904 Hydrocyanic Acid from Linseed Cake, [feb., 



which are not very subject to disease. But should Phyto- 

 phora infestans be very prevalent, either Royal Kidney or 

 King Edward may be preferred before it. The quality of 

 these last two is much inferior to that of the British Queen. 



Late Varieties. — The ideal potato is yet to be found, 

 though there is a large list of varieties to be had. At 

 present none of them combine the three necessary factors 

 which make an ideal potato. These factors are quality, 

 quantity, and disease resistance. Any two of these can be 

 correlated, but not at present all three. 



The Up-to-Date type (Group I.) stands out as the best 

 cropper, coupled with fair to good quality, but lacks the 

 immunity to disease. 



The Maincrop types (Group V.) are suitable for rich soils 

 in districts affected with disease, as they are practically 

 immune, and are of the best quality possible, but these 

 again are lacking in yielding power, 



The Northern Star (a type by itself) combines the features 

 of heavy cropping powers with comparative resistance to 

 disease, but in this case the quality is somewhat deficient, 

 and it grows too large a proportion of small potatoes. 



The grower must, therefore, decide which one of the three 

 characters (which go to make "the perfect potato") he can 

 afford best to dispense with in his own district and for his 

 own requirements. 



The figures given above relating to the weight of the crop 

 of different varieties represent in all cases the yield per acre. 



THE FORMATION OF HYDROCYANIC ACID 

 FROM LINSEED CAKE. 



G. D. Lander, D.Sc, F.I.C., 



Royal Veterinary College, London. 



The occurrence of cyanogenetic glucosides in linseed has 

 been long known, and the work of Dunstan and Henry 

 (Proc. Roy. Soc., B. 78, 1906, 145) established the identity 

 of this substance with phaseolunatin, the glucoside of Java 

 beans. The linseed contains the same enzyme, capable of 

 resolving the glucoside, which is also chemically resolved by 

 10 per cent, hydrochloric acid. 



Regarding the occurrence in linseed cakes ? the same 



