THE 
AMERICAN JOURNAL 
OF 
PHARMACY. 
APRIL., 183 8. 
ORIGINAL COMMUNICATIONS. 
ART. I. — BOULLAY'S FILTER AND SYSTEM OF DIS- 
PLACEMENT, WITH OBSERVATIONS DRAWN FROM 
EXPERIENCE. By Augustine Duhamel. 
The term methode de deplacement , is of recent origin, 
and is applied to a mode of extraction by hydrostatic pressure, 
practically known for more than twenty years in Ger- 
many and elsewhere, though very limited in its application. 
It was bestowed by Mr. Boullay and Son, in 1833, who, by 
a development of the theory of this phenomenon, conferred 
inestimable benefit upon science. 
The instrument employed for the purpose, was modelled 
after the cafetiere de Dubelloy, an apparatus once limited to 
the confines of the cuisine, but withdrawn from its humble 
sphere by the wisdom and foresight of Messrs. Boullay, to 
be rendered subservient to the uses of a scientific profession, 
in a more exalted and varied range of application. 
Conjointly with the coffee apparatus of Dubelloy, the 
filter press of Real, of which the other is a modification, and 
the filter of Dumont, used for the decoloration of syrups by 
charcoal, were instruments in use, affording a practical illus- 
tration of this method. Besides these, the long adapters of 
Mr. Robiquet, placed in a matrass, should be noticed. In 
VOL. iv. — no. i. 1 
