A compendium of the course of chemical instruction in the Medical department of the University of Pennsylvania
Robert Hare
Paperback
(RareBooksClub.com, March 6, 2012)
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1836 Excerpt: ...This process has already been mentioned as one of the means of obtaining nitrogen. In its reaction with ammonia iodine differs from chlorine. When iodine is brought in contact with dry ammoniacal gas, it forms a thick black fluid, which, when saturated with ammonia, becomes more liquid. This compound is decomposed by water forming the iodide of nitrogen. See page 243. With various metallic oxides, ammonia forms explosive compounds; especially those known as fulminating gold, and the most dangerous species of fulminating silver. By these appellations, however, other compounds of those metals are designated. By some mysterious influence, probably electro-chemical, the affinities between the oxygen and hydrogen are suspended without being destroyed. Yet by slight causes, whether mechanical or chemical, the equilibrium is subverted with explosive violence. 218. Process for obtaining Water of Ammonia. If instead of being conveyed into a bell glass over mercury, the gas be received in water contained in a phial, the water may be saturated, constituting aqua ammoniae, or water of ammonia. The saturation may be effected in an apparatus, similar to that represented in the above cut. The absorption of ammoniacal gas by water, causes so much heat, that, to produce a saturated solution, refrigeration by ice-water is necessaryWater, saturated with ammonia, when gradually cooled to the temperature of--40 F., crystallizes in long needles having a silky gloss. No doubt these crystals owe their existence to the presence of water, which exists in them as water of crystallization. Water of ammonia is lighter than water. In combining with the gas, the water loses weight in proportion to the degree of impregnation. At the maximum, at ordinary temperatures, the alkali constitute...