THB EMPLOYMENT OF FORCE IH DYSTOHA 393

nearly uniform manner, the eccentric pressure which ths
chest of the foetus transmits to the walls of the genital canal,
to which it is very closely applied daring its passage out-
wards. If, then, it be admitted that the total of this eccentric
pressure amounts to about one-half the tractile force expended
on the foptus, it will be easy to find, by a simple calculation,
the pressure on each square inch. Supposing the traction to
be equal to 1,540 pounds—the estimated strength of seven or
eight men pulling with all their force at the cords—the
pressure on each square inch would be about 7| ounces, or
one-half that exerted on the same extent of surface with a
tractile force of 132 pounds in woman !

Saint-Cyr does not pretend that these calculations give a
rigorously exact measure of what really takes place during
parturition; but he believes they may assist, up to a certain
point, in explaining certain facts in comparative obstetrics
which otherwise would remain obscure—how, for instance,
natural birth, which is always so painful in woman, is com-
paratively painless in the larger animals; and why traetion,

the very idea of which alarms the aoeouebear of wommn. is

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in the majority of instances so well soskdned by the veterinary
surgeon's patients.

It must be eonfesa^d, however, that we have as yet no
certain data by which we can estimate the exact amount
force oeesassary, or wfaieb may be &

and on this point the opinions of the best authorities are
widely divergent. Some declare for moderate traction—two,
three, or four men at the most, pulling simultaneously at the
cords with all their force, are, in their opinion, quite sufficient

r •* i*» m

in all cases if well managed; and they assert that it is rash

^iff ^^

and dangerous to employ

eieet with the cow—oae at the head, another at the tail, arid

mare—one at the head, another holdiag the rope which