GALVANIC SOLDERING. 85 



upon the end of the copper wire, which formed the negative elec- 

 trode a strong ring of sheet-copper was placed. This ring was cut 

 asunder at one point, and the distance left between the severed 

 parts was about the sixtieth of an inch. At the end of a few days 

 (during which time the exciting liquors were several times renewed) 

 the space in the severed portion of the ring was completely filled up 

 with copper regulus, which had been precipitated ; and on partially 

 cutting with a file through the part thus filled up, and examining it 

 with a lens, it was observed to be very equally filled with solid and 

 coherent copper. 



" Another copper ring was then cut into two parts, and the two 

 semi-annular segments thus obtained were placed with the faces of 

 the sections opposite each other, and submitted to the action of a 

 galvanic current. At the end of a few days, the segments were 

 united by the copper precipitated, thus forming again a complete 

 ring. It was also found in this case, on removing with a file a 

 portion of the thickness of the ring at the points of contact, that 

 the spaces had been completely filled up by copper galvanically 

 precipitated, which had united the whole. On observing these 

 points carefully with a' lens, the regular deposition of the copper 

 could be readily traced between the formerly separated portions of 

 the ring. 



"A third experiment was made in the following manner: Two 

 strong rings of sheet-copper were laid with their freshly-cut faces 

 one upon another, so that the two rings constituted a cylinder. 

 These rings were surrounded by a band of sheet- tin, which was 

 coated with a solution of wax, so that the two rings were equally 

 surrounded by a conducting material. Thus disposed, these rings 

 were attached to the negative wire of the battery, and immersed in 

 the bath of sulphate of copper. At the end of a few days, the 

 interior surface of the rings was covered with precipitated copper, 

 and between the contact surfaces of the two rings copper was also 

 precipitated. These rings had only been submitted to the galvanic 

 current to such an extent as to cover their interior surface with a 

 thin coating of precipitated copper, and yet they were already 

 completely re-united, and formed a cylinder consisting of a single 

 piece. The exterior conducting covering consisting of a sheet of 

 tin, was of course removed before testing the cohesion or persist- 

 ence of the galvanic precipitate. It may be remarked, that these 

 rings, after being for a certain time in contact (during the galvanic 

 action), together with the plate of copper upon which they rested, 

 became so encrusted with precipitated metallic copper that some 

 force was found necessary to effect their detachment from the copper 

 wire. 



"There would appear to be no doubt, then, according to the 



