The times., 1897-05-09
A MACHINE THAT BREATHES.

Two curious instruments were recently
placed on exhibition by the New York
Academy OF Sciences They were simple
little mechanical contrivances designed to
show the action of the lungs and of the
rib muscles when we breathe By closely
observing them any person may learn in
a moment just now the inside OF the chest
behaves when we inhale a deep breath
They were made by Prof. John F Wood
hull, OF the New York Teachers College.
One of these instruments consisted OF an
ordinary lamp chimney over the bottom of
which was stretched soft rubber sheet
and in the top of which was inserted 4
rubber stopper. Through the center Of
the stopper was piece of glass tubing.
On the end OF the tubing, inside of the
lamp chimney, was tied little bag made
OF what is known as gold beater's skin.
Ordinarily the little bag of skin In the
chimney hangs limp and loose, like a col
lapsed balloon. If, however, the rubber
sheeting is caught by the fingers in the
middle aud pulled downw ard, the enclosed
bag will Immediately swell out to its fun
size. This is because pulling the rubber
sheet makes the space within the lamp
larger than the enclosed air can fill, or
outside air rushes down the glass tube 10
supply the vacancy, and in doing so swells
the little bag out to its fullest extent On
the contrary, If the rubber sheet on the
bottom Of the chimney is pushed In by the
finger, the little bag folds up limp again.
BY quickly pushing the sheet in and pull
ing it out again, the little bag initiates and
folds, out aud in, in perfect time to the
action OF the fingers
Now, this is precisely the action thattakes
place when we breathe. The sheet OF
rubber on the bottom of the chimney cor
responds to the diaphragm in the human
body. The diaphragm is the large MEM
brane which separates the chest from. the
lower part of the body. The little bag
represents the lungs and the glass tube is
the windpipe 1t is a mistaken idea with
many persons that when we breathe the air
rushing into the lungs causes the lungs and
the muscles surrounding them to expand
But precisely reverse action takes place
Weinvariably move our muscles and diaph-
Tagm first, thus expanding the lungs, into
which the air rushes to fill up the space,
which would otherwise become a partial
vacuum. The action is all unconscious, and
1t appears to be the opposite OF what it
reallyis, but that is how it occurs, neverthe-
less. Thus lamp chimney can he made to
perform several actions of the human body
1t breathes Just as truly, and it's lungs are
q good facsimile of our own
The other instrument looked somewhat
like q band saw. II consisted of several
sticks Of wood arranged in the manner Of
the Illustration. The cross pieces on the
frame representation our ribs and rubber bands
stretched on tacks between them acted pre-
ciseiy as do our rib muscles. Over the
lower points of the frame was a piece Of
tape, which had been stiffened by starch.
This represented the diaphragm. By NOV.
ing the frame so as to contract the rubber
hands the upper part Of the frame Cor lung
cavity became smaller. By stretching the
bands it became large. It's imitation of the
human chest moveme mt is perfect, and the
lesson it teaches should he appreciated by
every one.