330 transactions of the american institute. 



China Grass. 



The report of M. Cordier, of the Chamber of Commerce, first broi]{:^ht this 

 article into notice, and the manufacturers of Rouen, France, *dre turhing 

 their attention to its use. Specimens in all stages of its preparation are 

 shown, and recently samples of its tissue mixed with wool and cotton have 

 been exhibited. 



Mr. Bartlctt stated that tlie grass alluded to had been manufactured into 

 cloth in Massachusetts more than a j'ear ago. 



Explosive Compounds. - 



Mr. Scott Russell has repeated before the Royal Institution, London, the 

 opinions expressed by him at the last meeting of the British Association 

 for the Advancement of Science, regarding the force, cleanliness, and com- 

 parative safety of Baron Lenk's gun cotton. He spoke also of the uncer- 

 tainty, as a chemical composition, of gunpowder, and expressed his convic- 

 tion that 68 per cent (solid matter) of its ingredients were useless, and 

 encumbered the action of the remaining 32 gaseous parts. 



In relation to this item, Mr. Samuel H. Maynard remarked that the ex- 

 periments with gun cotton in this country had not been as successful as 

 was expected. Baron Lenk's compound is woven into ropes or fine threads 

 in order that the whole product will be isochronal in its explosion, but this 

 regularity in the time of explosion does not seem to have been accomplished. 

 If gun-cotton is rammed down into a gun it may at first work well, but if, 

 again, it is rammed down too hard it will explode and burst ttie gun. The 

 difficulty is that, in getting the ball down it may often be necessary to give 

 the ball an extra ram, and this will cause a premature explosion. Gun- 

 cotton possesses many good qualities; one of the best is that it does not 

 absorb moisture; it is also very light. Perhaps the danger of premature 

 explosions might be avoided by making it into cartridges. For blasting- 

 purposes it is valuable, but for guns it is too quick in its action. Dr. Do- 

 remus, of tliis city, was the first to make two charges of gunpowder into 

 one, and have them burn the same length of time as one charge. 



Mr. Bartlctt said that the chemical peculiarity of Baron Lenk's gun-cot- 

 ton was that it contained more oxygen than the ordinary kind. He inquired 

 whether Dr. Doremus' gunpowder was still used in the army. 



Mr. Maynard knew it had been very largely used in the six-pound batte- 

 ries. Officers connected with them have expressed a preference for it, as 

 it leaves nothing in the gun that requires swabbing out. Therefore it is 

 not necessary to cover the touchhole with the finger while re-loading. This 

 pressed or cake powder, invented by Doremus, is highly prized in France 

 and Austria. 



Mr. Page said that the 68 per cent of gunpowder, the solid part spoken 

 of as useless, was a large amount to.be transported, but is not the solid 

 matter really essential to hold the gases resulting from the explosion in a 

 solid form before they are used ? 



Mr. Maynard stated that interesting experiments are now being made 

 regarding the feasibility of dispensing with some of the solid constituents, 

 by parties in this country. 



