CHEMICAL SCIENCE. 271 



into and through the cylinders; the color is externally brown, and yellowish- 

 gray when freshly fractured. The hardness is greater than calc spar or 

 dolomite, and nearly that of fluor spar. Specific gravity, 2.414; and the 

 general appearance that of the imitative forms of brown iron ore. 



Boiling distilled water dissolves an organic salt of lime, and the solution 

 has a strong earthy odor. Carbonate of soda solution takes up crenic and 

 humic acids. There are no other acids or bases present. One hundred parts 

 consist of 



Organic acids and moisture, 14.46 



Carbonate of lime, 72.82 



Magnesia as a base, 



Bi-phosphate of magnesia, 



A little silica and a mere trace of carbonate of iron were detected. The 

 composition of this substance indicates that crenates of lime and magnesia, 

 and some ammonia phosphate of magnesia, were absorbed from the soil, and 

 in the subsequent decomposition the carbonate of lime formed Avas rendered 

 more compact and hard by the portion of crenate which is undecomposed 

 acting as a cement; the humus and humic acids are the usual attendants of 

 this decomposition. The mineral substance in such cases has hitherto been 

 found occupying the space near the concentric rings of a tree; and not the 

 medullary canal, as in this instance. 



CONSOLIDATED GUNPOWDER. 



Up to the present time the received opinion among the several authorities 

 on gunnery has been that gunpowder must be presented to the action of the 

 firing material in a granulated condition, in order to make it explode readily. 

 Great care has always been taken to proportion the size of the grains to the 

 wants of each gun, it being supposed that the powder would burn more or 

 less rapidly in accordance with the size of the grains. Captain Brown, R. A., 

 of Woolwich, England, has, however, recently introduced with success a 

 powder consolidated into somewhat porous cakes, but compressed into a 

 space one-fourth less than it occupied as ordinary powder. The process by 

 which consolidation is effected is not made public; but, as the compressed 

 powder explodes at a slightly lower temperature than ordinary gunpowder, 

 we conclude that some solution of an explosive compound, similar to gun- 

 cotton, is emplo3*ed. We are assured that the cylinders which have been 

 given us for the purpose of experimenting on are composed of government 

 powder; and undoubtedly their appearance is exactly like that which might 

 be expected from this well-known material, supposing it to be compressed 

 and united by some adhesive substance. They are of the Enfield bore, 

 containing two and one half drams of powder, capable of resisting any 

 ordinary force, and not breaking to pieces without being submitted to some 

 strong cutting or crushing instrument. Hence they may safely be carried 

 loosely in a cartouch box divided into compartments, and they may each 

 readily be united to a ball by means of any gummy matter, with or without 

 paper or a patch. We have tried these cylinders, and find them to explode 

 ju>t as sharply as ordinary powder, and apparently with the same power 

 and with as little residuum. On placing them on an iron, heated over a 



