— 140 — 



molecules. But as regards this property, analogous behaviour has 

 been observed in other cases, for instance in that of benzoic acid. 

 In fact, the ability of giving double molecular reactions appears to be 

 more frequent generally than could have been expected up to the 

 present. Erlenmeyer attributes the isomerism observed in the 

 cinnamic acids to the power possessed by the benzene nucleus of 

 existing in several more or less stable conditions which, in the case 

 of the cinnamic acids, are distinguished by special stability. Thus it 

 was possible to obtain the benzaldehydes corresponding to the two 

 cinnamic acids; but particulars as to this part of the investigations 

 are deferred to a subsequent communication^ 



Shortly before the appearance of the above-mentioned work of 

 Erlenmeyer, a paper by E. Biilmann 1 ) had appeared, which seemed 

 to give a surprisingly simple solution of the problems of isomerism 

 which exist in the chemistry of cinnamic acids. In this paper no 

 speculations with regard to new varieties of isomerism were propounded. 

 In Biilmann's opinion, allo-cinnamic acid (m. p. 68°) and the two iso- 

 cinnamic acids with respective melting points of about 57 and 38 

 to 4 6°, are not isomeric, but are chemically identical bodies, in which 

 the only question at issue is one of simple trimorphy. Provided certain 

 exceptional measures of precaution were observed, each of the three 

 acids could be converted quantitatively in the time of a few seconds 

 into any of the others, by melting it and inoculating the molten 

 substance, when cooled, with the desired variety. Thus a plausible 

 explanation might be found for the origination of the separate forms. 

 But Erlenmeyer 2 ) points out that Biilmann's observations are 

 not quite sufficient to disprove the theory that the three cinnamic 

 acids present exceedingly labile, mutually inter-convertible isomers. 

 The assumption of simple polymorphy would not be consonant with 

 several of the facts observed, and further investigations are therefore 

 considered necessary before a definite opinion can be formed. 



Nitrogenous Bodies. 



From a paper by F. Weehuizen 3 ) we abstract the following data, 

 referring to the detection of indol in flowers. If the available quant- 

 ity of flowers is large enough to admit of the preparation of essential 

 oil, the presence of indol may be proved by means of the crystalline 

 combinations which it gives with sodium bisulphite and picric acid. 

 In other cases the method given by Verschaffelt 4 ) may be applied, 



1 ) Ibidem 513. 



2 ) Ibidem 521. 



3 ) Pharm. Weekblad 45 (1908), 1325. From a copy kindly sent to us. 



4 ) Report October 1905, 123 



