SCIENTIFIC NEWS. 153 



Cit. Vauquelin, wiihing to know the nature of this earth, This, by ana- 

 and to difcover if it contained any nutritive parts, has analyfcd ^ainno nu! 

 it by the ufual methods, from fome fpecimens which were trimem. 

 jfent him by Cit, Labillardiere. 



This earth is foft to touch, compofed of fmall fibres, which 

 are ealily feparated, and when ignited it lofes y*^ of its 

 weight. It is compofed of, . 



37 parts of pure magnefia. 

 26 of filex. 



17 of oxide. • •' 



3 or 4 of water. 

 2 or 3 of lime and copper. 

 It does not therefore contain any alimentary parts, and can 

 only be confidered as filling the /tomach ; a kind of mechanic 

 cal expedient to fufpend the pains of hunger. 



Soc. Philomath. A r o. 55, An. 10, 



Account of a blue Oxide of Iron. By Cit. Vauquelin. 



This fubftance was fent to the Counfel of Mines, by the B hie oxide of 

 Baron de Molt. It is of a light blue colour, and has the form hos ] S ye * 

 of fmall infulated maffes in the cavities or clefts of quartz and 

 hard green fleatites. It is friable, but rather greafy to touch, 

 and changes its colour before the blow-pipe, and at laft melts 

 jnto a greenifli white glafs. 



Neither acids or weak alkalis alter its colour. Thcfe cir- 

 cumftances diflinguim it from lapis lazuli and the pruffiate of 

 iron. v 



This fubftance communicates a faffron yellow to the muriatic 

 acid in which it was digeiled, and changes its own colour a 

 little, but cannot be difcoloured unlefs it be at the fame time 

 diflblved. There only remains a fmall quantity of filex, which 

 appears to have conftituted its gangue. 



On examining the muriatic acid that was ufed for this 

 operation, it was found it had taken up alumine, lime, and 

 oxide of iron, but neither fulphurated hidrogen, manganefe, , 

 nor phofphoric acid Were difcovered in it, fubitances to which 

 the blue colour of this oxide of iron might be afcribed. It 

 therefore remains to be determined what is the caufe of the 

 Remarkable colour of this oxide, a colour which has never yet 



been 



