298 PROCEEDINGS OF THE AMERICAN ACADEMY 



The vanadate of ammonia present in the balanced solution from tlie 

 silicates, by the mode of analysis described above, may be separated by 

 over-saturating the solution with ammonic chloride, when amnionic 

 vanadate separates ; although pl;iosphoric acid is present. From the 

 vanadate other combinations of vanadium may be formed. The solu- 

 tion does not then respond to the gall test ; and the ammonic vanadate 

 separated, when heated, leaves vanadic acid. The deposit caused by 

 tinct. galls may be calcined for VO'. In testing for i^hosphoric acid, 

 in this mixed solution, the magnesia mixture does not respond at once, 

 unless the device of Wollaston be used ; and, in strong .solutions, plu- 

 mose vanadates form. If heat is applied to the salts in mixture with 

 clilorides, much of the vanadium will be lost. In most of the rocks 

 containing phosphorus, vanadium has been found associated. Manga- 

 nese is also a congener ; and, without repeating here the list of rocks, 

 I can promise in a future paper to give a tabulated series. 



In Utah, in the Tintic District, there is a chalcedonic rock, with 

 brown ferric and cupric ore. In the brown part of this ore both phos- 

 phorus and vanadium are abundant. The presence of vanadium, in 

 crusts on copper rock of Lake Superior, announced some years since, 

 by my late fi-iend, J. E. Teschemacher, has been lately confirmed. It is 

 jjresent in light grayish earth-like substance of the datholite beds in 

 the Calumet and Hecla mines. At present it appears that vanadium 

 is as common a constituent of rocks as manganese. 



VANADIC COMPOUNUS IN "WATER. 



The beautiful suburb of Boston, Brookline, owes its varied surface 

 and scenic effect largely to water action in forming the gravel drift 

 into elevations and depressions, having clirved and graceful lines. 

 This drift pi-esents us with a magazine of rock aggregates, which not 

 only supply the laboratory, but, in various cuttings, allow us to watch 

 the influence of air, frost, and water on the rocks ; which, stable 

 in their beds, become changed, even rapidly, on exposure to these agen- 

 cies. This gravel, permeated by air, changing under every variation 

 of pressure, is jjowerfully oxidizing ; and the rain water, even if colored 

 on entering it, becomes colorless and sparkling at eight yards below 

 the surface. The gravel contains strata and inclined dykes of ex- 

 tremely finely divided micaceous earth, or "quicksand," in which the 

 water circulates and passes to the ocean at different levels. An average 

 result of partial analyses is : 1 litre affords by evaporation and drying 

 at 100° 0.350 grm., of this amount 0.182 grm. is nearly insoluble 

 matter; 0.1 G8 grm. again dissolves in water, and contains, besides the 



