A 



JOURNAL 



OF 



NATURAL PHILOSOPHY, CHEMISTRY, 



AND 



THE ARTS. 



APRIL, 1803 

 j 1 



ART T CLE I. 



An Analyfis of a Variety of the Corundum. By the Reverend 

 Wm. Greg or. Communicated by the Author. 



JL HE mineral, which is the fubject of the following obferva- Hiftory of iht 

 • tions, was prefented to me by my valuable and refpe&ed [u"™^ 11 . ^ 

 friend Philip Ralhleigh, efq. who was ftruck with the pecu- Thibet, 

 liarity of its colour. Mr. Rafhleigh informed me, that he had 

 found its fpecific gravity to be 3,6 at the temperature 60, and 

 my experiments gave the fame refult. 



The country where this flone was found, is Thibet : but 

 in what particular part of that extenfive region I am not in* 

 formed. 



" The colour of this ftone is motled : the prevailing tint is Charafters^ 

 a diluted lilac. The mafs appears to be a confufed cryftalli- . 

 zation, the parts of which are unequal, but moftly very mi- 

 nute. The larger grains refleft a luftre not inferior to that ©f 

 the common adamantine fpar. Although the adhefion of the 

 parts of the mafs is not confiderable, the parts themfelves have 

 a great degree of induration, and from the fame caufe, proba* 

 bly, a greater fpecific gravity than the mafs itfelf," which I 

 found to be 3,603. 



Vol. IV.— April. P 100 



