This was the invention of gun-cotton, made by Schonbein in Germany by the action of nitric and sulphuric acids on cotton, or some other form of cellulose. It was the first practical explosive that depended for its usefulness on the decomposition of a chemical compound, and not on the combustion of a mechanical mixture, like gunpowder. The explosive power of gun-cotton was declared by the chemist Abel to be fifty times that of an equal weight of the gunpowder of that day; but this does not mean that it possessed fifty times the energy. The action of gun-cotton is very much more sudden than that of gunpowder; and for that reason, it exerts a much greater force for an instant, and has much greater efficacy for such purposes as breaking into structures, bursting shells, etc. On the other hand, the very fact that its energy is developed with such suddenness, causes its force to fall to zero very soon, and makes it useless for such purposes as gunpowder fulfils in firing projectiles from guns. In a gun, especially in a long gun, the endeavor is made to keep down the pressure of the gas and prolong its continuance; so that the projectile will receive a comparatively gentle but prolonged push, that will start it gradually from its seat, and will continue to push it, and therefore to increase its velocity, all the way to the muzzle. Gun-cotton does not belong in the class with the typewriter and the telegraph, that merely assist men to transact business: gun-cotton transacts business "on its own account." Gun-cotton belongs in the class with the gun; and its main influence has been to increase the self-protectivity of the Machine. It has done this mainly by increasing the power of the submarine torpedo against the hulls of warships. It may be objected that both sides in a war between civilized nations would use torpedoes, that no persons except organizations controlled by civilized nations (such as those in warships) would use torpedoes, and that therefore, whatever effect the torpedo might have on the Machine is neutralized by the fact that two civilized bodies use it against each other. True; but the fact that the torpedo and the gun-cotton in it require a high degree of civilization in the people who use it, gives civilized people an immediate and tremendous advantage over uncivilized people; and furthermore, the fact that the torpedo and the gun-cotton in it depend for their ultimate effect not only on their being used, but on the degree of knowledge and skill with which they are used, gives an advantage to which every nation in any war is willing and able to utilize the most knowledge and exert the most skill. That is, the torpedo and the gun-cotton in it combine to give the advantage to the nations possessing the highest degree of civilization and willpower. They enable the Machine of the most highly civilized nation to protect itself if it will against the Machines of less highly civilized nations.