Lawrence Scientific School. 347 
meyer’ has extended the same process to the separation of iron 
from titanic acid and zirconia. Other analytical applications of 
the hyposulphite have been made in which.the salt is employed 
either as a solvent or in volumetric processes: these do not re- 
uire notice in this place, The following observations on the 
behavior of the hyposulphite toward certain metallic salts are 
interesting from a purely chemical rather than from an analyti- 
cal point of view. ‘ 
fickel— When a neutral solution of sulphate, chlorid or ni- 
trate of nickel is boiled with a solution of hyposulphite of soda, 
a black precipitate of sulphid of nickel is thrown down, an 
after very long boiling the precipitation is complete and the so- 
lution is free from nickel. If the solution of nickel be pre- 
viously acidulated by the addition of a drop or two of acetic 
acid the precipitation is more rapid. It is very difficult to de- 
termine the exact point at which the solution ceases to contain 
slowly. Rammelsberg* long since observed that a solution of 
hyposulphite of nickel is partially decomposed by evaporation, 
and that the dry mass on heating yields a yellow sulphid of 
He solution of nickel is introduced by a long funnel together 
with the solution of hyposulphite which should be in excess 
and concentrated. After sealing the tube before the blast-lamp 
itis to be heated in an air-bath and kept for half an hour at a 
temperature of about 120° C. Every trace of nickel is thrown 
down in the form of sulphid mixed with free sulphur: the tube 
May then be opened at the point, the liquid allowed to flow into 
4 Deaker, the tube cut across and the sulphid of nickel washed 
Sut. It may be thrown on a filter and washed with boiling 
Water without oxydizing in the smallest degree. The equation 
tepresenting this reaction appears to be - 
NiCl-+-2Na0, 8,0, =NiS-+NaCl +Na0, 8,0,. 
* Ann. der Chem, und Pharm., exiii, 127. © Pogg. Ann., lvi, 295. 
