Correspondence. 475 
of purely volcanic ash—mostly of a clearly sedimentary origin— 
reposing upon thin seams of coal and shale, and enclosing a con- 
siderable number of fossil plants in a beautiful state of preservation. 
Up to the present time, I have accurately surveyed a distance of 
only about 400 feet along the shore; and within this comparatively 
narrow area are found no less than ten distinct beds of trappean ash. 
Trunks of trees, 18 to 24 inches in diameter, and 2 to 3 feet in 
height, standing erect upon the original beds of thin coal and shale 
upon which they grew, and covered by layers of ash 2 to 3 feet in 
thickness, are found regularly dispersed over the area; while the 
ash overlying them, in which they are embedded, contains numerous 
branches, from 4 inches in diameter down to the minutest dimensions, 
some of the impressions displaying an almost feathery foliage, as 
though suddenly covered up before the vegetation had had time to 
decay or become water-worn. The larger branches remain perfectly 
round, and show the pith in an admirable state of preservation; and 
the cellular tissue, filled up with mineral matter, is plainly visible to 
the naked eye. 
The specimens of the smaller branches thus far obtained indicate 
the genera Lepidodendron and Halonia; but I have had no oppor- 
tunity as yet of having them examined microscopically. As far as 
can be determined by a simple botanical glass, the structure is very 
similar to the sections of Lepidodendron, &c. figured and described 
by Mr. Binney in the ‘ Quarterly Journal of the Geological Society’ 
for January 1862. 
The whole of the beds belong to the Lower Carboniferous series 
underlying the Producta-limestones, and there are indications of 
beds of a similar character both above and below those described. 
The mineralogical character of the beds is highly interesting, and 
has been examined jointly with me by my friend and colleague, 
_ Mr. John Young, of the Hunterian Museum. A joint paper on the 
subject will be laid by us before the Geological Society of Glasgow 
at an early date: meanwhile, if you think the announcement of the 
discovery of fossil plants under the circumstances stated may be 
interesting to your geological readers generally, the above details 
are quite at your service, and I remain, dear Sir, 
Yours very truly, E. A. Wiinscu, 
ANDERSONIAN UNIvERSITY Buinp1nes, V.P. Geol. Soc., Glasgow. 
Guascow: Sept. 9, 1866. 
NOTE ON THE ANALYSIS OF A DEPOSIT CONTAINING 
SULPHATE OF BARYTA. 
To the Editor of the GEOLOGICAL MAGAZINE. 
Srr,—At a late meeting of the Glasgow Geological Society, Mr. 
Thomson exhibited a compact mass which had been deposited in a 
pipe, apparently a square wooden one, used for conveying water 
from Harton Pit, near South Shields, which is about 200 fathoms 
deep. 
The deposit is a hard, compact, light-brown mass, with dark- 
brown streaks running through it. The portion shown was about 
