The halogens may be estimated by ignition with quicklime, or by heating with nitric acid and silver nitrate in a sealed tube.
A piece of bibulous paper, moistened with silver nitrate, is held over the mouth of the tube, and if arsenic be present, a grey or black deposit is seen on the paper, due to the silver nitrate being reduced by the arseniuretted hydrogen.
Bromous acid is formed by adding bromine to a saturated solution of silver nitrate (A.
The oxidation, which is effected by chromic acid and sulphuric acid, is conducted in a flask provided with a funnel and escape tube, and the carbon dioxide formed is swept by a current of dry air, previously freed from carbon dioxide, through a drying tube to a set of potash bulbs and a tube containing soda-lime; if halogens are present, a small wash bottle containing potassium iodide, and a U tube containing glass wool moistened with silver nitrate on one side and strong sulphuric acid on the other, must be inserted between the flask and the drying tube.
The above series of salts show striking differences in their behaviour towards reagents; thus, aqueous solutions of the luteo chlorides are strongly ionized, as is shown by their high electric conductivity; and all their chlorine is precipitated on the addition of silver nitrate solution.
Silver chromate, Ag2Cr04, is a dark red amorphous powder obtained when silver nitrate is precipitated by an alkaline chromate.
Chlorides can be estimated quantitatively by conversion into silver chloride, or if in the form of alkaline chlorides (in the absence of other metals, and of any free acids) by titration with standard silver nitrate solution, using potassium chromate as an indicator.
If silver nitrate salts be administered for a long period as a medication, the skin that is exposed to light becomes of a bluish-grey colour, which is extremely persistent.
In pruritus of the vulva and anus a weak solution of silver nitrate will relieve the itching, and strong solutions painted round the base of a boil at the beginning will abort its formation.
In granular lids and various forms of ophthalmia solutions of silver nitrate (2 grs.