202 M. Peschiero?j the Extraction of Titanium from Minerals. 



infusion of galls on the washings, and mix them with the two 

 before mentioned. 



4. The titanium not dissolving so easily in the potash as 

 the alumina every time they meet, the insoluble residuum pre- 

 serves a gelatinous character ; and in order to separate it from 

 the substances with which it is mixed, this residmim is dissolved 

 in hydrochloric acid, by which treatment some portions of si- 

 lica are also separated : the iron of this solution is precipitated 

 by the hydrocyanate of potash and of iron; the liquid is then 

 saturated with an alkaline subcarbonate, and it is carried to 

 ebullition. The precipitate which becomes formed is white, 

 bulky, and has the aspect of alumina : as it may consist of 

 a mixtui'e of titanium, magnesia, and lime, the first is ren- 

 dered insoluble in acids by being strongly heated, and the 

 earths are dissolved by digestion for some hours in a weak 

 acid — say distilled vinegar. The insoluble parts are separated 

 by a filtre ; the liquid is treated with ammonia, in order to re- 

 move the magnesia, with oxalate of ammonia for the lime: 

 and we know that the operation has been well conducted, if it 

 does not afterwards undei'go any change with the infusion of 

 galls. To the liquids which have been put aside is then also 

 added that from which the iron and other substances have 

 been separated. 



5. Lastly, as titanium forms double salts with all acids, and 

 as the tannate of titanium is easily re-dissolved by the infusion 

 of galls, we next obtain that which by these two causes al- 

 ways escapes analysis, by evaporating to dryness all the li- 

 quids which have been put aside, igniting the residuum, dis- 

 solving in water the resulting saline mass, throwing the solu- 

 tion on a filtre, washing the insoluble parts, heating them to 

 redness in order to desti'oy the carbonaceous matter, and 

 washing afresh in acidulated water the white powder they 

 give, which is the titanium sought for. If it is found to be 

 coloured by iron or manganese, it is easily rendered pure by 

 digestion in nitronna-iatic acid, after having exposed it to a 

 very strong heat. By repeating this series of operations twice 

 upon the washings, and adding each time some infusion of 

 galls, all the titanium contained in the mineral under exami- 

 nation is extracted. I may state by the way, that considering 

 its property of forming double salts, I have always separated 

 several grains from the salts obtained in the examination of the 

 alkaline principle in minerals of this kind ; that its presence is 

 known hy the spongy state that the hydrochlorates of potash 

 or of soda take, which, thoroughly deprived of ammonia and 

 Btrongly ignited, do not enter into fusion ; and that several so- 

 lutions, 



