518 SEC. 13. CHEMISTRY. 



2479. Sulphur Liquor, the soluble portion of Oxydized 

 Alkali, or Thick Waste. John Hutchinson $ Co. 



The oxydized waste, lixiviated in the vats with warm water, gives a yellow 

 solution containing polysulphides of calcium, hyposulphite of calcium, and 

 hydrosulphate of calcium. 



Liquor generally contains equal to 5 of sulphur, distributed as follows : 

 2 ' hyposulphite of calcium. 

 2-0 polysulphide do. 

 1 hydrosulphate do. 



2480. Precipitated Sulphur, formed when sulphur liquor 

 and muriatic acid are mixed. John Hutchinson fy Co. 



Sulphur liquor is mixed with common hydrochloric acid from the con- 

 densers, the mixed liquors being heated to 140 Fahr. and well stirred. 



The muriatic acid forming chloride of calcium in the liquor, sulphur is 

 deposited as a yellow flocculent precipitate. 



In a good sample of liquor all the sulphide of hydrogen disengaged by 

 decomposition of the sulphides reacts on the sulphurous acid liberated at the 

 same time from the hyposulphite, sulphur and water being the products. 



2481. Lump Sulphur, prepared by melting the moist 

 sulphur of a previous stage of the process in a strong cast-iron 

 vessel. John Hutchinson fy Co. 



After washing out the chloride of calcium from the moist sulphur, the 

 drained product is put into a strong cast-iron cylinder, the filling-in aperture 

 screwed down, and steam of a pressure of 35 Ibs. admitted through a coil of 

 cast-iron pipe. The sulphur rapidly melts, and at the expiration of a certain 

 time, found out by experience, the whole charge is forced by the pressure of 

 the steam through the discharge pipe into tight wooden wagons, and when 

 cool broken up for sale. 



2482. Roll Sulphur. The roll brimstone of commerce, used 

 in medicine. John Hutchinson fy Co. 



Melted sulphur run into round wooden moulds and allowed to cool. 



2483. Bicarbonate of Soda (lump), prepared by exposing 

 crystals of carbonate of soda to a current of carbonic acid gas till 

 saturated, and drying the product. John Hutchinson fy Co. 



The dry lump bicarbonate ground in a mill and dressed to separate coarse 

 particles, as in grinding and preparing flour from wheat. 



2484. Bicarbonate of Soda. Carbonate of soda of the shops, 

 used in medicine and for making effervescing drinks. 



John Hutchinson fy Co. 



Soda crystals, or carbonate of soda, made by dissolving the soda-ash of 

 Leblanc's process in hot water, and, after settling, allowing to cool and 

 crystallize, are put in an air-tight iron chamber, and carbonic acid gas 

 (prepared by decomposing limestone with waste muriatic acid from the con- 

 densers) turned in by a pipe on the roof of the chamber. After some hours 

 the crystals are changed into bicarbonate of soda, part of the water of crystal- 

 lization escaping during the process. 



The moist bicarbonate is dried in kilns heated not over 100 Fahrenheit. 



