Year: 1879

NJ. Javel, of Paris, in a recent lecture, tries to
answer the question, Why is reading specially
fatiguing exercise and also suggests some reme-
dies for this fatigue. First NJ. Javel says, reading
requires an absolutely permanent application Of
the eyesight, resulting in permanent tension Of
the organ which may be measured by the amount
Offatigue or by the production fpermanentmyopy;
secondly, books are printed in black on a white
ground. The eye is thus in presence Of the most
absolute contrast which can be imagined. The
third popularity lies in the arrangement of the
characters in horizontal lines, over which run
eyes.


If we maintain during reading perfect immo-
bility of the book and the head the printed lines
are applied suceessVely to the parts Of the
retina, while the interspaees, more bright, also
affect certain regions Of the retina always the same
There must result from this a fatigue analogos
to that which we experience when we make exper-
iments in accidental images" and physicists
will admit that there is nothing more disastrous
for the sight than the prolonged contemplation Of
these images Lastly, and most important of all,
in NJ. JavePs estimation, is the continual variation
of the distance of the eye from the point Of fxa-
ton on the book. simple calculation demon
strates that the accommodation of the eye to the
page undergoes a distinct variation in proportion
the eye passes from the beginning to the end Of
each ine and that this variation is all the greater
in proportion to the nearness of the book TO the
eye and the length of the line.


As to the rules which NJ. JaveI incucates in or
der that the injurious effects of reading may be
avoided, with reference to the permanent appliea-
tiOn Of the eyes, he counsels to avoid excess, to
take notes in reading, to stop in order to reflect,
or even to roll cigarette; but not to go on read
ing for hours on end without stopping. As to the
contrast between the white of the paper and the
black characters, various experiments have been
made in the introduction of colored papers. M.
Javel advises the adoption of slightly yellow tint.
But the nature of the yellow to be used is not
matter of Indifference; he would desire yellow
resulting from the absence of the blue rays, an
alogous to that of paper made from wood paste,
and which is often mistakenly corrected by the
addition Of an ultramarine blue, which produce
grey, and not white. NJ. Javel has been led
this conclusion both from practical Observatio
and also theoretically from the relation which mus
exist between the two eyes and the colors Of tn
spectrum.


His third advice is to give preference to SINAI
volumes which can be held in the hand, which
obviates the necessity of the book being kept fixed
in one place, and the fatigue resulting from acci-
dental images. Lastly, NJ. Javel advises the
avoidance of too long lines and therefore, he pre-
fers small volumes, and for the same reason those
journals which are printed in narrow columns.-
Of course every one knows that it is exceedingly


injurious to read with insufficient light, or to read
too small print and other common rules.


NJ. Javel concludes by protesting against an in
vdious assertion which has recently been made
'in neighboring country" Germany, no dOubt)
according to which the degree of civilization Of
people is proportional to the number of the short
sighted shown to exist by statistics; the extreme
economy of light, the abuse of reading to the de-
triment of reflection and the observation of real
facts the employment Of Gothic characters and Of
too broad column for books and journals,
the conditions which, NJ. Javel believes, lead to
myopy, especially if successive generations have
been subjected to these injurious influences.