Cell, Standard Voltaic, Latimer Clark's

A mercury and zinc electrode couple with mercurous sulphate as excitant and depolarizer. The positive element is an amalgam of zinc, the negative is pure mercury. Each element, in a representative form, the H form, is contained in a separate ve el which communicate by a tube. Over the pure mercury some mercurous sulphate is placed. Both ve els are filled to above the level of the connecting tube with zinc sulphate solution, and kept saturated. It is tightly closed or corked. The E. M. F. at 15° C (59° F.) is 1.438. Temperature correction (1 -  (.00077 *(t - 15° C) ) ) t being expre ed in degrees centigrade (Rayleigh). A diminution in specific gravity of the zinc solution increases the E. M. F. The cell polarizes rapidly and the temperature coefficient is considered too high. IMG:8956969607833025625_111F80.jpg: Fig. 80. LATIMER CLARK'S STANDARD CELL. 111   STANDARD ELECTRICAL DICTIONARY.