260 Mr. R. Phillips on Volta-Electric Induction. 



benzoic acid and glycocoll minus two equivalents of water. 

 Before this view, however, can be considered as established, 

 it will be necessary to examine carefully the aethers derived 

 from lecanoric, erythric and orsellic acids, in regard to their 

 crystalline form, specific gravity, action on light, &c, and also 

 to compare accurately 'together orsellesic, erythrelesic and 

 lecanoric acids. If the aethers derived from various sources 

 should possess the same physical properties, and if orsellesic 

 and erythrelesic acids should prove to be identical in proper- 

 ties and composition with lecanoric acid which has been dis- 

 solved in alkali and reprecipitated, then I contend that my view 

 of the composition of these bodies will best explain the mani- 

 fold changes which they undergo. 

 Rochdale, August 26, 1848. 



XXXIX. An Account of some Experiments on Volta-Electric 

 Induction. By Reuben Phillips, Esq.* 



THE apparatus I employed consisted of three similar coils 

 of covered copper wire, number 16, each coil being about 

 3'5 inches diameter, and containing eleven yards of wire; the 

 ends of the wire were left exposed, so that by binding-screws 

 the coils could be united in any order. I call these coils re- 

 spectively A, B and C. To ascertain the force and direction 

 of the induced current, I generally used an indicating helix 

 containing a needle; this helix was made by winding covered 

 copper wire, No. 24, on a piece of glass tube about -Jjth of an 

 inch in diameter; the wire was wound on the glass until it 

 had acquired the depth of nine layers. This helix, which I 

 call the indicator, was maintained in the same relative position 

 with regard to an induced current, and the needles were 

 always inserted with their points in the same relative direction ; 

 consequently the direction of the magnetism imparted by a 

 current traversing the indicator was always the same for cur- 

 rents in that direction. I call a needle after it has been placed 

 in the indicator, the indicating needle \ the needles employed 

 were of one size, and by the same maker. The magnetism 

 imparted to them by the indicator was discovered by present- 

 ing them to one of two sewing-needles, which had been mag- 



* When I had completed this paper, which I thought was altogether 

 new, I acquainted Dr. Faraday with it, who informed me Dr. Henry had 

 previously given the same results in a paper entitled "Contributions to Elec- 

 tricityand Magnetism" (Transactions of the American Philosophical Society, 

 vol. vi.J ; hoivever, Dr. Faraday thought very well of my paper and advised 

 its publication. It is proper to remark, the paper has been a little altered 

 since Dr. Faraday expressed this good opinion of it. 



