142 Hugh Taylor, Esq., on the Chemical Constitution 



of any nitrous acid formed during the process. Nitrogen by War- 

 rentrap and Wills' method. The Sulphur was determined by de- 

 flagrating the substance with pure nitrate of potash and carbonate of 

 soda, precipitating with chloride of barium, and calculating the sul- 

 phur from the sulphate of baryta obtained. Ash of coals by com- 

 plete ignition in a platinum crucible. The Inorganic substances 

 were estimated in the hydrochloric acid solution. The portion not 

 soluble in acids (or a substance in the first instance only slightly 

 affected by them) was fused with a mixture of carbonates of potash 

 and soda, and the analysis conducted in the usual manner. The 

 alkalies were determined in some instances by fusion with carbonate 

 of baryta, in others by attacking the substance with hydrofluoric acid. 

 The carbonic acid was determined in the ordinary way. All the 

 substances were dried at 212°; and in those which contained no 

 organic matter the water of combination was determined by ignition. 



The details of the analyses are as follows : — 



No. 1. Fire-clay. — Sp. gr. 2'519, of a grey colour, streak dull, 

 very soapy to the touch. It constitutes usually the basement of each 

 coal seam. As that from " Buddie's Hartley" was not a fine spe- 

 cimen, one was taken from the base of the coal at Blaydon Burn 

 Colliery in Tyneside, where it is made use of for the manufacture of 

 fire-bricks, &c. 



99-827 

 No. 2. Good Coal. — Sp. gr. 1*259, fracture conchoidal. Inter- 

 spersed rather abundantly with iron pyrites ; depth from surface 

 64 fathoms ; is from the "Low main seam" principally used for 

 steam purposes, to which end it is largely exported. 



Composition. 



Carbon, 78-690 



Hydrogen, 

 Nitrogen, 

 Oxygen, . 

 Sulphur, 

 Ash, 



100-000 



