418 Mr Gustav Mann on the 



Thus we get the yellow colour in petrol ether and the 

 green colour in alcoholic ether. The yellow colour crystal- 

 lises in dark yellow needles out of the petrol ether, or after 

 this has been evaporated and the residue treated with 

 absolute alcohol out of the latter. 



The green colour crystallises in sph?ero-crystals, and to 

 get it pure we proceed thus : — 



1. Filter the dark green ethereal solution. 



2. After twenty-four hours repeat the process. 



3. Eemove all traces of yellow colour with petrol ether, 



after having evaporated the ethereal solution to 

 dryness, 

 4 Eedissolve and crystallise out of an alcoholic ethereal 

 solution. 

 The sphaero-crystals the author calls " chlorophyll-green." 



Hoppe-Seylers Method of jircparing Chlorophyllan 

 Crystals* 



1. Grass is washed three or four times with ether to 

 remove the waxy covering of the leaves. 



2. The leaves are then treated with boiling absolute 

 alcohol, which extracts the green colour. 



3. The green alcoholic extract is evaporated by heating it 

 at a low temperature. The resulting residue is washed in 

 cold water and redissolved in ether. 



4. The ethereal solution is slowly evaporated in loosely- 

 covered glass vessels, and thus are got : — 



0. Granular crystals, brown with transmitted, dark green 

 on reflected light. These crystals are purified by recrystal- 

 lisation, and are called " Chlorophyllan" crystals. 



A. Meyer's Method of preparing Chlorophyllan.^ 



Since chlorophyllan is readily soluble in hot glacial acetic 

 acid, A. Meyer proceeds thus : — 



Treat the leaves directly with hot glacial acetic acid, 

 filter the extract, evaporate it, extract the residue with 

 alcohol, and let the chlorophyllan crystallise out. 



* Zeitschriftf. Physiologische Chemie, iii. 339, iv. 193, v. 75. 

 + Arthur Meyer says [Das Choloroiihyllkorn, Leipzig, 1883) Pringsheim's 

 liypoclilorin is identical with Hoppe-Seyler's chlorophyllan. 



