Comparative Study of Chlorophyll. 419 



Pringsheims Method of Preparing Hypochlorin* 



Pringsheim's method for the separation of the colouring- 

 matter of chloroplasts from the ground-substance consists in 

 warming green tissue for fifteen minutes to an hour in water 

 heated up to 50°— 80° C, or by exposing the tissue to steam of 

 boiling water from fifteen minutes to several hours, when 

 variously-coloured drops exude (the commonest colours are 

 shades of green up to olive-green; rarer are blue-green, 

 yellow, or reddish-brown). These are of an oily nature, 

 and keep the colouring-matters in solution ; they are soluble 

 in alcohol and ether. When the exudation is completed 

 the ground-substance of the chloroplasts shows up as a 

 hollow sponge-like ball, and the oil is believed to have been 

 contained in the meshes of this hollow ball. 



Exposure to intense light has the same effect, for by 

 bleaching the colouring-matter the ground-substance is re- 

 vealed, and shows the hollow spongy nature of it. 



The exuded drops the author calls " Hypochlorin." 



Sachsse's Method of preparing Chlorophyll.^ 



Sixty kilogrammes of Primula elatior and the same quan- 

 tity of Allium ursinum are boiled in water, well pressed to 

 get rid of the water, extracted with 44 litres of boiling 90 

 per cent, alcohol to each 60 kilogrammes of raw material, 

 then the material pressed again to get rid of the alcohol, and 

 twice boiled in so-called " light " benzin (07 sp. gr.) After 

 each boiling the material is pressed, and the benzin extracts, 

 after filtering, are added to the alcoholic extract, when the 

 benzin will take up most of the green colour, leaving the 

 yellow colour to the alcohol. 



After several days' standing the benzin solution is decanted, 

 bottled, and treated with pieces of sodium. 



After eight to fourteen days the benzin solution becomes 

 cloudy, and ultimately a precipitate is thrown down. The 

 process is completed when the benzin has assumed a pure 

 golden-yellow colour, and when it does not show even in 

 very thick layers the characteristic band of chlorophyll 

 between the lines B and C. 



* LicMwirkung Chlorophyllf unction in dcr Pflanzc, Leipzig, 1881. 

 t Phytochcmischc Untersuchungcn, Dr Kobert Sachsse (Leipzig, Verlag von 

 Leopold Voss, 1880). 



