ON STIBIC0NI3E, A NATURAL OXIDE OP ANTIMONY FROM BORNEO. 133 



by the ' London Pharmacopoeia,' to prevent any precipitate with the prepa- 

 rations of iron. It is also used in combination with iodide of potash. 

 Chemical Composition: 



Tinct. Ferri — dark precipitate. 

 Tinct. Iodine — beautiful blue. 

 Oxalic Acid — grey precipitate. 

 Govt Civil Hospital, Colombo, September, 1861. 



ON STIBICONISE, A NATURAL OXIDE OF ANTIMONY FROM 



BORNEO. 



BY T. L. PHIPSON, 

 Phil. Nat. Doct. Bruxelles University, Member of the Chemical Society of 

 Paris, &c, &c. 



We get from Borneo a compact mineral, somewhat resembling certain 

 varieties of Leptynite feldspar, and which is found more or less abundantly 

 among the Stibine (sulphide of antimony) which the Island of Borneo 

 launches into European commerce. It was at first looked upon as a portion 

 of the rock which enveloped the native sulphide of antimony, and I believe 

 many smelters have thrown it aside as such. It results from the examina- 

 tion to which I have submitted this mineral, that it is an oxide of anti- 

 mony often very pure, and constitutes an ore sometimes superior in value to 

 Stibine itself. 



The mineral in question presents itself in form of a compact matter 

 with a crystalline structure, yellowish-white or reddish, always giving 

 a yellowish-white powder, and showing here and there crystals about half- 

 an-inch in length, of a peculiar pearly lustre, and having numerous hori- 

 zontal stripes ; these striped crystals are straight rhomboidal prisms, 

 terminating with two facettes (biseau), and modified upon two of the 

 perpendicular edges. 



This substance is not volatile in a tube closed at one end (by which 

 character it is distinguished from oxide of antimony Sb s ) ; before the 

 blow-pipe, the purer samples are entirely volatilised in the flame of reduc- 

 tion, but are not volatile in the outer or oxidating flame. It cannot be 

 melted before the blow-pipe (by which it is distinguished from Exitelite, or 

 antimonic acid Sb 6 which is fusible) ; with carbonate of soda upon char- 

 coal it gives a button of metallic antimony. 



These characters prove the substance in question to be Sb 4 — the 

 Stibiconise of mineralogists, the antimoniate of antimony of some chemists. 

 The samples which I have examined contain, as impurities, sulphur, 

 stibine, oxide of iron, &c, but they were sometimes so pure that one of 

 them gave me 65 per cent, of metallic antimony ; whilst Stibine seldom 

 yields more than 45 per cent. 



