NOTE ON A ROCK FROM GLYN CEIRIOG. 201 
soon be spoilt; but if baked carefully they may be destroyed 
without injury to the fungus. The great point is not to render the 
fungus too dry, and so apt to break. Then the pores which cover 
the underside must be removed with a blunt knife ; they are easily 
separable after the plant has been dried, and leave behind a nearly 
smooth surface. Those who wish to make sure of the preservation 
of their work for the future should next poison it, by painting it 
thoroughly on all parts with the following solution :— 
Methylated spirit.1 pint. 
Corrosive sublimate .1 ounce. 
Carbolic acid.1 ounce. 
This quantity will cost about eighteen pence, and will be 
sufficient for two or three large Polypores. It is made of double the 
strength used for phanerogamic plants, but is not too strong for 
this purpose ; it can only be obtained from a chemist to whom one 
is known. There are two other ways of preserving the fungus, 
which have been suggested, but I have not tried them. One is to 
soak it in a solution of borax ; the other is to paint it with 'paraffin , 
which will certainly render it unpalatable to all insect life. 
Now, when dry, cover every part with a thin coating of the 
best copal varnish , applied with a small brush ; about sixpenny- 
worth will be enough to give two coats to a large fungus. Then, 
when thoroughly dry, fasten the flaps together (if not already fast) 
with thin copper wire passed through them, which can easily be 
done in such a way as not to show, and the ornament is complete. 
It can be cut flat at the base in such a way as to stand securely on 
a mantel-piece, and the spaces between the flaps are convenient for 
placing letters, cards, &c,, for temporary preservation. 
NOTE ON A ROOK FROM GLYN CEIRIOG.* 
BY THOS. H. WALLER, B.A., B.SC. 
After the meeting of the Midland Union of Natural History 
Societies at Oswestry last year, Dr. T. Stacey Wilson brought to 
me a very curious specimen of rock collected by Mr. Cobbold from 
* Prepared for the meetiug of the Midland Union of Natural History 
Societies, July 11th, 1893. 
September, 1893. 
