428 J. P. Cooke— New Mode of Manipulating Hydric Sulphide. 



of about four liters' capacity served as a generator, and from 

 this the gas passed through a wash -bottle into two other bottles 

 of the same size and strength as the first. The intermediate 

 bottle was three-fourths filled with water, while the last served 

 simply as a gasholder. The connections were so arranged that 

 the gas, after bubbling up through the water, was delivered at 

 the top of the gasholder ; and. by a tube uniting the bottom of 

 the gasholder with the water-pipes ol the laboratory, the interior 

 of the apparatus could be submitted to the pressure of a column 

 of water sixty feet high. The gasholder was also provided with 

 an exit tube, which could be closed by a compression cock. 

 The connecting tubes all passed through rubber stoppers which 

 were firmly wired to the necks of the bottles, and the water- 

 bottle was connected with its neighbors by two lengths of stout 

 rubber hose so that the water could be shaken up with the gas 

 without disturbing the rest of the apparatus. In order to satu- 

 rate the water with hydric sulphide, a charge of ferrous sulphide, 

 sulphuric acid and water sufficient to yield at least three times 

 the amount of gas theoretically required was placed in the 

 generator, and, after the connections were made, the gas was 

 allowed to steam through the apparatus until all the air was 

 displaced. The exit tube of the last bottle was then closed, the 

 water pressure turned on and the water-bottle frequently shaken, 

 until absorption ceased, and the aqueduct water — at first forced 

 by its pressure into the gasholder — was driven back into the 

 pipes. Before dismounting the apparatus, the rubber connec- 

 tors were all closed by compression cocks, and care was taken 

 to vent the generator gradually. Moreover, the connectors 

 of the water-bottle were so arranged that when the apparatus 

 was dismounted a short piece of rubber hose was left attached 

 to each orifice of the bottle, both of which were closed by com- 

 pression cocks. To one of these a vent tube was subsequently 

 attached, and by this the solution was drawn off at pleasure, as 

 from a soda-water siphon. 



This simple apparatus was constantly used by us for two 

 years, and served an excellent purpose:" but it was found that 

 after the glass generators had been charged several times they 

 were liable to burst under the same pressure which at first they 

 v sustained. The same accident never happened to 

 the other bottles. But of course, if the pressure is Ions contin- 

 ued, bottles of glass of the size named, however well made. 

 would be liable to such an accident; and, if the apparatus is to 

 be remounted, it would be better to use a metallic vessel for 

 the generator, and to cover the glass bottles with some kind of 

 netting. The experience with the glass apparatus led us to seek 

 to adapt to the same purpose some one of the various soda-water 

 apparatuses which are greatly used in the United States for the 



