PANCREAS.
Bat these views, so neat and complete in
themselves, and so nicely put forth by Ber¬
nard, have of late been vigorously assailed by
the German school, and their fidelity and
conclusiveness altogether impugned. Frerichs,
and Bidder and Schmidt, have, by a repetition
of Bernard’s experiments, as well as by many
ingenious and well-devised ones of their own,
failed to verify any of his results, but have been
led by them to conclusions with which they are
altogether discrepant. These experimenters
state that they carefully followed all Bernard’s
directions — they tied the pancreatic duct,
and, having previously kept the animals on
short food from twelve to twenty-four hours
so that there might be no remains of the se¬
cretion in the intestine, fed them with fatty
aliment, and killed them in from four to eight
hours. They always found the lacteals
“most beautifully injected, and the recep-
taculum chyli distended with milky chyle.”
Frerichs found on tying the' small intes¬
tine some distance below the opening of
the pancreatic and bile ducts in cats and
puppies, and injecting into the bowel below the
ligature olive oil and milk, that after two or
three hours the lacteals were filled with white
chyle. He, however, believes that he has
found the extreme comminution of fat, and
hence in some measure its resorption, pro¬
moted by the bile and pancreatic juice ; for
when in cats that had long fasted, he cut
through the small intestine near the middle,
injected olive oil into both halves, and tied
the two cut extremities, he found the lacteals
springing from the upper part of the intestine
always far more injected than those proceed¬
ing from the lower, which he attributes to the
bile and pancreatic juice having access to the
fat in the upper portion.
With regard to the permanence of the
emulsion produced by the mixture of pan¬
creatic juice and fat out of the body, Fre¬
richs and Bernard are quite at issue; for
while Bernard states, that on being examined
fifteen or eighteen hours afterwards, it was
found to be perfectly maintained, Frerichs
affirms that the particles of oil soon separate
again on the surface.
There certainly are some circumstances
which detract from the conclusiveness of Ber¬
nard’ s experiments : one is, that the chyle
contains far less fatty acids than the ordinary
neutral fats ; another, that other animal
fluids, as soon as they begin to putrefy, cause
a similar decomposition of the neutral fats ;
another, that Bernard’s experiments merely
had reference to the production of this change
out of the body. This last deficiency has been
filled up by Lenz* He fed healthy cats with
fresh butter, or, if necessary, injected it into
their stomachs, and killed them in from six
to fourteen hours afterwards. Although all
the lacteals and the thoracic duct were dis¬
tended with milky chyle, no trace of butyric
acid could be detected in the stomach and
intestinal canal, or in the thoracic duct, the
* De Adipis Concoctione et Absorptione. Inaug.
Diss. Dorp. Liv. 1850.
portal vein, or gall-bladder. By further ex¬
perimental investigation, he found that the
metamorphic action was hindered by the acid
gastric juice in proportion to the amount of
free acid present, that a similar action might
be artificially induced by other acids, as di¬
luted lactic, tartaric, and acetic acid, and that
it might be overcome by neutralising the free
acid by bile, or by an alkali. Hence he con¬
cluded, that it is only in exceptional cases that
the pancreatic fluid decomposes the neutral
fats into acids and bases in the living body.
The argument derived from the experiment
on rabbits has been thus explained away by Bid¬
der andSchmidt. They say that if the rabbit is
killed two hours after the fat has been given
it the lacteals given off between the pylorus
and the mouth of the pancreatic duct, are fully
distended with white chyle very rich in fat ;
if not till four hours after the injection, the
lacteals situated about three or four inches
above the mouth of the duct are still filled ;
if at six hours, those only below the duct con¬
tain white chyle ; and if not till eight or ten
hours after, the first lacteals well injected with
milky chyle are found to be situated ten or
twelve inches below the duct. Hence it must
have been by always killing the animals six or
eight hours after feeding them with fat, that
Bernard was able apparently to maintain his
view. The facts of the case, say they, were
simply these. The chyle had already passed on¬
wards from the lymphatics proceeding from the
first portion of the duodenum, and there was no
more fat to be absorbed in that portion of the
intestine when Bernard began the investiga¬
tion. I cannot admit the correctness of this
explanation given by Schmidt and Bidder,
because some of the rabbits on which I re¬
peated Bernard’s experiments and verified his
results were killed within four, or even three
hours after the injection of the lard.
It was formally maintained by MM. Ber¬
nard and Barreswill, that the pancreatic juice
when acidified had an equally solvent power
on the precipitated protein compounds with
the gastric juice, and that its acidity or alka¬
linity alone determined whether it should act
on albuminous or amylaceous matters. This
opinion has also been refuted by Frerichs.
Lastly, this physiologist ascribes to the pan¬
creatic fluid a peculiar power of hastening the
conversion of the bile into insoluble products,
and so favouring its more perfect elimination.
This view has been completely overthrown by
the experiments of Bidder and Schmidt, who
have shown, first, that the greater part of the
bile is not thrown off with the faeces, as
Frerichs believes ; and, secondly, that the
lime, to which Frerichs especially ascribes
this power, only exists in very subordinate
quantity in the pancreatic fluid.*
In taking a review of all that has been done
with regard to the functions of the pancreatic
secretion, we must, admit that the only one
that has been established beyond dispute is its
sugar-making action on amylaceous matters.
* British and Foreign Med. Chir. Review. On the
“ Chemistry of Digestion,” by Dr. Day.