154 



Prof. J. C. Bose. On the Continuity of [Apr. 18, 



Dhurrin crystallises well, and is soluble in both water and alcohol. 

 When hydrolysed by emulsin or by dilute acids it is converted 

 into parahydroxybenzaldehyde, dextrose, and hydrocyanic acid accord- 

 ing to the equation Ci 4 H l7 O r N + H 2 = C 7 H 6 2 + C 6 Hi 2 6 + HCN. 

 When warmed with alkalis, dhurrin is resolved first into dhurrinic 

 acid and ammonia This acid subsequently undergoes further hydro- 

 lysis when warmed with dilute hydrochloric acid, being converted into 

 parahydroxymandelic acid and dextrose (1) C14H17O7N + H 2 = 

 € 14 H 18 9 + NH 3 , (2) C 14 H 1S 9 + H 2 = C 8 H s 4 + CeHxoO,. 



The identity of the parahydroxymandelic acid was established by 

 its synthesis from the cyanhydrin of parahydroxybenzaldehyde. 



Dhurrin differs from the other two known cyanogenetic glucosides, 

 the amygdalin of bitter almonds and the lotusin found by the authors 

 in Lotus arabicus, in being derived from dextrose and not from maltose. 



The authors point out the protective purpose served by the exist- 

 ence of the cyanogenetic glucoside in the young plant. 



The authors intend to fully investigate the several problems which 

 are raised by the occurrence of cyanogenetic glucosides in plants. 



They are at present engaged in examining several other plants 

 which have furnished prussic acid, among them being Manihot utilis- 

 sima, Linum usitatissimum, Lotus australis, and Phaseolus lunatus. 



" On the Continuity of Effect of Light and Electric Eadiation on 

 Matter." By Jagadis Chundee Bosk Communicated by 

 Lord Eayleigh, F.RS. Beceived April 18, — Bead June 20, 

 1901. 



Introduction. 



Though the theory of coherence gives a simple explanation of many 

 cases of diminution of resistance in a mass of metallic particles under 

 electric radiation, yet there are other cases which are not explicable 

 by that theory. If coherence be due to electric welding, it would 

 follow that all sensitive particles would exhibit a permanent diminu- 

 tion of resistance ; in other words, the action should be non-discrimi- 

 native and there should be no self-recovery. In my previous paper,* 

 however, I have shown that the effect of radiation is by no means non- 

 discriminative. To the contrary, while its effect on the positive class of 

 substances, e.g., Mg.Fe.Ni, is a diminution of resistance, it acts on the 

 negative class, e.g., K.Ag'.Br.I, in a precisely opposite way, that is to 

 say, it produces in these an increase of resistance. Further, the conduc- 



* " On Electric Touch and Molecular Changes produced in Matter by Electric 

 Waves," ' Roy. Soc. Proc.,' vol. 66. 



