392 Intelligence and Miscella7ieoiis Articles. 



within a square of forty or fifty yards. Some fell on hard ground, 

 when they were smashed into small particles ; others in soft ground, 

 where they were dug out. Prior to the real cause of the phsenome- 

 non being kno^vn, it was talven for an earthquake." Letter from 

 G. Thompson, Esq. of Cape Town, dated Nov. 28, 1838, inserted in 

 Charlesworth's Magazine of Natural History, vol. iii. p. 145. 



" On the 13th of October last (1838) a most brilliant meteoric ap- 

 pearance was seen about seventy miles from Cape Town, attended 

 by a shower of stones which extended itself about 150 miles, that 

 is, some stones have been found at 10, 15, 20, 50, and so on miles, 

 all in the same line of direction. Some say that the stones were 

 so soft at first that they could be cut with a knife, and others say 

 that in falling the ground was torn up to some depth and a loud ex- 

 plosion was heard." Letter from E. J. Jerram, Esq. of Cape Town, 

 dated Jan. 29, 1839, addressed to Mr. Brayley. 



SELENIURET OF MERCURY. 



Del Rio and Kersten have already described some Mexican ores 

 of mercury which contain selenium, but hitherto they appear to have 

 been found only in very small quantity. Very lately M. Ehrenberg 

 has received some minerals from M. Carl. Ehrenberg, director of the 

 Real del Monte mines, among which there is a series of mercurial 

 ores met with at San Onufre, where they are so abundant, that it is 

 intended to work them on the large scale to extract the mercury. 

 In colour and lustre the mineral resembles fahlerz, and occurs with- 

 out the least indication of foliated structure, disseminated in a gan- 

 gue of calcareous and heavy spar, from which it is extremely difficult 

 to separate them in a quantitative analysis. It is entirely volatile ; 

 the sublimate, reduced to powder, is black, without any admixture 

 of red. 



This mineral consists of sulphuret and seleniuret of mercury ; and 

 analysis shows that its composition closely approximates four atoms 

 of the first and one atom of the last. It is probable that these two 

 isomorphous bodies may combine in all proportions. — L'Institut, 14 



Mars, 1839. 



NONEXISTENCE OF CARBONATES OF OUINA AND CINCHONIA. 



M. Langlois makes the following statements respecting the non- 

 existence of the above compounds : 



Chemical works make no mention of the action of carbonic acid 

 upon organic bases. M. Berzelius (Chimie, tome 5,) says, however, 

 that carbonate of cinchonia is obtained by double decomposition 

 from a soluble salt of this alkali, and a solution of carbonate of pot- 

 ash. The decomposition certainly occurs ; and a white precipitate 

 falls, which, after being washed, and dried between folds of paper, 

 effervesces slightly on the addition of weak acids, which unques- 

 tionably indicates the presence of a carbonate ; but this effervescence 

 does not occur unless the carbonate of potash has been employed in 

 excess. Imagining then that this effect might be occasioned by the 

 carbonate of potash retained in the cinchonia, notwithstanding re- 

 peated washings, the precipitate was treated with cold concentrated 



