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detected in the urine. The temperature of the skin is mode- 
rately elevated, and the insensible perspiration increased. On 
one occasion, having taken ten grains for a dose, it almost 
immediately caused an uneasy sensation at the epigastrium, 
accompanied with nausea that continued for several hours ; 
and a slight degree of head-ache. These symptoms were re- 
lieved by a copious stool, which was perfectly black. Two 
hours after swallowing the medicine, a large quantity of urine 
was discharged ; and on being tested, it displayed the pre- 
sence of both the iodine and the iron. — Am. Journ. Med. Scien. 
ART. LXII. ON THE EMPLOYMENT OF THE PROCESS OF DIS- 
PLACEMENT IN PHARMACEUTIC PREPARATIONS. By M. A. 
GuiLLERMONJ). 
A process long made use of in certain arts for the purpose 
of extracting the soluble principles of a substance, with the 
least possible quantity of a menstruum, has within a short 
time been happily applied in pharmacy. This process is 
founded on the fact, that a fluid impregnated with the soluble 
portions of a powder with which it is in contact, can be 
driven off by the addition of another fluid, or an additional 
quantity of the same fluid. Lixiviation, claying of sugars, 
&c. are well known applications of this fact, which was first 
announced by V^auquelin, who by alternately passing fresh 
and salt water through sand, verified that one fluid could be 
displaced by another. 
At a more recent period, M. M. Robiquet and Boutron in- 
troduced this process into organic chemistry, and remarked 
that on adding ether to powder of bitter almonds to obtain 
the fixed oil, the ether acted like a piston, and drove off the 
oil without mixing with it. But we are indebted to M. M. 
Boullay for a more extended application of this method, and 
