The times., 1901-06-16

water. for example. the pressure of the
pulse beat manifests its full disteuding
power.
Measurements. therefore, Of the mean
blood pressure are made by means OF a
large glass jar. into which the subject"
inserts his arm-a water-tight connection
being made by a surgeons glove Of rub
Der and heavy rubber bands at the mouth
Of the jar. The jar is then filed with wa
ter, supplied through tube from a bottle
which is raised by a pulley until pres
sure equal TO that of the blood is secured
ANY extra pressure of the blood, as for in
stance, the pulse beats is then apparent,
and is communicated by means Of another
tube to a column Of mercury, where it is
recorded by a floating needle which marks
the result upon Il revolving cylinder.
Starting with records made when the sub
ject eadeayoreG to make no mental exer-
tion, the comparative blood pressure has
been measured when ne was solving a
problem in mathematics. translating a
difficult passage from the German. or at
tempting to recall something which he
had once heard read. Much has already
been done to record the change in blood
pressure consequent upon degrees of vio-
lent exercise, but the rapidity Of the heart
terially increased the difficulty in OBJ
tanning accurate measurements.
The apparatus used in the determina-
tons Of muscular fatigue and soreness is
comparatively simple. The mo iement
measured by Prof. Hough has been the
fiexion Of the middle finger uf the left
hand The hand is strapped firmly In a
fiat position to a rest. palm downward
with straps passing over the back of the
hand. and the first and third fingers. 4
N-shaped notch In the rest permits an up
and down movement Of the second finger
at the joint between the second and third
phalanges. BY means of a cord and pull
ley the downward pun Of the finger is
eXerted against the spring of one OF the
simple weighing machines ordinarily used
by housewives. Thus only the muscle or
set Of muscles drawing the finger down
ward are employed. The muscular effort
is farther specialized by "a metal splint
fastened about the finger TO restrict the
fiexion TO a single joint and to furnish a
fastening for the cord. A magnifying le-
Yer, with it's long arm bearing upon re-
vOlvinE cylinder records the extension Of
the spring upon smoked paper.
The experiments cannot fail 10 impress
one with the fact that the fatigue record
is a most accurate Indication Of the work
ing capacity Of a muscle. and gives rise
to the theory that the cause Of ordinary
fatigue il d trained muscle is the pres
ence Of waste products Of activity, which.
il may be reasonable 90 suppose limit
the work done in proportion to their
amount. If the rhythm is slow enough
the blood completely removes these waste
products in the interval Of rest between
the contractions and no fatigue appears
upon the tracing. But the traciugs nave
been so mathematically exact that the ef-
feet Of a slight physiological disturbance
like that caused by the smoking Of "a ci-
gar, is plainly recorded.
The tests Of unframed muscles have !
resulted very differently. The unframed
muscle failed to come TO a constant ia
tigue level. but the height Of it's Contrac-
tions continued to diminish TO the end Of
an experiment lasting 20 or y minutes.
There was no painful sensation during, |
or Immediately after. the experiment., but
eight hours later the muscle began TO feel |
sore, the soreness reaching its height IN |
twelve hours. Tracinss given by the |
muscle IN this condition We're, for the first |
few minutes. very painful, and the height |
Of contraction against a spring showed |
marked diminutiOn of strength even when |
all the feelings Of soreness had passed |
away. Little or no power of recovery |
was noticed upon the charging TO a |
slower rhythm and no Improvement was |
record-f in the working capacity of the
muscle so long as daily experiments were !
made-a most significant fact In its pos
5ible application to methods OF physical |
training. Improvement, however, took |
place as soon as periods Of four or more
days rest were allowed.
one of the suggestions drawn from these
experiments is that fatigue. strictly |
speaking. is a phenomenon which accom-
Ianies work and is the change in the
working capacity of the living cell. An
Jther is that muscular soreness is not
atigue phenomenon, but is due TO injuries
o the organ, either the tearing apart Of
he muscle fibres, or of the connective !
eems cleaF 10 Prof Hough that no muscle |
s suitable for experiments in fatigue |
which has not been trained TO DO its work
Without resulting soreness. That is, a