Here, then, was what might be termed direct experimental evidence
for the hypothesis of Prout. Unfortunately, however, it is
evidence of a kind which only a few experts are competent to
discuss--so very delicate a matter is the spectral analysis of
the stars. What is still more unfortunate, the experts do not
agree among themselves as to the validity of Professor Lockyer's
conclusions. Some, like Professor Crookes, have accepted them
with acclaim, hailing Lockyer as "the Darwin of the inorganic
world," while others have sought a different explanation of the
facts he brings forward. As yet it cannot be said that the
controversy has been brought to final settlement. Still, it is
hardly to be doubted that now, since the periodic law has seemed
to join hands with the spectroscope, a belief in the compound
nature of the so-called elements is rapidly gaining ground among
chemists. More and more general becomes the belief that the
Daltonian atom is really a compound radical, and that back of the
seeming diversity of the alleged elements is a single form of
primordial matter. Indeed, in very recent months, direct
experimental evidence for this view has at last come to hand,
through the study of radio-active substances. In a later chapter
we shall have occasion to inquire how this came about.



IV. ANATOMY AND PHYSIOLOGY IN THE EIGHTEENTH CENTURY

ALBRECHT VON HALLER

An epoch in physiology was made in the eighteenth century by the
genius and efforts of Albrecht von Haller (1708-1777), of Berne,