Mr. Richardson on the Composition of Coal. 401 



No. XXII. — Researches upon the Composition of Coal, by Thomas 



Richardson. 



Read 16th October, 1837. 



W e are at present in possession of various analyses of Coal, but at the 

 time when these were made, the method of analysis was too imperfect to 

 enable any chemist to obtain accurate results. This fact, together with 

 the great and important use made of Coal in manufactures, had induced 

 me to undertake the present researches, which have been conducted with 

 every possible care and attention, and throughout I have been indebted to 

 the kind instruction and advice of Professor Liebig. 



Method of determining the different Constituents. 



The first object was to determine the amount of water which Coal con- 

 tained, and whether this water was chemically combined or merely hygro- 

 metrical. With this view the following experiments were made : — 



I. A certain quantity of Coal finely pounded was dried at 100° C. by 

 means of Professor Leibig's apparatus, and the loss amounted to 1*23 per 

 cent. 



II. "854 grin.* Coal as finely pounded as the preceding was dried in a 

 chloride of zinc bath at the temperature of 185° C. when it sustained 

 a loss of - 0105 or T229 per cent. 



It may, therefore, be concluded, that if the Coal contains water, it 

 must exist in a state of the most intimate chemical combination. 



The determination of the ashes was very simple. A weighed quantity 

 of Coal was heated to redness in a small platina crucible, till the whole of 

 the carbon was oxidized, and the residue constituted the amount of ashes 



* The measure of quantity used in these analyses is the French gramme 1 gramme 



equalling a little more than 15 grains English. 



