5l 
2 NA LORE 
| Marcu 28, 1907 
ant, first to the late Dr. Augustus Voelcker, and then 
to! Prof. AS HS @hurch. In the next mine years 
Warington was chemist at Sir John Lawes’s tartaric 
acid works, but in 1876, being desirous of devoting 
himself entirely to research, he came again to the 
Rothamsted Laboratory, where he remained until 
18go. 
Although Warington’s chief interest was in agri- 
cultural chemistry, he published a number of papers 
dealing with inorganic chemistry, and a _ detailed 
account of the various salts of tartaric and citric acids 
as they occur in their natural sources and in the 
manufacture of these substances. 
On his return to the Rothamsted Laboratory in 
1876, Warington introduced several improved methods 
of analysis to save time or ensure greater accuracy 
in the routine determinations; there also he carried 
out the investigations on nitrification by which he 
made his name. In 1877 appeared the paper of 
Schloesing and Mintz which showed that the produc- 
tion of nitrates in the soil must be due to living 
organisms; this work was repeated by Warington, 
who continued to investigate the conditions favour- 
able to the process. He showed that light would 
inhibit the change, and that the drying of the soil 
was sufficient to destroy the organism; he also in- 
vestigated the distribution of the organism, and 
showed that it was confined to the surface layers of 
ordinary soil, being only present in any quantity in 
the portion usually stirred by the plough. Observ- 
ing that the oxidation of the ammonia or urea 
employed sometimes stopped at the stage of nitrite, 
he succeeded in demonstrating that the process in 
ordinary soils takes place in two stages due to 
different organisms, one oxidising ammonia to nitrous 
acid, the other completing the oxidation to nitric 
acid. Warington had actually accomplished the final 
step in the isolation of the two organisms, though 
he had not brought his worl to the stage which 
satisfied himself, when his researches were unfortu- 
nately interrupted, and before he could resume 
Winogradsky published his elegant method of 
isolating the nitrous and nitric organisms by the use 
of a nutrient silica jelly. 
The circumstances which led to Warington thus 
missing the credit of the crowning point of his long 
researches on_ nitrification undoubtedly caused him 
bitter disappointment; he continued to live in 
Harpenden, but took no further part in research. In 
the course of his investigations on_ nitrification 
Warington also observed and studied that other pro- 
cess of denitrification, by which previously formed 
nitrates are reduced again, often with loss of the 
nitrogen as gas. In later years this subject became 
very prominent for a time, but the essential conditions 
of the action had been laid down before in Waring- 
ton’s papers. He also investigated the method of 
estimating small quantities of nitrates by means of 
indigo, and devised a standard process which, in a 
simplified form, is now used by most water analysts. 
Warington gave a course of lectures in America 
for the Lawes Agricultural Trust in 1891; these were 
afterwards published by the United States Depart- 
ment of Agriculture; he was also Sibthorpian pro- 
fessor of rural economy at Oxford, 1894-7. 
His “Chemistry of the Farm’? was published in 
1881, and has since gone through fifteen editions; 
though only a small book, it is noteworthy for its 
lucidity and compactness in the handling of a mass 
of experimental data: it is a model text-book which 
has no rival in any language, and on it the present 
generation of agricultural chemists in this country 
has been educated. ; 
Warington was elected to the Royal Society in 
t886; his connection with the Chemical Society, of 
1952, VOL. 75] 
which his father was one of the founders, dates back 
to 1863; he was vice-president from 1889 to 1893, and 
in its Transactions appeared nearly all his original 
work. 
Warington’s scientific work is distinguished by 
clearness and precision; the range is not wide, but 
everywhere it shows the minute care and the regard 
for accuracy with which he worked; in these respects 
his work only reflected his personal character. 
A. .D; Hi 
M. PP. E. BERTHELOT. 
HE death of M. Berthelot was briefly recorded 
in the columns of Nature last week. The 
writer has been asked, as a former pupil of the great 
master, to give some account of his life and work. 
Marcelin Pierre Eugene Berthelot was born in 
Paris on October ‘25, 1827. He was the son of a 
medical man, Dr. Jacques Martin Berthelot, and was 
educated at the Lycée Henri IV. In 1846 he obtained 
the prix d’honneur de philosophie at the concours- 
général, open to the best students of the highest 
classes of the lycées of Paris. In February, 1851, 
he became assistant (préparateur) to Balard, the dis- 
coverer of bromine, who held the chair of chemistry 
at the Collége de France. He kept this minor position 
until December, 1859, when he was appointed professor 
of organic chemistry at the Fcole supérieure de 
Pharmacie. In 1865 a chair of organic chemistry 
was created for him at the Collége de France, which 
he held until his death. In 1870-1 he acted as presi- 
dent of the Comité scientifique de défense during 
the siege of Paris. In 1873 he was elected member 
of the Academy of Sciences, of which he afterwards 
became perpetual secretary. In 1876 he was appointed 
inspector-general of higher education; in 1881, 
senator for life. He was Minister of Public Instruc- 
tion from December, 1886, to May, 1887, and Minister 
of Foreign Affairs in 1895-6. In 1900 he was elected 
a member of the French Academy. 
The French nation has from the time of the Revolu- 
tion turned more than once to its scientific men for 
help in the conduct of national affairs. The names 
of Lavoisier, of Lazare Carnot, mathematician and 
organiser of victory, of Fourcroy, of Dumas, and of © 
Paul Bert recur to the memory. But if Berthelot 
took an untiring part in public affairs, and 
especially, as member of the Conseil supérieur de 
I’Instruction publique, in educational affairs, it is not 
as an administrator or as a minister that he will be 
remembered, but as a chemist, and perhaps the 
greatest, as he was the most prolific, chemist of his 
age. 
Of his first studies in chemistry I have found no 
account, but we know that Claude Bernard in 1848 
asked him for chemical assistance in his early work 
on glycogen. 
It was in 1850 that he published his first paper, on 
a method of liquefying gases. Between that date and 
1883 the Royal Society’s catalogue records against 
his name the titles of between 600 and 7o0o papers; 
it is probable that their total number falls little, if 
anything, short of a thousand, and to these must be 
added eighteen or twenty books, some of them, it is 
true, being only the summaries of published papers, 
but others, and especially his works on the history 
of chemistry, in a large measure independent publi- 
cations. To estimate justly the value and influence 
of this colossal contribution to science would be the 
work of months rather than of a few hours, and, 
indeed, the very mass of the work has perhaps hidden 
something of its significance and of the pn oe 
of the underlying ideas. 
Berthelot first gave his measure in his doctoral 
