--Softening of the stomach, haemorrhagic spots
on all organs and under the skin, fatty degeneration of liver, kidneys,
and heart, blood-stained urine, phosphorescent contents of alimentary
canal.

_Treatment._--Early use of stomach-pump and emetics, followed by the
administration of permanganate of potassium or peroxide of hydrogen to
oxidize the phosphorus. Oil should not be given. Sulphate and carbonate
of magnesium, mucilaginous drinks. Sulphate of copper is a valuable
antidote, both as an emetic and as forming an insoluble compound with
phosphorus.

_Fatal Dose._--One grain and a half.

_Fatal Period._--Four hours; more commonly two to four days.

_Detection of Phosphorus in Organic Mixtures._--Mitscherlich's method is
the best. Introduce the suspected material into a retort. Acidulate with
sulphuric acid to fix any ammonia present. Distil in the dark, through
a glass tube kept cool by a stream of water. As the vapour passes over
and condenses, a flash of light is perceived, which is the test.

XXI.--ARSENIC AND ITS PREPARATIONS

=Arsenic= is the most important of all the metallic poisons. It is much
used in medicine and the arts. It occurs as metallic arsenic, which is
of a steel-grey colour, brittle, and gives off a garlic-like odour when
heated; as arsenious acid; in the form of two sulphides--the red
sulphide, or realgar, and the yellow sulphide, or orpiment; and as
arsenite of copper, or Scheele's green. It also exists as an impurity in
the ores of several metals--iron, copper, silver, tin, zinc, nickel, and
cobalt. Sulphuric acid is frequently impregnated with arsenic from the
iron pyrites used in preparing the acid. It is a constituent of many rat
pastes, vermin or weed killers, complexion powders, sheep dips, etc.

=Arsenious Acid= (White Arsenic, Trioxide of Arsenic).--Colourless,
odourless, and almost tasteless. It occurs in commerce as a white powder
or in a solid cake, which is at first translucent, but afterwards
becomes opaque. Slightly soluble in cold water; 1 ounce of water
dissolves about 1/2 grain of arsenic. Fowler's solution is the
best-known medicinal preparation of arsenic, and contains 1 grain of
arsenious anhydride in 110 minims.

_Symptoms._--Commence in from half to one hour. Faintness, nausea,
incessant vomiting, epigastric pain, headache, diarrhoea, tightness and
heat of throat and fauces, thirst, catching in the breath, restlessness,
debility, cramp in the legs, and conv