"The gravest charge made against this new explosive material was, that it was liable to spontaneous combustion, as was known to be the case with gun cotton made in the ordinary way. It was of the utmost importance that this vital question should be thoroughly investigated, and for this purpose a committee of the three first Austrian chemists was appointed to report upon this and other objections urged against the adoption of gun cotton for war purposes.

"The results of this investigation, made with great ability and extreme care, are highly satisfactory and furnish proofs, both theoretical and practical, that General Lenk's gun cotton is not liable to this fatal objection.

"The commission, after weighing maturely all that could be said in opposition to General Lenk's gun cotton, and its adoption for war purposes, closed their report with the following unqualified commendation: 'According to our experience up to the present time, June, 1863, we recognize in gun cotton from Hirtenberg an improved explosive compound, having many and great ad-vantages, several of which gunpowder from its very nature can never possess.'

"It has been urged that the gases of gun cotton were more poisonous than those of gunpowder, and on that account it could not be safely used in mines. The following table gives the analyses of the gases of combustion of General Lenk's gun cotton, as determined by Lieutenant Von Karoly, in the chemical laboratory of the engineer corps committee, and those of gunpowder by Bunsen.

"A comparison of the results, as above given, will show that the products of the combustion of either of the two materials contain gases which are irrespirable, and in this particular belong to the same class of gases. The relative quantities of some of those evolved from gun cotton are different from those produced from gunpowder, but they are both of such a nature as to require, that after an explosion of a mine with either gunpowder or gun cotton, the air should be renewed by ventilation before the place of the explosion can be approached without danger. The gases from the latter will be removed more quickly by ventilation than those from the former, as they contain in the latter case much solid matter which alone would suffice to make respiration almost impossible.

"The English Government has recently made experiments with the new explosive material, Baron Von Lenk having visited England, by invitation, for the purpose of assisting at the trials. More recently the French Government has taken up the subject, and is now engaged in an investigation into the merits of this new gun cotton.

"General Lenk is, at the request of the Emperor Napoleon, in France, to be present at these experiments. The attention of the United States Government was drawn to the success attending the experiments with gun cotton in Austria, by Mr. T. Carrisius, U. S. Consul at Vienna, and the Secretary of War has directed, experiments to be made to determine whether its merits are such as to warrant its introduction into our service, in whole or in part. These experiments will soon be commenced.

"There are many considerations which make it important for us that the subject should recive a full, fair, and impartial investigation.

"We are now dependent upon India for our supply of saltpetre. By the introduction of gun cotton, wo shall bo enabled to substitute for saltpetre, the nitrate of soda, found in South America, much nearer home, and more easy to be obtained, and from a supply of which we are not so liable to be cut off.

"We have a long extended coast to defend against new and most formidable modes of attack. Our large sea-coast guns will require the assistance of the most destructive explosive for their shells, and the most powerful subma-rine batteries that we can devise, to protect our sea-board cities from the attacks of hostile iron-clads.

"Gun cotton will not, probably, supersede the use of gunpowder; it may prove a valuable co-adjutant."