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470                                               MEDICAL JURISPRUDENCE

pungent taste. It melts at 38° C. It is insoluble in liquid paraffin, and is
slightly soluble in cold water (1 in 13), but freely in boiling water, alcohol

(90), ether, chloroform, glycerin and fixed and volatile oils. To all these it
communicates its characteristic odour. The non-official dose of carbolic acid

(Phenol, B.P.) is 1 to 3 grains1. The other preparations prepared from it

1.    Phenol Liquefactum   (Acidum  Carbolicum  Liquefactum).—It  con-
tains 80 per cent of phenol.

2.    Glycerinum Phenolis.—It contains 16 per cent of phenol in glycerin.

3.    Suppositoria Phenolis   (Suppositoria Acidi Carbolici).—1  grain of
phenol in each.

4.    Trochisci   Phenolis-    (Trochisci   Acidi    Carbolici).—Each    contains
approximately i grain of phenol.

5.    Unguentum, Phenolis  (Unguentum Acidi Carbolici).—Phenol 3 per
cent made up with white beeswax, lard and soft and hard paraffins.

Phenol camphor (Carbolic camphor) is a non-official preparation con-
taining 1 part of phenol and 3 parts of camphor. It is a clear solution
smelling strongly of camphor, and is not miscible with water or glycerin. It
is used as a local anaesthetic in toothache.

The crude carbolic acid of commerce is a dark-brown liquid containing (
several impurities, chiefly cresol.

Poisoning by carbolic acid is known as car&oJism. The acid in a con-
centrated form acts locally as a corrosive, and remotely as a narcotic^poison.
It coagulates proteins but does not enter into chemical combination with
them, and thus it has a great penetrating power. Applied to the skin, it
causes a burning sensation, followed by tingling, numbness and anaesthesia,
and produces a white, opaque eschar which, falling off in a few days, leaves
a brown stain, which may persist for several weeks. When applied forborne
time and prevented from evaporating by the application of India >^ubber
tissue, carbolic acid may cause necrosis of the part even in weak solutions.
It causes irritation and necrosis of the mucous membranes and, if applied .in
sufficient quantity, may lead to sloughing and inflammation.

Symptoms.—Immediately after swallowing the concentrated acidLjJj^re
is an intense burning sensation in the mouth, throat and stom^enfwith
occasional vomiting of frothy mucus. The mucous membranes of the lips
\ and mouth become hard and white. Owing to the rapid absorption of the
acid these symptoms are soon followed by giddiness and insensibility, which
soon deepens into coma. The face is pale or cyanosed, the pupils are con-
tracted, the temperature is subnormal, the skin isjcold and clammy, the
pulse is small and thready, and the respirations are slow, laboured or
stertorous. There is a strong c^our_of carbolic acid in the breath. Con-
vulsions and lock-jaw may be present. The urine is suppressed or scanty.
When voided, fTls normal in colour, or of a greenish hue, which becomes
dark or olive green on exposure to the air, and stains the linen as well.
This change of colour is due to the formation of hydroquinone and
pyrocatechin, oxidation products of carbolic acid, and serves as a warning
of the toxic properties of the acid when used as an antiseptic dressing for
some time. This symptom is known as (^rboluria.

Death results from paralysis of the respiratory and cardiac centres.

Fatal Dose.—Five to seven grains of carbolic acid may cause dangerous
symptoms. Four drachms is the average fatal dose, although an oily solution
of one drachm has proved fatal. A quarter of a tea-spoonful dissolved in
glycerin killed a child, six months old. Recoveries have, however, ensued
after large doses, as much as six ounces.