APRIL 15, 1915| 
NATURE 
179 

conditions, the constitution of the germ is un- 
affected thereby, and that any change in it is 
necessarily discontinuous. Hence, though in- 
dividual growth is inevitably continuous, organic 
evolution must be discontinuous; and any analogy 
between race-history and individual history must 
be false. The idea that the latter recapitulates 
the former ‘‘cannot be applied to concrete 
instances.” 
That likeness does not necessarily imply 
relationship is true enough; but there is more 
than “likeness” when we find the last of an 
ascending series of fossils repeating in its life- 
history the adult stages of the successive species 
immediately preceding it, all those stages having 
been linked by gentle gradations. The semblance 
of continuous evolution may conceivably be ex- 
plained by an appeal to the mongrel (hetero- 
zygote) constitution of the germ, and by allowing 
wide limits of modification to the soma, in suc- 
cessive species. But why is the trend of germinal 
saltation so often the same as that of somatic 
modification, and why should individual growth 
repeat and follow this trend? These are ques- 
tions not of analogy, but of fact, and are not 
to be dismissed with a bare denial. 
Biologists may differ on these matters, but all 
might read with pleasure Dr. Johannsen’s critic- 
ism of Prof. Bergson’s ‘Elan vital.” 
Ff. A. BATHER. 

JEUXONDS OANIO) IN, iE TIN ANG 
Y the sudden death, through heart-failure, on 
March 23, of Otto Nikolaus Witt, Geheimer 
Regierungsrat and professor in the Technical 
High School of Charlottenburg, at the compara- 
tively early age of sixty-three, and in the full 
maturity of his intellectual power, Germany loses 
one of the most distinguished of her teachers of 
chemical technology, and one of the most success- 
ful of her pioneers in the application of organic 
chemistry to industrial pursuits. Of Russian ex- 
traction, Witt had intimate associations with all 
the countries now warring against Germany. Like 
Hofmann, Griess, Caro, Martius, and others who 
could be named—the founders of Germany’s un- 
rivalled supremacy in the manufacture of the so- 
called coal-tar dyes—upwards of thirty years ago 
Witt spent some time in England as a member 
of the now defunct firm of Williams, Thomas and 
Dyer, then engaged in the industrial production 
of this class of colouring matters. He took kindly 
to English life, moved freely in~ scientific and 
_ literary circles in London, joined the Savile Club, 
which had then its home in Savile Row, had his 
boat on the river, and enjoyed to the full the 
hospitality which his many social gifts, the range 
of his knowledge, his admirable conversational 
powers and charm of manner readily secured for 
him. 
Witt spoke and wrote our language with 
ease and fluency. Habitués of the Royal Institu- 
tion well remember the brilliant Friday evening 
discourse he gave on the development of the 
NO. 2372, VOL. 95| 

| synthetic indigo industry, illustrated with a wealth 
of material and a mass of detail which his close 
connection with the great firms which have com- 
bined to exploit that industry had enabled him to 
accumulate. Among the many fruits of his scien- 
tific activity in England at that time may be men- 
tioned his paper in collaboration with Thomas, on 
the induline group, published in the Transactions 
of the Chemical Society for 1883. At another 
| period of his career he was associated with Ndlt- 
ing and Grandmougin, at Mulhouse, in develop- 
ing the chemistry of the indazole derivatives, and 
| his Alsatian connections brought him into contact 
with the leading manufacturers of synthetic 
colouring matters in France, and he learned to 
know Paris and to appreciate its scientific in- 
terests as fully as he knew and valued those of 
London. 
The most fruitful period of Witt’s scientific 
activity was comprised between the years 1876 
and 1892. During the earlier years of his con- 
nection with the Charlottenburg institution, he 
was hampered by the want of adequate laboratory 
accommodation, and in spite of his acknowledged 
position as an authority on that particular section 
of applied organic chemistry with which his name 
and fame are indissolubly associated, and not- 
withstanding his generally recognised powers as 
| a teacher, his success in creating a school fell 
| short of his hopes, and neither the number of his 
students nor the character of their output, as 
determined by the quality and number of their 
| communications to chemical literature, were com- 

| the literature. 
mensurate with his aspirations. 
Witt was one of the earliest to attempt to 
explain the properties and colour of dyes in terms 
of chemical constitution, and his memoir of 1876, 
published in the Berichte of the German Chemical 
| Society, attracted considerable attention by the 
originality and boldness of its views, and the in- 
genuity with which they were supported. The 
terms “chromophor”’ and “chromogen” which he 
introduced in order to denote the special groups 
and molecules which he conceived to be concerned 
with the production of colour are still current in 
Although Witt’s hypotheses have 
not wholly stood the test of time, the paper will 
always have its place in the history of the subject. 
It is at least noteworthy as the production of a 
young man of twenty-four. 
Witt’s name is associated with the discovery of 
certain typical classes of synthetic dye-stuffs. His 
published work includes papers on the indulines 
and indophenols; on the nitroso-derivatives of 
aromatic amines, eurhodines, eurhodols, safra- 
nines, etc., and he contributed the monographs on 
azines, indamines and indophenols, artificial in- 
digo and indigoid dyestuffs, and triphenylmethane 
colouring matters to the “Dictionary of Applied 
Chemistry,” published by Messrs. Longmans, 
Green and Co. They are amongst the most valu- 
able articles in that work, and are characterised 
by Witt’s excellent literary qualities, his grasp of 
principles, his power of ‘co-ordination, his sense 
of proportion, and felicity of expression—qualities 
“c 
