180 Description of a Carbon Voltaic Battery. 



Art. XIX. — Description of a Carbon Voltaic Battery; by B. 

 Silliman, Jr., A. M., of the departments of Chemistry, Min- 

 eralogy, and Geology, in Yale College. 



It was mentioned in the last number of this Journal (Vol. xliii, 

 p. 393,) that a battery of considerable series was constructing by 

 me on a plan, in many respects, similar to the nitric acid battery of 

 Mr. Grove, but differing in the important particular of employing 

 carbon as the negative element, in place of the platina of Mr. 

 Grove's arrangement. I have since completed this battery, and 

 made a series of experiments with it, and propose now briefly to 

 describe it. 



The substitution of plumbago for the platina, and the use of 

 circular in place of flat cups, with certain details of less impor- 

 tance, are the principal points of difference between this and other 

 nitric acid batteries. Fig. 1, gives a vertical and cross section of 

 one member of the battery. The lettering is the same in both, 

 and the drawings are on the scale of half the real size. C, the 

 external cell, is of a peculiar glazed ware, which withstands the 

 action of acids remarkably well.* This cell contains the dilute 

 sulphuric acid, and is four inches in diameter, and three in height. 

 Z is the zinc element, which is of cast zinc, and amalgamated 

 with mercury. It is cast with two ears, (e e, in vertical section,) 

 which pass up through the bar of the frame F, in which they are 

 supported, being crowded by the small wedges w. The zinc 

 rests on the bottom of the outer cell C. C, the inner cell, is 

 of porous queen's ware, strengthened by a band of the same ma- 

 terial at top and bottom, and resting within the zinc on the bot- 

 tom of the outer cell ; it is five eighths of an inch less in diame- 

 ter than the zinc. In this cell is placed the nitric acid. P is the 

 plumbago, which is in the form of a solid cylinder, three inches 

 high, and two in diameter. It is supported by the brass screw S, 

 which passes through the frame F. By this arrangement, one objec- 

 tionable feature of Mr. Grove's battery is avoided, viz. the elements 

 can be raised from the acids when not in use, each member drip- 

 ping its acid into its own cup, and the whole being securely fixed 



* This ware, as well as the porous cups, is manufactured at Jersey City pottery, 

 where any similar articles can be obtained to order. 



