ched with nitrate of silver; or a ligature may be used.
Curetting is a valuable operative method. The growths may also be
removed by electrolysis. When warts are numerous and close together
parasiticide applications can be daily made to the whole affected
region. For this purpose a boric acid solution, containing five to
thirty grains of resorcin to the ounce, and Vleminckx's solution, at
first diluted, prove the most valuable.

Verruca acuminata is to be treated by maintaining absolute cleanliness,
and the application of such astringents as liquor plumbi subacetatis,
tincture of iron, powdered alum and boric acid. The salicylic acid
solution may also be used. In obstinate cases, glacial acetic acid or
chromic acid may be cautiously employed.

#Naevus Pigmentosus.#
(_Synonym:_ Mole.)

#Describe naevus pigmentosus.#

Naevus pigmentosus, commonly known as mole, may be defined as a
circumscribed increase in the pigment of the skin, usually associated
with hypertrophy of one or all of the cutaneous structures, especially
of the connective tissue and hair. It occurs singly or in numbers; is
usually pea-, bean-sized or larger, rounded or irregular, smooth or
rough, flat or elevated, and of a color varying from a light brown to
black; the hair found thereon may be either colorless or deeply
pigmented, coarse and of considerable length. It is, as a rule, a
permanent formation.

#Name the several varieties of naevus pigmentosus met with.#

Naevus spilus, naevus pilosus, naevus verrucosus, and naevus lipomatodes.
So-called linear naevus might also be considered as belonging in this
group.

#What is naevus spilus?#

A smooth and flat naevus, consisting essentially of augmented
pigmentation alone.

[Illustration: Fig. 34. Linear Naevus.]

#What is naevus pilosus?#

A naevus upon which there is an abnormal growth of hair, slight or
excessive.

#What is naevus verrucosus?#

A naevus to which is added hypertrophy of the papillae, giving rise to a
furrowed and uneven surface.

#What is linear naevus?#

Linear naevus is a formation usually of a verrucous character, more or
less pigmented, sometimes slightly scaly, occurring in band-like or
zoster-like areas, and, as a rule, unilaterally.

#What is naevus lipomatodes?#

A naevus with excessive fat and connective-tissue hypertrophy.

#State the etiology of naevus pigmentosus.#

The causes are