Reynolds — On the Comioosition of Lievrite. 53 



treatment with pure caustic soda for the separation of alumina. The 

 iron and manganese were then separated by the baric-carbonate method. 

 From the weight of iron thus found, that previously ascertained to be 

 present in the ferrous state was deducted ; the difference represented 

 the weight of metal in the ferric condition. The filtrate from the first 

 precipitate caused by ammonia had the calcium separated from it as 

 oxalate, and the latter was determined in the usual way. The filtrate 

 from the calcium precipitate was then evaporated to dryness, and the 

 residue heated to expel ammoniacal salts ; the product of this treat- 

 ment was dissolved with the aid of a few di'ops of hydrochloric acid, 

 the magnesium separated by means of baric hydrate and estimated, 

 while the alkalies in the filtrate were converted into chlorides and 

 weighed, and the potassium separated by platinic chloride. No trace 

 of lithium was detected in the mineral. 



2 '841 grms. of the freshly powdered and unaltered mineral were 

 heated gradually to redness in a hard glass tube connected with a 

 weighed chloride-of-calcium tube; a ciuTent of dry air was at the same 

 time slowly drawn through the apparatus. The water collected 

 weighed -012 grm. ='422 per cent. only. 



The percentage composition of the specimen analyzed by Mr. Early 

 may be thus stated, when the metallic and other components are calcu- 

 lated as oxides : — 



SiO, 29-93 



PeO 31-83 



FejOg 20-16 



MnO 3-02 



CaO 13-71 



MgO 0-30 



AljOs 0-36 



K2O 0-20 



Na-,0 0-29 



HoO 0-42 



100-22 



These data, when discussed in the usual way, give the following 

 ratios : — 



SiOo =0-4983 = 3-85 = 4-00, 



RO =0-7431 = 5-74=5-96, 



R.O3 . . . .=0-1294=1-00 = 1-04; 

 or 



R2O3, 6 RO, 4 SiOo, 



where 6 RO = 4 (Fe, Mn)0 + 2 CaO nearly, neglecting the small 

 amount of alkalies. 



As the water present in the particularly pure specimen of the 

 mineral analyzed did not reach 0-5 per cent., it is difficult to admit, 

 with Stadeler, that it enters into the molecule of the compound ; I 

 therefore prefer to regard Lievrite as an anhydrous silicate. 



