return of all the previous accidents, and
often the constitution was entirely ruined.

We think that this argument might be exactly paralleled by the
following, which should prove whisky drinking to be an efficient[37]
cause of yellow fever. A physician might select twenty cases of men,
personally known to him, who had lived twenty and thirty years in New
York or Boston, and never had yellow fever. During this time they had
taken little or no whisky, but afterwards, removing to New Orleans, they
fell into the habit of drinking, and, at varying intervals from that
date, caught the fever, and in many instances, died. Therefore, fever
was due, at least in these cases, to the newly contracted habit of
drinking whisky.

-A and -B = -C -A +B = C. Therefore, C = A.

Hamerton, in his little book on the intellectual life, accuses women,
even the bright and intelligent among them, of a "plentiful lack" of
intellectual curiosity. If their attention is attracted to a phenomenon,
they rarely inquire as to its cause. If an assertion is made, they
accept it with enthusiasm or repel it with indignation, but rarely
analyze the conditions upon which the assertion is based. This remark
seems justified, though perhaps not exclusively among women, by the
total absence of curiosity that has been shown in regard to the
physiological facts in question. The assertion that nervous excitement,
produced by intellectual work, is capable of affecting an apparatus
apparently so remote from the organ of the intelligence as is the
vascular system of the uterus, certainly implies some most interesting
physiological facts and a mechanism the reverse of simple. Into these
facts and this mechanism it behooves all to inquire, who assume the
responsibility of either accepting or rejecting Dr. Clarke's theory and
the deductions that have been made from it.

This theory concerns exclusively one class of uterine haemorrhages,
those, namely, which may be traced to the influence of the nervous
system. Before analyzing such influence it is important to notice two
other causes of menorrhagia, that are very frequently present in just
such cases as Dr. Clarke describes. These are prolonged sedentary
position, and deficiency of physical exercise. Either may determine
anemia, or impoverishment of the blood, a condition which alone is
sufficient to induce excessive menstrual flow.[38] But, in addition,
each has a special action more direct. By long continuance of a