nuance of sleep, as in some fits of epilepsy,
asthma, and haemoptoe mentioned in the preceding article.

3. _Hemicraniae periodus._ Periods of hemicrania. Class IV. 2. 2. 8. The
torpor and consequent pain of some membranes on one side of the head, as
over one eye, is frequently occasioned by a decaying tooth, and is liable
to return every day, or on alternate days at solar or lunar periods. In
this case large quantities of the bark will frequently cure the disease,
and especially if preceded by venesection and a brisk cathartic; but if the
offending tooth can be detected, the most certain cure is its extraction.
These partial head-achs are also liable to return at the greater lunar
periods, as about once a month. Five drops from a two-ounce phial of a
saturated solution of arsenic twice a day for a week or two have been said
to prevent the returns of this disease. See a Treatise on Arsenic by Dr.
Fowler, of York. Strong errhines have also been recommended.

4. _Epilepsiae dolorificae periodus._ Class III. 1. 1. 8. The pain which
induces after about an hour the violent convulsions or insanity, which
constitute the painful epilepsy, generally observe solar diurnal periods
for four or five weeks, and are probably governed by solar and lunar times
in respect to their greater periods; for I have observed that the daily
paroxysms, unless disturbed by large doses of opium, recur at very nearly
the same hour, and after a few weeks the patients have recovered to relapse
again at the interval of a few months. But more observations are wanted
upon this subject, which might be of great advantage in preventing the
attacks of this disease; as much less opium given an hour before its
expected daily return will prevent the paroxysm, than is necessary to cure
it, after it has commenced.

5. _Convulsionis dolorificae periodus._ Class III. 1. 1. 6. The pains,
which produce these convulsions, are generally left after rheumatism, and
come on when the patients are become warm in bed, or have been for a short
time asleep, and are therefore perhaps rather to be ascribed to the
increasing sensibility of the system during sleep, than to solar diurnal
periods, as in Species first and second of this Genus.

6. _Tussis periodicae periodus._ Periodic cough, Class IV. 2. 1. 9. returns
at exact solar periods; that described in Sect. XXXVI. 3. 9. recurred about
seven in the afternoon for several weeks, till its periods were disturbed
by opium, and th