less. He
claims that the powder is tested in its natural state, all the products of
decomposition are taken into account, whilst in the old tests only the
acid products are shown, and in the Will test only nitrogen, that it
affords an indication of the effect of small quantities of added
substances or foreign matters on the stability and that it is simple, and
not subject to the variations of the old tests.

Obermueller (_Jour. Soc. Chem. Ind._, April 15, 1905) considers Bergmann
and Junk's test is too complicated and occupies too much time; he proposes
to heat gun-cotton to 140 deg. C. _in vacuo_, and to measure continuously by
means of a mercury manometer the pressure exerted by the evolved gases,
the latter being maintained at constant volume; the rate at which the
pressure increases is a measure of the rate of decomposition of the nitro-
cellulose.

SPECIFIC GRAVITIES OF EXPLOSIVES, &C.

Nitro-glycerine 1.6
Gun-cotton (dry) 1.06
" (25 per cent. water) 1.32
Dynamite No. 1 1.62
Blasting gelatine 1.54
Gelatine dynamite 1.55
Ballistite 1.6
Forcite 1.51
Tonite 1.28
Roburite 1.40
Bellite 1.2-1.4
Carbo-dynamite 1.5
Turpin's cast picric acid 1.6
Nitro-mannite 1.6
Nitro-starch 1.5
Emmensite 1.8
Mono-nitro-benzene 1.2
Meta-di-nitro-benzene 1.575 at 18 deg. C.
Ortho-di-nitro-benzene 1.590 "
Para-di-nitro-benzene 1.625 "
British gunpowder, E.X.E. 1.80
" " S.B.C. 1.85
Cannonite (powder) 1.60
Celluloid 1.35
Cellulose 1.45
Ammonium nitrate 1.707
Mercury fulminate 4.42

TABLE OF THE TEMPERATURE OF DETONATION.

Blasting gelatine 3220 deg.
Nitro-glycerine 3170 deg.
Dynamite 2940 deg.
Gun-cotton 2650 deg.
Tonite 2648 deg.
Picric acid 2620 deg.
Roburite 2100 deg.
Ammonia nitrate 1130 deg.

RELATIVE SENSITIVENESS TO DETONATION (by Professor C.E. Munroe, U.S. Naval
Torpedo Station).

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