century. While at the same time it is not improbable, that other new
diseases may arise, and for a season thin mankind!

16. _Urticaria._ Nettle-rash begins with mild sensitive fever, which is
sometimes scarcely perceptible. Hence this eruption has been thought of two
sorts, one with and the other without fever. On the second day red spots,
like parts stung with nettles, are seen; which almost vanish during the
day, and recur in the evening with the fever, succeeded in a few days by
very minute scales. See Trans. of the College, London.

17. _Aphtha._ Thrush. It has been doubted, whether aphtha or thrush, which
consists of ulcers in the mouth, should be enumerated amongst febrile
diseases; and whether these ulcers are always symptomatic, or the
consequence rather than the cause of the fevers which attend them. The
tongue becomes rather swelled; its colour and that of the fauces purplish;
sloughs or ulcers appear first on the throat and edges of the tongue, and
at length over the whole mouth. These sloughs are whitish, sometimes
distinct, often coalescing, and remain an uncertain time. Cullen. I shall
concisely mention four cases of aphtha, but do not pretend to determine
whether they were all of them symptomatic or original diseases.

_Aphtha sensitiva._ A lady during pregnancy was frequently seized with
ulcers on her tongue and cheeks, or other parts of the mouth, without much
apparent fever; which continued two or three weeks, and returned almost
every month. The thrush in the mouths of young children seems to be a
similar disease. These ulcers resemble those produced in the sea-scurvy,
and have probably for their cause an increased action of the secerning
system from increased sensation, with a decreased action of the absorbent
system from decreased irritation. See Class I. 2. 1. 15.

M. M. Solutions of alum, of blue vitriol. Powder of bark taken frequently
into the mouth in very small quantity. See Class II. 1. 3. 1.

_Aphtha irritata._ Inflammatory aphtha. A case of this kind is related
under the title of suppurative rheumatism. Class IV. 1. 2. 16.

_Aphtha inirritata._ Sloughs or ulcers of the mouth, attended with
sensitive fever with great arterial debility. They seem to spread downwards
from the throat into the stomach, and probably through the whole intestinal
canal, beginning their course with cardialgia, and terminating it with
tenesmus; and might perhaps be called an erysipelas of this mucous
membrane.