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Monday, Ath March 1850. 



General Sir THOMAS MAKDOUGALL BRISBANE, 

 Bart., President, in the Chair. 



The following Communications were read : — 



1. Analysis of the Anthracite of the Calton Hill, Edinburgh. 

 By Dr A. Voelcker. Communicated by Dr George "Wilson. 



Dr Voelcker observed, in the introduction to his paper, that we 

 are in possession of analyses of anthracite from different localities, 

 from which it appears that different specimens vary much in the pro- 

 portion, but very little in the nature, of their ingredients. All 

 samples of anthracite which have been analysed, have been found to 

 contain carbon, oxygen, hydrogen, and nitrogen, as well as more or 

 less inorganic matter. Sulphur also has generally been found, at 

 least when sought for ; but it does not appear in many recorded 

 analyses. 



The anthracite employed in the following analyses was furnished 

 by Dr Fleming, and first carefully dried, after being finely pow- 

 dered, by exposing it for several hours to a current of dry air, at a 

 temperature of 230° F. The carbon and hydrogen were ascertained, 

 by burning from three to four grains of the mineral with a mixture 

 of oxide of copper and oxide of lead, which is much less hygroscopic 

 than the pure oxide of copper. A mixture of this oxide and chlorate 

 of potass was also placed in the shut end of the combustion-tube, 

 from which oxygen was evolved in the usual way towards the close 

 of the process. 



The nitrogen was determined by Will and Varentrapp's method. 

 The sulphur was ascertained by projecting into a red-hot platina 

 crucible, in successive small quantities, a mixture of anthracite in 

 powder, with nitrate of potass and carbonate of soda, and afterwards 

 maintaining the product of deflagration at a high temperature for 

 some time. The resulting fused mass which was perfectly white, 

 was dissolved In water, super-saturated with hydrochloric acid, and 

 precipitated by chloride of barium. 



About ten grains of the mineral were employed in the determina- 

 tion of the amount of ash. It was red, and contained oxide of iron. 



The following are the results of the analysis : — 



