4 
The following analysis by Biewend, made upon a specimen 
found at Andreasberg, agrees remarkably well with the 
foregoing determinations : — 
Ferric Oxide 37 ‘30 
Silica 41-10 
Water 21-56 
99-96 
Dr. Schunck, F.R.S., called attention to a paper by 
Vogelsang and Geissler, on the nature of the liquids en- 
closed in certain minerals, such as rock crystal, topaz, and 
quartz, which appeared in the number of PoggendorfFs Anna- 
len for last May. The Authors find that these liquids, sup- 
posed by some observers to be hydro-carbons, always consist 
of liquid carbonic acid, mixed in some cases with a little 
water. The experiments by which they were led to this 
conclusion are fully described in the paper. 
Mr. Binney, Y.P., stated that during the last year or two, 
attention had been directed to the hollows which appear on 
the surface of limestone rocks, especially those belonging to 
the carboniferous series. Some 25 years ago Mr. Jopling* 
in his description of the Hundred of Furness, and more 
recently, Mr. Darbishire and myself have brought the sub- 
ject before this Society, and Mr. Pengelly, Mr. A. Tylor 
and Mr. Mackintosh, have made communications to the 
Geological Society of London. At the reading of the last- 
named gentleman’s paper, on the 12th day of May, last 
session, he stated that the holes he described were made 
by a Photas. This was doubted by Mr. Gwyn JefFerys, 
who stated “that the borings of the Pholas, Saxicava, and 
Gastrochcena , were not parallel but enlarged towards 
the base into a pear-shaped form. They were also com- 
paratively straight, and not curved or bifurcated as in 
