Fourth Member of the Calcium group of Metals. 87 
one blue line*, situated between the lines Sr d+ and K £8, about 
twice as far from the former as from the latter. In brightness 
and sharpness of definition it is quite equal to the line Sr6. 
The method which, after repeated trials, we found most advan- 
tageous for obtaining it in a state of comparative purity is the 
following. The deposit formed by boiling the water was dissolved 
in hydrochloric acid, and a small quantity of sulphuric acid added 
to the clear solution. The precipitate formed, consisting prin- 
cipally of sulphate of calcium, but containing some sulphate of 
barium, sulphate of strontium, and sulphate of the metal under 
consideration, was collected, washed, dried and fused with car- 
bonate of sodium. The fused mass was then boiled with water, 
and the insoluble carbonates of the above-named metals collected 
and treated several times successively in the same manner as the 
original deposit. By these means the lime was gradually re- 
moved, the carbonates becoming proportionally richer in barium, 
&c. Owing to the small quantity of substance at our command, 
we did not attempt to remove the lime entirely. The carbonates 
finally obtained were once more dissolved in hydrochloric acid, 
and the solution, after considerable dilution, mixed with a few 
drops of sulphuric acid. After standing at rest for twenty-four 
hours, the slight quantity of deposit formed, consisting of almost 
pure sulphate of barium ft, was filtered off, and some alcohol added 
to the filtrate, by which a further deposit was obtained, com- 
posed chiefly of the sulphates of strontium and the new metal, 
though not quite free from sulphate of calcium. These sulphates 
were again converted into carbonates, which were then dissolved 
in hydrochloric acid, and the solution evaporated to dryness. 
When a portion of this dry residue was brought into the flame 
of the apparatus, the spectra of calcium and strontium appeared ; 
and, in addition, beyond the line Sr 6, in the position indicated 
avove, a blue line, rivalling the strontium-line in brilliancy and 
distinctness of outline. 
As far as we have been at present able to ascertain, the car- 
bonate, oxalate, and sulphate of the new metal are insoluble in 
water, the last-named possessing about the same insolubility as 
sulphate of strontium. The chloride of the metal does not seem 
to be hygroscopic, resembling in this respect that of barium 
rather than those of strontium and calcium. 
* Having been unable to separate it completely from calcium and stron- 
tium, we are not quite positive whether or not it gives any lines at the red 
end of the spectrum. 
T In our last communication there is a typographical error, Sry being 
. put for Sr 6d. 
{ We have detected the presence of barium in several London waters 
since the publication of our notice in the November Number of the Phi- 
losophical Magazine, 
