Chemistry and Physics. 413 



of hydrogen are taken up, forming hydro-quinone C 12 H 6 8 . By 

 the union of the two substances, the first yellow, the second colorless, 

 an intermediate body, green hydro-quinone (C l2 H 5 4 ) is found ; this 

 substance has been represented as the most beautiful known to chem- 

 ists, excelling murexide in its rich metallic golden green crystals ; 

 they are formed of great size even in a small quantity of solution. 



Dr. Staedeler has formed chlorinized species both of quinone and of 

 hydro-quinone, in all cases the former being yellow and the latter color- 

 less. In one instance the union of the two formed a substance interme- 

 diate in composition and of equal beauty with green hydro-quinone. Of 

 the quinones, we have according to our author, 1, 2 and 3 equiv. of H 

 replaced by CI ; four equiv. replaced in the well known chloranile. 



Of the hydro-quinones, one equiv. is replaced in the chloro-niceic 

 acid [see above], the others were formed by the action of sulphurous 

 acid on the corresponding quinone ; the most remarkable is that formed 

 from chloranile, as by means of it the true relation of that substance 

 to quinone is demonstrated. 



Some other compounds are described by the author, although of no 

 particular interest. VVohler has also recently reviewed his investiga- 

 tion of the sulphur compounds of the series. He finds that in some 

 instances there is direct union with S H. G. C. S. 



9. Volatilization of Carbon ; by C. Despretz, (Compt. Rend., 1849, 

 48.) — M. Despretz has commenced a series of experiments on the fu- 



L sion and volatilization of various refractory substances. As one of his 



first results, he announces the fusion and volatilization of carbon. He 

 used a battery of 496 elements in four parallel series. Carbon from 

 sugar in an " ceuf electrique" was subjected to its action ; a high de- 



I gree of incandescence was produced, and the globe was covered with 



a black powder, dry and crystalline. After many precautions to test the 



I reality of the result, and various changes in the mode of experiment, 



I Despretz satisfied 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 sud- 

 denly 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 farther shown that carbon is best fused into globules 

 in nitrogen under a pressure above the ordinary atmospheric pressure. 

 Glass vessels break too easily, and therefore it is necessary to use 

 metallic. 



Alumina, rutile, anatase, nigrine, oxyd of iron, kyanite and other 

 species were fused immediately into globules and then gave off vapors. 

 Despretz has this subject still under investigation. 



[Note.— The fusion and volatilization of carbon by Prof. Silliman, 

 was long since announced in this Journal, (see vols, v, 108, 361, vi, 

 841, 378, x, 109, 119, 1822-1826.) The condensation of carbon upon 

 the inner surface of a globe has been a frequent class experiment with 

 p rof. S., and it has been customarily mentioned in his lectures as a case 

 of vaporization. The battery used in the Yale College Laboratory con- 



Skcond Skriks, Vol. VIII, No. 24.— Nov., 1849. 5 



o 



