472 MEDICAL JURISPRUDENCE
Millon's reagent is prepared by dissolving 1 part of mercury in 1 part of
strong nitric acid (sp. gr. 1.4) by diluting with twice its volume of water.
The solution is allowed to stand overnight and a clear liquid is then decanted
off for use as a reagent.
4. Heated with a little dilute ammonia and a few drops of a freshly
prepared solution of calcium or sodium hypochloride, an aqueous solution of
carbolic acid yields a blue, bluish-green or green colour, which depends upon
the amount of carbolic acid present in the aqueous solution. This is known
as Lex's test.
5. Liebermann's Test.—This is a very delicate and characteristic test,
which is performed as follows : —
Dissolve a crystal or drop of carbolic acid in concentrated sulphuric
acid, cool if necessary, then add a very small crystal of sodium or potassium
nitrite, a deep blue or green colouration will be produced; when poured on
a beaker of water, it is turned red which is again turned green or blue on
adding an alkali.
Medico-Legal Points.—Carbolic acid is largely used as an antiseptic and
as a disinfectant. It is used in the preparation of many disinfecting powders.
For instance, MacdougalTs disinfecting powder consists of crude carbolic
acid and calcium sulphite. Calvert's carbolic acid powder is made by adding
carbolic acid to the siliceous residue obtained from the manufacture of
aluminic sulphate from shale.
Being easily procurable several cases of accidental and suicidal poison-
ing by carbolic acid have occurred. On account of its powerful odour and
taste carbolic acid is very rarely used for homicidal purposes, though it has
been sometimes used for murdering children and infants. It has also caused
death when used as an abortifacient by injection into the vagina or uterus.
Poisonous symptoms, followed by fatal results in some cases, have
occurred from, swallowing carbolic acid, from its application to a wound or
an unabraded skin, from injection into an abscess cavity, rectum or uterus,
as also from inhalation of its vapour.
Cases.—1. On October 20th, 1921, a man, aged 30 years, in robust health and sober
habits, broke accidentally a bottle of crude carbolic acid he was carrying home in his
trouser pocket, and became unconscious in twenty minutes. About an hour later he was
removed to the Whipps Cross Hospital, where he was found unconscious with stertorous
breathing and extensive carbolic acid staining and burning of the left hip, left thigh and
scrotum. His pupils were contracted. Later in the evening he became irritable and
vomited. The next day he regained consciousness, but complained of severe abdominal
pain, and passed blood in the urine. On the 22nd, he appeared better, but did not pass
urine, and on the 23rd it was recognized that there was complete suppression of urine.
He remained mentally clear till the 28th. At 6-20 p.m. there was a sudden change; he
felt cold and collapsed. The pulse went, and the extremities became cold and clammy.
He died at 6-25 pjn. At the autopsy there was no erosion of the mucous membrane of
the stomach. The liver and spleen were congested, and the kidneys showed acute
hsemorrhagic nephritis.—Turtle and Dolan, Lancet, Dec. 16, 1922, p. 1273.
2. A youth employed at a chemist's shop dropped a Winchester of crude carbolic
acid. He immediately got a cloth and went down to mop up the fluid. Within a few
minutes he fell to the ground unconscious and was at once despatched to hospital. Here
he was examined in less than thirty minutes of the accident. He was absolutely coma-
tose, cyanosed, stertorous, with a subnormal temperature and a thready, rapid pulse.
The breath smelt strongly of carbolic acid, and the mouth and nose were covered with
froth. He was cold, but not clammy, and generally livid. He was given intravenous
saline injections to which two drachms of sodium bicarbonate per pint were added. The
effect was certainly marked. The breathing assisted by the use of oxygen improved
almost at once, and the patient recovered fully in two days. The urine showed the
presence of carbolic acid.—Smith, Lancet, Dec. 23, 1923, p. 1350.
3. On September 18, 1930, a nurse had the misfortune to slip on a wet floor, upset-
ting in her fall a vessel containing a moderate quantity of " pure carbolic", i.e. acidum
carbolicum licfuefactum. The drug was spilt over a considerable area of her clothing,
and affected the skin of the face and neck, the whole length of both upper limbs, ihe