Apparatus. Tumbler two-thirds full of dilute sulphuric acid (258); strips of zinc, Zn (No. 60); copper strips, Cu (No. 67); iron strip, I (No. 76); lead strip, L (No. 77); carbon rod (No. 64); the galvanoscope, G V (No. 58); 2 wires with connectors ([§ 226]), so that the plates can be changed quickly; the wooden cross-piece, W C P (No. 70).
Arrange as in [Fig. 90]. The metal strips are all of the same size; they may be held with the hand firmly against W C P, in order to have them the same distance apart in each trial. They should be lowered to the bottom of the tumbler in each case, in order to have them acted upon by the same amount of acid. Place G V properly.
298. Directions. (A) With Zn and Cu connected to G V as shown ([Fig. 90]), take the reading in degrees, and note in which direction (east or west) the N end of the needle is deflected. Tabulate results, as shown in [Fig. 91], filling in each column of your table made out on paper.
(B) In like manner try the following combinations in the order given, in each case connecting the first-mentioned plate with the left-hand binding-post, L, of G V. For (B) use zinc-iron.
(C) Use zinc-lead; (D) iron-copper; (E) iron-lead; (F) lead-copper; (G) copper-carbon.
| PART | PLATES. | LIQUID. | DEFLECTION. | CURRENT IN CELL FROM | |
| (A) | ZINC. | COPPER. | DIL. SULP. ACID. | 65° WEST. | CU TO ZN |
| (B) | |||||
| (C) | |||||