1906.] 



Cyanogenesis in Plants. 



151 



by Joiissen and Hairs to the cyanogenetic glucoside of flax should be 

 retained. 



Other Constituents of Flax. 



It has already been mentioned that a considerable amount of potassium 

 nitrate was found to have accumulated in the purified extract from which the 

 flax glucoside eventually crystallised. 



This occurrence of potassium nitrate with the cyanogenetic glucoside in 

 flax is of some significance, since Treub* has pointed out that the accumulation 

 of potassium nitrate in the stems and petioles of Phaseolus lunatus has an 

 intimate connection with the secretion of phaseolunatin by that plant, and 

 has suggested that this store of nitrate may be the raw material from which 

 the cyanogenetic glucoside in this plant is eventually produced. 



From one of the purified extracts, obtained from flax 12 inches high, 

 grown in Ireland, a small quantity of a sugar crystallising in characteristic, 

 cauliflower-like masses separated after the extract had stood for some time. 

 It melted at 78° to 80° after recrystallisation from alcohol, did not reduce 

 Fehling's solution, and was slightly dextrorotatory. When an aqueous 

 solution was boiled with mineral acids a reducing sugar was produced. 

 These observations seem to indicate that this material may be identical with 

 raffinose (melting point 80° C), but a sufficient quantity of the sugar could 

 not be obtained for complete examination. 



The Enzyme of Flax. 



Preparations of this were made by macerating finely-ground flax seed 

 (linseed) with water, previously saturated with chloroform to render the 

 liquid antiseptic. This extract was found to have a range of activities 

 similar to that of the emulsin of almonds, and it readily hydrolysed amygdalin 

 and salicin. When added to an aqueous solution of the purified flax 

 extract, prepared as already described, it speedily hydrolysed the contained 

 phaseolunatin, yielding acetone and hydrocyanic acid, which were identified 

 in the usual way. 



Preparations of the enzyme were also found to hydrolyse phaseolunatin 

 prepared from the seeds of wild Phaseolus lunatics and, vice versd, preparations 

 of the glucosidolytic enzyme contained in seeds of Phaseolus lunatus were 

 found to hydrolyse the phaseolunatin obtained from flax seed, the volatile 

 hydrolytic products being in both cases the same, viz., acetone and hydro- 

 cyanic acid. 



It seems probable, therefore, that the same enzyme is contained both 

 * ' Ann. Jard. Bot. de Buitenzorg,' 1905, vol. 2, 4, p. 86. 



