Physiologie. 517 



In the extraction of Chlorophyll as little water as possible should 

 be used, and the Operation should be conducted in darkness or in 

 subdued light, with but little exposure to air, as light and air cause 

 oxidation of formaldehyde.and the resulting acid brings about changes 

 in the separated colouring matters. 



No living green tissue of any kind was found to be capable of 

 transmitting the ultra-violet rays. 



According to the author the Chlorophyll appears to act as a 

 ray-filter and as an absorbent of radiant energy. The active sub- 

 stance or a group of substances in the living leaf shows powerful 

 absorption bands in the red, but none appreciably in the green and 

 the spectrum ends in the bluish green. The bands which may appear 

 in the yellow and green are due to abnormal chemical action such 

 as oxidation. It is claimed that the colouring matters from dry leaves 

 have been extracted in an apparently unchanged condition so far as 

 spectoscopic examination shows. E. Drabble (Liverpool). 



ITALLIE, L. VAN, ThaUctriitn aqnilegifoliiim, eine Blausäure 

 liefernde Pflanze. (Arch. Pharm. Bd. CCXLIII. 1905. p. 553 

 —554.) 



Wie Guignard, so gewann auch Verf. aus den Blättern von 

 Sambuciis nigra Blausäure, 100 gr. frischer Blätter lieferten 8,3 mg, 

 solche von Sambuciis nigra var. laciniata 1,1 mg.; im Destillat von 

 «S. £'6///KS-Biättern fehlte Blausäure. Reichlich fand sie sich aber 

 bei Tkalictriim aqnilegifoliiim, 100 gr. zerquetschte und destillierte 

 Blätter lieferten 50,2 bis 60 mg. Cyanwasserstoff, die frischen 

 Stengel kaum ^/lo davon, die Wurzeln aber keine Spur; die Säure ist 

 als Glykosid vorhanden, das vielleicht mit dem von Dunstan und 

 Henry aus Phaseolns ///««/«s erhaltenen Phaseolunatin identisch ist, 

 denn bei der Spaltung entsteht neben Blausäure kein Benzaldehyd, 

 sondern Aceton. Das vorhandene Enzym vermag auch Amygdalin zu 

 -Spalten. Wehmer (Hannover). 



Miller, N. H. T., TheamountsofNitrogenas ammoniaand 

 as nitric acid, and of chlorine in the rain-water col- 

 lected at Rothamsted. (Journal of Agricultural Science. 

 Vol. I. 1905. p. 280—303.) 



Analyses of rain water at Rothamsted for the years 1888—89 

 to 1900 — Ol show that the average amount of nitrogen in the forms 

 of ammonia, and nitric (and nitrous) acid is 3,84 Ib. pro acre per annum. 

 The extremes for particular years were 4,43 Ib. and 3,31 Ib.. The 

 variations dont appear to depend on the total amount of the rainfall. 



The amount of nitric nitrogen was found to be approximately 

 uniform during summer and v.'inter, but in the summer the proportion 

 of ammoniacal nitrogen was higher. 



Comparison is made between the composition of rain at 

 Rothamsted and other places in temperate and tropical regions. 

 The results are very confiicting but „the one conclusion which may 

 safely be drawn is that tropical rain does not supply to the soil 

 an essentially greater amount of nitrogen than the rain of temperate 

 climates". 



The sulphuric acid and chlorine constituents are also discussed. 



The paper has a very copious bibliography, from the earliest 

 records of Marggraf 1761, onwards. W. G. Freeman. 



