pancalstite
donald haarmann
NOTE ON SO-CALLED "PANCLASTITE."
BY H. SPRENGEL, PH.D., F.R.S.
IN " Notice sur la Panclastite, etc., 'par' Eugène
Turpin, Paris, E. Bernard & Cie., 1882, we read :—
P. 11.-" PANCLASTITE. (Brise tout;—de: ----, tout; ---, je brise.) Explosifs à base
de peroxyde d'azote.
" Principe dècouvert par Eug. Turpin (1878 à 1882).
" Le corps comburant est le peroxyde d'azote pur et anhydre à l'état liquide.
" Cette section a cela de tout à fait remarquable, c'est qu'aucun des produits qui
entrent dans la composition des nombreux explosifs qui en font partie n'a jamais
été employé à la connection d' un autre mélange détonant. 'Le comburant ou les
combustibles n'ont jamais été a appliqúes aucun cas, dans ce but, soit
ensemble, soit séparément, tandis que dans les lre, 2e et 4e sections on
retrouve le soufre et le charbon.
" Recherchant de suite toute ce que pouvait lui donner la découverte de ce
nouveau principe, M. Turpin est parvenu à produire plus de cent explosifs
nouveaux, c'est-à-dire un nombre plus considérable que celui qui comprend tons
les explosifs connus antérieurement. "
P. 5. " La Panclastite est dans ce dernier cas. Déconverte par M. Eugène Turpin,
elle constitue une invention de principe qu'il ne faut pas confondre avec une
invention reposant sur des principes connus, ce qui est le cas de la dynamite ;
les inventions de principe sont extrêmement rares et tendent à diminuer encore
au fur et à mesiire lue le progrès se développe, tandis que les inventions d'
application ou de perfectionnement augmentent constamment."
On this "invention de principe" Sir Frederick Abel, in his Presidential Address at
the annual meeting of the Society of Chemical Industry, July 11, 1883 (vol. ii. p.
313), kindly expresses himself thus :-
" Sprengel urged that the facts brought forward by him were susceptible of
important application, because powerful explosive cartridges or charges might at
any time be rapidly prepared from two ingredients which, kept separately, are
non-explosive. The suggestion to deal, in mining or military operations, with
highly corrosive and more or less volatile liquids, upon the extensive scale which
would be necessary if Sprengel's system were turned to practical account, has
not commended itself to those experienced in such matters ; but attention has
quite recently been directed to the subject by a M. Eugène Türpin, who puts
forward as an invention of his own what he calls it a new series of explosives,
which he has christened 'Panclastite,' but which are actually Sprengel's explosive
mixtures. In his memoir of 1873, Sprengel gives a table of the total percentages
of oxygen, an the percentages of available oxygen, in a great number of
oxidising agents, and the superiority of monohydrate of nitric acid over the
majority in the latter respect is there shown. Turpin uses, or says he uses,
anhydrous nitrogen peroxide as the oxidising agent in his Panclastite series,
together with carbon bisulphite or nitro products of hydrocarbons. He therefore
carries out Sprengel's suggestions, selecting for the purpose an oxidising a
agent of comparatively costly and inconvenient nature, and certainly not superior
in oxidising power to the strongest commercial nitric acid. The publication in
France of researches or inventions as original, the results or description of which
have long been published in England, is an occurrence to which we are not un-
accustomed, and so the performances of Sprengel's offspring, furnished by M.
Turpin with an impressive family name, are exhibited at Chatou-Rueil, near Saint
Germain, with much flourish of trumpets, and have recently been officially
reported upon by a Royal Engineer officer as marvels of novelty and of explosive
power."
Though it may appear to be, somewhat late to refer at this time to the foregoing
comments on my paper in the Journal of the Chemical Society of August, 1873, I
hope that the importance which this matter promises to attain will excuse and
justify the following note:—
Note—The " beau idéal " of a detonating explosive is a mixture of 8 parts (88.9
per cent.) of liquid oxygen and 1 part (11.1 per cent.) of liquid hydrogen.
In my paper of 1873 I say (page 799) :—"On referring to the foregoing table the
reader will be reminded that peroxide of hydrogen is the highest oxygen
compound known, while nitric anhydride is the compound which contains the
largest amount of oxygen available for combustion (74 per cent.). But as this
compound, as well as the next two, nitric peroxide (69.5 per cent. oxygen) and
tetranitromethane (65.3 per cent. oxygen) are, at present, on account of their
nature and their difficult preparation, mere chemical curiosities, my attention
naturally turned to the fourth, to nitric acid (63.5 per cent. oxygen), which is a
cheap and common article of commerce."
Now when M. Turpin's attention turned to the second oxidiser on my list—to
nitric peroxide—he found that this substance does not corrode metals, such as
iron, copper, and tin under 356o F. (180o C.) ; and further, that combustible
liquids, such as petroleum, carbon bisuphide, and nitrobenzene are readily
soluble in nitric peroxide without rise of temperature. These are valuable
properties, first noticed by M. Turpin.
What was formerly a chemical curiosity is now an article of commerce. Nitric
peroxide maybe bought to-day at eighteen-pence the pound, an I see ways and
means of producing it a great deal more cheaply. Nitric peroxide is a yellowish
liquid, heavier than water (sp. gr. = 1.451) and boils at 71 o F. (22 o C.), but may
be kept like ether or similar volatile liquids. In France it is sent about in
tinned-iron cans.
Taking as a typical example a benzene mixture
[17.0 C ]
C 6H6 = 18.4 = [1.4 H ] = 62.6 CO2
[56.8 O ] 12.6 H2 O
7 ½ (NO2) = 81.6 N = 21.8 N
———-
100.0
we see that the 18.4 parts of benzene require 56.8 parts of oxygen for the
oxidation of their carbon and hydrogen to carbonic acid and water. This oxidation
or combustion takes place at the moment of explosion at the expense of the 56.8
parts of oxygen contained in the rest of the mixture—the 81.6 parts of nitric
peroxide. No other explosive now in use (including blasting gelatin) contains
weight for weight a greater amount of combustible matter, and as an explosion of
these bodies is simply a sudden combustion, I again beg to draw attention to the
fact that the oxygen available for combustion in gun-cotton is most probably not
more than 32.3 per cent, and in nitro-glycerin 42.3 per cent. while in this , we
have, without a doubt, 56.8 per cent. Hence no other explosive now in use can
rival this and similar mixtures in power, as I published in 1873. They still remain
the most powerful explosives known.
It hardly need be said that an explosive of this nature consists of two parts—an
oxidising and a combustible agent,—and that M. Turpin with the same naïveté
lays claim not only to the first, but also to the latter half of the subject.
None of my safety explosives are licensed in England, though many of them
when mixed, are much less sensitive to concussion than common gunpowder.
--
donald j haarmann
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...the results of an explosion are
visited upon all in the vicinity.
Dr. WG Hudson ca 1918