86 
MISCELLANY. 
48. By dissolving Iodide of Zinc in a solution Ammonia and allowing 
the mixture to evaporate spontaneously^ brilliant prismatic crystals were 
obtained, which were permanent in the air, but rapidly decomposed when 
treated with cold w T ater. The formula of this combination is Znl2-}-4N H 3 . 
When dry Iodide of Zinc was treated with gaseous Ammonia, a combi- 
nation is obtained which contains a large proportion of Ammonia. Its 
formula is Znl2-f-6NH 3 . It is also rapidly decomposed by water. 
Iodide of Cadmium, by similar treatment with Ammonia, produces 
compounds of which the formula are Cal2-f-2NH 3 and CaI 2 -f-6NH3. 
Compounds may be formed with Iodide of Cobalt and Ammonia, which 
consist of Col2-f4NH3 and Col3-f6NH 3 . 
When Ammonia is added to a solution of Iodide of Nickel, a blue pre- 
cipitate is formed which entirely dissolves on warming the liquor, from 
which, on cooling, it crystallizes in small crystals. These consist of 
N1I2+6NH3. 
A compound may also be obtained of the Biodide of Copper and Ammo- 
mo n i a. Ann. des Mines. 
Researches on the Composition of Crystallized Phosphoric Acid. By M. 
Peligot. — Having kept for some time phosphoric acid of a syrupy con- 
sistence in stopped bottles, it formed two beds of crystals; the superior, 
transparent and hard ; the inferior, of the consistence of candied honey. 
On analysing them separately, after drying, I found 0.27 to 0.28 water in 
the former, and 0.22 to 0.23 on the second; the hydrate with three equiva- 
lents should contain 0.274, and with two equivalents 0.201. It is known 
that glacial phosphoric acid contains only one equivalent. The supposi- 
tion of M. Graham on the existence of two hydrates is thus confirmed. 
Double Nitrate of Potassa and Soda. By M. Loole. — By dissolving with 
heat equal parts of the nitrates of potassa and soda, in three parts of wa- 
ter, and cooling the liquor gradually, crystals of the double salt were 
formed half an inch long, in radiated groups, and having a silky lustre. 
Protection of Iron by Zinc. By M. Munckel. — M. de Althaus, di- 
rector of the salt works of Durheim, has succeeded in completely pro- 
tecting the pans, thirty feet long, which are used for evaporating brine, 
by riveting to their exterior bands of zinc ; and he has remarked that it 
was not necessary that the metals should be polished at the points of con- 
tact. This fact, which is established by an experience of more than ten 
years, tends to support the theory of contact. Ann. des Mines. 
Mr. Donovan on Cod-Oil.* — It appears that cod-oil has been a good deal 
used, of late, in France and Germany, in certain scrofulous cases. They 
* Dublin Journal, July 1, 18 10. 
