306 Biography of Berzelius. 
gation with untiring industry, and was thus able to furnish even 
those mineralogists who but unwillingly admitted the influence 
of chemistry upon mineralogy, with an extremely welcome gift, 
since, by simple blowpipe experiments, it was made possible 
to distinguish minerals with ease and certainty, especially sili- 
ceous compounds, which were with difficulty, or only ambigu- 
ously, recognizable by means of their external characters. 
This work bore so manifestly the stamp of perfection, even on 
its first appearance, that, with the exception of Plattner, in Frei- 
berg, no one has contributed any essential additions or improve- 
ments to blowpipe investigations; and it is quite as indispensable 
to the chemist and mineralogist at the present day as it was thirty 
years ago. : 
About this time, Berzelius discovered selenium, and was en- 
gaged upon his admirable investigation of this element. Never 
was there an examination so accurate and thoroughly exhaustive, 
of an interesting and hitherto unknown element, comprising a 
its characters and remarkable combinations, so that, if we except 
the discovery of selenic acid by Mitscherlich, which escaped Ber- 
zelius, nothing essentially new was added to our knowledge of 
this element during the next thirty years. Our astonishment at 
this will be the greater when it is recollected that all these inves- 
tigations were carried on with a very small quantity, only about 
2 ounce of selenium, of which a part was lost through the care- 
~ Jessness of a servant. 
This paper upon selenium can be compared only with that by 
Gay-Lussac upon iodine, which appeared several years before, and 
has yielded, in so many respects, such valuable results. It must, 
nevertheless, be remarked, that Gay-Lussac was not the discoverer 
of iodine, and did not undertake the investigation until after the 
first chemist of that time, Davy, had almost established the true 
nature of iodine; and that he had large quantities of materials at 
his disposal. 
Almost at the same time that Berzelius was engaged in the ex- 
amination of the compounds of selenium, Arfvedson was en- 
gaged in his laboratory with the analysis of some Swedish min- 
erals ; and under the guidance of Berzelius, succeeded in discover- 
ing lithium, which, as it came so unexpectedly, justly created 
great interest. 
The following larger papers of Berzelius form, as it were, 4 
series of monographs upon separate and important branches of 
chemistry, which were at that time still obscure. It was natural, 
when he commenced the demonstration of the law of definite 
proportions by means of a succession of laborious investigations, 
that he should throw aside much, in order to sketch the ground- 
work of his system. The investigations which he now undertook, 
Were all instituted in accordance with a matured plan, and he 
had long meditated upon them before actually undertaking them. 
