ORIGINAL COMMUNICATIONS. 
the use of them, with Mr. Boutron, in a course of experi- 
ments when treating bitter almonds with ether, he remarked, 
that the ether acted in the manner of a piston, driving out 
the oil at a distance before it, without mixing with it ; and 
we must not forget the experiments of Vauquelin, who veri- 
fied the principle of displacement, by causing fresh and salt 
water alternately to pass through sand. These facts possess 
claims entitled to consideration, inasmuch as they contri- 
buted to the establishment of this theory. 
But to the Messrs. Boullay belongs the honor of having 
established what was before a mere hypothesis. By their re- 
searches they not only proved that it admitted of very 
extensive application, but by furnishing practical results in 
some new and efficient preparations, they demonstrated it 
to be of the highest utility in pharmacy. 
As it is necessary to bring into review what has been 
already written for the proper understanding of the subject 
before us, and as several elaborate treatises have been given by 
Messrs. Boullay, and a very able one by Mr. Guillermond, 
of Lyons, wherein they fully detail the modus operandi of the 
methode de deplacement, and the results of their experiments, 
I cannot but avail myself of their labors; and though clothing 
their language in other words, and abridging the voluminous 
matter with the view to conciseness, I shall endeavor to do 
them justice. 
The methode de deplacement is founded upon the ejectment 
of a quantity of liquid with which a powder may be saturated, 
by being subjected, in a proper instrument, to the action of a 
column of liquid, equal in quantity to that you would withdraw; 
or in other words, " a liquid impregnated with the soluble 
parts of a powder, in the midst of which it is interposed, 
abandons this powder when another liquid is made to act 
upon it." 
To illustrate, Saturate with its menstruum some vegetable 
matter, in such a state of division as renders the liquid sus- 
ceptible of ready contact with its particles, and then place it 
upon a funnel; by the addition of a column of water, alcohol, 
