TKAKSACTIONS OF SECTION B. 587 



one of my pupils, has also found more than traces of tellm-ium. Arsenic is also 

 present in quantity. 



A former pupil of mine, Mr. Nakagawa, now a chemical engineer in the 

 Imperial Mint, states that the flue-deposits of the sulphur burners are rich in 

 tselenium. 



I had hoped to have obtained by this time fuller particulars, but have been 

 disappointed by not receiving in time supplies of acid and flue-dust. I must, there- 

 fore, limit my communication to the announcement of the presence of these two 

 elements in Japanese sulphuric acid, and of the probable occurrence of material 

 quantities of selenium in Japan. A fm-ther communication will be published when 

 particulars have been ascertained. 



10. On the Chrome Iron Ore of Japan. By Professor Edward Divers, M.D. 



The serpentine rocks of Japan, like those found elsewhere, contain small quan- 

 tities of chrome iron oxide ; but a few years ago masses of this mineral were sent 

 from Oita prefecture (Bungo) to the Tokiyo Industrial Exhibition, and its nature 

 then recognised. It has lately been analysed in the laboratory of the Imperial 

 College of Engineering, Tokiyo, by my former pupil, Mr. T. Haga, now one of the 

 instructors in chemistry in the College. 



It is massive, has a specific gravity 4*50, and a hardness 5"5, and is of a grey- 

 black colour without any shade of brown, except where weathered. Its fracture is 

 partly slaty, partly crystalline, showing numerous large faces inchned at aU angles. 

 Its lustre is resinous to sub-metallic, so that in appearance it is much like coal. Its 

 powder is brown. Besides brown and green coatings on the faces of natural fractures 

 in the mass, there are many small deposits of a greyish pink, but nearly white, soft 

 and unctuous mineral. The behaviour of this chrome iron oxide to heat, presents 

 nothing needing to be recorded, beyond that it slowly gains in weight. It contains 

 only traces of magnetic matter. 



Reduced to very fine powder and heated for three hours with hydrochloric 

 acid, 2-53-2*87 per cent, dissolve, which together with some of the silica in the 

 ore, make perhaps 4 per cent, decomposed. The soluble part has been separately 

 analysed. An analysis of the soft white matter has also been made, but the portion 

 of this which could be got was very small, and largely mixed with the chrome iron 

 oxide. The following are the results of analyses : — 



I. The whole ore, air-dried. 



I. II. Mean 



Chromic oxide , . .'59-39 69-20 59-30 



Ferrous oxide . . . • ■ . . . ■ 2832 • 28-22 28-27 



Chroine iron oxide 87-30 



Magnetite 0-29 



Ma.gnesia 9-17 (9 10-9 24) 



Silica 1-58 



Alumina 0-80 (0-82-0-78) 



99-14 



This leaves 0'88 for water (undetermined because of the difficulty arising from 

 the already noted absorption of oxygen), additional oxygen if present, and other 

 substances which may have escaped detection. 



2. The part decomposed by hydrochloric arid. 



I. II. Mean 



Chromic oxide 0-32 038 0-35 



Iron oxide (if ferric) 053 0-55 054 



Magnesia ]17 144 1-30 



Alumina 0-51 050 0-51 



Silica (assumed as) — — 1-30 



Part at least of the iron dissolved in the ferrous state. The residual ore still 

 yielded traces of soluble matter to fresh acid. 



