PATHOLOGY. 
of cinchona. A fimple cooling unguent, as the rofe po¬ 
matum, or litharge plafter foftened with oil of almonds, 
allays the troublefome heat or itching. All ftirnulating 
applications are both painful and injurious. 
tj. L. urticofus, nettle-ra(h: pimples very minute, 
(lightly elevated, reddilh; intolerable itching, efpecially 
at night; irregularly fubfiding, and re-appearing; chiefly 
fpotting the limbs; occafionally fpreading over the body, 
with gnat-bite fliaped wheals; from the violence of the 
irritation at times, accompanied with veficles or blifters, 
and fucceeded by an extenfive exfoliation of the cuticle. 
It chiefly attacks children or young adult perfons. Fre¬ 
quent tepid bathing, light covering, efpecially in bed, 
with the ufe of fmall dofes of fulphur, or the hydrar- 
gyrus fulphuratus niger, internally, appear to relieve 
the fymptoms. The Ikin will not bear ftimujation, 
and is irritated even by a bath of too high temperature. 
When it has occurred in feeble and emaciated children, 
it may often be relieved by chalybeate medicines, as the 
vinum ferri. This combination of inflamed papulae, with 
intenfe itching, feems to unite the characters of the li¬ 
chen with thofe of the next fpecies. 
3. Exormia prurigo : eruption diffufe ; pimples nearly 
of the colour of the cuticle ; when abraded by fcratching, 
oozing a fluid that concretes into minute black fcabs ; 
intolerable itching, increafed by fudden expofure to heat. 
Three varieties. 
a. P. mitis : pimples foft and fmooth ; itching, at times 
fubfiding; chiefly common to the young, and in fpring 
time. Eafily yields to a courfe of warm ablutions, and 
the internal ufe of fulphur. 
( 3 . P. fonnicans: pimples varying from larger to more 
obfcure than in the laft ; itching inceffant, and accompa¬ 
nied with a fenfe of pricking, or flinging, or of the creep¬ 
ing of ants over the body, (whence the name ;) duration 
from two months to two or three years, with occafional 
but fliort intermiflions ; chiefly common to adults. 
y. P. fenilis; pimples moftly larger than in either of 
the above; fometimes indiftinCf, giving the furface a 
fliining and granulated appearance; itching inceflant; 
common to advanced years, and nearly inveterate. 
Plate VII. fig. 1. exhibits the varieties of this fpecies. 
A points out the (lighter eruption of the Prurigo mitis ; 
B the deeper and more marked appearance of P. formi- 
cans and P. fenilis. Each of thefe varieties is apparently 
the refult of gaftric and inteftinal irritations, and the laft 
of much nervous debility likewife. The firft is more 
eafily cured than the two latter; cold fpirituous lotions, 
a drift attention to diet, gentle laxatives (avoiding 
purges), and, according to the (late of the ftomacb, ful¬ 
phur and the carbonate of foda, or ftomachic medicines, 
as farfaparilla, bark, &c. with mineral acids (efpecially 
the oxygenated muriatic acid), are the meafures chiefly 
to be depended on. In the Prurigo fenilis, pediculi are 
commonly generated. Oil of turpentine much diluted 
■with oil of almonds appears to exterminate thefe infeCFs 
very effectually. 
4. Exormia milium : pimples very minute; tubercular; 
confined to the face ; diftinCt; milk-white ; hard ; gla¬ 
brous; refembling millet-feeds. 
Dr. Good feems to have inferted this fpecies on the 
authority of Plenck alone ; for we find no mention of it 
in any other author. 
Genus IV. Lcpidojls, [from Aettk, a fcale.] Scale-lkin. 
Efflorefcence of fcales over different parts of the body, 
often thickening into crufts. (Squammas, Willun.) There 
are four fpecies, with numerous varieties. 
1. Lepidofis pityriafis, dandrifF: patches of fine branny 
fcales, exfoliating without cuticular tendernefs. The fu- 
perficial ftate of the fcales, and the abfence of all ulcera¬ 
tive procefs, diftinguifhes the varieties of pityriafis from 
other maladies. Without thefe diftinCtive marks we 
might miftake dandrifF for fcalled-head (into which it 
snuft be confeffed it degenerates if negleCted), and P. ver- 
353' 
ficolor for fecondary fymptoms of fiphilis. The follow¬ 
ing are the three varieties. 
cc. Pityriafis capitis: fcales minute and delicate; confined 
to the head; eafily feparable. Chiefly common to infancy 
and advanced years. Cutting off the hair, and waffling 
the head frequently with foap and water, are all the means 
neceflary for the cure of dandrifF on the head. 
( 3 . P. rubra : fcalinefs common to the body generally ; 
preceded by rednefs, roughnefs, and fcurfinefs of the 
l'urface. To give gentle purges, and apply cooling lo¬ 
tions, in the ftage of roughnefs and rednefs, and to ufe 
gentle diaphoretics and the warm falt-water bath when 
the fcales appear, is all that is required in the treatment 
of this complaint. 
y. P. verficolor : fcalinefs in diffufe maps of irregular 
outline and divers colours, chiefly brown and yellow : 
for the mod part confined to the trunk, though occa¬ 
fionally fpreading over the limbs. This diforder, from its 
flow progrefs, morbid colour, and ufual caufes, (de¬ 
bauchery, bad food, and atmofpherical viciffitudes) feems 
to be much connected with a difeafed ftate of the blood. 
Dr. Willan found internal medicine of little ufe ; but Dr. 
Bateman recommends the oxygenated muriatic acid and 
ftirnulating lotions. He alfo recommends a trial to be 
made of pitch in large dofes. 
2,. Lepidofis lepriafis, leprofy: patches of fmooth la¬ 
minated fcales of different fizes, and a circular form. 
Four varieties. 
a. Lepriafis vulgaris, common leprofy : fcales gla¬ 
brous; whitifti; fize of a crown-piece; preceded by 
fmaller, reddifh, and glofly, elevations of the (kin, encir¬ 
cled by a dry, red, and (lightly-elevated, border ; often 
confluent. Beneath the fcales the (kin is found red, and 
in early ftages fmooth. Sometimes covering the whole 
of the body except the face ; but moft commonly com¬ 
mencing on the extremities, where the bones lie neared 
to the furface; efpecially below the elbow and the knee, 
and ufually on both arms, or both legs, at the fame time. 
From thefe points it gradually extends, by the formation 
of new and diftinCt patches, along the arms or thighs, to 
the bread and (boulders, and to the loins and fides of the 
abdomen. In feveral cafes, Dr. Bateman has obferved 
the eruption moft copious and moft permanent round the 
whole lower belly. The hands alfo become afteCted, and 
in many cafes the hairy fcalp. Though the face is not 
the feat of large patches, Come fcalinefs occafionally ap¬ 
pears about the outer angles of the eyes, and on the 
forehead and temples, extending from the roots of the 
hair. In the more fevere cafes, the nails of the fingers 
and toes are often much thickened, and become opaque 
and of a dirty yellowilh hue, and are incurvated at the 
extremities: their furface is alfo irregular, from deep lon¬ 
gitudinal furrows, or elevated ridges. 
When the eruption of Lepriafis is moderate in degree 
and extent, it is not attended with any uneafy fenfations, 
except a (light degree of itching when the patient is 
heated by exercife, or becomes warm in bed; and a lit¬ 
tle occafional tingling in certain dates of the atmofphere. 
When it is generally diffufed, however, and there is a 
confiderable degree of inflammation in the (kin, it is ac¬ 
companied with extreme forenefs, pain, and (liffnefs ; 
fometimes indeed fo great, as to render the motions of 
the joints impracticable, and to confine the patient to 
bed. Yet even under thefe circumftances, there is no 
conftitutional difturbance : and, if no medicine be em¬ 
ployed, the difeafe of the.(kin may continue for months, 
or even years, without any material derangement of the 
fyftem. 
Nothing is known of the immediate caufe of this dif¬ 
eafe. It has been obferved to follow the taking of cer¬ 
tain improper articles of diet. It has been attributed to 
dirtinefs, to over-exertion, and to fudden changes of 
temperature. It is faid to be hereditary, but not conta¬ 
gious. Dr. Bateman aflerts that it is a very common 
difeafe in this metropolis; but we are inclined to think 
he 
