S. P. Sadtler— Analytical Notices. 181 
such a high heat without decomposition, that they strike one at 
once as very suitable forms for the detenninasion of these ele- 
ments by evaporation with excess of sulphuric acid, in cases 
where the method by precipitation is not used. Accordingly, 
we find that the determination as sulphates by evaporation, of 
these three, is given by Fresenius, although not strongly recom- 
mended. W0ohler, in his “ Mineral-Analyse,”+ does recommend 
the determination of strontia and lime as sulphates. However, 
the evaporation of the excess of sulphuric acid over the ordi- 
nary forms of Bunsen-burner is so precarious an operation, as 
to effectually shut out these methods, except in case of necessity. 
ith the “ring-burner,” the evaporation of the excess of sul- 
phurie acid is as safe as the evaporation of so much water over 
the water-bath. doe 
ryta.—Any of the compounds of baryta with volatile acids 
can, as Fresenius states, be determined as sulphate by evapora- 
tion with excess of sulphuric acid, and with the “ring-burner 
rapidly and safely. I did not, however, make any quantitative 
determinations here, as the determination as sulphate by precipi- 
tation is so perfectly reliable and is generally applicable. 
_ Strontia.—Here the determination as sulphate by precipitation 
Is acknowledged to be of only tolerable accuracy, on account 
siderable importance. The results of some tests made by Mr. 
- S. Eyster on this subject are as follows : 
* This Journal, March, 1870. } Mineral Analyses, 161, pp. 14 and 19. 
