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POPULAR SCIENCE REVIEW. 
occupy an area of about one-seventeenth of the whole of Scotland. The 
uppermost of the coal strata is found at Fisherrow, and between it and the 
old red sandstone, which forms the floor of the coal formation, there are 337 
alternations of strata, having a thickness in the aggregate of 5,000 feet. In 
the thickest part there are 62 seams of coal, counting the double seams as 
one, and about one-half of these are workable. The depth of strata at 
‘ Musselburgh is, however, exceptional j and the average depth is estimated 
to be about 3,000 feet, of which the coal-seams occupy 126 feet. The 
thickest bed of coal in the Lothian field is 13 feet ; but at Johnstone, in 
Renfrewshire, there is a seam of 100 feet in thickness. This latter owes its 
extraordinary bulk to the overlapping of the coal strata during some great 
convulsion in the locality. The most important of the coal-fields is the 
Clydesdale, on which one-half of the entire number of collieries in Scotland 
are situated. Thirteen counties lie over or touch upon the coal-fields, and 
of these Lanarkshire has by far the largest share of the store. Judging 
from the number of collieries possessed by each, Ayrshire, Fifeshire, and 
Stirlingshire, come next in order. In nearly all the counties, more or less 
valuable beds of ironstone, shale, and limestone, are intermixed with the 
coal. The Scotch cannel or parrot coals are very valuable on account of the 
high proportion of gas and oil which they yield. The Boghead variety 
gives 120 gallons of crude burning oil, or 15,000 cubic feet of gas per ton ; 
and the brown Methil 90 gallons of oil, or 10,000 cubic feet of gas per ton. 
In the Edinburgh Industrial Museum, there is a collection of specimens of 
the different kinds of coal found in Scotland and elsewhere, together with ^ 
the tools used in mining. The cannel coal found at Wemyss, Fifeshire, is 
carved into various articles of a useful and ornamental character — such as 
picture-frames, inkstands, brooches, &c. — and a table formed of it is exhi- 
bited in the museum. — Vide the Artizan, February. 
The Distribution of Gold . — A newly published American journal takes up 
for examination some of the popular beliefs regarding the distribution of 
gold as a mineral, and corrects the erroneous supposition that gold-bearing 
veins diminish in value with increasing depth. It alleges that it is esta- 
blished that lodes bearing gold at the surface contain gold at every known 
depth, that the value of it frequently remains the same, and more frequently 
increases than diminishes, that lastly, the gold in the majority of lodes is 
diffused according to simple laws, while the ores which contain it are in the 
forms of extended columns. — Vide the Mining Gazette, Vol. I., No. 2. 
The formation of Mineral Veins . — Professor Wurtz has published a 
paper recently read by him before the American Association for the Advance- 
ment of Science, in which he urges the following conclusions : — First. The 
contents of the primary metalliferous strata, as well as the lodes therein 
contained (both ore and gangue) were deposited from suspension and solu- 
tion in the hot water of the primeval ocean. Second. These waters con- 
tained on all the metals, in forms soluble, if not in pure water, yet in 
solutions of some one or other of the saline constituents of the ocean. 
Third. The metals now found in these rocks as sidphides, must have existed 
in the waters of that ancient ocean as sulphates, or certainly associated with 
enough of the sulphates of other bases (alkalic and earthy) to furnish the 
sulphur now extant in the sulphides. Fourth. Through some great and all- 
