118 Dr Turner's Ajialysis of Oxahverite. 



Mr Henderson has given the following account of the hot 

 springs of Oxahver, where this mineral was found. 



The middle fountain, or Oxahver, the most celebrated of 

 these springs, (the springs of Reykiahverf,) is situated about 

 150 yards S. W. from Nordur-hver. Its pipe is eight feet 

 at its greatest diameter, and is surrounded by a strongly in- 

 crusted brim almost close to the orifice. The incrustations 

 formed by the depositions of this fountain are peculiarly beau- 

 tiful. The greater part of the mound seems covered with 

 small thin pieces of wood, some of them half a foot long, which 

 lie in almost every possible direction. The cavities, by the 

 junction of the pieces, are often filled with a fine efflorescence, 

 and various other curious petrifactions. — See Henderson's Ice- 

 land, p. 145. 



Art. XXIV. — Analysis of Oxahverite. * By Edward Tur- 

 ner, M. D. F. R. S. E. &c. Lecturer on Chemistry, and 

 Fellow of the Royal College of Physicians, Edinburgh. 

 Communicated by the Author. 



On exposure to heat in a glass tube, the oxahverite emits a 

 considerable quantity of water, becomes brittle, and acquires 

 a yellow ochrey tint, but does not suffer any change of form. 

 Heated before the blowpipe, it fuses without difficulty, and 

 yields a transparent colourless globule. With borax it melts 

 into a transparent bead, and when fused with the phosphate 

 of soda and ammonia, assumes the appearance indicative of 

 the presence of silica. When heated before the blowpipe 

 with the flux of bisulphate of potash and fluor-spar, as de- 

 scribed in a former paper, the flame did not receive either a 

 green or a red tint, and hence the absence of boracic acid and 

 lithia may be inferred. 



The oxahverite is readily attacked by the nitric or muria- 

 tic acid, even when diluted with water ; so that these men- 

 strua cannot be safely employed for separating the carbonate 

 of lime in which the mineral is imbedded. When a crystal 

 is put into strong muriatic acid, it gradually becomes opaque 

 and brittle, but retains its form. Subjected in the state of 



• Communicated to the Royal Society May 7, 1827. 



