68 



REPOET 1871. 



The Estimation of Sulphur in Coal and Coke. 

 By F. Crace-Calteet, F.E.S. 



The sulphur found in coal or coke often exists in two states, partly as sulphuric 

 acid combined with lime, and partly as sulphur combined with iron. The part 

 combined with lime, however, does not injure the quality of the iron produced 

 when used in the manufacture of that article, as it remains in combination with 

 the calcium, whilst the portion existing as sulphuret of iron greatly deterio- 

 rates its commercial value. To determine the quantity of sulphur in the former 

 state, the author proposes to boil the pulverized coal or coke with a solution of 

 carbonate of soda, which decomposes the sulphate of lime or sulphuret of calcium, 

 and the sulphur is estimated in the solution. To show the importance of this fact 

 in estimating the suitability of coal or coke for use in the mauufactm-e of iron, the 

 author gave the following percentage of sulphur as the mean of the determination 

 in six samples of coal : — 



Estimated Present in Present in -p-.^ 



together. washings. residue. iJitterence. 



1-51 -92 -64 -87 



These coals by the old process would be condemned as unsuitable for use in the 

 blast-furnace, while they are really good coals for the purpose. 



In the residue from the above operation is found the sulphur combined with the 

 iron. After attacking with oxidizing aqua regia, the author treats with carbonate of 

 soda and heats to'near the fusiug-poiut. By this means there can be no formation 

 of an insoluble subsulphate of iron, and the prevention of precipitation by a salt of 

 baryta, which occurs in a liquor containing free nitric acid, is avoided. 



On the Existence of Sulphur Bichloride. By John Daizell and T. E. Thoepe. 

 The authors have confirmed the experiments of Hiibner and Gueront, who con- 



