TRANSACTIONS OF THE SECTIONS. 39 
sometimes to a very considerable extent. A large quantity is separated from the 
coal on its arrival at the surface of the mine; but a great part of it is thrown to 
waste, and forms the “ fire-heaps” attached to nearly every colliery, and is fre- 
quently the cause of considerable damage to vegetation when they take fire. 
Probably as much as 20,000 tons per annum are saved, and used in the manu- 
facture of sulphate of iron and sulphuric acid. 
The following is an analysis of cleaned coal-pyrites from Walker Colliery :— 
PUPAE bos sicseltorwe me cece tae oe sees. 40°50 
ETT Papo, o Susid «Gee eal ts Paste Rl Gee 86:35 
ODE AR i, osterg snus «0 nds Shen SERRE rie Ten mete 17:90 
RAI oon dt cs sx eyo tvs sh EM oan peta aa 1:55 
Carbonate of lime ..........0:- Sapte 4:00 
100-30 
Still more recently a further quantity—(D.) Specimens of Hatchetine—was found 
in the South Hetton Pit, some of which the writers hoped to have been able to 
lay before the members of the Association; but unfortunately the pit-boys found it 
out, and used it for greasing the axles of their trams, thus making it deserve the 
name of “ mineral grease,” which it sometimes receives. 
(&.) Specimen of coprolite found in the bituminous shale lying immediately over 
the Low Main seam at Newsham Colliery, near Blyth: from the numerous fish- 
remains found in this bed, it has received the name of “ Fish-bed.” This speci- 
men contains 30 per cent. of phosphate of lime. 
(F.) Specimen of sulphate of baryta, found in Felling Colliery, near Newcastle, 
by Mr. G. B. Foster, in quite a large mass. The writers are not aware of sulphate of 
baryta having previously been noticed in connexion with coal, except by Dr. Richard- 
son, of Newcastle, who observed it in the waters of Walker Colliery in 1847. 
(C.) Specimen of carbonate of lime, generally found in layers, occasionally of 
several inches thick, and frequently presenting the appearance of fine marble. 
(EL.) Specimen of carbonate of iron, also found in layers, and frequently mixed 
with lime, also in large masses. 
(I.) Arsenic is not found isolated, but in some coal “brasses”’ it exists to the ex- 
tent of 0-1 to 0:3 per cent. 
(J.) Specimen containing fine crystals of sulphuret of nickel, imbedded in car- 
bonate of lime, from South Wales. 
4. The Salts formed by Decomposition and Recombination.—Through the rocks 
described in the first part of this memoir water is constantly percolating, and this, 
becoming charged with various salts in its passage through the upper strata, in- 
duces decomposition of many of the previously mentioned substances, thus forming 
new combinations. These are in some cases found in solutions of various densities, 
sometimes in crystallized masses of great purity, and at other times in layers de- 
posited from solution or by evaporation. e shall give a few illustrations :— 
(K.) A specimen from Hetton Colliery, which consists of crystallized sulphate 
of iron (copperas). This is sometimes found in considerable quantities. 
(M.) Specimen of sulphate of alumina, containing 29°6 per cent. sulphate of 
alumina, soluble in water. This substance is found in considerable quantities in 
Hetton Colliery. 
(N.) Specimen of sulphates of iron and alumina (iron-alum, very pure). This 
is found in fine crystallized masses. 
(O.) Specimen of sulphate of lime, from Walker Colliery, from a large mass of 
snow-like crystals. 
(P.) Specimen of needle-shaped crystals of Epsom salts. This substance is 
found in large quantities in Hetton Colliery, and is quite pure. 
(Q.) Specimen of nearly pure common salt, with a trace of sulphate of lime. 
(R.) Specimen of chloride of potassium, mixed with common salt, 
- In presenting the above imperfect results to the Members, the writers are well 
aware that they have not exhausted the subject; but, amidst the more important 
duties of the last few months, it has been found difficult to find time sufficient to 
complete the paper that they had sketched out for themselves. 
