342 Mr Connell on the Action of 



or by test-paper. The battery was then reversed, the muria- 

 tic acid being now connected by the same platinum foil as be- 

 fore, with the positive side of the battery, and the acidulated wa- 

 ter with the negative. A brisk effervescence took place as before 

 from the negative pole, and a slight effervescence from the posi- 

 tive, and in less than two minutes, a decided smell of chlorine was 

 evolved from the positive tube, and shortly after test-paper held 

 close to the positive foil was bleached, and the muriatic liquid 

 got a yellow tint from dissolving chlorine. In this experiment it 

 is evident that, before the reversal of the poles, no decomposition 

 of muriatic acid took place, and that the whole, or greater part, 

 of the oxygen which was evolved before the reversal from the po- 

 sitive wire, was employed after that change in reducing muriatic 

 acid by combining with its hydrogen and liberating chlorine. 

 When the diluted muriatic was at once connected with the posi- 

 tive pole of the battery in fresh action, and the acidulated water 

 with the negative side, the smell of chlorine was even sooner, and 

 more distinctly observed. 



In another experiment, I examined more particularly the gas 

 evolved from the positive pole, when the muriatic acid was posi- 

 tive, and found it to be chlorine. A small evaporating basin con- 

 taining muriatic acid diluted with twice its bulk of water, was 

 connected with another evaporating basin containing sulphuric 

 acid diluted with five parts of water, by asbestus moistened with 

 the latter fluid. The negative foil was placed in the dilute sul- 

 phuric acid, and the positive foil brought under a tube filled with 

 the dilute muriatic acid, and inverted in the basin containing the 

 latter liquid. The gas evolved from the positive pole was shewn 

 to be chlorine, by being gradually entirely absorbed by the li- 

 quid, and by the strong smell of chlorine which the liquid ac- 

 quired. 



The experiments with hydriodic acid led all to the same 

 views, and, from the phenomena being more apparent to the 

 senses, were even more satisfactory. 



