470 Physiologie. 



le Saccharose dans un tres grand nombre d'organes provenant 

 de vegetaux divers. Comme il existe plusieurs Polysaccharides 

 hydrolyses par l'invertine, il faut toujours verifier au polari- 

 metre si les changements optiques qui se sont produits sont 

 identiques ä ceux que donnera le calcul, en admettant que 

 tout le sucre reducteur forme est ä Petat de sucre interverti. 

 Alors seulement, on peut conclure en toute certitude ä la pre- 

 sence du sucre de canne. 



On a opere sur des organes renfermant: 1. de l'amidon 

 (racines de Tamier et de Pivoine, bulbe de colchique, lentille), 

 2. de l'amyloide (graines de Pivoine et de capucine), 3. de 

 l'inuline (tubercules de topinambour), 4. des mannanes et des 

 dextromannanes, 5. des mannogalactanes, 6. des matieres 

 grasses, etc. 



Dans tous les cas, sauf deux (Selaginella denticulata et 

 Fucus serratiis) le ferment a determine la formation de sucres 

 reducteurs. Dans la grande majorite des cas, ces sucres pro- 

 venaient de Saccharose. Le Saccharose est un des composes 

 les plus repandus des plantes ä chlorophylle ; il est meme plus 

 repandu que le glucose. Jean Friedel. 



BrÜNNICH, J. C, Hydrocyanic Acid in Fodder Plant s. 

 (Journ. of Chem. Soc. No. 448. p. 788—796.) 



Dunstan and Henry have shown that a glucoside 

 „dhurrin", which on treatment with water yields free hydrocyanic 

 acid occurs in young plants of Sorghum. This accounts for 

 the occasional sudden death of cattle after eating Sorghum. 

 The author shows that the amount of hydrocyanic acid rapidly 

 diminishes as the crop matures, but it is impossible to give 

 a general statement as to the age at which the crop becomes 

 quite safe for use as fodder, this depending on the individual 

 animals and also on the conditions under which the crop was 

 grown. It may however be safely stated that as soon as the 

 seeds are ripe the amount of hydrocyanic acid is so much dimi- 

 nished as to be innocuous. Sun-drying will not eliminate the 

 danger. High nitrogenous manuring increases the amount of 

 poisonous glucosides. 



Maize contains a small amount of dhurrin, which increases 

 rapidly as soon as the inflorescences begin to form, but the 

 actual quantity does not become dangerous under ordinary 

 circumstances. 



Dhurrin was also found in Panlcum maximum and P. mu- 

 ticum, but none was detected in Sugar-Cane, Paspalum 

 dilatatum, or Cynodon dactylon. E. Drabble (London). 



DOJARENKO, A., Einiges zur Loew 's Hypothese über die 

 Rolle des Kalks im Boden. (Journ. für experimentelle 

 Landvvirthschaft. 1903. p. 183 — 187. Russisch mit deutschem 

 Resume.) 



