, than by its velocity of motion. 

 Now the quantities of eleftricity affording equal fliocks, according to the preceding con- 

 ditions and doftrine, are inverfely as the intenfities, or in our cafe as 40 to 75000, or 

 J to 187s, and our jar might have exploded about lo times by each turn of a good 

 eleftrical machine. The large battery of 3^ millions of feet would, confequently, have 

 required 187 turns to charge it to the low galvanic intenfity -, and as the pile was found 

 to charge itfelf in two feconds, which is very nearly the time required for each turn of 

 a 24 inch (fmgle) plate machine, we may affert that the produflion, or extrication, of elec- 

 tricity in a fmall apparatus of this kind is almoft two hundred times as rapid as that which 

 can be obtained by fricSlion by the labour of one man. 



I cannot forbear adverting again to the novelty of the field of refearch in which I have 

 thus ventured to fpeculate. We may reafonably hope that the difcoveries to which this 

 new exhibition of the joint actions of chemiflry and ele£l:ricity may lead us, will fhew 

 other powers and energies of what is called the ele£brical fluid, and induce us to reje£l with 

 gladnefs the imperfed theories afforded by our prefent knowledge of the fubjeft f. 



Account of a Series of Experiments, undertaken with the View of decompojing the Muriatic 



Acid. By Mr. Wiiuam Henky. 



(Concluded from page 2i^.j 



X\ GREAT variety of fimllar experiments convinced me, that by cleflrifying together 

 the carbonated hydrogenous and muriatic gafes, not the fmalleft progrefs was made towards 

 the decompofition of the latter. All that was thus effefted, confifled in, the decompofitioo 



• The charge at equal intenfities Is inverfely as the thicknefs, as determined by Mr. Cavendiih in loco 

 citato. In extreme cafes, however, I find that the charge follows a higher ratio. 



■f I have fmce been favoured with another communication from Col. Haldane,, which I am obliged to 

 iiiei to our next.. 



