THE SCIENTIFIC AMERICAN�
374
TALK
WITH
THE
lead into very small tubes or ducts, by which the chyle
BOYS.
No. 8.-THJ� '>VAY WE DIGEST OUR FOOD-1'HI;
S'rOMACH-THl!) LIVER-THE WAY THE FOOD IS
POURED INTO THE BLOOD AND CARRIED OVER
THE SYSTEM.
"Good morning, Charles.
Good morning, John.
To-day we are to take a glance into our own stomachs,
are we?"
"You don't mean literally, I suppose, but by some
mysterious scientific investigation."
"It has been done literally, in one case at least.
However, let me tell you first what is known about the
movements of the food after it passes into the body, and
then perhaps I C:111 give y0u some idea of the Illode
which the facts have been learned.
in
The stomach is a
bag, lying pretty nearly across the middle of the body,
a liUle to the left, of a size sufficient to hold about a
quart.
As the food is swallowed it passes through a
long, flexible,
moist tube, called the esophagus, and
falls into the stomach.
The presence of f ood in the
stomach stimulates the gastric
gastric, juice.
glands to secrete the
These glands are situated in the inner
coating of the stomach, t.hey are very numerous and
The gastric juice which they secrete
exceedingly s maiL
partially dissolves the food, converting it into a semi­
fluid mass, called chyme.
In order to mix the gastric
juice thoroughly with the' food, the stomach has all
instinctive movement which carries Its contents along
THE
is sucked in, as it flows along through the intcstine, and
POr
..
YTECHNIC. ASSOCIATION OF
THE
AMERICAN INSTITUTE.
these tubes meet, like the branches of a river, till they
[Reported eXl're••ly for the Scientific American.]
form one large pipe or duct, which leads up by the side
of the back bone carrying up the chyle and emptying it
into a large vein
On Thursday evening,
Nov. 22d, the usual weekly
ill the left side of tho neck, by which meeting of the Polyteehnic Association was held at its
it is borne directly to the heart and distributed over the room in the Cooper Institute, this city; Professor Mason
system.
The little tubes which suck up the chyle from presidi!Jg.
the intestine are
called lacteals, and they have the
power of rejecting the undigested waste matter, which
lIliSCELLANEOUS
BUSINES3.
Stoneware Post Butt.-Mr. James Holland exhibited
accordingly continues on its course, passmg through the
and explained an invention for securing wood that is
stomach, down the left side, and out by the rectum."
&c. -from decay.
of carbonic acid in 0ur bodies."
so that its top shall be about an ineh above the surface.
a general notion of the mode in which nourishment is
post thoroughly filled with pitch.
colon, up the right side, across the body just under the
planted in the ground-as fence posts, telegraph poles,
It consists of a stoneware covering
"I thonght you were going to tell us about_the action i f"r Ihe end of the post, which is to be set in the earth
"I was, but thought it best that you should have first The post is then placed in it,
I will next explain to you the
supplied to the system.
way in which a portion
The material is com­
posed of fire clay and sand (any kind of pottery clay
of this food is used as fuel to will answer), dried, and then burned in a kiln nntil
heat our bodies, but as this will take some hme, we wili
postpone it till next Saturday."
IN
WATER
perfectly dry and hard.
Not being porous, it excludes
all moisture from the wood, and thus obviates the cause
of decay.
_
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.
...
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...
IMPROVEMENTS
!Ind the space around the
LOCOMOTIVES-FEED
HEATING.
We find the following remarks in the editorial columns
of the London Engineer:-
Reverting for a few lines to the superheating of steam,
it is tolerably evident that the difficulties opposed to the
its greater curve 'lnd returns them by the lesser, mixing successful introduction of superheated steam are to be
them by 'a churning JoI\otion, occupying about three found chiefly in leakage and deposit o f sediment in the
minutes in each revolution. Thus the fooil is frequently superheating tubes, and the erosion to which metallic
Mr. Dibben inquired whether
the
dwelling of the
wood upon the absorption' of moisture would not split
the butt; and remarked that it is a common Ilractice to
split stones by drilling holes, driving in wooden plugs,
and then wetting them.
Mr. Holland said that for that purpose a porous wood
-such as willow-would be used.
danger of these being rotten
There would be n o
from that cause.
The President inquired what was to prevent the pole
presented to the passage f rom the stomach in the duo­
surfaces, thus exposed to high temperatures, are liable.
from rotting off just at the surface, immediately above
myst�r[ous adjustments that we find in the operation of
purities in the steampipes, we must either have recourse
Mr. Holland said that the IJitch would be a sufficient
denum, and, by one of the most wonderful of all the For the prevention of deposited sediment or other im-
the stone.
the human system, as soon as any portion of the food
to pure water or to surface condensation and distilled protection there.
sage, the passage opens and allows the chyme to flow
course, instigates the external erosion, as the overheat-
not be a sufficient protection u ndergroull<J�
great measure prevented by the comparative freedom
the pitch f rom scaling uff when the wood is swelled by
which is thoroughly digested presents itself to this pas­
When f ood not perfectly
out into the duodenum.
digested is presented, the passage refuses to open, and
thus the food is retained in the stomach until all of it
wate-r;. the prevention
indigestible matter has been presented several times to
" How does this passage know whether the food
digested or IIOt."
of
The President inquired why, then, the Ilitch would
wiLh which heat is conducted through an unobstructed
Another cause of difficulty in the
superheating apparatus
is the unequal expansion and
contraction to which the parts of the apparatus are sub
,age finally opens, and all the contents of the stomach ject.
flow out into the duodenum."
sedimentary deposits,
ing of pipes, which is the cause of such action, is in a
-that can be conve,'ced into chyme is so converted. Mter metallic medium.
I he pyloric orifice and returned to the stomach, the pas­
of
:
It appears that, on board the Woolwich steam
boats, the saving of fuel by superheating the steam is
to ask but impossible to answer.
sidered upon the whole questionable, whether the extra
place? "
"Some years ago a soldier in Canada was wounded
stomach by a bayonet, and when the wonnd
healed, it left an opening into his stomach by which
'persons could look in and see the operations of digestion
'going on.
Dr.
Beaumont,
of St.
Louis,
took this
soldier, St. MarLin, under his care, and made a long
series of investigations of the process of digestion.
He
had a little silver ladle made, and used to dip out the
gastric juice and try its action on meat and other sub­
stances outside of the body.
The 1I"0?d must be thoroughly painted abo\'e
the ground.
Mr. Dibben inquired whether the in',entor would
be
willi�g to put one into a pail of water with the wood
unpainted.
Mr. HollallLl-Ye"
sir; I haTe done it before. wit-
Mr. Garvey suggested that Mr. Holland furnish spe-
cimens for trial by Mr. Dibben's test.
working pressure in the boiler of 20 Ibs. or 21 Ibs. per
men of quartz gold, sent from California by the last
Mr. Holland agreed to do so.
Gold Washe,·s.-Mr. Bruce exhibited a beautiful spe-
square inch above the atmosphere, the proportion of
fuel saved by superheating the steam is from 15 to 20
mail.
gained, and it is for engineers to secure the entire saving,
pable of yielding anything valuable.
per ce!lt on board those steamboats.
The President exhibited a 8p�cimen of gold gathered
That is one point from tailings which had been rejected as utterly inca­
by improving their details, simplifying the apparatus,
effective than before, and superseding the additional
maintenance heretofore expended.
With respect to feed water heaters operating by the
Upon running
ten bushels through a new machine, a quantity of gold
rendering every square inch of superheating surface more worth
But with this wonderful means of the exhaust steam, they are either surface-
opportunity he did not discover much which had not
stone co\'ering was to keep
cost of mamtenance, due to the application of the super-
Nobody knows."
heating process, is materially lcss than the saving. It
"Well, how do they know that these motions d o take is, however, without doubt, established that, with a
the
moisture.
is found to average from 15 to 20 per cent; but it:is con_ nesses.
"That is another of those questions which it is easy
in
Mr. Garvey said that the
9�
cents to the bushel was separated.
Two men
with five of these machines would obtain a clear profit of
about $25 per day.
mercury.
It is done, as usua!, by the .aid of
Mr. Wood sal« that a
friend of his cxpected far
heaters or h�aters by direct intermixture; and the latter greater profits from a machine which he had inv.ented,
been previously known, a fact which proves, in a very
must be allowed to be, in all respects, the most conveni- without using any mercury at all.
investigations \Thich had been made before."
the best surface-heaters by waste steam, like those by after atmospheric exposure for some years, would be so
the waste gases, require a large extent of surface for the changed that they could be workcd profitably.
striking manner, the thoroughness of the physiological
" We will believe your statements, then. What takes
place next? "
.
"The proper way is to receive the present conclusions
of science till you acquire sufficient knowledge of the
subject to test them for yourselves.
You will find that
it will take very careful and laborious experiments to
disturb these· conclusions.
After the chyme has passed
into the duodenum, it is mixed with two other fluids,
which dissolve it further and convert it into a milky
ent, the most compact, the most efficacions-in short,
absorption of a sufficient quantity of heat, involving an
arrangement of concentric pipes, or faggots of tubes, or
similar expedients for eking out the needed surface, to
the painful v-iolation of the principles of taste in design,
Mr. Dibben said that it had been found that tailings,
The President cited
earned
the case of a man w.ho had
$3,000 in California in a single year by work­
ing old tailings by the old methods.
Personal Explanatirm.-Mr. Seely offm'ed a resolution
and to the grievance of the manufacturer who studies with reference to remarks which he c(msidered as im­
simplicity in all his works.
Some inventors will work
plicating the integrity either of an officer or member of
ten times as hard as others, and 'the fruit of their labors the association.
will be a design ten times more complex.
Given-any
The regular sub ject-" Sewing Machines "-was then
These two fluids that mix with the
quantity of tubes, a rather extensive supply of cocks, in
the pancreatic juice, which is formed by the pancreas.
out, a few dozen union-couplings, and a gross of bolts
Mr. Babcock said that the sewing machine had bcen
is the gut which, in engine, may be taken to be in the ratio ot its weight, it
is no donbt better to dismiss complications, or to seek
it preserves the meat whieh'is stuffed into it from decay. for permanent arrangements in things which are simple,
Along the small intestines are numerous mouths which direct and to the point.
operation, sewing rapidly and with perfect success. This
liquid called ehyle.
chyme are the bile, which is secreted by the liver, and
various shapes, with from one to four passages in and
introduced.
DISQUSSION.
From the duoden'um, the chyle, mixed with the waste and nuts, and inventors are to be found who will not called the miracle of the present age. Twenty years
indigestible portions of the food, passes on .through the oQly scheme a feed water heater out of t.hese materials, ago, the practicability of sewing seams by machinery
jejunum into the small intestines, which, in man, are but who. will use them all up, or " bring them all in." was considered ItS out of the question. At tht; present
about 15 feet lon�, and are folded back and forth in the Rut as the cost or making, maintaining and working an time, tens of thousands of sewing machines are in daily
10lver part of the abdomen.
Thi�
the hOK, is used for making sausages; being air tight,
© 1860 SCIENTIFIC AMERICAN, INC
has,
of course, occasioned a considerable degree of suf­
fering and want, by depriving the poor lleamstresa of
her ronner _ of support j but the am�DDt of 8uf,