176 Dr. C. A. Burghardt on the 



treatment was rendered acid with hydrochloric acid, when 

 chromic chloride was at once obtained without reduction by 

 means of a reducing medium, and the chromium was pre- 

 cipitated out by means of ammonia, filtered off, the precipi- 

 tate dried, ignited, and weighed as Cr 2 3 . I cannot at 

 present explain this remarkable reduction of the chromic 

 acid, because in some experiments I had to employ a reducing 

 medium as usual, such as boiling the acid solution with a 

 little alcohol. I hope to investigate this reaction further. 

 The results obtained are as follow, viz : — 



Cr 2 O s 43*4° 



FeO 1 9 '44 



MgO 8-86 



Alumina and Silica 28-30 



After the fusion and extraction with water, the insoluble 

 matter on the filter paper was ferric oxide, magnesium 

 carbonate, carbon, &c. 



Qualitative Experiments. 



Rutile (Ti02) was at once decomposed and titanate of 

 sodium produced, which, on being acidified with hydrochloric 

 acid, gave the various reactions for titanium ; for instance, a 

 portion of the solution on having a piece of metallic tin 

 placed in it gave a fine purplish-red coloured solution. 



Titanate of Iron or Ilmenite gave the same reactions 

 for titanium. It was easily attacked by the method. 



Barytes (BaS0 4 ) gave insoluble carbonate of barium 

 which was then filtered off and dissolved in hydrochloric 

 acid and tested with sulphuric acid, when it at once furnished 

 a precipitate of barium sulphate. The filtrate from the 

 barium carbonate on being tested with hydrochloric acid 

 did not give off any sulphuretted hydrogen, proving the 

 absence of sodium sulphide, therefore no reduction of the 



