DETECTION OF ARSENIC. ll' 



Again, it occurs in the Hagerstown valley in several places, 

 but has less of the external appearance of hematite, although 

 it has the same composition. 



Both the brown and red hematite occur in the clay and 

 loam which forms the surface of parts of the Frostburg coal 

 region, the latter kind at the gap formed in the Savage moun- 

 tain by Savage river. 



It having been thought desirable that this volume should 

 contain an article upon the mineralogy of Maryland ; the 

 writer has attempted to supply it by the foregoing notices, 

 which are intended as a mere outline in order to give a 

 general idea of the mineralogical character of the State, or 

 rather of the eastern portions of it. The consideration of the 

 western portion is the more willingly deferred, because the 

 professional avocations of the writer, during the present year, 

 will probably enable him to become better acquainted with its 

 mineralogy. 



ARTICI. EVII. 



On the detection of Arseiiic in Medico Legal Investigations. 

 By William R. Fisher. 



[Read before the Academy, Feb. U, 1836.] 



The form in which arsenic may be most readily adminis- 

 tered intentionally as a poison, or accidentally, without any 

 design to destroy life, in this country, is in the condition of 

 white oxide, that being almost the only form in which it is 

 accessible to the community at large. It is the white powder 

 familiarly known as ratsbane or arsenic, and sold in all the 

 shops, subject to no other restraint in its dispensation, than the 

 conscience of the dealer may impose. There are, however, 

 several preparations or forms, in which arsenic is found, in 

 commerce and the arts ; — the white oxide of arsenic already 

 alluded to, metallic arsenic commonly called cobalt or Jly- 

 powder ; the red and yellow i^ulphurets, realgar and orpiment, 

 and Fowler's solution, the arsenite of potassa. The latter of 

 which may be employed as a poison, though more likely to be 

 administered accidentally, as its composition is not generally 

 known. A description here of these several substances is 



