^■iG Biographical Memoir of the late Dr Turner. 



nickel and a little cobalt, — a constitution compatible only with a 

 meteoric origin, and almost identical with that of the celebrated 

 meteoric mass found by Pallas in Siberia. 



Of Dr Turner's chemical researchep, that which has been 

 commonly thought the most important by chemists is the last of 

 those I have mentioned as brought forth by him this year, where 

 lie has determined the atomic number of manganese and the con- 

 stitution of its several oxides. He was led to attempt this very 

 difficult investigation, one of the most delicate and complex in 

 the whole range of inorganic chemistry, in consequence of being 

 requested by Mr Haidinger to aid him in an elaborate mineralo- 

 gical inquiry into the ores of manganese, and finding his purpose 

 obstructed by the doubts prevailing as to the constitution of va- 

 rious compounds of that metal. He therefore undertook a full 

 examination of the subject ; in which he first fixes the atomic 

 number, or combining proportion of manganese, from three in- 

 dependent and remarkably concordant results obtained from 

 several analyses of the carbonate, the sulphate, and the chloride ; 

 and he then proceeds to ascertain the composition of four ad- 

 mitted oxides, the quantities of the oxygen in three of them being 

 in the ratio of 2, 3, and 4, while the fourth seems a definite com- 

 pound of the first and third. In a supplement to this inquiry, 

 he shews that several of the oxides exist in nature, both hydrated 

 and anhydrous, constituting some of the mineral species deter- 

 mined by Mr Haidinger ; and in a subsequent paper in ISSO, 

 his " Chemical Examination of Wad," * he adds to the number 

 two Cornwall ores known by that name, which he found to be 

 essentially, the one the hydrated, the other the anhydrous, per- 

 oxide of manganese. 



This whole train of investigation is usually regarded by com- 

 petent judges as one of the most beautiful and perfect that has 

 yet appeared in the extensive department of inorganic analysis, 

 and, even though its author had done nothing else, would have 

 raised him to the very first rank as an analytic inquirer. 



There now remains for notice but one of Dr Turner's origi- 

 nal researches, — one which was undertaken in a somewhat re- 

 markable conjuncture ; for he appears in it expressly in the 



• Edinburgh Journ. of Science, N. S. ii. 213. 1830. 



