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HYDROCYANIC ACID IN PLANTS. 



Partu. Its Occurrence in the Grasses of New South Wales. 



By James M. Petrie, D.Sc, F.I.C., Linnean Macleay Fellow 

 of the Society in Biochemistry. 



(From the Physiological Laboratory of the University of Sydney.) 



The systematic examination of Grasses for cyanogen compounds 

 was the direct outcome of tests made to ascertain the cause of the 

 sudden fatalities among stock, which took place in this State 

 about two years ago. The sheep apparently had eaten nothing 

 besides grass, and this- grass when tested was found to contain a 

 cyanogenetic glucoside and the corresponding enzyme. 



It was conceived, that at least some of the frequent deaths from 

 unknown causes, and which are often attributed to supposed 

 poisonous plants, might possibly be due to such grasses. 



Reference to the literature on this subject shows that hydro- 

 cyanic acid in grasses, was first discovered by Jorissen, in 1884, in 

 Poa aquatica Linn., and this was followed by its detection in the 

 sorghums, in 1902 (Dunstan and Henry). Up to the present, all 

 the cyanophoric grasses recorded are included in about 14 genera, 

 and are given in Table i. 



Some of these exotic grasses have been naturalised in this coun- 

 try, and among them Briza minor, Lamarckia aurea, and Poa pra- 

 tensis, are recorded by Couperot, as yielding hydrocyanic acid, 

 when tested by him. ( Journ. Pharm. Chim., 1908, 28, 542) . 



These three grasses growing in this State, have been examined 

 at various seasons, and have never given positive results, neither 

 did they contain any trace of an enzyme capable of decomposing 

 amygdalin. I 



