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ALIPHATIC NITRO COMPOUNDS 593

The high, values for the lead block expansion test given by mixtures of tetranitro-
methane with higher nitrated aromatic compounds are striking. On the other hand,

the rates of detonation of these mixture are lower than those of mixtures containing
lower nitrated compounds or benzene.

As illustrated by Table 13 1, the sensitiveness to impact of the same mixtures with

dinitrobenzene, TNT or tetryl is distinctly higher than that of pure dinitrobenzene,

TNT and tetryl.

Other component

m- Dinitrobenzene 19.5 12

α− Trinitrotoluene (^127)
Tetryl (^73)
TABLE 131
Sensitiveness of the
Sensitiveness to
impact of the
pure component mixture
(impact energy)
kgm
(impact energy)
kgm
These mixtures are also more sensitive to flame than nitro compounds alone
and can be ignited more readily. A mixture with benzene ignites most readily, hence
it can be inferred that ignition is initiated in the gaseous phase.
TOXICITY
Tetranitromethane is highly toxic. Kiese [48] found that 25 mg/per kg of body
weight of tetranitromethane slowly injected intravenously caused transitory
methaemoglobinaemia, as well as lung oedema and damage to the liver, kidney and
central nervous system. Tetranitromethane injected quickly caused necrosis
around the puncture which could be fatal.
PREPARATION
Shishkov obtained tetranitromethane by treating nitroform with a mixture
of fuming nitric acid with sulphuric acid. Pictet [67] found that tetranitromethane
was formed when nitric acid was reacted with acetic acid, or acetyl nitrate with
acetic anhydride.
For the preparation of tetranitromethane on the laboratory scale Chattaway’s
method [68] is commonly used. It consists in treating acetic anhydride with fuming
nitric acid at room temperature or below. After a few days the homogeneous solu-
tion is poured into water, causing the oily tetranitromethane to separate.
This method was applied in the U.S.A. on a larger scale by Nitroform Products
Co., Inc., Newark, N. Y. However, the plant was completely destroyed by an explo-
sion that occurred in the manufacture of tetranitromethane.
Investigation indicated [69] that the probable cause was a rise of temperature
in the mixing tank, where nitric acid and acetic anhydride reacted at a temperature