1814.] On the Electricity oj Paper. 20S 



Article VIII. 



On the Electricity of Paper. By Mr. Walsh. 



(To Dr. Thomson.) 

 SIR, 



Not knowing that the electrical properties of paper have hitherto 

 been noticed in the high degree I have had occasion to remark 

 them, I will trouble you with a short account of some experiments 

 I have lately made on the subject: if they have any claim to 

 novelty, it may prove interesting to the readers of your .fournal 

 to be acquainted with tiicm, before the season favourable to the dis- 

 play of electrical appearances be at an end. 



About four weeks ago, having rubbed with elastic gum a piece of 

 foolscap paper, whicii 1 hrid previously held to the fire to dry some 

 drawing made on it, I observed that it adhered strongly to the 

 quire on whicii it was placed: as I attributed this to electricity, I 

 resolved to repeat tlie experiment to more advantage ; and for that 

 purpose I wanned two sheets of the above-mentioned kii.d of paper, 

 and having spread them out, laid them one on another on a well 

 dried woollen table cloth, and then rubbed tlie uppermost of them 

 for a few seconds : their adherence became considerable ; and on 

 forcibly parting them, a loud crackling noise was'heard; in the dark 

 tliis noise was accompanied by vivid flaslies of light. 



Forty sheets well dried before the fire, spread out, and placed 

 over one another, were next electrified, by the rubbing of the 

 uppermost, as before : their adherence to each other w as then such 

 that the two extreme sheets being held suspended by means of silk 

 threads the intermediate ones did not slip from between them: the 

 flashes and various ramifications of light emitted, in th.e dark, when 

 these sheets were separated from each other, ;)resented a beautiful 

 appearance; and when they, after this separation, were held up 

 suspended, currents of luminous fiuid an ineli long or more conti- 

 nued visible at cacii angle of the paper for a considerable time. 



The above electrified pile served as a most powerful base for an 

 electrophorus, and by its means sparks two inches in length were 

 obtained from a metallic plate, made of two sheets of tin, each of 

 which was not much above a foot square. 



Two sheets of paper were coated, each on one side, with tin foil 

 (gold paper will answer the purpose better), and a dozen uncoated 

 slieets, well dried, placed between tliem; a few sparks from the 

 ek'etropliorus were discharged on the uppermost insulated sheet of 

 the paper l)<ittery, which thus became sufliciently charged to give a 

 smart shock. 



If the sheets interposed between tiie coated ones had previously 

 been electrified by nibbing, a long succession of slight shocks was 

 t/btained, with the only precaution, after each di:jchurge, of sepa- 



