GUN-COTTON. 
Ill 
In some experiments with the ignited platinum-wire hermetically sealed into a tube 
of glass, the end of the tube containing the platinum wire was placed in a larger tube 
of oil, to lessen the risk of cracking the glass. After some days’ experimenting, though 
the sealing remained perfect, a slight portion of carbon was found in the interior liquid. 
Tliis does not affect the results of my experiments, as I repeated them with glass tubes 
closed at the end and without platinum wires, and also without the oil-bath; but it 
shows how difficult it is to exclude sources of error. When water has been deprived of 
air to the greatest practicable extent, it becomes very avid for air. The following ex¬ 
periment is an instance of this:—A single pair of the gas-battery, the liquid in which 
was cut off from the external air by a greased glass stopper, having one tube filled with 
water, the other with hydrogen, the platinized platinum plates in each of these tubes 
were connected with a galvanometer, and a deflection took place from the reaction of 
the hydrogen on the air dissolved in the water. After a time the deflection abated, and 
the needle returned to zero, all the oxygen of the air having become combined with the 
hydrogen. If now the stopper were taken out, a deflection of the galvanometric needle 
immediately took place, showing that the arr rapidly enters the water, as water would 
a sponge. Absolute chemical purity in the ingredients is a matter, for refined experi¬ 
ments, almost unattainable; the more delicate the test, the more some minute residual 
product is detected; it would seem (to put the proposition in a somewhat exaggerated 
form) that in nature everything is to be found in anything if we carefully look for it. 
I have indicated the above sources of error to show the close pursuit that is necessary 
when looking for these minute residual phenomena. Enough has, I trust, been shown 
in the above experiments to lead to the conclusion that, hitherto, simple boiling, in 
the sense of a liquid being expanded by heat into its vapour without being decomposed 
or having permanent gas eliminated from it, is a thing unknown. Whether such boiling 
can take place may be regarded as an open question, though I incline to think it can¬ 
not ; that if water, for instance, could be absolutely deprived of nitrogen, it would not 
boil until some portion of it was decomposed ; that the physical severance of the mole¬ 
cules by heat is also a chemical severance. If there be anything in this theoretic view, 
there is great promise of important results on elementary liquids, if the difficulties to 
which I have alluded can be got over. 
The constant appearance of nitrogen in water, when boiled off out of contact with 
the air almost to the last drop, is a matter well worthy of investigation. I will not 
speculate on what possible chemical connection there may be between air and water ; 
the preponderance of these two substances on the surface of our planet, and the proba¬ 
bility that nitrogen is not the inert diluent in respiration that is generally supposed, 
might give rise to not irrational conjectures on some unknown bond between air and 
water. But it would be rash to announce any theory on such a subject; better to 
test any guess one may make, by experiment, than to mislead by theory without suffi¬ 
cient data, or to lessen the value of facts by connecting them with erroneous hypotheses. 
GUN-COTTON. 
BY JOHN SCOTT RUSSELL, C.E., F.R.S. 
The elements are proverbially good servants, but bad masters—Eire, water, wind, and 
steam are fierce demons when they get the upper hand; yet what would civilization be, 
wanting the fire of the kitchen, the smith’s hearth, and the foundry ; how should we be, 
without seas to carry our boats or rivers to turn our mills ? Commerce and merchandise 
are mainly conducted by the wind and the sails of our merchantmen ; and steam clothes 
us, and carries us from city to farm, and from island to continent; yet the earthquake, 
the volcano, the conflagration, the torrent, the storm, the hurricane, and the explosion 
—what are they but servants become masters ? 
It is peculiarly true of steam and gunpowder that they are among the most useful 
and most dangerous of human inventions ; but danger in both is generally admitted to 
be a matter merely of skill and care. No one proposes to put down railways because a 
locomotive explodes, or to give up shooting because a gun has burst, or a gunpowder 
manufactory blown up. 
Gun-cotton is a new power coming under the same category as steam and gunpowder. 
It is highly dangerous to those who do not possess the necessary knowledge and skill; 
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