(Stephen
Mackenzie, "The Etiology and Treatment of Acne Vulgaris,"
_British Medical Journal_, September 29, 1894. Laycock [_Nervous
Diseases of Women_, 1840, p. 23] pointed out that acne occurs
chiefly in those parts of the surface covered by sexual hair. A
lucid account of the origin of acne will be found in Woods
Hutchinson's _Studies in Human and Comparative Pathology_, pp.
179-184. G.J. Engelmann ["The Hystero-neuroses," _Gynaecological
Transactions_, 1887, pp. 124 et seq.] discusses various
pathological disorders of the skin as reflex disturbances
originating in the sexual sphere.)

The influence of menstruation in exacerbating acne has been
called in question, but it seems to be well established. Thus,
Bulkley ("Relation between Certain Diseases of the Skin and the
Menstrual Function," _Transactions of the Medical Society of New
York_, 1901, p. 328) found that, in 510 cases of acne in women,
145, or nearly one-third, were worse about the monthly period.
Sometimes it only appeared during menstruation. The exacerbation
occurred much more frequently just before than just after the
period. There was usually some disturbance of menstruation.
Various other disorders of the skin show a similar relationship
to menstruation.

It has been asserted that masturbation is a frequent or constant
cause of acne at puberty. (See, e.g., discussion in _British
Medical Journal_, July, 1882.) This cannot be accepted. Acne very
frequently occurs without masturbation, and masturbation is very
frequently practiced without producing acne. At the same time we
may well believe that at the period of puberty, when the
pilo-sebaceous system is already in sensitive touch with the
sexual system, the shock of frequently repeated masturbation may
(in the same way as disordered menstruation) have its
repercussion on the skin. Thus, a lady has informed me that at
about the age of 18 she found that frequently repeated
masturbation was followed by the appearance of _comedones_.

FOOTNOTES:

[2] A. Franklin, _Les Soins de Toilette_, p. 81.

[3] W. James, _Principles of Psychology_, vol. ii. p. 347.

[4] Numerous passages from the theologians bearing on this point are
brought together in _Moechialogia_, pp. 221-220.

II.

Ticklishness--Its Origin and Significance--The Psychology of
Tickling--Laughter--La