HENRY DEACON 177 



method of washing the colours in circulating 

 lixiviating tanks. 



No. 1,403. 29th April, 1868. Chlorine is 

 usually produced by heating peroxide of 

 manganese in aqueous solution of hydroch- 

 loric acid, the materials if perfectly utilized 

 yielding one equivalent of free chlorine and 

 one equivalent of chloride of manganese in 

 solution (as a by product of little value) for 

 every one equivalent of peroxide of man- 

 ganese and two equivalents of hydrochloric 

 acid employed. The patent specifies the 

 heating of oxide of copper or oxide of man- 

 ganese or other similar oxides or compounds 

 in a current of hydrochloric acid gas and 

 atmospheric air. In this manner the whole 

 of the hydrochloric acid gas may be decom- 

 posed at a moderate temperature, say about 

 400 Fahrenheit ; the chlorine of the acid gas 

 is set free, and the hydrogen of the acid gas 

 combines with atmospheric oxygen. The 

 mixtures of oxides remain unaltered, and the 

 process becomes continuous. Water that is 

 formed is removed by condensation, and the 

 chlorine absorbed and utilized in any well- 

 known manner. 



In this process oxygen is the element 

 n -quired to unite with the hydrogen of 



