e heat was also greater than
natural. Rayer recites the case of a young man whom he saw, whose
eyelids and adjacent parts of the cheeks were of a bluish tint, similar
to that which is produced on the skin by the explosion of gunpowder.

Billard has published an extraordinary case of blue discoloration of
the skin in a young laundress of sixteen. Her neck, face, and upper
part of the chest showed a beautiful blue tint, principally spreading
over the forehead, the alae, and the mouth. When these parts were
rubbed with a white towel the blue parts of the skin were detached on
the towel, coloring it, and leaving the skin white. The girl's lips
were red, the pulse was regular and natural, and her strength and
appetite like that of a person in health. The only morbid symptom was a
dry cough, but without mucous rattle or any deficiency of the sound of
the chest or alteration of the natural beat of the heart. The catamenia
had never failed. She had been engaged as a laundress for the past two
years. From the time she began this occupation she perceived a blueness
around her eyes, which disappeared however on going into the air. The
phenomenon reappeared more particularly when irons were heated by a
bright charcoal fire, or when she worked in a hot and confined place.
The blueness spread, and her breast and abdomen became shaded with an
azure blue, which appeared deeper or paler as the circulation was
accelerated or retarded. When the patient's face should have blushed,
the face became blue instead of red. The changes exhibited were like
the sudden transition of shades presented by the chameleon. The
posterior part of the trunk, the axillae, the sclerotic coats of the
eyes, the nails, and the skin of the head remained in their natural
state and preserved their natural color. The linen of the patient was
stained blue. Chemical analysis seemed to throw no light on this case,
and the patient improved on alkaline treatment. She vomited blood,
which contained sufficient of the blue matter to stain the sides of the
vessel. She also stated that in hemorrhage from the nose she had seen
blue drops among the drops of blood. One cannot but suspect indigo as
a factor in the causation of this anomalous coloration.

Artificial discolorations of the skin are generally produced by
tattooing, by silver nitrate, mercury, bismuth, or some other metallic
salt.

Melasma has been designated as an accidental and temporary blackish
discoloration o