DISEASES OF THE SKIN, 467 
ounce carbolic acid in a pint of water, bound on with cotton wool or 
lint, may cut them short. The more common course is to apply a 
warm poultice of linseed meal or wheat bran, and renew daily until 
the center of the boil softens, when it should be lanced and the core 
pressed out. 
If the boil is smeared with a blistering ointment of Spanish flies 
and a poultice put over it, the formation of matter and separation of 
the core is often hastened. A mixture of sugar and soap laid on the 
boil is equally good. Cleanliness of the skin and the avoidance of 
all causes of irritation are important items, and a teaspoonful of 
bicarbonate of soda once or twice a day will sometimes assist in 
warding off a new crop. 
NETTLERASH (SURFEIT, OR URTICARIA). 
This is an eruption in the form of cutaneous nodules, in size from 
a hazelnut to a hickory nut, transient, with little disposition to the 
formation of either blister or pustule, and usually connected with 
shedding of the coat, sudden changes of weather, and unwholesome- 
ness or sudden change in the feed. It is most frequent in the spring 
and in young and vigorous animals (good feeders). The swelling 
embraces the entire thickness of the skin and terminates by an abrupt 
margin in place of shading off into surrounding parts. When the 
individual swellings run together there are formed extensive patches 
of thickened integument. These may appear on any part of the 
body, and may be general; the eyelids may be closed, the lips ren- 
dered immovable, or the nostrils so thickened that breathing becomes 
difficult and snuffling. It may be attended with constipation or 
diarrhea or by colicky pains. The eruption is sudden, the whole 
skin being sometimes covered in a few hours, and it may disappear 
with equal rapidity or persist for six or eight days. 
Treatment.—This consists in clearing out the bowels by 5 drams 
Barbados aloes, or 1 pound Glauber’s salt, and follow the operation 
of these by daily doses of one-half ounce powdered gentian and 
1 ounce Glauber’s salt. A weak solution of alum may be applied to 
the swellings. 
PITYRIASIS, OR SCALY SKIN DISEASE. 
This affection is characterized by an excessive production- and 
detachment of dry scales from the surface of the skin (dandruff). 
Tt is usually dependent on some fault in digestion and an imperfect 
secretion from the sebaceous glands and is most common in old horses 
with spare habit of body. Williams attributes it to feed rich in sac- 
charine matter (carrots, turnips) and to the excretion of oxalic acid 
by the skin. He has found it in horses irregularly worked and well 
