: 
Medical Chemistry. 81 
I regret very much, to find the Geological Ob- 
servers in your vast and interesting country, so very com- 
monly to omit stating bearings and distances, from known 
Towns, as well as nearest distances and bearings from known 
Streams, as the means of more pefectly fixing the localities 
of their particular observations, and conveying an idea of 
the same to Readers here and elsewhere, who can have no 
mode of denoting the latter, is, by the proportion of the 
measure of /evel, to one of perpendicular fall: as for in- 
NE 1 in 5, or SW 1 in 2, &c. ; and #% ory,* 
Freestone, Ironstone, Gypsum, Clays &c. will always in- 
clude the above particulars, in their descriptions sent for 
your work. 
MEDICAL CHEMISTRY. 
PRUSSIC ACID. 
Arr. VII. Abstract and translation of Dr. F. Magenpie’s 
late publication on Prussic Acid—by the Exitor, with re- 
marks. 
* Mr. Farey’s marks in his MS. are arrow heads ; nor characters of nearer 
1! 
resemblance were at hand. 
3) eg 
fe i ee 
