1821.] Dr. Clarke on Arragonite. 57 



Article X. 



On the Chemical Examination, Characters, and Natural History, 

 of Arragonite, explaining also the Causes of the different 

 Specific Gravity of its different Sub-Varieties. By Edward 

 Daniel Clarke, LLD. Professor of Mineralogy in the Univer- 

 sity of Cambridge. 



(To the Editor of the Annals of Philosophy .) 



SIR, Cambridge, June 19, 1S21. 



About the time that Mr. Belzoni published the interesting 

 •volume of his Travels in Egypt, he sent to me for examination a 

 fragment of the magnificent Soros, which he discovered in the 

 sepulchres of the kings of Thebes, and which has excited so 

 much curiosity, from the description given of it by this enter- 

 prising traveller. According to his account of that Soros, no 

 relique, even of Egyptian splendour, has yet been found of a 

 more marvellous nature. It is of one integral mass, of a polished 

 translucid stone, which he believed to be oriental alabaster,* 

 covered within and without with hieroglyphics, cut in the sur- 

 face of the stone, and afterwards filled with a blue pigment,+ 

 which yet remains in the several cavities. After a careful exa- 

 mination of this supposed alabaster, I had the satisfaction to 

 inform Mr. Belzoni, that the material used by the ancient The- 

 bans in the construction of this beautiful Soros was yet more 

 remarkable than he had imagined ; for that it consisted of one 

 entire mass of arragonite. As no instance had ever occurred in 

 the present state of our knowledge respecting arragonite, where 

 this mineral had been before observed in equal magnitude, the 

 opinion I had given of it was of course liable to be called in 

 question ; but it was soon afterwards confirmed by the testi- 

 mony of one of the most illustrious chemists living, who consi- 

 dered that no doubt whatever as to the real nature of this 

 substance could be entertained.^ 



In the examination, however, of the stone used in the con- 

 struction of the Theban Soros, were not the other characters 



The terms oriental and occidental alabaster are usually applied to two distinct spe- 

 cies of minerals The oriental, or alabaster of the ancients, is a carbonate of lime. The 

 occidental, or alabaster of the moderns, is a sulphate of lime. 



■f This curious blue pigment is instantly reducible upon pipe-clay with a little borax 

 to a bead of pure copper, using the common blowpipe. It is, however, insoluble in the 

 nitric, muriatic, and nitromuriatic acids, being a frit, or glass, which contains oxide of 

 copper. 



* Dr. WollastOD, to whom I transmitted a few grains only of the specimen I had 



received from Mr. Belzoni, immediately pronounced it to be chaux carbonates dare. 



' The novelty," said he, "consists in the magnitude of the specimen : One is led to ask 



how large it may not be found ? Why may there not be mountains of arraeonitie 



marble? " 



