196 ANNUAL OF SCIENTIFIC DISCOVERY. 



A modification of this plan is proposed for extinguishing fires in 

 ships. It is proposed to fill with chalk or broken marble several flat 

 vessels, which are to be distributed in the lowest part of the ship, and 

 near them are to be placed vessels containing muriatic acid, which are 

 connected with other vessels of carbonate of lime by valved pipes. 

 These valves must be furnished with strong wires leading to the deck. 

 As soon as the fire shows itself, all ports and means of communication 

 with the open air must be stopped. The valves may then be opened 

 by means of the wires, and the acid will flow upon the carbonate of 

 lime, producing large quantities of carbonic acid. This gas, being 

 heavier than common air, will displace it, and the whole ship will be 

 filled with it, so that all combustion will be at once extinguished. 



VOLATILIZATION OF CARBON. 



BY the Comptes Rendus we learn that M. Despretz has commenced 

 a series of experiments on the fusion and volatilization of various re- 

 fractory substances. As one of his first results, he announces the 

 fusion and volatilization of carbon. He used a battery of 496 ele- 

 ments in four parallel series. Carbon from sugar in an " oeuf elec- 

 trique" was subjected to its action; a high degree of incandescence 

 was produced, and the globe was covered with a black powder, dry 

 and crystalline. After many precautions to test the reality of the re- 

 sult, and various changes in the mode of experiment, Despretz satis- 

 fied himself that the effect was owing to a volatilization of the carbon. 

 In one case, when the carbon reached a white heat, some white traces 

 were deposited on the sides of the vase ; then suddenly it was reduced 

 to a state of vapor, with nearly the appearance which iodine presents 

 when a fragment is cast on a heated body. The glass was lustrous 

 with the crystalline sublimate. This result failed with less than 496 

 elements. Experiment has further shown that carbon is best fused into 

 globules in nitrogen under a pressure above the ordinary atmospheric 

 pressure. Glass vessels break so easily that metallic must be used. 



The authority from which we copy the above, Sillimari's Journal, 

 states that the fusion and volatilization of carbon was long since 

 announced (as early as 1822) by Prof. Silliman, while the con- 

 densation of carbon upon the inner surface of a globe has been a 

 frequent class experiment with Prof. S., and has been customarily 

 mentioned in his lectures as a case of vaporization. The battery used 

 consists of 900 pairs, being one of the largest ever constructed ; but 

 Prof. Silliman, Jr., has shown that the same result may be obtained 

 by a Bunsen's battery of 60 pairs. Prof. Silliman has also melted 

 various other refractory substances, which had never before been 

 fused, and in due time we shall probably learn that Despretz has suc- 

 ceeded in doing the same. This is not the first time that Prof. Silli- 

 man has far preceded the chemists of the Old World. Editors. 



EXPLANATION OF THE TRICKS OF FIRE-JUGGLERS. 



M. P. H. BOUTIGNY states in the Comptes Rendus, that, his atten- 

 tion having been turned to the " spheroidal state of bodies," he sus- 



