OCTOBER 29, 1897. ] 
water action, and I cannot believe that the 
banded region composed of sand heavily 
mixed with clay could have been laid down 
in any other way than those just below. 
Certainly no wind action can ever be held 
responsible for such level and uniform de- 
posits over such an area, but it might rather 
be explained by a change in level affecting 
the velocity of the ecurrent—in fact, I be- 
lieve the existence of this bed can be ex- 
plained only in this way.” 
G. FREDERICK WRIGHT. 
OBERLIN, September 20, 1897. 
_ PROFESSOR RUDOLPH HEIDENHAIN. 
THE announcement of the death of Pro- 
fessor Rudolph Heidenhain, though not en- 
tirely unexpected, will call forth in physio- 
logical circles a note of deepest regret. It 
brings to memory the names of Brucke, 
Helmholtz, Karl;Ludwig and Emil DuBois- 
Reymond, members of that coterie of brill- 
iant scientists whose unusual ability for 
many years attracted to the German labora- 
tories students of medicine from every part — 
of the civilized world. And with these 
names are largely associated the remarka- 
ble transformation and progress which 
physiological science has experienced since 
the days of Johannes Miller. 
Rudolph Peter Heinrich Heidenhain was 
sixty-three years of age at the time of his 
death, having been born Marienwerder, 
January 29,1834. The elder Heidenhain 
was a physician, and it was not strange 
that the young man should inherit an en- 
thusiasm for the natural sciences; it is 
told, in fact, that his interest in the work 
to which his life was devoted was early 
aroused by the reading of Volkmann’s 
‘Haemodynamik,’ which had just been 
added to the father’s library. Heidexhain 
pursued the usual .university medical 
studies at Konigsberg, Halle and Berlin, 
receiving his degree at the latter place in 
1854 with a dissertation entitled ‘ De nervis 
SCIENCE. 
645 
organisque centralibus cordis cordiumque 
ranae lympaticorum.’ As assistant to Du- 
Bois-Reymond, the following three years 
were devoted to investigations in muscle 
physiology, a series of studies being pub- 
lished in 1856. In 1857 Heidenhain quali- 
fied at Halle as ‘ Privatdocent’ in physi- 
ology, with a thesis entitled ‘ Disquisitiones 
criticae et experimentae de sanguinis quanti- 
tate in mammalium corporis exstantis’; two 
years afterward, in 1859, at the early age of 
twenty-five, he accepted the chair of physi- 
ology and histology at Breslau in Silesia, a 
position which he occupied until his death. 
Heidenhain obtained many official distine- 
tions during his academic career, and 
among these the Harveian medal with 
which he seemed especially pleased; he 
was a member of numerous learned socie- 
' ties, and for many years enjoyed the title of 
‘Geheimer Medicinalrat.’ 
The advent of Heidenhain to Breslau and 
to the institution in which, years before, 
Purkinje had been active, was followed by 
a series of physiological researches con- 
tinued almost uninterruptedly until the 
past year. These contributions have been 
marked not alone by the originality with 
which the subjects have been treated, but 
especially by a deep insight into the prob- 
lems presented and a thoroughness of in- 
vestigation and devotion of energy as untir- 
ing as it was characteristic. The results of 
these labors have had so important an in- 
fluence in determining certain chapters of 
physiology as taught to-day that it may, 
perhaps, be permitted to present a few frag- 
ments of Heidenhain’s work and to indi- 
cate their bearing. 
In 1864 appeared the well known mono- 
graph on ‘Mechanische Leistung, Warme- 
entwickelung und Stoffumsatz bei der 
Muskelthatigkeit.? Helmholtz had shown 
that the tetanic contractions of a muscle, 
when continued for some minutes, are at- 
tended by a production of heat, but it re- 
