the Tlier mo- Electric Properties of Liquids. 



531 



No. 139. The solution of bromide of nickel of No. 106. Gold pla- 

 tinum positive 27° at about 150° F., and declined to 10° at 200° F. 

 (Compare No. 106.) 



No. 140. The solution of bromide of cobalt of No. 107. Cold pla- 

 tinum positive 29° at 200° F., and increased to 40 by continued heat. 

 (Compare No. 107.) 



No. 141. The solution of chloride of nickel of No. 103. Cold pla- 

 tinum positive 17° at 200° F., and decreased 10° by continued heat. 

 (Compare No. 103.) 



No. 142. 14 oz. of water and ^ oz. of very pure hydrate of sodium. 

 Hot platinum feebly positive 1J° at 180° F., but increased gradually 

 to 74° in half an hour at 200° F. by continued heat, and then began to 

 decline. The needles returned to zero on cooling. (Compare Nos. 87, 

 108, 110, and 112.) 



No. 143. The dilute hydrochloric acid of No. 13. Cold platinum 

 positive 3° at 200° F., and decreased to 1° by continued heat. (Com- 

 pare No. 13.) 



No. 144. 6 oz. of water, and 1 oz. of anhydrous sulphate of cobalt. 

 Cold platinum positive 6° at 200° F., but declined to 1° by continued 

 heat. 



No. 145. The solution of potassic cyanide of No. 109. Hot platinum 

 positive 35° at 200° F., and increased to 57 by prolonged heat. No 

 signs of corrosion of the plates. (Compare No. 109.) In these two 

 instances a difference of metal was apparently attended by a reversal 

 of direction of the current (see No. 167). 



No. 146. 6 oz. of water, and J oz. of bichloride of mercury. Not 

 the slightest sign of a current. Remark. This is the most neutral solu- 

 tion yet found. 



No. 147. 6 oz. of water, and 1 oz. of dry crystals of argentine 

 nitrate. Hot platinum positive 5° at 200° F., and increased to 16° by 

 continued heat, and was still increasing when the experiment was 

 stopped. Remark. This solution behaved like one of an alkali. (Com- 

 pare Nos. 108, 110, 112, 142, and 149.) 



No. 148. 12 oz. of water, and 4 oz. of clear, dry crystals of sulphate 

 of manganese. Hot platinum positive 17° at 200° F., and increased to 

 25|° by continued heat. Remark. This solution also behaves like an 

 alkaline one. 



No. 149. 6 oz. of water, containing the carbonate of rubidium from 

 2^° oz. of dry and well crystallized bitrartrate of rubidium, which 

 yielded the exact equivalent weight of the carbonate by ignition, &c. 

 Hot platinum positive 5° at 200° F., and increased to 32° by continued 

 heat. The needles returned to zero on cooling. (Compare Nos. 151 

 and 153.) 



No. 150. 6 oz. of water, containing the carbonate of caesium, from 

 875 grs. of the bitartrate. (N.B. — The salt contained some silica.) 



