Rosenstiehl

Caro, Rosenstiehl, Schorlemmer, Hantzsch, Nietski.—A few other chemists whose names belong in any list of those who have developed the aniline dye industry may also be mentioned. The first three were concerned principally with the dyestuff industry, while the last two developed theories in regard to the relationship between constitution and color in dye compounds. 

The composition of iodine green was determined by Hofmann and Girard in 1869 [21] and Rosenstiehl demonstrated the existence of several rosanilines [22]. 

By heating with hydriodic acid in a sealed tube it splits up into aniline and paratoluidine. Pararosaniline was discovered by Rosenstiehl [16], and its constitution determined by E. and O. Fischer [13]. The above constitutional formula is deduced fron> the following facts —... 

Nitrobenzene appears to take no part in the formation of ros-aniline, and simply acts as oxidant being converted to dyestuffs of the indnline class. When nitrobenzene is replaced by chlor-nitrobenzene, rosaniline is produced, and not, as might be expected, a chloro-derivative. Dyestuffs of the rosaniline series are formed by oxidation of numerous bases in presence of aniline and parato-luidine. Rosenstiehl and Gerber divide the homologues of aniline into three classes, according to their behaviour on oxidation with arsenic acid. 

Muspratt and Hofmann reduced nitrobenzene to aniline by Zinin s method, and nitrotoluene to toluidine, mentioning that aniline cannot be nitrated but nitraniline can be obtained by reducing dinitrobenzene, a reaction later described in detail. Hofmann s paper on the chloro- and bromo-derivatives of aniline has a note by Liebig certifying the accuracy of the work. Hofmann and Muspratt s toluidine was a mixture of ortho- and para-toluidine. Pure orthotoluidine was first obtained by A. Rosenstiehl, metatoluidine by Beilstein and A. Kuhlberg, and paratoluidine by Hofmann. ... 

As early as October 1875 the Alsatian chemist Daniel-Auguste Rosenstiehl had started his own investigation on this subject. He reported his results on 27 October 1875 and 29 March 1876 to the Societe industrielle de Mulhouse, but could not establish a production process that brought all the chemicals together in solution, a necessary precondition for industrial manufacture. Caro probably knew of Rosenstiehl s work, although he never admitted it, and eventually succeeded in inventing a wet-process manufacturing procedure after extensive trials with several nitration methods and solvents. Ironically he filed a pli cachete for this reaction with the Societe industrielle de Mulhouse on 22 March 1876, shortly before Rosenstiehl published his second contribution on this subject in the journal of the society. 

Meanwhile Caro and three assistants developed manufacturing processes for the production of the alizarin orange. In May 1877 Rosenstiehl left the further development work to Caro. The dye was not a big seller, but would later gain... 

D.A. Rosenstiehl, L Alizarin nitree , Annalesde chimie et de physique (5. Sen), 12 (1877), 519-529. For a biography of this Alsatian chemist see the contribution of Anne-Claire Dere in this volume. 

Letter from Rosenstiehl to Caro, Mulhouse, 2 May 1877. SSDM, without signature, in N 93-007. 

It is not my intention here to write or rewrite the history of synthetic dyes in the latter half of the nineteenth century/ Numerous historians have already done so in such great detail that it is hard to think of anything new to say/ Likewise the special role played by Alsace in this history has been extremely well documented/ The aim of this article therefore is a fairly modest one. The person we examined in 1994 for the purpose of compiling a biographical dictionary is in fact very little known.While Daniel August Rosenstiehl sometimes received credit as the chemist who solved the mystery of what we now call toluidine... 

C. Fontanon and A. Grelon eds., Les professeurs du Conservatoire national des arts et metiers - Dictionnaire biographique 1794-1955, 2 vols. (Paris, 1994). On Rosenstiehl, see also the obituary by Albin Haller in Bulletin de la Societe Chimique de France [4] 21 (1917), i-xxiv. 

Charles Lauth advocated the provision of a new type of training for scientists required by the science-based chemical industry. In contrast to Germany, a considerable amount of prejudice would had to be overcome in France. In this case Eminent scientist, chemist, and physicist all at one, A. Rosenstiehl was not unfaithful to his ideals when he placed his science at the service of industry . Ch. Lauth, Rapport sur les produits chimiques et pharmaceutiques, exposition nationale de 1878, group V, class 47, (Paris, 1881), quoted by Leprier and Papon, op.cit. (2), p. 219. 

The discovery of mauve by Perkin dates back in fact to 1856, while Rosenstiehl s first publication appeared in 1858. 

That I write in some detail on Alsace is mainly because Daniel Auguste Rosenstiehl was bom in Strasbourg in 1839, and the early part of his career (1865-1877) was spent in Mulhouse. It was also as an Alsatian that the Paris municipal authorities appointed him, in 1905, to the chair of tinctorial chemistry which they had recently created at the CNAM. Likewise, back in 1882, they had placed Paul Schiitzenberger - also a native of Strasbourg and professor at the Mulhouse school of chemistry - in charge of the EPCI in Paris. 

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