Evening star. [volume] (Washington, D.C.) 1854-1972, 1906-04-08
EXPLOSIVE LETTERS.
How They Are Made With illuminate
of Mercury.

OF Mercury.
From the Dundee Advertiser.
The Russian postal authorities not long
ago discovered amid the letters addressed
to three Russian ministers, and on the
same day. three explosive letters-one for
each One of the principal members of the
Paris municipal laboratory has recently
given an inquiring representative of the
Grand Illustre some details of the manufac-
ture Of these Internal machines. which.
looking harmless enough. can be treach-
erously slipped In among papers and letters
and infiict frightful injuries or death. One
of the most convenient of explosives for the
preparation of these criminal attempts is
illuminate OF mercury, the employment of
which, however, compared with the more
generally used explosives. such dynamite
and elaborated powders, is restricted The
reason is that illuminate Of mercury is dam
gerous in the hands of those who not
accustomed to handle chemical prepara-
tons. and 1t Is not easy to obtain.
illuminate of mercury is a salt which has
been known since 1880, and 1t is the most
powerful of all explosives, developing an
enormous force. 1t is sensitive to heat. to
even a slight shock, and to the action OF
concentrated sulphurc acid. Notwithstand-
ing the danger of handling 1t, this eXplo-
sive has sometimes been employed for GRIM
inal purposes notably by Orsini in the
bomb which was intended to murder Ma
poleon III. and quite recently in the at
tempt made at Paris on the life of Alfonso
XIII In 1894 explosive books were sent to
Madame Constans, whose husband was at
the time minister of the interior. also to Nj.
Treble, chief physician of the colonies, and
to NJ Etienne, assistant colonial secretary
of state In these cases the middle part of
the book followed out to receive box
containing illuminate of mercury and nails
and other projectiles. The pages were gum
med together, and the book could be opened
on one side only A "cosaque' (cracker),
that species of firework containing a YES
tfge of illuminate of silver, exploding by
friction, sand fixed i'll the bottom of the box,
was arranged so as to explode the charge
when an attempt was made to open the
book.
1t would seem at first sight to be some
what difficult to make an explosive letter
which should be capable of producing such
serious effects, from the fact that there is
SO little room in such a letter for a sutti-.
Client quantity of the explosive But, on the
other hand. very small quantities, a few
grains only, of illuminate are enough TO
cause terrible results. The letters accord
Ing to the Paris scientists. were made as
follows; A piece of corrugated packing
paper prepared four square holes
being cut in the smooth surface, and
the corrugations filed with illuminate of
mercury, over which thin paper was fas-
tened by cumming around the edges Then
decorators from bonbon crackers were
gummed to the little Internal machine and
also to the flap of the envelope in which it
was placed, so that If the envelope were
opened with a paper knife torn open the
charge would he exploded. illuminate of
mercury although, as has been said II is
difficult to buy, can be made with the few
materials and chemical reagents required to
produce the salt, provided that certain pre-
cautions are taken at the time when it Is
dried. When only a few grains are re-
quired, a little of the mercury of nitric acid
and alcohol easily obtainable suffice. The
manner of its manufacture is no secret,
and indeed, is described in treatises On
chemistry.