412 Berzelius on a new Mineral Body. [June, 
At the same time a portion of the-selenium is reduced, and dry 
selenic acid remains in the retort, coloured red by the radical 
reduced. If we distil a mixture of sulphuric acid, selenic acid, 
and alcohol, we obtain a product having an insupportable odour, 
and a great deal of selenium is reduced. The very disagreeable 
smell of the product prevented me from examining it. We do 
not always obtain at each operation equal quantities from the 
same proportions of the materials. 
Selenic Acid and Muriatic Acid. 
Selenic acid seems to have no particular affinity with the acids 
which contain water, since it is easily separated from them by 
distillation without exhibiting any phenomena which would indi- 
cate combination. But it has the property of combining with 
anhydrous muriatic acid, producing a double acid similar to those 
which phosphoric acid, carbonic acid, &c. form with muriatic acid. 
If we put selenium into a small glass globule formed in the 
middle of a barometrical tube, and introduce into it chlorine gas, 
this gas is absorbed by the selenium, which becomes hot, liqui- 
fies, and forms a brown coloured liquid.. More chlorme gas 
being introduced, additional quantities of it are absorbed till the 
acid is converted into a white solid mass, composed of muriatic 
and selenic acids free from water. If we heat this double acid, 
it contracts a little without melting, and then evaporates in the 
form of a yellow vapour, just as selenic acid itself does; and 
condenses upon the cold part of the apparatus in the form of 
small white crystals. If we continue the sublimation, the sub- 
limate becomes hot, and assumes the form of a white, dense, 
semifluid mass, which, on cooling, becomes filled with small 
cavities. It dissolves im water, with the evolution of heat, and 
with a kind of effervescence, occasioned by a gas whichis again 
condensed by the liquid. The solution is colourless, limpid, and 
very acid, ! 
If we mix the double anhydrous acid with selenium, the acid 
immediately assumes a yellow colour at the place where it is 
touched by the selenium ; and if we apply heat, the two bodies 
combine and form an oily body of a brownish-yellow colour, 
transparent, and volatile ; though a greater degree of heat is 
necessary to distil it over than is required by the double acid, 
The oily body sinks to the bottom in water, and remains for a 
little in a liquid state; but the water gradually decomposes it, 
separating from it muriatic acid and selenic acid, and leaving the 
selenium preserving the form of the oily body. But it is diffi- 
cult to deprive it entirely of the muriatic acid ;: and it has always 
happened to me, after having pulverized the remaining selenium 
and digested it in boiling water, that the paper on which I dried 
ait. became friable by the influence of a portion of muriatic acid 
which was disengaged during the drying. 
(To be continued. ) 
