J. M. Ordway on Nitrates of Iron. 327 
acter and composition, and its close correspondence to the ni- 
trates of alumina and chromi 
: tion, at a very moderate heat, to the consistency of syrup, and 
then adding to it half its volume of nitric acid, By analysis, 
____ the crystals pressed in absorbent paper, gave him per-centages 
E corresponding to Fe, O,,83NO,+13HO, equal to Fe, 0,; 
8NO, , 12HO+2(NO, 4HO). oh 
Wildenstein” found several pounds of cubic crystals aay os 
at ha 
appear to have come from a somewhat basic liquor deficient in 
crystallized, that the attraction of the tetrahydrat 
- for water, shall be rather more than counteracted by the at- 
_ traction of an excess of nitric acid for water ;—that is, so that 
4] 
~ 
. 
_ Water than will make up Fe, O,, ved 12HO+n(NO,, 3HO) 
may afford afew of the rhombic sexhydrate crystals mixed with 
the cubic; and one containing less water will hardly give any 
solid nitrate at all. When there is water enough present to @ 
make up Fe, O,,3NO, 18HO+n(NO,, 4H0), the crystals will - 
When a solution is not basic and contains between 
six and twelve equivalents of water to one of perchlorid of iron, = 
it first deposits the deutohydrate, Fe, Cl, 6HO, in transparent - 
crystals, and then goes on to form the light yellow, opaque, in 
distinct tetrahydrate, Fe, Cl,12HO. Unless the liquid lacks 
Water, no transparent crystals can make their appearance. ae 
_ For making cubic nitrate, the oblique crystals afford a defini ae 
Material that admits of appreciable treatment. We = tal ee . 
weighed quantity of these crystals in a tared dish, and sig jen 
by a senithy heat about fourteen per cent of their weight, SL 
- _ ® Erdmann’s J. fiir Pr. Ch, lexxiv, 243.00 
