60 Improvements in Physical Science (JAN. 
knowledge ; though they might without impropriety have been 
placed under the head of chemistry. 
1. Berzelius’s little treatise on mineralogy* claims our first 
attention. It displays the characteristic sagacity and industry of the 
author. Its object is to show that minerals, like other substances, 
are true chemical compounds, the constituents of which exist 
always in unvaried proportions. He has succeeded in proving that 
this holds in a great many cases where it was not suspected. Silica, 
he considers with Mr. Smithson, as an acid capable of neutralizing 
the other earthy bodies, and forming with them siliciates, bisi- 
liciates, trisiliciates, &c. He has pointed out a very simple but 
accurate method of determining how many atoms of these bodies 
are united together. He has assigned, also, very probable reasons 
to account for the discordancy of the analyses of the same mineral 
that have been hitherto made. I believe that one great cause of 
this discordancy is the want of sufficient pains in choosing pure 
specimens for analysis. This proceeds, in too many cases, from 
chemists not having attended sufficiently to the external characters 
of minerals, so as to be able to discriminate between pure and 
impure specimens of the same mineral. 
Berzelius and Gahn were employed during a considerable part of 
the summer of 1814, in examining and analyzing minerals, which 
they had discovered in the neighbourhood of Fablun. Among 
others they found yirocerite, a violet-coloured powder, which 
Berzelius found composed of 
DTG iene e be ccidele «up eee ay Die 
PU ALIMAL picts ast ie Wee RES sieges bibles stot) seh a ORE 
* Oxide oF ceria so 2ce 6 sieges Sein dg FSIS 
Puoric MO, Gis dstinve deaths aiale'on ime eee 
99°98 
Another mineral found by them was the fluo arseniate of lime. 
It is a yellow-coloured substance, found at Finbo near Fahlun, and 
composed of fluoric acid, arsenic acid, and lime. It usually coats 
the quartz and felspar of the rock in which it occurs. 
Berzelius has likewise ascertained that gadolinite contains 
cerium, and that the yttria of Gadolin and Ekeberg contained a 
portion of cerium. 
2. Arragonite.—Since Stromeyer’s discovery, that arragonite 
contains a portion of carbonate of strontian, a great many analyses 
have been made of that substance, almost all of which confirm the 
precision of Stromeyer’s, which are now established beyond the 
reach of controversy. In France, strontian was found in arragonite 
by Vauquelin, Laugier, and Vogel. In Germany, by Gehlen, 
Bucholz, Meissner, and various other chemists. ‘The most ela- 
borate set of experiments on the subject are those of Bucholz, 
published in Schweigger’s Journal, (vol. xiii. p. 1.) He in the 
* Translated into English and published in one small volume, 
