476 
SECOND REPORT —1832. 
earths. Neutral solutions of strontian are not precipitated by 
this salt, while those of barytes give immediately white flocks, 
and the precipitation is so complete that no trace of barytes 
remains in solution. 
Lime. —Mr. Andrews * has also given a very simple method 
of detecting the presence of barytes and strontian in lime. The 
whole is dissolved in nitric acid, evaporated to dryness, and 
the acid expelled by heating to redness in a platinum crucible. 
The caustic residue is boiled with water, when the whole of 
the barytes and strontian and only a little of the lime are dis¬ 
solved. Sulphuric acid added to the solution shows if any of 
these two earths are present, while a boiling saturated solution 
of sulphate of strontian troubles it if it contain barytes, but 
causes no precipitate if the earth be strontian. 
Thorium.-— In a notice of the most important discoveries re¬ 
cently made, that of the metal thorium by Berzelius must not be 
passed over. In 1816, in analysing the gadolinite of Korarvet 
nearFahlun, and some other rare Swedish minerals, he obtained 
an earthy base which differed from all other known substances, 
and which he therefore concluded to be the oxide of a new 
metals to which he gave the name of thorium. More lately, 
however, he found that he had been led into an error, and that 
the supposed oxide was a subphosphate of yttria, in which the 
phosphoric acid could be detected with very great difficulty. 
But in 1828, Pastor Esmarck, of Brevig in Norway, trans¬ 
mitted to Berzelius a black heavy mineral which he supposed 
to contain columbium. On analysis, however, it proved to 
consist chiefly of a silicate of a new earth which constituted 
about fifty-eight per cent, of the whole mineral. To the base 
of this earth Berzelius gave the name thorium, partly on ac¬ 
count of a resemblance between its properties and those of the 
subphosphate of yttria to which it had formerly been applied, 
and partly because that term had already found its way into 
chemical works. It is allied in properties to yttria, glucina, and 
zirconia. 
The mineral thorite , in which it is found, is very rare. Only 
one mass of it has hitherto been found in a primitive rock 
near Brevig in Norway. I visited the locality last summer, but 
succeeded only in obtaining a small fragment, for which I was 
indebted to the kindness of its discoverer Pastor Esmarck. 
Manganese.— The nature and composition of the several 
oxides of manganese have been beautifully cleared up by the 
united labours of Turner, Haidinger, and Phillips ; and the 
* Phil. Mac/, and Annals , vii. p. 40 L 
