The first essays tried by Messrs. Pelouze and Prelat, and those of Lassaigne have proved, without any contest, the remarkable energy of the new powder; but in these essays, the ballistic pendulum had not been used, and the substance employed was principally nitric paper. Messrs. Seguier and Clerget by using this paper have established the superiority of this new agent over hunting powder, and it has been admitted that at equal weight its force is about four times greater than that of the ordinary gunpowder. Soon this proportion was substituted by that of one to three, result of experiments made with the ballistic pendulum, and communicated by M. Arago.

However, the committee of artillery, established in France, was unfavorable to the new powder. Messrs. Piobert and Morin named inconveniences, which, in reality, were due only to defective process of preparation, such as the residues of water and charcoal; and those two savants came to the conclusion that this singular substance did not seem proper to substitute for gunpowder.

The discussion was animated on both sides, and in a communication made to the Academy of Sciences, Mr. Piobert insisted on the bursting properties of gun cotton, which he looks upon as a spring of dangers, and a cause of inferiority, relatively to gunpowder, in the use of fire-arms. He speaks of two proof mortars of cast iron, broken by small proportions of pyroxyline. On the other hand, Messrs. Seguier and Clerget, continuing their experiments, announced the following results: -

Standard

Ballistic effects of a charge of common hunting powder. Distance, 45 feet. Load, 6 grains. Target, cast-iron plate. Effect, flattened half of the bullet

1st Comparative Essay. Load of gun cotton, 6 grains. Effect, dissemination of the bullet in lead spangles.

2d Essay.

Load, 3 grains.

Effect, flattening the bullet into tbe form of a sun to 3/4 of its original diameter,

3d Essay.

Load, 1 grain.

Effect, similar to the standard shot with 6 grains of ordinary powder.

We see, that with 1/6 of gun cotton, the results are the same as with ordinary gunpowder.

Struck by the inconveniences, and the dreadful examples indicated by Mr. Piobert, Seguier tried if it could not be possible to avoid the effects of a too instantaneous production of gas. In his researches, he tried the experiments of Mr. Piobert himself, who ought to have known that in working a mass of powder into a spheroid form, the slowness of the combustion follows a certain law, and is in proportion to the diameter of the sphere.

It is this delay in the deflagration which suggested to Mr. Seguier the idea of studying the influence of the bringing together of the fibres of the gun cotton, on the duration of the combustion of this cotton in fire-arms, and con-sequently the difference of its ballistic effects. Having taken for a standard the ballistic results of one grain of cotton, given above, ho loaded successively the gun, with the same weight of a kind of lint, proceeding from tissues of cotton of different thicknesses of threads. He ascertained that this lint furnished ballistic effects superior to cotton. Besides, ho ascertained that the superiority of the effects was more marked with the barrel of a musket, 2 feet long, than with that of a pistol 9 inches long.

Numerous experiments have been made, but much is still left unachieved on this subject Mr. Payen has demonstrated that the mode of preparation of the pyroxyline has a great influence on the ballistic properties of the effects obtained. Mr. Morin has tried with the ballistic pendulum two products of the same cotton, one prepared with pure sulphuric and nitric acids in the proportion of equal equivalents, the other with the same mixture containing gaseous hyponitric acid.

The following table indicates the great difference in the properties of the two products: -

Thirty-one grains of pyroxyle prepared on a large scale, with cotton and ordinary acid, give to a bullet a mean velocity of 342 yards.

Such are the results of experiments made carefully by competent men. It is to be desired that this subject should bo more fully investigated.

The following views touching it are from the anniversary address of the President of the Royal Society of Great Britain, for this year (1864), and are certainly entitled to respect and consideration.

"The advantages which are claimed for gun cotton over gunpowder for ordnance purposes and mining operations are so many and so important as to call for the fullest investigation. The absence of smoke and the entire freedom from the fouling of the gun, are points of great moment in promoting the rapidity of fire and the accuracy of aim of guns employed in casemates, or in the between decks of ships of war. To these we must add the innocuous character of the products of combustion in comparison with those of gunpowder, and the far inferior heat imparted to the gun itself by repeated and rapid discharges. With equal projectile effects, the weight of the charge of gun cotton is but one-third of that of gunpowder; the recoil is stated to be reduced in the proportion of 2 to 3, and the length of the gun itself to admit of a diminution of nearly one-third. These conclusions are based on the evidence of long and apparently very carefully conducted courses of experiments in the imperial factory in the neighborhood of Vienna. The results appear to be especially deserving the attention of those who are engaged in the important problems of facilitating the employment of guns of largo calibre and of great projectile force in the broadsides of our line-of-battle ships, and in reducing, as far as may be possible, the ports. When the material was first introduced by Schoenbein, in 1846, its distinctive qualities in comparison with gunpowder were recognized. To the employment of gun cotton, as then known, there was, however, a fatal drawback in its liability to spontaneous combustion. The elaborate experiments of the Austrian General Von Lenk have shown that this lia-bility was duo to imperfection in its preparation! and ceases altogether when suitable pro-cesses are adopted in its manufacture. Perfect gun cotton is a definite chemical compound; and certain processes for the removal of all extraneous matter and of every trace of free acid are absolutely indispensable. But, when thus prepared, it appears to be no longer liable to spontaneous combustion: it can be transported with perfect security, or bo stored for any length of time without danger of deterio-ration. It is not impaired by damp, and may be submerged without injury, its original qual-ities returning unchanged on its being dried in the open air, and at ordinary temperatures. "A scarcely less important point towards the utilization of gun cotton, and the safety with which it may be employed in gunnery, is the power of modifying and regulating its explosive energy at pleasure, by means of variations in the mechanical structure of the cartridge, and in the relative size of the chamber in which it is fired."