CHEMICAL AND PHARMACEUTIC MANIPULATIONS. 109 
wire gauze. The interior is fitted with trellis shelves for the 
support of the wooden frames, stretched over with white 
muslin, and upon which the substance rests between or 
upon, as may be required, folds of bibulous white paper. 
The heat is communicated by sheet iron flues proceeding 
from a stove placed outside of the enclosure, or by means 
of steam pipes fed by the generator. The temperatures 
should range from 75 to 100° F. 
This apartment is also useful for pharmaceutical pur* 
poses, for drying plants, roots, seeds, woods, &c. They 
may either be suspended or spread in thin layers upon 
frames, and repeatedly turned for the purpose of exposing 
fresh surfaces. 
The air chamber of the furnace may, to a limited extent, be 
made to replace this apartment, and in an experimental labo- 
ratory it is, together with the means mentioned in this chap- 
ter, sufficient for all purposes. 
As the salts effloresced as above still retain a little water, 
they require to be repeatedly pressed between the folds of 
white paper until dampness ceases to be imparted to them, 
Sometimes a previous trituration is necessary to facilitate 
the process. 
Fig. 8. 
Filters containing precipitates, after careful removal from 
the funnel and compression between the folds of bibulous 
paper, may be further dried in the same manner. Those, 
however, which contain the results of analytic experiments 
require more careful manipulation. For their treatment a 
copper-plate oven is olten used. It consists (Fig. 8) of a 
10 
