THE CHEMICAL GAZETTE. No. CCCCII.— July 15, 1859. SCIENTIFIC AND MEDICINAL CHEMISTRY. On the Action of Coal-gas upon various Saline Solutions, especially on an Ammoniacal Solution of Protochloride of Copper. By Pro fessor Rudolf Bottger. As early as 1852 the author commenced experiments upon the behaviour of ordinary lighting gas (prepared from coal or resin, or from a mixture of Boghead coal and resinous wood) to various saline solutions and fluids. For the removal of various impurities which weakened the illuminating power of the gas, the author employed amongst others the absorbent so highly extolled by Le blanc for carbonic oxide gas, namely an ammoniacal solution of protochloride of copper. Leblanc states (and his statement is con firmed by Dr. Vogel, jun.) that when a current of carbonic oxide gas is passed through a solution of protochloride of copper in muriatic acid or in caustic ammonia, the gas is absorbed with as much rapi dity as carbonic acid by caustic potash, and that this furnishes a new analytical means for separating carbonic oxide with facility from gaseous mixtures. The author found, however, that the solu tion of carbonic oxide gas in this fluid takes place with extreme slowness. If a very slow current of carbonic oxide (obtained by heating cry stallized oxalic acid in concentrated sulphuric acid), completely freed from carbonic acid by means of solution of potash, be passed through three Liebig’s bulb-tubes placed one behind the other, and filled with ammoniacal solution of protochloride of copper, neither turbidity nor precipitate is seen to be produced in the solution, however long the passage of the stream of gas may be continued, and the gas flowing out from the last bulb-tube burns, when a flame is brought near it, with its peculiar beautiful blue flame just as quietly and continuously as if it had passed through no absorbent agent. Now Chem. Gaz. 1859. p