1914] Clarence J. West 233 



Chlorophyll with a purity of about 95 percent, so-called " roh- 

 chlorophyll," is more easily obtained as follows : 2 kilos of meal are 

 extracted (as above) with 6 liters of 78 percent acetone for 30-40 

 minutes, giving 4 liters of extract. This is diluted with one-fourth 

 to one-half of its volume with 80 percent acetone, and the Chloro- 

 phyll precipitated by the gradual addition of 1.2 liter of water. 

 The Suspension is shaken with 300 to 400 gm. of talc, filtered, 

 washed with 2 or 3 Hters of 65 percent acetone, the Chlorophyll ex- 

 tracted with ether, the ether evaporated to a syrupy consistency and 

 mixed with 1.5 to 2 liters of petroleum ether. The yield is from 

 12 to 14 gm., and the purity about 95 percent, as mentioned above. 



The preparation from fresh leaves is practically the same as 

 given above, except that pure acetone is used for the extraction, the 

 water content of the leaves diluting it to such an extent that two 

 extractions remove practically all the Chlorophyll. 



Properties of Chlorophyll.^^ Pure Chlorophyll conforms to 

 the f ollowing Standards : 



1. The ash content is 4.5 percent; the ash is pure magnesium 

 oxide. (The Statements of Stoklasa concerning the phosphorus 

 and potassium content of the ash are not correct.) 



2. The phytol content of the Chlorophyll is one third of the 

 molecule; the phytol is free from solid admixtures. 



3. The Chlorophyll does not contain yellow pigments. 



4. When saponified with alkali (an ether sol. is shaken with 

 methyl alcoholic potash sol.) the color changes to a pure brown. 

 Mixtures give a dirty brown ; the allomerised product does not give 

 the test. 



5. Decomposition, by boiling with alcoholic potash, yields the 

 normal mixture of phytochlorine e and phytorhodine g. 



6. The Spectrum agrees with that of a fresh leaf extract. 

 Chlorophyll is a bluish black substance with a strong, nearly 



metallic luster. When dry, it may be easily pulverized to a greenish 

 or bluish black powder. It does not possess a definite melting point, 

 93°-96° and 103°-! 06° being found for two samples. It is soluble 

 in absolute alcohol with a bluish green color. It is quite insoluble 

 in cold petroleum ether, but becomes easily soluble after the addi- 



12 Willstätter and Hug : Ann. d. CJiem., 380, 204 (1911). 



