On Electrklhj. 443 



degree, that the disk of paper had possibly hcen deprived of a 

 part of the water ivhicii appears necessary to its action !jy the 

 alkali. 



Mr. De Luc's valuable experiments and observations load to 

 the conclusion, that the presence of water, or of sorae coiiflucting 

 uuid, in the substances which have been hitherto interposed be- 

 tv.-een the metals, is ncees^;^ry to the accumulation of electricity. 

 Whether this effect is occasioned by the presence of water only, be- 

 cause a conducting fluid is essential ? wiiicli i take to be his opinion ; 

 Whether water acts merely as a conductor, differing in some lui- 

 known electric relation from the metals ? which I imagine to be 

 that of Mr. Singer ; or, Whether any kind of decomposition is 

 necessary? are questions not yet determined; but I have no doubt 

 the researches of those inteUigent gentlemen will contribute very 

 materially to elucidate the sul)ject. 



Mr. De Luc aKo supposes, of course, that I have not been 

 aware of the effect of a moist atmosphere, to increase the power 

 of the column : but I wa^i induced to place moistened cards ia 

 the receiver with the column and hygrometer, in order to com- 

 pare the effect of moisture on both instruments, susj)ecting, 

 certainly not being fully aware of its influence. I was also is- 

 duced by the observations of Mr. De Luc in the pajier above re- 

 ferred to, to Tuulertake the following experiment, for the pur- 

 pose of examining, more closely, this influence ; and, if possible, 

 of ascertaining what increments of moisture coincided with dif- 

 ferent electrical intensities. 



About half the interior surface of a tall glass receiver was 

 covered with a piece of linen. A column of about 800 groups 

 of zinc, silver, and paper, connected by a silken cord passing 

 through their centres, was suspended in this receiver, by a cop- 

 per wire attached to the arm of a balance, and the balance was 

 insulated and connected with an electrometer. Thus I could 

 weigh the water which was absorbed by the column when the 

 air of the receiver was rendered moist, by moistening the linen 

 from the upper opening ; and the insulation of the balance was 

 so \vell preserved, that I could produce extreme moisture iii 

 the receiver, without sensibly injuring it ; which was ascertained 

 by means of an electrometer charged nmch more highly than 

 the column could at any time charge the other. But the silken 

 cord, no doubt, became more conducting as moisture penetrated 

 it ; to which circumstance I attribute some of the results which 

 might otherwise appear anomalous. The divergence of the 

 electrometer was measured by an arc placed under the gold- 

 leaves, and divided into tenths of an inch : an hygrometer and 

 thermometer were also placed in the receiver. 



Time. 



