Bildersaal deutscher Geschichte

Bär, Adolf; Quensel, Paul

Bibliografische Daten

Monografie

Persistenter Identifier:: 1646837127308

Titel:: Bildersaal deutscher Geschichte

Untertitel:: zwei Jahrtausende deutschen Lebens in Bild und Wort

Autor:: Quensel, Paul

Herausgeber:: Bär, Adolf

Verleger/Verlag:: Union Deutsche Verlagsgesellschaft

Erscheinungsort:: Berlin

Erscheinungsjahr:: 1902

Umfang:: XII, 400 Seiten, 48 Tafeln

Sprache:: deutsch

Strukturtyp:: Monografie

Standort:: Bibliothek des Historischen Instituts, Universität Stuttgart

Signatur:: Ae 95 sekr

Lizenz:: https://creativecommons.org/publicdomain/mark/1.0/deed.de

Kapitel

Titel:: Im neuen Reich

Strukturtyp:: Kapitel

Kapitel

Titel:: Im neuen Reich

Strukturtyp:: Kapitel

CTueas Nowe} Direct Production of Phenol from Benzene. 229 » Attached to the vessel containing this mixture was a wash- bottle charged with cold water, in order to condense, so far as practicable, such substances as might be volatilised in the oxidiser and carried over in the air-current. From time to time further quantities of benzene and turpentine were placed in the oxidiser. As the oxygen was absorbed the oil-mixtute became dark yellow in colour and increased in density: the aqueous solution also became coloured. It was proved by actual determinations, which were made from day to day, that the presence of the benzene did not interfere with the production of the peroxide of hydrogen.* Thus, on the seventh day, 5 c.c. of the aqueous solution contained HO, equal to 12 c.c. N/ro Na,S,0; solution, and the oxidised oil-mixture was proved to contain a large amount of that organic peroxide which by conta& with water gives rise to the peroxide of hydrogen. On the third and seventh days the aqueous solutions contained in (both) the oxidiser and the wash-bottle were examined for phenol, which substance was not found pre- sent. An addition of excess of bromine water caused the liberation of oxygen gas, but yielded no precipitate of tri- hromo-phenol, nor did the solution give any of the other reactions characteristic of phenol. On the seventh day the oil-mixture itself was tested for phenol, by agitating a part of it with caustic soda, sepa- ation of the alkaline extra&, neutralisation of this with lilute sulphuric acid,’and examination of the solution thus obtained. Phenol was not found present. After the seventh day, more benzene and turpentine wera added to the oxidised oil-mixture, and the temperature raised to 100° C., a reflux condenser being attached to the oxidiser, The air-current was then kept up for several days, after which, however, the aqueous solution still contained some peroxide of hydrogen (100 c.c. = 10 c.c. N/10 thio-sulphate), but apparently no phenol.. The oxidised oil was now of a very dark yellow colour and quite thick, The bulk of the aqueous solution was rendered strongly alkaline by dis- solving caustic potash therein, and this solution was then well agitated with the oil-mixture. This treatment caused the whole mass to become almost black by the dire¢t ab- orption of oxygen from the air, strongly reminding the observer of the behaviour of pyrogallic acid, After a shor time the alkaline lye was separated from the oil, and neu- tralised with dilute hydrochloric acid, filtered from a little :arry matter, and the resulting solution carefully examined for phenol and pyrogallic acid. 1. Treated with a great excess of bromine water it be- came milky, and in course of time deposited a slight amount of yellowish substance. This deposit presented charadters distin® from those of tribromo-phenol, but almost identical with those of the similar or identical sub- stance which is precipitated from an aqueous solution of thymol on addition of bromine water, It was readily soluble in absolute alcohol and in ether, and was re- precipitated from the alcoholic solution on the addition of much water. . 2. With ammonia and calcic hypochlorite the produced reaction was not that of phenol, but resembled that given by a dilute solution of pyrogallic acid examined con- currently. 2%. 2 3. With ferrous sulphate it developed a greenish blue colour, like that which can be obtained by adding dilute acid to the pyrogallic blue obtained side by side. 4. With ferric chloride the solution was coloured reddish brown. 5. On addition of excess of caustic soda it darkened very much, and oxygen was absorbed from the air. 6. It reduced potassic permanganate just as acid pyro- gallic solutions do. Experiment B was pradically a repetition of the first ex- periment, and identical results were obtained. On this occasion it was observed that the substance which gives the slight precipitate with bromine water is lost—presumably by volatilisation—if the faintly alkaline * Journ. Chem. Soc, vol. xiii, ps 210, and CHEMICAL NEWS, vol. X%xii., p» 138. THE CHEMICAL NEWS. ON THE OCCURRENCE OF SELENIUM AND TELLURIUM IN JAPAN.” By Professor EDWARD DIVERS, M.D. Ar the Sulphuric Acid Works of the Imperial Japanese Mint, and at a private works, both in Osaka, the sulphur now employed comes from different parts of Japan, Kagoshima, Oita, Hokkaido, &c.. In some of the sul phuric acid made there I have found not inconsiderable quantities of selenium, and Mr. M, Shimosé, one of my pupils, has also found more than traces of tellurium. Arsenic is also present in quantity. A fcrmer pupil of mine, Mr. Nakagawa, now a chemical engineer in the Imperial Mint, states that the flue deposits of the sulphur burners is rich in selenium. 1 had hoped to have obtained by this time fuller parti- culars, but have been disappointed by not receiving in time supplies of acid and flue dust. 1 must therefore limit my communication to the announcement of the presence of these two elements in Japanese sulphuric acid, and of the probable occurrence or material quantities of selenium in Japan. A further communication will be published when particulars have been ascertained. AT a meeting of the New York Academy of Sciences on March 14ta of this year, Dr. A. R. Leeds, of the Stevens Institute of Technology, made a communication? relating chiefly to peroxide of hydrogen, ozone, and benzene. Among other matters of interest therein referred to, he describes an experiment wherein 20 c.c. of benzene had been digested with 300 c.c. of a slightly acidulated 1°2 per cent solution of hydrogen peroxide during some days and under certain conditions as to temperature, &c.:—* At the end of this time the liquid had become yellow; and was found to contain, beside the colouring matter, oxalic acid and phenol.” Benzene does not absorb oxygen when ex- posed to the air in sunlight or otherwise, and therefore it is unlike the terpenes and certain other classes of hydro- carbons in this respect. This observation was recorded by the writer some years ago,} and Dr. Leeds confirms it in his paper. After reading Dr. Leeds’s communication it occurred to me that it would be interesting to ascertain if phenol is produced by placing benzene in prolonged conta with air, water, and a hydrocarbon known to give rise to the formation of peroxide of hydrogen by aérial oxidation in the presence of water. Accordingly, I have condué&ed some few experiments to determine this question, and although the obtained results are chiefly negative in charader, the matter is of sufficient interest to justify a brief description. Experiment A.—100 c.c.benzene were mixed with roo c.c, of Russian turpentine; 100 c.c. of water were added, and the mixture was maintained at 60° C. during some six 01 seven days, and exposed meanwhile to a current of air * Read before the Briitsh Association, York Meeting, Section B. | See CueMrcaL News, vol. xliv,, p. 210. t Fourn. Chem, Soc., 1874, D. 513.

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