upon the Decomposition of IVatcr. 341 



the tube which corresponded with the gold wire, and con- 

 tained seven scruples of pure water, remained half full of a 

 liquor viih which I dyed turnsole paper of a red colour, and 

 this paper resumed its colour by means of an alkaline solu- 

 tion : some drops of a solution of nitrate of silver, poured 

 upon this liquor, 2;ave in a moment a precipitate insoluble 

 in the nitric acid ; the piece of cloth which corked the lower 

 end of the tube in question, appeared, in a great measure, of 

 H violet red. I cut this coloured part into two pieces; I 

 applied nitro-muriatic acid to the one, and oxy-muriatic acid 

 to the other : a few minutes afterwards the colour disappear- 

 ed, and the cloth resumed its whiteness. A solution of nitro- 

 muriate of tin restored to these liquors, which had been thus 

 discoloured, the violet colour. The gold wire of the same 

 pole was worn away a good deal at every part of it, and re- 

 sembled a needle at its extremity. An analvsis of the gas 

 liberated from the negative tube yielded pure hydrogen gas ; 

 it filled two bell-glasi-es and a half, each of which might 

 perhaps contain about six scruples and a half of water. The 

 tube of this pole, which had at the beginning of the opera- 

 tion about seven scruples of water, remained half full of a 

 liquor, which reddened the tincture of turmeric, to which 

 the acids again restored its yellow colour: the nitrate of silver 

 applied to this liquor furnished an ash-coloured precipitate, 

 perfectly soluble in the nitric acid*. 



In order to dissipate the least idea that the muriatic salt, 

 with which I moistened the disks in the experiment of the 

 1 1th of November, had the smallest influence upon the pro- 

 duction of the muriatic acid at the positive pole, I recom- 

 menced the same experiment on the l6ih, by employing 

 other disks of paper soaked in a solution of sulphate of alu- 

 mine, and by carefully wiping the metal ones : in a few days 

 I obtained the same results f* 



• Tlie nitrate of bilver, oxalate of ammonia, muriate uf barytes, did not at 

 all trouble the water which was used in these experiments. 



f This suljihatc of aluniine certainly does not contain muriatic salts: wish- 

 ing to ascertain this, I dissolved six scruples of il in ilisiilled water, and I preci- 

 pitated it by the nitrate of barytes. I filtered this liquid ; and, having treated it 

 with nitrate of silver, no precipitate at nil appears. 



y 4 We 



