110 M. Sch mitt on Cinnamic Acid. 



mover accordingly heated it with iodide of phosphorus, from 

 which he obtained iodide of propyle, agreeing in its properties 

 with ordinary iodide. To free the alcohol from water, it was 

 treated with sodium ; and its boiling-point after this operation 

 was found to be 85°. Berthelot states that the propylic alcohol 

 obtained from propylene boils at 81° to 82°. 



By the action of biniodide of phosphorus, PI 2 , on glycerine, 

 iodide of allyle, C 6 H 5 I, is obtained. Dragendorff recommends* 

 a method for the preparation of this substance, which consists 

 in the simultaneous action of amorphous phosphorus and iodine 

 on concentrated glycerine. Woieikofff, who has investigated 

 this method, using various proportions, has found that the body 

 obtained is not iodide of allyle, C 6 H 5 I, but iodide of propyle, 

 C 6 ' H 7 1. This difference in the results might have arisen from 

 the glycerine used having contained more water; but he found 

 that the same glycerine, when treated with iodide of phosphorus, 

 yielded iodide of allyle with propylene, and not a trace of iodide 

 of propyle. Hence the action of a mixture of iodine and amor- 

 phous phosphorus, in the proportions in which they form bin- 

 iodide of phosphorus, on glycerine is different to that which 

 iodide of phosphorus already formed exercises on the same 

 substance. 



SchmittJ has found that when cinnamic acid is placed in 

 bromine vapour at ordinary temperature, it absorbs an amount 

 of bromine corresponding to 2 equivs. of bromine for 1 equiv. of 

 cinnamic acid. The body thus formed, bibromo cinnamic acid, 

 C 18 H 8 Br 2 4 , dissolves readily in warm alcohol, and crystallizes 

 out in rhombic plates. When heated in a closed vessel, it 

 decomposes with evolution of hydrobromic acid vapours, while 

 an agreeable aromatic odour resembling hyacinths is perceived. 

 The acid is dissolved, but not otherwise changed, by water at ordi- 

 nary temperature; but when heated, the solution becomes tur- 

 bid, and an aromatic odour resembling hyacinths is perceived; 

 on distillation, an oil passes over which possesses this odour in 

 the highest degree. The nature of this oil, which appears to be 

 formed in all decompositions of brominated cinnamic acid, has 

 not been ascertained; but it appears to be a brominated hydro- 

 carbon. 



With baryta, bibromocinnamic acid forms a salt which under 

 the microscope is seen to consist of minute crystals. It has the 

 composition C 18 H 7 BaBr 2 4 . A soda-salt was also prepared 

 of analogous composition. 



* Pharmaceutische Zeitschrlft fur Russland, No. 2, 1862. 



t Zeitschrift fur Chemie, part 3, 1863. 



% Liebig's Annalen, May and September 1863. 



