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Nitro-Explosives: A Practical Treatise by P. Gerald Sanford
page 282 of 352 (80%)
tested must stand a temperature of 160° F. for a period of ten minutes
before producing a discoloration of the test paper corresponding in tint
to the standard paper.

_N.B._--Non-gelatinised nitro-glycerine preparations, from which the
nitro-glycerine cannot be expelled by water, are tested without any
previous separation of the ingredients, the temperature being as above
160° F., and the time being seven minutes.

~Gun-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° F. (49° 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° F. (66° 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
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