Dr. Pring on Etching by Electricity. 



107 



panied by a slight indentation on the steel, was the result of 

 each contact of the wire with the plate. 



The wire by which the etching was made was of platina; 

 the part at which it was held was carried through a glass tube 

 for the purposes of affording a more convenient handle, and 

 of protecting the hand from shocks to which it might other- 

 wise have been exposed. 



By using the wire connected with the zinc of the batteries 

 as the etching-tool, and attaching the steel plate to the plati- 

 nized silver, a very different effect is produced. With the 

 apparatus thus arranged, the spark that results from the con- 

 tact of the wire with the steel plate is accompanied by a depo- 

 sition of a minute portion of the substance of the wire on the 

 steel; by using different wires, therefore, as of gold, silver, 

 platina, &c, a variety of ornamental designs may probably be 

 formed on polished steel surfaces. 



The effect of the electrical agency here described is not 

 however confined to steel ; a somewhat similar one may be 

 obtained by substituting plates of other metals. By augment- 

 ing the quantity and intensity of the electrical current, it seems 

 probable that the effect on the steel, or other metals, would 

 be proportionally increased ; and it may be anticipated that, 

 by other modifications of the process, its applications may be 

 advantageously extended. 



I remain, Sir, yours respectfully, 

 Bath, July 5, 1843. James Hurly Pbing, M.D. 



The accompanying sketch, in which the apparatus is re- 

 presented lying ready for use, may perhaps serve to illustrate 

 the foregoing description. 



A. The steel, or other metallic plate to be etched upon. 



B. The etching point of platina wire projecting from the glass handle. 



C. The coil of covered wire. D. The batteries. 



