60 Chemico- Galvanic Observations. 



substance was the true muriatic acid. It had the same 

 smell ; it quickly whitened the nitrates of silver and of mer- 

 cury, and turned the blue tinctures into a lively red. 



With the same apparatus the author afterwards obtained 

 muriate of soda upon galvanizing with a gold wire a weak 

 solution of pure soda until all the alkaline character had dis- 

 appeared. 



Upon galvanizing with an iron wire instead of a gold one 

 pure water with the positive pole of the pile for sixteen hours, 

 he obtained a white precipitate, which became a bright blue 

 with the prussiate of potash, and black with the infusion of 

 galls. 



In lime water, submitted to the same process, the decom- 

 position of the water was very rapid. The liquid, when re- 

 duced to two-'thirdfi of its volume, exhaled the smell of the 

 muriatic acid and reddened the blue tincture a little; it was 

 formed of muriate of lime, precipitabic by potash but not 

 at all by oxalic acid, which is consequently a re-agent, not to 

 be" trusted for detecting lime in its various combinations, 

 particularly when they are acidulated. 



Induced by theoretical reflections, the author tried to sub- 

 stitute in place of gold the crystallized oxide of manganese 

 in the Galvanic decomposition of water. He filled two 

 tubes, in each of which was plunged a piece of this oxide 

 suspended by a copper wire : one of these wires touched the 

 negative and the other the positive pole of the pile ; the two 

 tubes were placed against the inner side of a conical drink- 

 ino-ivlass, at the bottom of which water completed the cir- 

 cuit. The water in the tubes was in contact with the man- 

 ganese only, and not touching the copper. At the end of 24 

 hours the water of the positive tube contained muriatic acid 

 united to a little manganese, by means of which the silver 

 precipitated from its solution assumed an obscure red tint. 

 The water of the positive tube was strongly alkaline. There 

 had been a considerable disengagement of gas in the other 

 tube. The manganese, however, on the negative side did 

 not appear to have been reduced by the influence of the hy- 

 drogen in the act of its formation, 



7 § II. 



