38 -  ~ REPORT—1863. 
‘the decomposition of the stones with which the sides of many of the up-cast shafts 
in this district are lined, by the sulphurous vapours from the ventilating-furnaces 
and engine-fire. This is remedied by the adoption of fire-bricks in the place of 
sandstone, the latter not being liable to decomposition under the circumstances to 
which they are exposed. , : ‘ 
With the object of showing the action of these gases, the writers have examined 
various specimens of metal tubbing taken from the shafts of Hetton and other 
collieries, after having been some years in use, and append the analyses :— 
No. 1. No. 2. No. 3. No. 4. 
NGOU cites ce, PO rae EU. by ae O00 ee 
Sulphur ...7. 300 ..5. L427 .). o2G oeeeeup 
@atoons. esa, TSO cee OD ns. DN ae ee 
Silica ...... 0:65 84:15 — 
Water ....., 1600 .... 620..., 1472 1.0. = 
95-50 100-12 100:00 
The following are some analyses of sandstones :— 
Recent Analyses of Sandstones. 
PENSHER. COX GREEN. Crag- | Mica- 
Ss |  —_} leit ceous 
Brown | White | Grey | Top | Middle |Bottom| S@=4- | sand- 
rock, rock. rock. | stone. | stone. | stone. | Stone | stone. 
Silica tire 78°50 | 88-00 | 84:50 |'78-83 |81-60 | 83-30 | 86:33 | 76:25 
Alomine la cveccse en 16:00} 10:00 | 5:50 |12°16 | 9:60 | 9:16 | 9-83} 8-12 
Oxide of iron.............4. 5:00} 1:16 | 530 | 6:00 | 660 | 6:00 | 2:60} 9°53 
Carbonate of lime......... 0:21} 0:20] 030) 1:40] 1:20] 0:34 160 1:11 
Carbonate of magnesia...) 0:30) 0:20 | trace! 0°30 | 0:40 | 0:30 | trace} 0:32 
Salts of soda and potash | traces | trace | trace | trace | trace | trace | trace | 3:40 
100-01 | 99:56 | 95:60 | 9869 |99:40 19910 |100-36 |98°73 
3. Minerals and other Foreign Substances found in Coal.—Many of these are 
omitted in printed analyses, as they exist in separate masses and are not uniformly 
intermixed throughout the coal. They chiefly consist of— 
(1.) Carbonate of iron. (6.) Arsenic. 
ce Sulphuret of lead. (7.) Hatchetine. 
tt Sulphuret of copper. 8.) Sulphuret of iron. 
4.) tee cana of baryta. {3 Sulphuret of nickel. 
(5.) Carbonate of lime. 
A few of these we shall describe. 
(A.) Specimen from the centre of the Hutton coal-seam, at Seaton Colliery, 
near Seaham, at a depth of 1500 feet; it consists of sulphurets of iron and copper. 
The analysis of a large specimen is as under :— 
Copper...... Pra RITE CEE abicianeye 33°20 
(ESSE ERIS Ce ART ee IR “Se R.. 28:20 
BUG E os cate eta ees at oc ps ameV poke a cle 37-00 
Carbon, &.. 14... ausaireteatg Pinter) (sitet 1:60 
100-00 
(B.) Specimen of Sulphuret of Lead from Seaton Colliery, 
The following in an analysis of a specimen :— 
1 BE heetnes et be RSH ge or re boa .. 62°48 
SUL PTt errnrs Se 1 RE FFA PHONE E 11-40 
PEOH career cei ctcss. «0th ieee serrsat 2:10 
COA cere eran: wcaacs face n Laine sees 34:02 
100-00 
(C.) Iron pyrites, locally termed “brasses,” is found in nearly all coal, and 
