Process of Displacement. 
309 
for their having caused greater attention to be paid to it by 
pharmaceutists. 
M. Guillermond says, that all his experiments on the sub- 
ject were performed under the supervision of M. Soubeiran. 
He divides them into two classes; 1, treatments with water; 
2, with alcohol. 
In each of these series I followed, says he, three different 
modes of operating. 1. Maceration, or the method of M. 
Cadet, that is, moistening the powder with double its weight 
of water, subjecting it to the press after a maceration of 12 
hours, and replacing the expressed fluid by a fresh quantity, 
equal to the original weight of the powder: 
2d. Continued displacement: 
3d. Maceration and displacement, that is, subjecting the 
powder to displacement after a previous maceration. 
The two first operations were conducted simultaneously, 
and the results compared, that any differences that existed, 
might be at once perceived. 
The third was performed alone, except with a few sub- 
stances, in which case the results were compared with those 
of the two first. 
After having finished the experiments with alcohol, I was 
naturally led to examine if the displacement had taken place 
in as regular a manner as had been announced by M. M. 
Boullay. 
It need scarcely be observed that in all these experiments, 
the greatest care was taken to prevent contravening acci- 
dents or mistakes. In all cases I used distilled water; each 
substance was coarsely powdered, passed through a seive, 
and the fine powder which resulted, divided into equal portions 
according to the number of experiments to be performed. I 
employed glass funnels, in which the powder was retained at 
a certain height, by means of a little straw and a layer of 
cotton; the surface was covered with filtering paper, pierced 
with holes. Finally, the continued displacement was per- 
formed as exactly as possible, and in all cases, I divided the 
liquors as I collected them, and evaporated them on a stove. 
