Cheltenham was able to continue his research, which was finally published in the Philosophical Magazine and the British Association Report for 1889. In the following year, he worked for a time with Professor T. E. Thorpe on persulphocyanogen. In 1893, he was appointed science master at the Gravesend Municipal Technical School. He began an investigation on the fixed points of mercurial thermometers, attempting to correlate the indications of standardised thermometers, made of different kinds of glass, with the absolute scale. An account of this work was read before the Royal Society in 1897. He met with a bicycle accident in March, 1899, from the results of which he died a few weeks later. He was ardently devoted to experimental study, and by his death we lose one who could scarcely have failed to win distinction in the world of science.

H. B. B.

WILLIAM THORP, B.Sc. (Lond.), whose recent death, at the comparatively early age of 53, will be felt as a serious loss to industrial chemistry, was a Londoner by birth and training. In 1857, he entered the City of London School, a school which had already undertaken for some years systematic instruction in Natural Science, and in this respect was a pioneer in scientific education. Under the genial and stimulating influence of the science master of that school, Thomas Hall, B.A., William Thorp was led to interest himself in chemistry, with the view of following it as a profession, and, like many others who came under Hall's influence, Thorp always spoke of his old master and school in terms of devoted affection. In 1864, he proceeded to the fuller study of chemistry and related branches of science at the Royal School of Mines and the Royal College of Chemistry, and was again fortunate in being brought into contact with A. W. Hofmann, who then filled the chair of chemistry. Frankland, who succeeded Hofmann in this chair, appointed Thorp to the position of Assistant Chemist to the Rivers Pollution Commission, on which Frankland was the chemist, and Thorp's important work in this direction only terminated with the conclusion of the Commission's labours in 1877. During his student days in the laboratory of the Royal College of Chemistry, Thorp had associated himself with two active investigators. With one of them, E. T. Chapman, he subsequently published the results of conjoint researches upon the extent to which a boiling alkaline solution of permanganate decomposes various organic sub

With the other, Capel Berger, he prosecuted investigations into the hydrolysis of starch and other carbohydrates at temperatures higher than 100°. The latter investigations were undertaken for industrial purposes and were not published. At the death of Capel Berger in 1872, Thorp was asked by the firm of Lewis Berger and

Co. to continue the chemical work of their deceased partner. When the Rivers Pollution Commission had completed their experimental work, Thorp was appointed chief chemist to this firm, in which he afterwards held the position of director, and latterly the position of consulting chemist. During his active connection with chemical manufacture, Thorp carried out much original work of the greatest value and was considered to be an expert in the chemistry of vermilion and of white lead. As a literary chemist, he worked with Groves in editing the technological volumes on Lighting and Gas-lighting; he also contributed the section of water analysis to Sutton's "Volumetrie Analysis," whilst he rendered constant aid on the publication committee of the Society of Chemical Industry. Of the last-mentioned society he was an invaluable member, and had served as chairman of the London section and as Vice-President of the whole society. An original Fellow of the Institute of Chemistry, he advanced the interests of that Institute by his energetic, tactful, and judicious service on the Council, and, indeed, the councils of various associations of chemists have always placed much value on Thorp's assistance and advice.

William Thorp was elected a Fellow of the Chemical Society in 1866; he contributed to the Transactions and served on the Council of the Society, whilst few have preserved over so long a period a regular attendance at its meetings and have shown so great an interest in its procedure and success.

Those who knew Thorp and had broken through his natural reserve are unanimous in their esteem and affection for him. A man of absolutely unimpeachable honour, a sincere and unwavering friend, an indefatigable worker throughout a life of weak and broken health, one who made it a duty to show courtesy and kindly consideration to all, it is felt by those who knew him best that his loss will indeed be an irreparable one. F. C.

With JOHANN KARL FERDINAND TIEMANN, there passed away, on the 14th of November, 1899, one of those men whose memory will remain fresh with all who had the good fortune to be pupils of A. W. Hofmann during the period of his greatest activity at the University of Berlin.

Dr. Tiemann was born on the 10th of June, 1848, at Rübeland in the Harz. At his father's wish, he became apprentice to a druggist, but left in 1866 in order to study chemistry and pharmacy at the Collegium Carolinum-the present Technical High School-at Brunswick. In 1869, he proceeded to Berlin and entered Hofmann's laboratory. The marvellous influence which the great master exercised over all who came in contact with him was especially ex

perienced by Tiemann. None of his pupils was so long and so intimately associated with Hofmann or appeared more anxious to adopt his characteristic manners and habits. With the exception of one year's absence whilst he served his country as a soldier in the Franco-German war, Tiemann was connected with the laboratory in the Georgenstrasse until Hofmann's death. In his capacity as laboratory assistant for twenty years, he gave instruction in practical chemistry to hundreds of the students who thronged to the school of Berlin from all parts of the world, and who, like the writer of this brief sketch, gratefully remember the valuable help and kind advice they received from him. Hofmann's striking personality and his astonishing faculty for making others work had a most stimulating effect on Tiemann. In 1878, he became a Privatdocent and four years afterwards was made Extraordinary Professor. His lectures on inorganic analysis and on a variety of subjects connected with organic chemistry, gave ample proof of his elocutionary ability and the great delight he took in lecturing. Besides the astonishing activity he displayed in teaching and in scientific investigation, he took for a long period an important part in the work of our sister Society in Berlin, fulfilling the double duties of Editor and Secretary. After holding the former office for fifteen years he resigned it in 1897, but remained Secretary until his death. The ability and tact he displayed during the tenure of these posts will be recognised by everyone who had to deal with him in his official capacity. In connection with the perfume industry, which was largely developed by his discoveries, he had occasion frequently to visit London, and this gave him opportunities of keeping up his acquaintance with English chemists. He became a Fellow of the Chemical Society in 1881.

Tiemann's work, although principally belonging to the field of organic chemistry, which he enriched by many brilliant discoveries, also dealt with chemical analysis. For many years he devoted himself to testing the various chemical methods for the examination of water, with the view of selecting those which allowed of the greatest simplicity in the necessary operations and apparatus, without impairing the accuracy of the results. This comparative study, besides forming the subject of Tiemann's earliest publications in the Berichte, is embodied in the revised edition of Kubel's treatise on water analysis, which he produced in 1874. Fifteen years later, he published, with Gaertner, the large handbook which treated of both the chemical and bacteriological examination of water.

The work, however, which stamped Tiemann as an original investigator of the highest order, as well as making his name known beyond the chemical world, was his synthetical preparation of vanillin. In the important research on coniferin, which he carried out with the assist.

ance of W. Haarmann, he showed that this glucoside yielded, on oxidation, the aromatic principle of vanilla. Tiemann elaborated a method for the quantitative determination of this substance in the bean, established its constitution, and ultimately made the manufacture of vanillin from coniferin possible. The application of Reimer's well-known method for the production of hydroxyaldehydes by the action of chloroform and potash on phenols, whilst affording a method of obtaining vanillin, supplied Tiemann at the same time with experimental material which, with the additional use of Perkin's reaction, led to our extensive knowledge of the whole group of substances related to protocatechuic acid and its isomerides.

The results arrived at by the study of coniferin induced him similarly to investigate other natural glucosides, such as hesperidin, daphnetin, and æsculetin, which he undertook in conjunction with Dr. Will and others. Hand in hand with these researches went the preparation of artificial glucosides by acting on the natural members of this group with acetaldehyde, or acetone in the presence of dilute alkali.

He also carried out a series of experiments upon the nitriles, the results of which formed the subject matter of a large number of doctor-theses for his pupils. This work led to a general method of formation of amido-acids, amidoximes, azoximes, and hydrazoximes.

The researches on glucosides, mentioned above, illustrate the predilection Tiemann had for the investigation of plant products. It was due to the influence of his friend, Prof. E. Baumann, that he also took up the study of substances occurring in the animal organism. They jointly determined, in 1879, the constitution of indoxylsulphuric acid which had been recognised previously by Baumann and Brieger as the indigo-forming constituent of animal urine.

Five years later there followed Tiemann's work on glucosamine, the base obtained by Ledderhose from chitin. Those who at the time worked in Hofmann's laboratory will remember the quantity of earthenware vessels filled with lobster shells which were required in this research for the preparation of glucosamine hydrochloride. Tiemann succeeded in establishing the relation of this base to grape sugar by transforming it into phenylglucosazone. By the action of nitric acid on glucosamine, he obtained isosaccharic acid; he repeatedly studied this acid in order to fix its constitution, and finally concluded that it was to be regarded as an hydrogenised furfuran derivative.

In 1893 there began the series of papers containing Tiemann's masterly researches on the terpenes and camphors which continuously occupied his attention until his death. The starting point of these investigations was the isolation and study of irone, the aromatic principle of the violet root, which was carried out by Tiemann in

conjunction with G. de Laire and P. Krüger, and culminated in the artificial preparation of the valuable perfume ionone. Then came in quick succession his researches on pinene and camphor, which led to the knowledge of a large number of new derivatives, and especially those of the limonene group. Prof. von Baeyer has summed up the importance of Tiemann's researches on this group by his statement that “with this work the chemistry of the limonene group is to be regarded as fully established."

In the above sketch, the writer has attempted as briefly as possible to give an account of Tiemann's scientific life work. His task has been rendered comparatively easy, as he was able to consult the excellent obituary notice of his late friend which Prof. Emil Fischer has recently published in the Berichte.

S. R.

DR. DAVID WATSON was born on July 27th, 1846, in Kensington. He received his chemical education at the College of Chemistry in Oxford Street and at the Royal School of Mines in Jermyn Street, where he took his Associateship in metallurgy and geology in 1867. After obtaining his doctorate at the University of London, he became a teacher of chemistry at Chester College, but subsequently turned his attention to technology, and after holding appointments with Cammell and Co., of Sheffield, and with Sir Lowthian Bell at Washington, he became chemist, and afterwards manager, of the Broughton Copper Works, Manchester. He was elected into the Chemical Society on January 18th, 1872, and at the time of his death, December 15th, 1899, was chairman of the Manchester section of the Society of Chemical Industry.

L-Electrolysis of the Nitrogen Hydrides and of Hydroxylamine.

By EMERIQUE CHARLES SZARVASY, Ph.D.

THE present communication forms part of a comprehensive research I have undertaken in order to examine the behaviour of nitrogen compounds under the influence of the electric current, and therefore only a short account of the experimental facts will be given, leaving general considerations to a future occasion.

The electrolyses of ammonia, hydrazine, azoimide, hydroxylamine, and their salts were carried out at different current densities, tem