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UN REAGENTS ANT) THEIR USES. 
ART. XX.—REAGENTS AND THEIR USES. 
By Augustine Duhamel. 
REAGENT. 
Under this title is included all those nice chemical prepa- 
rations indispensably necessary for the use of the analytic 
chemist as tests. These, from the degree of purity demanded, 
have heretofore been required to be imported from distin- 
guished French houses, such as Robiquet, Pelletier and others, 
but of late this necessity has been saved us by the advanced 
state of chemistry in this country, and the existence here of 
laboratories that have acquired general confidence where- 
eyer known by the excellence of their products. Their pre- 
paration, however, is not confined to manufacturing chemists, 
as some of the Cabinets of Reactives, belonging to our Pro- 
fessors, have been supplied by the skill of a number of our apo- 
thecaries. These latter, who give any attention to this important 
branch, are so few in number that an experimental chemist is 
often at a loss to procure such of them as he may wish, out of 
two or three principal cities. 
Many, styling themselves " Apothecary and Chemist," 
limit their stock of chemicals to such substances as belong ex- 
clusively to the Materia Medica, and thereby neglect the ad- 
vantage that would accrue to them did they devote but a little 
attention to keeping on hand supplies of such pure chemical 
tests as are most needful in a chemical laboratory. 
The following substances, which should be pure, comprise 
those most commonly used for analyses of minerals, mineral 
waters, &c. The use to which these substances are applied 
is likewise indicated, which may not be without interest to 
many. 
Boracic Acid, used to discover small quantities of phos- 
phoric acid in minerals. 
