344 On Chinese Mercurial Preparations. [May, 
vessels by which the scales seem to have been supplied with nou- 
rishment. These vessels are likewise composed of a bony matter 
precisely similar in appearance to the scales themselves. 
Imbedded in the clay, of which the specimen chiefly consists, 
there are a considerable number of bodies precisely similar in ap- 
pearance and composition to the scales themselves; but they are 
generally smaller, pointed, convex on one side, and having a very 
distant resemblance to sharks’ teeth. 
From the experiments made by Mr. Hatchett upon the scales of 
fish, we learn that their constituents are the same with those which 
I found in the scales of this fossil. This gives a probability to the 
conjecture, which one cannot help forming, that the scales of this 
fossil constituted the covering of some unknown species of fish. 
This is not the first specimen of the kind which has been met with 
in Great Britain. In the Phil. Trans. for 1773 (p. 171) there is a 
figure of a similar fossil, together with a short description of it, by 
the Hon. Daines Barrington. His specimen was found near Christ 
Church, in Hampshire. Dr. Woodward, in his Catalogue of Eng- 
lish Fossils, describes a still larger specimen of the same kind, 
fcund in Stanfield Quarry, near Woodstock. Single scales from the 
same quarry have been several times met with. I am not aware that 
any light has been thrown upon the kind of fish to which these 
scales may have belonged. Perhaps some ichthyologist will have 
the goodness to inform us whether any fish at present known is co= 
vered with scales bearing a close resemblance to those in our fossil. 
Articie III. 
Some Notices respecting Mercurial Preparations in Use amongst the 
Chinese. In a Letter from Mr. Pearson, Surgeon, to Dr. Robert 
Briggs, Chandos Professor of Medicine in the University of St. 
Andrews. 
I wap long observed that the Chinese apothecaries’ shops were 
supplied with various preparations of quicksilver, and that they fur- 
nished nearly as many resources to medical practice derived from 
that mineral as our own; but to any inquiries respecting the che- 
mical processes by which they were prepared, I could obtain only 
vague and incorrect answers, it appearing to be no part of the duty 
or profession of the venders to possess knowledge of that kind. 
Having procured a person whose occupation it was to prepare some 
of them, and to dispose of them to the medicine shops, I engaged 
him to go through the different steps of the processes which he 
practised, in my presence. For this purpose he brought his mate= 
rials with him. 
