MENACANE, AND ITS ORES. 139 



racters we are as yet sufficiently acquainted -to. say, \yith nacanc and it$ 

 certainty, that they form distinct species. Between the ores, 

 three latter and iron sand, the intermediate transitions, as 

 between all adjacent fossils, are, probably, innumerable. 

 Were we to take analysis alone for our guide, it would muU 

 tiply the species without necessity, and lose sight of the in*, 

 tentions of Nature, who does not confine herself to 5 or 10 

 per cent, of an ingredient; beside, a Klaprothhas confessed, 

 that it is not so much the identity and proportion of the in- 

 gredients, as the particular state of their combination, 

 (which to us is perfectly unknown,) that determines the na- 

 ture of the resulting fossil. In addition to those fully de- 

 termined species, we have been favoured, by Klaproth, with 

 the analysis of a menacaniferous ore, from Aschaffenberg ; 

 by Vauquelin, with that of another, from Bavaria; and, by 

 Abildgaard, with that of a third, from Barboe, in Norway ; 

 all which differ from the foregoing species, and from one 

 another, in composition, or in the proportion of ingredients; 

 so that it is impossible to determine, with any probability, 

 to what species they belong, trom the want of an adequate 

 external description, and account of their geognostic oc 

 currence. 



The masterly hand of Klaproth has further detected this 

 metal, in the iron sand, which accompanies the hyacynths, 

 &c. in Ceylon, and in some of the iron ores of Norway; 

 and Lampadius has lately discovered it, in the iron sand of 

 llohenstein, near Stolpen, in Saxony, and in that found 

 with the pyrope of Bohemia. Besides these, I have seen, in 

 the imperial cabinet, at Vienna, and some few private col- 

 lections, ores, said to come from Stiria or Carinthia, and 

 from Bohemia, in which the menac calx probably abounded; 

 as may be conjectured, from the strong shade of brown in 

 the colour, together with the considerable adamantine lustre, 

 both which are strongly characteristic of this genus. 



The use of this metal is, as will readily be supposed, from 

 its scarcity, and the newness of its discovery, very confined. '^^' 

 The rutile, indeed, was, for a length of time, employed to 

 give a brown colour, in the porcelain manufacture of Se- 

 vres, near Paris; but, from the difficulty of communicating 

 an equal tint by it, has been since abandoned. The rock 

 crystal, inclosing capilliforra crystals of rutile, has been 

 ^ 2 employed 



