1825.] Mr. Children on the Analysis of Torrelile. 221 



Observations on the Analysis of TorrelUe. By J. G. Children, 



FRS. &c. 



Several months before the second number of the Annals of 

 the Lyceum of Natural History of New York (from which we 

 have copied the preceding article), arrived in this country my 

 friend Mr J F. Daniell, received a specimen of lorrelite from 

 Professor Renvvick, which he put into my hands for examination 

 with respect to Its containing oxide of cerium. I shall brieliy 

 state the results of the experiments to which I submitted it. 



Heated to redness in a small matrass, the assay gave off a 

 httle water; it did not decrepitate, nor suffer any change in its 



^^Kn-eThe blowpipe, ^vilh soda, on the platina wire, it gave 

 in the oxidatmg flame an opaque deep green globule rather 

 inclining to blue ; by the addition of nitre the colour became 

 pure deep green. In the reducing flame, the assay became 



brown. . , in xu 



With borax, it dissolved readily ; in the oxidating flame the 

 elobule was transparent, and of a fine amethyst colour. In the 

 reducing flame, hght yellow whilst hot, and colourless when 

 cold. It remained perfectly transparent. 



Salt of phosphorus had very little action on a small fragment 

 of the assay ; the globule in the oxidating flume was quite trans- 

 parent ; yellow hot, colourless cold. In the reducmg flame, 

 colourless both hot and cold. The fragment remained enve- 

 loped in the diaphanous glass, apparently very httle altered. A 

 portion of the assav reduced to tine powder was more readily 

 acted on by the salt of phosphorus than the fragment, but the 

 appearances were similar, except that the colour was mther 

 deeper. A considerable sihca skeleton remained m the fused 

 globule, which, when cold, was slightly opaline. 



Ahue in the forceps, the mineral fused with difliculty on the 

 surface, bubbled up, and became covered with a vitrified greenish 

 grey transparent coating. 



These experiments give no indication of the presence of oxide 

 of cerium, but as that substance, when in combination with iron 

 and silica, cannot be detected by the blowpipe, no certain infer- 

 ence, as to its presence or absence, could be drawn from them. 

 They demonstrate, however, that the mineral contains manga- 

 nese in considerable quantity, of which the analysis takes no 



notice. . ^ r,^ ■ r ^ 



It IS stated in Mr. Renwick's paper, that Dr. lorrey inferred, 

 that the mineral " might contain cerium as it formed with borax 

 a <^lass that was green whilst hot, but lost its colour on cooling. 

 The characters which Berzelius gives of oxide of cerium with 

 borax before the blowpipe are, "that itfornisin the exterior flame 

 a beautiful red or deep orange yellow glass, whose colour fades 



