16 M. Berzelius on Vanadium. 



is mixed with muriatic acid, and the solution is evaporated, 

 at first at a temperature of 85° to 95° Fahrenheit, until the 

 mixture becomes colourless, and afterwards spontaneously, a 

 brown cr3'stalline deposit is obtained, which when examined 

 by the microscope appears to consist of cubes. It is a mix- 

 ture of a supervanadate of ammonia with a subchioride of 

 vanadium; the formation of the latter depends upon the im- 

 possibility of ascertaining- the exact quantity of muriatic acid 

 v.'hich should be added to the mixture. 



The vanadates of anunonia, when mixed with infusion of 

 galls, form a black liquid, which is the best writing ink that can 

 be used. The quantity of salt necessary for a perfectly black 

 ink is so small, that it will be not worth considering when 

 vanadium is more generally known. The writing obtained 

 ■with this ink is perfectly black. Acitis render it blue, but do 

 not obliterate it, like common writing ink; the alkalies, when 

 sufficiently diluted not to act upon the paper, do not dissolve 

 it, and chlorine, which destroys the black colour, does not 

 however efface the writing, even when water is afterwards 

 suffered to run over it. In a word, if this ink is not perfectly 

 indelible, it strongly resists reagents, which instantly cause 

 common ink to disappear; added to which it is blacker and 

 flows better, because it consists of a solution and not of a pre- 

 cipitate suspended in a solution of gum. It remains to be 

 proved what the effects of time will be upon it. 



Vanadate, of Barytcs. — It is yellow when first formed, and 

 precipitates in a gelatinous mass. It gradually contracts, and 

 becomes white. It cannot be washed without loss, for it is 

 slightly soluble in cold water, and this solution when evapo- 

 rated covers the glass with small white crystalline grains. At 

 a red heat it fuses. 



Bivanadate of Barytes. — This is prepared by mixing a so- 

 lution of chloride of barium with bivanadate of potash, and 

 adding alcohol. The bivanadate then precipitates in the state 

 of a yellow powder, which when the liquor is stirred appears 

 to be composed of small brilliant scales. It is not very solu- 

 ble in water, and yields by spontaneous evaporation small 

 orange-yellow crystals. Sulphuric acid does not perfectly de- 

 compose vanadate of barytes. In order that the decomposi- 

 tion should be complete, the salt must be fused at a red heat 

 with bisuiphate of potash. 



Vanadate of Strontia. — This salt is more soluble in water 

 than the preceding. It does not precipitate when prepared 

 by double decomposition ; but if the solution be suffered to 

 remain, the salt is gradually deposited upon the glass, which 

 it covers with small white crystalline grains very slightly so- 

 luble in water. Bivana- 



