544 
NOTES AND ABSTRACTS IN CHEMISTRY AND PHARMACY. 
with that produced by phosphorized oil. Phosphide of zinc is selected in pre¬ 
ference to the other metallic phosphides, because it is at once perfectly stable, 
and easily decomposed by weak acids. Even lactic acid attacks it, evolving 
phosphoretted hydrogen ; according to Messrs. Vigier and Curie this explains 
the action which occurs in the stomach. Phosphide of zinc is prepared by pass¬ 
ing the vapour of phosphorus over zinc heated to ebullition, in a current of dry 
hydrogen. 
The authors administer it in doses of one milligramme (0 015 grain) several 
times a day. It is given either in the form of pilules or of powder. 
Soluble Peroxide of Iron. 
M. Jeannel points out that hydrated peroxide of iron retains ammonia, which 
cannot be removed by washing with water. According to this chemist, the pre¬ 
sence of this ammonia causes the molecular transformation which after some 
days renders the oxide of iron insoluble in weak acids, even though it be kept 
under water. In like manner sulphuric acid or soluble sulphates immediately 
induces a similar change. 
To prepare hydrated oxide of iron, which shall preserve indefinitely its soluble 
character, M. Jeannel recommends the following method :—pure perchloride of 
iron is precipitated by excess of ammonia, the resulting oxide is washed with 
distilled water until all the ammoniacal salt is removed, and then with water 
acidulated with one or tw r o parts of hydrochloric acid in a thousand. This 
saturates and removes the ammonia. The precipitate retains hydrochloric acid, 
but it is stable, and soluble in weak dilute acids and even in water. The oxide 
thus prepared can be dried at the ordinary temperature, or even on a water- 
bath without losing its solubility. 
Nitrate of iron may be employed in the place of perchloride, and nitric in¬ 
stead of hydrochloric acid. 
Action of Ammonia on Phosphorus. 
M. Blondlot has published some very interesting and curious experiments on 
the action of ammonia on phosphorus. If a piece of phosphorus be kept in a 
strong solution of ammonia it becomes first brownish, then green, and finally 
deep black. At the same time that these changes of colour are occurring, the 
phosphorus becomes hard and brittle; it cracks and splits, and will ultimately 
fall to powder. These effects are produced more or less rapidly according to cir¬ 
cumstances. Solar light is remarkably favourable to the change, causing it to 
become manifest in several days, and to be terminated in a few months, while 
in the dark more than a year is required for its accomplishment. The most 
concentrated ammonia produces the most rapid and decided change. When 
the phosphorus has become black it may be easily rubbed down to fine powder 
in a mortar with some water. It may then be dried in the air on a water bath. 
If it retains any unchanged phosphorus, which would cause its ignition, this 
may be removed by washing with sulphide of carbon. Passed through a fine 
sieve it constitutes an intense black impalpable powder, which may be pre¬ 
served under water without sensible alteration ; but, if exposed dry to the air, 
it slowly evolves a trace of ammonia, and little by little becomes yellow. In 
this new state it resembles amorphous phosphorus in several of its chemical 
characters, although in some others it differs considerably, and notably in 
colour. The yellow powder, heated in a tube to 200° C., evolves some phos¬ 
phoretted hydrogen, and passes to ordinary amorphous phosphorus. Treated 
with ammonia, it reassumes in the course of an hour its original black colour. 
M. Blondlot has not yet accurately determined the chemical nature of these 
changes, but he is inclined to regard the powder as containing solid hydride of 
phosphorus and hydrated amorphous phosphorus. 
