202 Mineralogy of Southern India. 



decomposed by carbonate of potash, according to Dr. Thom- 

 son's method, to separate the magnesia ; but this was not 

 satisfactorily done. The magnesia after weighing was super- 

 acidulated with sulphuric acid, and then dissolved in water ; 

 a few flocks remained, either lime or some lead, from the 

 acid not being quite pure. The precipitate of ammonia was 

 boiled with caustic potash to take of alumina, which was 

 again separated after filtering, by muriate of ammonia. The 

 ferruginous residue left on the filter was re-dissolved in 

 muriatic acid, and precipitated afresh by ammonia, and an 

 attempt was made to suspend manganese by an excess of 

 muriate of ammonia, but it was not proved satisfactorily that 

 the analysis contained manganese. The iron was considered 

 to be in the state of protoxide. Several analyses were made, 

 but they were all imperfect in one point or other, and an 

 attempt to separate manganese by benzoic acid also failed : 

 however, the subjoined proportions may be considered as a 

 tolerable approximation : — 



Silica, 





.. 48.93 



Magnesia, 





.. 29.31 



Protoxide of iron, 





9.23 



Alumina, 



. . 



6.29 



Water, 





4.73 and volatile matter 



• L • i. l~~Ul„ i.l,„i. It. ~, 



As the analysis was infusible, it is not probable that it con- 

 tained an alkali, and the loss is within the limits of a quanti- 

 tative analysis. 



Salem yellow Wood-stone. 

 This is a very beautiful mineral, and I believe quite new 

 in petrology, for I have been unable to find any notice by 

 authors of a similar one. I think the name is quite as good 

 as any coined one, and the only objection may be in the use 

 of the word e wood-stone,' as it has no resemblance to the mi- 

 neral generally so called. In my earlier notes I find it called 

 1 Salem yellow woody mineral.' I have not seen it in sites, but 



