150- Account of Professor Berzelius’s Method of detecting 
exhibiting, in a syphon-shaped glass tube, the formation of an 
arbor Diane, the tube having accidentally been placed in the- 
direction of the magnetic meridian, he remarked that finer and 
longer crystals were formed towards the north than towards 
the south, and yet every thing was the same in both legs of 
the tube. The solution of nitrate of silver in both legs of the 
tube was in communication, while the mercury covered only 
the bottom of the tube. The experiment was again repeated, 
in presence of Hansteen, with two-syphon-tubes, one parallel, 
and the other at right angles to the magnetic meridian. The 
silver began to separate in the tube which was placed in the 
north and south direction, and shot out into larger, more nu- 
merous, and more brilliant radiations in the leg towards the 
north, than in that towards the south. In the syphon in the 
east .and west direction no change was observed until the ex- 
piry of twelve hours. Hansteen afterwards repeated the ex- 
periment several times, and always with the same result, and 
deduced from his experiments the following inferences. 1. 
The arbor Diane is more strikingly developed when the tube 
is placed in the magnetic meridian, than when in the east and 
west direction. 2. When it remains in the magnetic meridian, 
the silver tree rises higher in the northern than in the southern 
leg. 3. The crystals are more acicular, and have a higher 
metallic lustre, in the northern than in the southern leg of the 
syphon. Thesame experiment has been successfully repeated 
by Deebereiner and Schweigger, from whose Journal the above 
details are extracted. —£din. Phil. Journ. 
ACCOUNT OF PROFESSOR BERZELIUS’S METHOD OF DETECTING 
ARSENIC IN THE BODIES OF PERSONS POISONED. 
Professor Berzelius has lately given some instructions for 
the discovery of arsenic in persons that have been poisoned 
with it.. He considers the reduction of arsenic to the metallic 
state as the only incontestible proof of the presence of this poison. 
Arsenic may occur in two ways, viz. when it is found in sub- 
stance (in the state of arsenious acid) in the dead body, and 
when it is not found in this state; though the intestines of 
the dead body may contain it in the state of a solution. 
_-In the first of these cases, it is easy to:determine the pre- 
sence of arsenic. In order to do this, take a piece about three 
inches long of an ordinary barometer tube, and having drawn 
out one end of it into a much narrower tube, close the nar- 
rower end. Let some of the arsenic found in the body be now 
put in at.the open wide end, so that it may fall down to 
the narrow end. Any quantity of this arsenic of sufficient 
volume to be taken from the body will suffice for this 
Sen purpose. 
