468 
SECOND REPORT— 1832. 
precipitate them in the metallic state. Thus, iron precipitates 
copper, zinc precipitates silver, &c. But in all such cases the 
reduced metal is generally obtained either in the state of a fine 
powder, or cohering together in a porous mass. In some in¬ 
stances, however, it has been met with in a solid malleable state, 
as if it had been submitted to fusion, sometimes even in regular 
crystals. Thus in the copper pits of Anglesea, where iron is 
thrown in to reduce the copper from its solutions, malleable and 
crystallized copper has often been obtained. To ascertain the 
circumstances under which it was deposited in this form, and 
above all to be able to produce it at pleasure, became a very 
interesting inquiry, not to the chemist only, but also to the 
geologist. 
Wach* has investigated these circumstances, and found that 
wherever the process proceeds with sufficient slowness the metal 
is deposited in this form. The process he recommends is 
founded on an observation of Fischer, that when a metal is 
placed in a tube containing water and separated at the lower 
end by a diaphragm of bladder from the solution of the metal 
it is intended to precipitate, the action takes place through the 
bladder, the precipitated metal is deposited on its outer surface, 
while the acid liquor passes through and dissolves the other 
metal. By this method Wach has succeeded in obtaining cop¬ 
per, antimony, bismuth, silver, and platina in a massive state, as 
if they had been fused. The metal may also be sewed up in 
two or three folds of bladder and immersed in the solution to 
be precipitated, when the same effects follow. 
Becquerel obtained copper in crystals by means of very weak 
galvanic currents. 
Metallic copper has also been found in large masses deposited 
in vessels made entirely of wood, into which the solution of 
sulphate of copper is collected in the vitriol manufactories pre¬ 
vious to boiling for crystallization. This has been found by 
Clement and Bischof to be due to the presence of a portion of 
a salt of the protoxide in the solution, one part of which gives 
up its oxygen, and is reduced to the metallic state. This 
phenomenon therefore is quite distinct from those above men¬ 
tioned. 
Electro-negative metals— Vanadium .—The most important 
addition to our knowledge of the electro-negative metals made 
during the last ten years has been the discovery of vanadium 
by Sefstrom, and the elaborate examination of the properties of 
the new metal since published by Berzelius. 
This metal was discovered by Sefstrom tow r ards the end of 
* Nenes Jahrbuch, i. p. 40. 
