less power
to produce quiescence than at first; yet the quiescence will daily increase
by the acquired habit acting at the same time, as explained in Sect. XII.
3. 3. till at length so great a degree of quiescence will be induced as to
cause the inaction of the veins of the uterus, and consequent venous
haemorrhage. See Sect. XXXII. 6. Class I. 2. 1. 11. IV. 1. 4. 4. See the
introduction to this Genus.

8. _Haemorrhoidis periodus._ The periods of the piles depend on the torpor
of the veins of the rectum, and are believed to recur nearly at monthly
intervals. See Sect. XXVII. 2. and Class I. 2. 1. 6.

9. _Podagrae periodus._ The periods of gout in some patients recur at
annual intervals, as in the case related above in Class IV. 1. 2. 15. in
which the gouty paroxysm returned for three successive years on nearly the
same day of the month. The commencement of the pain of each paroxysm is
generally a few hours after midnight, and may thence either be induced by
diurnal solar periods, or by the increasing sensibility during sleep, as
mentioned in the first species of this genus.

10. _Erysipelatis periodus._ Some kinds of erysipelas which probably
originate from the association of the cutaneous vessels with a diseased
liver, occur at monthly periods, like the haemorrhois or piles; and others
at annual periods like the gout; as a torpor of some part I suppose always
precedes the erysipelatous inflammation, the periods should accord with the
increasing influence of terrene gravitation, as described in the
introduction to this Genus, and in Species the seventh of it. Other periods
of diseases referable to solar and lunar influence are mentioned in Sect
XXXVI. and many others will probably be discovered by future observation.

11. _Febrium periodus._ Periods of fevers. The commencement of the cold
fits of intermittent fevers, and the daily exacerbations of other fevers,
so regularly recur at diurnal solar or lunar periods, that it is impossible
to deny their connection with gravitation; as explained in Sect. XXXVI. 3.
Not only these exacerbations of fever, and their remissions, obey the
diurnal solar and lunar periods; but the preparatory circumstances, which
introduce fevers, or which determine their crisises, appear to be governed
by the parts of monthly lunar periods, and of solar annual ones. Thus the
variolous fever in the natural small-pox commences on the 14th day, and in
the inoculated small-pox on the seventh day. The