404 F. W. Mar — So-called Per of shite from Arkansas. 



The solution of the mineral was then made slightly alkaline 

 with ammonia and the precipitated earth filtered off. The 

 lime was thrown out of the concentrated filtrate as oxalate 

 and after evaporation and volatilization of ammonia salts, mag- 

 nesia was determined in the residue. Alkalies should be found 

 at this point if present. There were none. 



The weighed earths obtained as above were fused in sodium 

 carbonate, enough sulphuric acid added to the mass to bring 

 about a bisulphate fusion and then enough more to keep the 

 whole in the liquid condition even when cold. After cooling, the 

 mass was poured into 300 cm 3 of cold water containing 1 grm. 

 of tartaric acid and after separating the iron, in alkaline solu- 

 tion, by hydric sulphide, the titanium, with which go the nio- 

 bium and tantalum, were separated by the acetic acid process of 

 Professor Gooch.* The greater part of the manganese was 

 separated by an ordinary acetate process and the acid oxides by 

 the strong acetate process. On neutralizing the filtrate from 

 this last with ammonia and boiling, only a trace of some earth 

 was found, showing absence of alumina. The titanium was 

 separated from the weighed oxides by Knop's chlorinating pro- 

 cess, and finally the niobium was determined in the mixture 

 of niobium and tantalum oxides by reduction in hydrochloric 

 acid and titration with permanganate after T. B. Osborne. f 

 Only a trace of titanium was found in the niobium and tanta- 

 lum oxides by the Osborne process with hydrogen peroxides, 

 and the titanium re-estimated by the same process gave practi- 

 cally the same result as before. 



A portion of the oxides having been lost during the opera- 

 tion, having gone, as it appeared, with the manganese used to 

 decompose the tartaric acid, another portion of mineral was 

 treated in the same manner as far as this point, and the tartaric 

 acid was destroyed by evaporation in platinum and ignition. 

 No aluminum having been found, the titanium, tantalum and 

 niobium oxides were separated by boiling with dilute sulphuric 

 acid. By evaporation of this filtrate a quantity of earths was 

 obtained. To this was added another portion separated by 

 ammonia from the filtrate (in the same portion of mineral) 

 after separation of lime, evaporation and ignition and solution 

 in hydrochloric acid, and before the precipitation of the mag- 

 nesia by microcosmic salt. The combined earths were pre- 

 cipitated in a slightly acid solution by oxalic acid in order to 

 separate from any uranium, the cerium and yttrium groups 

 separated by the sodium sulphate process and each precipitated 

 again as oxalate and weighed as oxide. As appears the main 

 portion of the rarer earths belongs to the yttrium group. 



* Proceedings Amer. Acad, of Arts and Sci., N. S., vol. xii, p. 435. 

 f This Journal, vol. xix, p. 329. 



