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On the Lamination of Clay hy Electricity. 

 Esq., F.G.S. &c. 



By R. W. Fox, 



Some clay was exhibited to the Poly technical Society of 

 Cornwall by R. W. Fox, Esq., which had become laminated 

 b\ long continued voltaic action, so as to resemble clay-slate in 

 its structure. 



The figure here given may serve to illustrate the process by 

 which this was accomplished. Let 

 a, 5, c, df represent the top or rim 

 of an earthenware cup or basin ; e, 

 a piece of copper pyrites ;/l the up- 

 per edge of a plate of zinc ; i, cop- J 

 per wire by which the two latter 

 were connected ; and g', h, the top 

 of a mass or wall of clay between 

 the copper-ore and zinc, and form- 

 ing for each of them, a water-tight 

 cell. The cell containing the copper-ore was filled with a metallic 

 solution, — the sulphate of zinc, for instance, — and the other with 

 water mixed with a little sulphuric acid. The water with which 

 the clay was worked up was also acidulated. Thus circum- 

 stanced, the apparatus was set aside for three or four months, 

 and was not disturbed till some little time after the water had 

 evaporated, and the clay had become perfectly dry throughout. 



It then exhibited, on breaking off a portion of its upper 

 part, lines of cleavage of a schistose character, parallel to the 

 sides of the clay and plate of zinc, or, at least, as nearly so 

 as was consistent with their undulatory form. In other 

 words, the lines or laminae were at right angles to the direction 

 of the electrical forces. 



They are indicated by the lines on g^ h ; and the strongly 

 marked line « c represents a principal - line of division which 

 separated the clay into two portions, from the top to the bot- 

 tom. 



These seemed to form, as it were, two voltaic plates in oppo- 

 site states of electricity, and one of them consequently, more 

 favourable than the other for the reception of metallic depo- 



