142 PREPARATION OF THE PERCHLORIDE OF IRON. 
ART. XXXIV. — PREPARATION OF THE PERCHLORIDE OF 
IRON. 
By M. Gobley. 
Sesquichloride or perchloride of iron exists in the an- 
hydrous state and in the state of hydrate. 
To obtain the anhydrous perchloride there are two pro- 
cesses. The first consists in placing in a luted glass or por- 
celain tube iron hammerings, and inserting the tube in a 
furnace ; the tube should project some distance beyond the 
furnace. When the apparatus is thus arranged, that por- 
tion of the tube where the iron is placed is heated to a 
temperature below red heat, about 752°, and a current of 
dry chlorine is then passed through by one of its extremities. 
The gas is rapidly absorbed the iron becomes incandescent, 
and gives off abundant vapors of sesquichloride, which 
condense in the cold portion of the tube projecting beyond 
the furnace, in the form of laminae of dark violet color, and 
possessed of a metallic lustre. 
The second process consists in saturating commercial 
muriatic acid with dry or moist hydrate of the peroxide of 
iron. The solution is first effected at the ordinary tempera- 
ture, then assisted by a gentle heat; and when the acid no 
longer takes up any oxide, the liquid is filtered, evaporated 
to dryness in a porcelain capsule, taking care to moderate 
the heat and to stir constantly. The product of this ope- 
ration is transferred into an earthen retort, and heat gradual- 
ly applied, taking care not to place any fire near the dome 
of the retort. Aqueous vapors are first disengaged ; when 
they have ceased a cork is adapted loosely to the aperture of 
of the retort, and the fire is then raised, so that the bottom 
of the retort is nearly red-hot towards the close of the ope- 
ration. The anhydrous perchloride sublimes on to the 
