Cotton, Schultze Gunpowder, E.C. Powder, &c.: A. Compressed Gun-
Cotton.~--Sufficient material to serve for two or more tests is removed
from the centre of the cartridge by gentle scraping, and if necessary,
further reduced by rubbing between the fingers. The fine powder thus
produced is spread out in a thin layer upon a paper tray 6 inches by 4-1/2
inches, which is then placed inside a water oven, kept as nearly as
possible at 120 deg. F. (49 deg. C.). The wire gauze shelves of the oven should be
about 3 inches apart. The sample is allowed to remain at rest for fifteen
minutes in the oven, the door of which is left wide open. After the lapse
of fifteen minutes the tray is removed and exposed to the air of the room
for two hours, the sample being at some point within that time rubbed upon
the tray with the hand, in order to reduce it to a fine and uniform state
of division.

The heat test is performed as before, except that the temperature of the
bath is kept at 170 deg. F. (66 deg. C.), and regulator set to maintain that
temperature. Twenty grains (1.296 grm.) are used, placed in the test tube,
gently pressed down until it occupies a space of as nearly as possible
1-5/10 inch in the test tube of dimensions previously specified. The fine
cotton adhering to the sides of the tube can be removed by a clean cloth
or silk handkerchief. The paper is moistened by touching the upper edge
with a drop of the 50 per cent. glycerine solution, the tube inserted in
the bath to a depth of 2-1/2 inches, measured from the cover, the
regulator and thermometer being inserted to the same depth. The test paper
is to be kept near the top of the test tube, but clear of the cork, until
the tube has been immersed for about five minutes. A ring of moisture will
about this time be deposited upon the sides of the test tube, a little
above the cover of the bath. The glass rod must then be lowered until the
lower margin of the moistened part of the paper is on a level with the
bottom of the ring of moisture in the tube. The paper is now closely
watched, The test is complete when a very faint brown coloration makes its
appearance at the line of boundary between the dry and moist parts of the
paper. It must stand the test for not less than ten minutes at 170 deg. F.
(The time is reckoned from the first insertion of the tube in the bath
until the appearance of a discoloration of the test paper.)

~B. Schultze Powder, E.C. Powder, Collodion-Cotton, &c.~-