146 



Drs. Dunstan, Henry, and Auld. [Apr. 11, 



abandon this idea, and he suggested that the acetone might occur in the form 

 of a glucoside. 



Quite recently Van Itallie has observed* that the leaves of Thalictrum 

 aquilegifolium yield acetone and hydrocyanic acid under similar conditions, 

 and he has suggested that this plant may contain the glucoside phaseo- 

 lunatin which we had isolated previously from the seeds of Phaseolus lunatus. 



A systematic investigation of these various plants is being made, as a part 

 of the general work on cyanogenesis we have undertaken, with a view to 

 ascertaining definitely whether they contain phaseolunatin, and in the present 

 and succeeding papers two cases are dealt with, namely, the " flax " and 

 " cassava " plants. The seeds of the Para rubber tree are at present under 

 investigation, and the examination of the other plants mentioned will be 

 commenced as soon as material, which is rather difficult to procure, becomes 

 available. 



Cyanogenesis in flax was first observed by Jorissen,f who stated (1) that, 

 when linseed meal (ground flax seed) is allowed to stand with warm water 

 at 25° C, hydrocyanic acid is produced, and may be obtained by distillation 

 of the mixture, and (2) that the acid does not exist preformed in the seed, 

 since the latter does not yield it when placed in boiling water. This author 

 suggested that flax seed probably contains a substance on which emulsin 

 acts in the same way as on amygdalin, and further noted that linseed meal 

 has the property of decomposing amygdalin, liberating benzaldehyde, hydro- 

 cyanic acid, and dextrose. In subsequent papers, Jorissen stated that both 

 Linum usitatissimum and Linum perenne contain amygdalin in the leaves 

 and stems, and that, in the case of the former, a notable increase in the 

 amount of hydrocyanic acid obtainable takes place on germination of the 

 seed. Thus, whereas a portion of one sample of flax seed yielded - 01 per 

 cent, of the acid, another portion of the same sample, after germination, 

 yielded 07 per cent, j 



Subsequently, Jorissen and Hairs§ succeeded in isolating the cyanogenetic 

 glucoside of flax in a crystalline condition. They named it " linamarin," and 

 described it as crystallising in groups of colourless needles, melting at 134° C, 

 having a cool and bitter taste, and being readily soluble in water. 



They assigned no formula to linamarin, but stated that, on combustion, it 

 gave the following results : carbon, 47'88 per cent. ; hydrogen, 6 - 68 per cent. ; 

 oxygen, 39 - 89 per cent.; and nitrogen, 5 - 55 percent.; and that, on hydro- 



* ' Journ. Pharra. Chim.,' 1905, vol. 6, pp. 22, 337. 

 t ' Bull. Acad. Boy. Belg.,' 1883 (iii), vol. 5, p. 750. 

 % Loc. cit., 1884 (iii), vol. 6, p. 718, and vol. 7, p. 736. 

 § Loc. cit., 1891 (iii), vol. 21, p. 529. 



