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XXII
HERMANN VON HELMHOLTZ
it. Take one of Helmholtz's minor researches, e.g. the theoreti-
cal paper in which he discusses the formation of liquid
jets. The problem is not one that appeals to the lay
mind: its solution is only attained by the aid of assumptions
which correspond but indifferently to the actual conditions;
the influence of the investigation upon science and life can
scarcely be called other than slight. And yet the manner in
which the problem is solved is such that in studying even a
paper like this one feels the same elevation and wonder as in
beholding a pure work of art. Upon our comprehension of
the difficulties to be surmounted depends the depth of this
feeling. We see a man of surpassing strength spring across a
yawning chasm apparently without effort, but in reality strain-
ing every nerve. Only after the leap do we clearly see how
wide the chasm is. Instinctively we break out into applause.
But we cannot expect the same spontaneous enthusiasm of
spectators from whose standpoint the chasm is not visible, and
who can only learn from our descriptions how trying the feat
was.
To give a brief but fitting sketch of Helmholtz's work is
difficult on account of its many-sidedness as well as its pro-
fundity. His scientific life interests us like an Odyssey
through the whole region of exact investigation. He began
as a doctor: he had to study the laws of that life which he
wished to succour, and this led him to the study of physiology,
which is the scientific part of medicine. He found himself
hampered by the gaps in our knowledge of inanimate nature:
so he set about filling these and thus drifted more and more
towards physics. For the sake of physics he became a
mathematician, and in order to probe thoroughly the founda-
tions of mathematical knowledge, and knowledge in general,
he became a philosopher. When we look through the techni-
cal literature of any of these sciences we meet his name: upon
all of them he has left his mark. Without attending to
chronological order we shall here only describe briefly three of
those great achievements which constitute his title to fame.
I consider that the most beautiful and charming amongst
these, although not the highest, is the invention with which
he has enriched practical medicine. I mean the ophthal-
moscope. Before him no one was able to investigate the