66 Intelligence an$ Miscellaneous Articles. 



CHRYSOLITE IN THE CAVITIES OF OBSIDIAN. 



Professor Gustavus Rose of Berlin has found in the cavities of 

 obsidian, in the Jacal Rock near Real-del-Monte in Mexico, little 

 crystals, greenish, and reddish-yellow, and transparent, which be- 

 long to the species of prismatic chrysolite.— Poggendorff's Annalen, 

 vol. x. p. 323. 



METEOR OF A GREEN COLOUR. 



[Communicated by Mr. B. D. Silliman, in a letter dated New York, 

 March 1, 1828.] 



On the night of the 1 1th of February, between 1 1 and 12 o'clock, 

 as 1 was crossing the East River, between this city and Long Island, 

 1 observed a beautiful meteor which was visible for about the space 

 of two seconds. Its course was from a point perhaps 5° below the 

 zenith, toward the horizon in a N.E. direction. It described an arc 

 of perhaps 20°, when it apparently exploded, but without any re- 

 port that I could hear. Its colour was a singularly pure grass green, 

 of a light shade ; the trail which it left was of the same colour, and 

 so were the scintillations which accompanied its apparent explosion. 

 The latter were distinct, like those accompanying the bursting of a 

 rocket, but by no means so numerous. — Two gentlemen who were 

 in the boat with me at the time, also saw it. — Silliman s Journal* 



BITTER OF ALOES. — CARBAZOTIC ACID. 



It is well known that the peculiar substance produced by the action 

 of nitric acid upon aloes, combines with bases, and forms salts which 

 detonate by heat ; this substance is the aloetic acid of M. Braconnot. 

 Mr. Liebig formerly made some experiments on this substance, 

 {Ann. de Chim. Mai 1827,) but they were not satisfactory. He has 

 lately renewed his experiments, and finds that the detonating prin- 

 ciple is carbazotic acid. 



The bitter of aloes is plentifully obtained by the action of nitric 

 acid of sp. gr. 1'25. With potash it forms a purple salt, which is 

 but slightly soluble, which precipitates the salts of barytes, lead, and 

 peroxide of iron in flocks of a deep purple colour ; the protonitrate of 

 mercury is precipitated of a light red. In order to decompose the 

 salt of potash, it was decomposed by acetate of lead; and, contrary to 

 all expectation, the weight of the precipitate was less than that of 

 the potash-salt employed. The washings were of a yellow colour, and 

 deposited crystals of the same. These crystals, treated with heat 

 and sulphate of potash, yielded carbazotate of potash, from which the 

 carbazotic acid was separated. 



When aloes are heated with nitric acid of 1*432 as long as vapours 

 of nitrous acid are disengaged, and on afterwards mixing the liquor 

 with a little water to separate the bitter, there may be obtained by 

 saturating the liquor with potash and evaporation, a large quantity 

 of carbazotate of potash in fine crystals. The bitter of aloes is con- 

 sequently a compound of a peculiar substance, possessing the proper- 

 ties of the resins, and carbazotic acid. 



Wool, 



