THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
[January 25,18?3. 
reason Toeing that the weaker packages are opened up by 
comparatively feeble pressure from within, hence when 
the contents of a box become raised to the inflaming 
temperature,, or become ignited by the penetration of 
flame to the interior, the pressure developed by the first 
ignition is not sustained by the box to a sufficient extent 
or for a sufficient time to bring about explosion. 
On the occasion of the Stowmarket accident there were 
two storesheds containing gun-cotton packed in boxes of 
light construction, which were ignited by the first explo¬ 
sion and burned out without exploding, while a third, 
which contained gun-cotton packed in the strong Go¬ 
vernment boxes, exploded with great violence after hav¬ 
ing been in flames for some time. 
Simple experiments demonstrate that if any explosive 
-compound or mixture be ignited when in a heated con¬ 
dition, it will-burn with a violence proportionate to the 
temperature to which it has been previously heated; if 
this be near the exploding point, explosion must ensue, 
which will be violent in proportion to the strength of 
confinement of the material. A practical demonstration 
of this was furnished by an explosion which occurred at 
Woolwich in 1866. Several very strong packages (metal 
lined-cases) filled with Von Lenk’s gun-cotton, some of 
which had been purposely left impure, had been exposed 
for seven months to artificial heat in a strong brickwork 
chamber, heated by steam. The impure gun-cotton in 
.some of the packages was then known to be in a decom¬ 
posing state, but the experiment was continued, and 
•eventually spontaneous ignition occurred and at a time 
when the boxes were heated to the maximum tempera¬ 
ture. The result was a violent explosion of all the 
packages; the very strong confinement and the heated 
condition of the gun-cotton which ignited, added to its 
being at the time in a state of chemical activity, de¬ 
termined its explosion, and the explosion of the other 
packages was a necessary consequence of the violent 
concussion to which they were exposed. 
There can be no doubt that the results of the recent 
experiments and of those made last year, as also the 
results of the Stowmarket accident, have to be considered 
in relation to the quantities of gun-cotton operated upon, 
a3 well as to its confinement. The confinement of the 
eight strong packages by the layers of boxes which sur¬ 
rounded them on all sides in the Woolwich experiment, 
was probably quite as great as that afforded by the light 
-and roomy shed in which the twenty-four boxes of the 
same kind were placed in double layers, in the South 
•Coast experiments; yet in the latter case an explosion 
was developed, and not in the former with the smaller 
quantity. In the South Coast experiments, with 6 cwt. 
of gun-cotton, the explosions occurred eight seconds and 
ten seconds after the ignition of the gun-cotton ; in the 
Stowmarket magazine, where several tons of gun-cotton 
were stored, the explosion appears to have almost im¬ 
mediately followed ignition ; it must be borne in mind, 
however, that in this case much of the gun-cotton was 
very closely confined by the large number of surrounding 
packages, and that the temperature of the gun-cotton 
was already raised considerably throughout by long-con¬ 
tinued very hot weather. Both of these circumstances 
must have greatly favoured the very rapid development 
of explosion, independently of the much more intense 
heat generated by the rapid spreading of fire through a 
large proportion of the gun-cotton. 
The satisfactory results obtained in the South Coast 
experiments with the lightly-constructed boxes, with 
•employment of 6 cwt. of material, appear to have re¬ 
ceived confirmation from the result of an accident which 
^occurred in 1869 at Penryn, when a magazine of brick¬ 
work containing 20 cwt. of compressed gun-cotton, 
packed in boxes of light structure, was burned down 
without any explosion. But it is nevertheless very 
possible that a similar result would not be furnished by 
.several tons of gun-cotton similarly packed; the much 
higher temperature which would be developed in that 
case by the first spreading of the fire, and the additional 
confinement, due to the larger number of packages, 
might combine to develope conditions favourable to the 
violent explosion of some portion of the mass, though no 
doubt a much larger proportion would burn non-ex- 
plosively than if strong boxes were used. While, there¬ 
fore, in storing dry gun-cotton, the probability of violent 
explosions resulting from the accidental ignition of a 
magazine. may be considerably diminished, or at any 
rate the violence of a possible explosion much reduced, 
by storing the material in packages of which some por¬ 
tions .will yield readily to pressure from within, or by 
adopting any other storage arrangement whereby the 
rapid penetration of flame or heat between the compressed 
masses is promoted, it must be considered as conclusively 
established by. the last twelve months’ experience that 
such regulations as experience and prudence have 
rendered essential in connection with the storage of gun¬ 
powder and other explosive agents, must also apply to 
the storage of compressed gun-cotton when in the dry 
state. 
The rapid development which has taken place within 
the last few years in the industrial applications of power¬ 
ful explosive agents bids fair to continue. In illustration 
of this a brief reference may be made to some recent 
interesting results arrived at by Dr. Sprengel, who has 
observed that mixtures of liquid oxidizing agents (such 
as nitric acid) with liquid or solid oxidizable substances, 
may be made to detonate, as also mixtures of readily 
oxidizable liquids with solid oxidizing agents. Thus, 
mixtures of picric acid or of nitrobenzol with nitric acid, 
or of chlorate of potash with bisulphide of carbon, may 
be readily detonated, and are more or less violently de¬ 
structive in their action. 
Important advantages, in point of power in the one 
instance and of economy in the other, appear to be 
promised by the production, in compressed masses, of 
mixtures of gun-cotton pulp with considerable proportions 
of chlorate of potash or saltpetre. Even the efficiency of 
gunpowder itself as a mining agent has been decidedly 
augmented in some directions by the lecturer’s observa¬ 
tion that it is susceptible of violent explosion by detona¬ 
tion, like all other explosive preparations, and that strong 
confinement is consequently not essential to the develop¬ 
ment of its full explosive force. This observation has 
proved to be especially valuable in connection with sub¬ 
marine operations, for which the charges of gunpowder 
need no longer, as formerly, be confined in cases of great 
strength. There are several other directions in which 
the study of the behaviour of explosive agents, under 
conditions compatible with their practical application, 
promises to be fruitful of important results. 
RETAIL TRADERS, BEWARE! 
. Mr. Punch begs to apprise the Retail Trade that its 
time has come. Up with all the Shutters! Announce 
Sale by Auction at any Sacrifice. Listen to the 
Lancet :— 
“ The fact is, that retail trade is gone mad. There are far 
more shopkeepers than the wants of the public require, and 
they think themselves entitled to all the luxuries and enjoy¬ 
ments of life. Their wives, glorious in sealskin-jackets and 
redundant jewellery, are to be seen everywhere ; and the pre¬ 
tensions of the class are becoming a nuisance that it is high 
time to put down.” 
Put it down, then—pretensions, class, sealskin-jackets, 
and all! Surge , carnifex ! The Lancet and the Profes¬ 
sion have the matter in their own hands. If every 
Medical Man will undertake to exterminate— of course 
in a regular way—a single streetful of retailers and 
their families, the business may be done in the twinkling 
of a pestle and mortar. 
“Charge for the golden guineas. Upon them with the—* 
Lancet .” 
