ANATOMY. 
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the breads fweil, and the pubes begins to be clothed: at 
the fame time the menfes in fome-rneafure make their ap¬ 
pearance by a common law of nature, although in diffe¬ 
rent countries both the time and quantity of the flux is 
different. But, before the menflrual flux commences, va¬ 
rious fymptomsof pain are excited in the loins; and pains 
refembling the cholic, an increafed pulfe, head-achs, cu¬ 
taneous puftules, and a difcharge of a whitifh liquor, ge¬ 
nerally pronounce its approach. For now the fleecy vef¬ 
fels of the uterus, which in the flate of the foetus were 
white, and tranfuded a fort of milk, as in the young 
girl they tranfuded' a ferous liquor, now begin to fweil 
with blood ; the red parts of which are depofited through 
the veffels into the cavity of the uterus. This continues 
fome days, while in the mean time the firfl troublefome 
fymptoms abate, and the uterine veffels, gradually contract¬ 
ing their openings, again diftil only a little ferous moiflure 
as before. But then the fame efforts return again at un¬ 
certain intervals in tender virgins; till at length, by de¬ 
grees, they keep near to the end of the fourth week, when 
the flux of blood follows, as before, which is periodically 
continued till between the forty-fifth and fiftieth year; 
though the diet, country, conftitution, and way of life, 
caufe a great variation in this difcharge. 
Since none but the human fpecies are properly fubjeil 
to this menflrual flux, (although there are fome animals 
who, at the time of their vernal copulation, diftil a fmall 
quantity of blood from their genitals,) and ffnce the body 
of the male is always free from the like difcharge, it has 
been a great inquiry in all ages, what fhould be the caufe 
of this fanguine excretion peculiar to the fair fex > The 
attraction of the moon, which is known to raife the tides 
of the fea, has been, in all ages, fuppofed to produce this 
effect; other authors have referred it to a fliarp flimulaf- 
ing humour, fecreted in the genital parts themfelves, the 
fame which is the caufe of the venereal difeafe. But, if 
the moon produces this effect, it would appear in all wo¬ 
men at the fame time, which is contrary to experience, 
fince there is never a day in which there are not many wo¬ 
men feized with this flux; nor are there fewer in the de- 
oreafe than in the increafe of the moon. As to any fliarp 
ferment feated in the uterus, it will be always inquired 
for in vain, where there are none but mild mucous juices, 
and where venery, which expels all thefe juices, neither 
iqcreafes nor lelfens the menflrual flux : for women deny 
that, during the time of their menfes, they have any in- 
creafed delire of venery ; for at that time mod of the parts 
are rather pained and languid; and the feat of venereal 
pleafufe feems rather at the entrance of the pudendum 
than in the uterus, from which lafl the menfes flow. Be¬ 
tides, that the menflrual blood is forced out by fome caufe 
exciting the motion of the blood again!! the veffels, appears 
moft probable; becaufe, by a retention, the courfes have 
been known to break through all the other organs of the 
body, where no vellicating ferment could be feated, fo as 
to burl! open the velfels of each organ ; and becaufe the 
effect produced by the retention of the blood is not con¬ 
fined to tllofe parts which pour out the venereal humour. 
Nature lias, in general, given women a more delicate 
body, and folids that are lefs elaftic ; their mufcles are alfo 
fmaller, with a greater quantity of fat interpofed both be¬ 
tween them and their fibres; the bones too are flenderer, 
and their furfaces have fewer proceffes and afperities, than 
in males. Moreover the pelvis of the female is, in all its 
dimenfions, larger; the offa ilia fpread farther from each 
other; and the os facrum recedes more backward from the 
bones of the pubes, while the offa ifchii depart more from 
each other below : however, the angle in which the bones 
of the pubes meet together to form an arch, is in the fe¬ 
male confiderably larger; which differences are confirmed 
by the obfervations of the belt anatomifls, and from necef- 
fity itfelf, which requires a greater fpace for a greater num¬ 
ber of vifeera in the pelvis. 
The female infant new-born has her lower limbs very 
fmall; and the greater part of the blood, belonging to the 
iliac arteries, goes to the umbilicals, fending down only a 
fmall portion to the pelvis. Hence the pelvis is fmall, and 
but little concave; fo that the bladder and uterus itfelf, 
with the ovaries, projeil beyond the brim of the pelvis'. 
But when the foetus is born, and the umbilical artery tied, 
all the blood of the iliac artery defeends to the pelvis and 
lower limbs, which of courfe grow larger, and the pelvis 
fpreads-wider and deeper; fo that, by degrees, the womb 
and bladder are received into its cavity, without being any 
longer compreffed by the inteftines and peritonaeum, when 
the abdominal mufcles prefs upon the lower parts of the 
abdomen. When the increafe is perfect, or nearly fo, then 
in general v. e find thofe arteries of the uterus largefl, and 
eafily injected with wax, which in the foetus were leaf! ; 
and all things are fo changed, that the hemorrhoidal ar¬ 
tery is now in place of the hypogaftric, when formerly the 
umbilical had been the trunk of that artery. More blood, 
therefore, at that time comes into the uterus, vagina, and 
clitoris, than formerly ufed to do. At the fame time* 
when the growth of the body begins confiderably to dimi- 
nifli, and the blood, finding eafy admittance into the com¬ 
pleted vifeera, is prepared in a greater quantity; and the 
appetite being now very fliarp, in both fexes, a plethora 
confequently follows. In the male, it vents itfelf frequent¬ 
ly by the nofe, from the exhaling velfels of the pituitary 
membrane being dilated to fo great a degree without a 
rupture, as to let the red blood diftil through them ; and 
now the femen firfl begins to be fecreted, and the beard to 
grow. But in the female, the fame plethora finds a more 
eafy vent downward ; being directed partly by the weiglit 
of the blood itfelf, to the uterine veffels now much en¬ 
larged, of a foft fleecy fabric, and feated in a loofe hol¬ 
low part, with a great deal of cellular fabric interiperfed, 
which is very yielding and fucculent, as we oblerve in the 
womb : for thefe cattles, the velfels being eafily diftenfible, 
the blood finds a more eafy palfage through the foft ex¬ 
haling velfels, which open into the cavity of the uterus, 
as being there lefs refilled than in its return by the veins, 
or in taking a courfe through any other part; and at the 
fame time the return of the blood from the uterus is im¬ 
peded, both becaufe the flexures of the arteries, from the 
increafed afflux of the blood, become more ferpentine and 
fit for retarding the blood’s motion, and likewife becaufe 
it now returns with difficulty through the veins. The 
blood is, therefore, firfl colleiled in the velfels of the ute¬ 
rus, which at this time are cbferved, in difle<Sbiorjs, to be 
fwelled ; it is alfo accumulated in the arteries of the loins 
and the aorta itfelf, which, urging on a new torrent of 
blood, augments the force, fo far as to difcharge the red 
blood into the ferous velfels of the uterus, which at firfl 
tranfmit an increafed quantity of warm mucus, afterwards 
a reddifh-coloured ferum ; and by buffering a greater dif- 
tenfion, they at lall emit the red blood itfelf. The fame 
greater iinpulfe of blood, determined to the genital parts, 
drives out the hitherto latent hairs, increafes the bulk of 
the clitoris, dilates the cavernous plexus of the vagina, 
and whets the female appetite to venery. Accordingly we 
find, that the quantity of the rhenflrual flux, and the ear- 
linefs of their appearance, are promoted by every thing 
that either increafes the quantity or momentum of the 
blood with refpect to the body in general, or direits the 
courfe of the blood more particularly towards the uterus ; 
fuch as joy, lull, bathing,of the feet, rich diet, warm air, and 
lively temparament of the body. It is diminifhed by thofe 
things which leffen plethora and the motion of the blood, 
as want, grief, cold air, floth, and antecedent difeafes. 
When five or fix ounces of blood have been thus eva¬ 
cuated, the unloaded arteries exert a greater force of elaf- 
ticity, and, like all arteries which have been overcharged 
with blood, gradually contrail themfelves to a lefs dia¬ 
meter, fo as at length to give paflage only to the former 
thin exhaling moifture ; but the plethora, or quantity of 
blood, being again increafed from the fame caufes, a like 
difcharge will always more eafily enfue through the vef¬ 
fels of the uterus, after they have been once thus opened, 
than 
