and on some other Covipou]uh oj' Vanadium. 



211 



Green 



Sulphate 



of Iron. 



Per- 

 sulphate 

 of Iron. 



Immediate Effect. 

 "An abundant flocculent dark slate 

 coloured precipitate, leaving the 

 liquid a paler shade of a similar 

 colour, with a tint of green. 



Little or no precipitate; the liquid 

 deep orange. 



Sulphate 



of 

 Copper. 



("An orange-coloured precipitate at 



I first contact, appearing greener 



J on mixing with the blue solution ; 



'^ settled, pale yellowish green, 



I leaving the liquid a deeper shade 



L of the same colour. 



Nitrate of) Slight precipitate, pale salnion-co- 



Cobalt. \ loured, liquid scarcely altered. 



Acetate ffrecipitate copious and heavy, of 



c I nearly the same colour as the 



1 ead 1 ^l^ove, settling paler and more 



(_ orange ; the liquid colourless. 



Corrosive C An orange precipitate; heavy, 



Subli- } settling yellower; the liquid dull 



mate. ( pale yellowish green. 



r 



Tartar J ^ l""ownish orange coagulum, re- 

 ■^ dissolved on shaking; and giving 

 I that hue to the liquid. 



L 



Emetic. 



After 12 Hours. 

 The precipitate unchang- 

 ed ; the liquid greener, 

 like solution of sul- 

 phate of iron. 



Unchanged. 



The precipitate inclines 

 to orange colour ; the 

 liquor remains yel- 

 lowish creen. 



Unchanged. 



The precipitate almost 

 bleached, probably by 

 taking down e.xcess of 

 lead. 



The precipitate yellow; 

 liquid the colour of 

 chlorine. 



The liquid opalescent, 

 dull pale green by re- 

 flected, and orange by 

 transmitted light; no 

 precipitate. 



With vanadium as abase, the operations were more embar- 

 rassing. The oxides formed simultaneously, during the decom- 

 position of vanadiate of ammonia, and were difficult to separate. 

 One of them would seem to possess acid properties ; and the 

 other to be partly converted into that in washing, and partly 

 to combine with it, forming a soluble compound, not precipi- 

 tated either by alkalies or acids *. The experiments were in- 

 conclusive, and the description of them must be very general. 



Two portions of vanadiate of ammonia were decomposed 

 by heating in a close platinum crucible : one of them had been 

 recovered from former experiments, by precipitation with 

 barytes, as above described, and probably was not free from 

 sulphuric acid. The other had only been converted into 

 vanadic acid, rediss(»lved in liquid anmionia and crystallized. 



The first left an oxide of a deep blue or green colour, al- 

 most black. As it was supposed to contain sulphuric acid, it 

 was subjected to tliat acid, a drop of which turned the part 

 with which it lay in contact, light green; but the addition of a 

 few dro|)s of water, after some hours, to give fluidity to tlie 

 whole, tiu-ned it deep blue, and syrupy, like undiluted sul- 

 phate ol' indigo. After twelve hours digestion, about 30 parts 



Sec our last Nuiniier, [). \b'-Z, — Euii. 

 2 E 2 



