44 o SCIENCE PROGRESS 



olefin alcohol. Several crystalline derivatives were obtained and 

 also, by treatment with an acetic acid solution of hydriodic acid, 

 and afterwards with zinc, a hydrocarbon phytene, C2oH4o. 



Crystalline Chlorophyll. — As already mentioned, different 

 preparations of phaeophytin yielded varying quantities of phytol 

 on treatment with alcoholic potassium hydroxide. This fact 

 suggested at first that the phaeophytins from different plants were 

 not all identical. Further research revealed the fact, however, 

 that in addition to the neutral chlorophyll which was the ester 

 of phytol, another body existed in plants which did not yield 

 phytol on hydrolysis. This product was the crystalline 

 chlorophyll, which had been originally described by Borodin 

 and later by Monteverde. The latter investigator distinguished 

 between three classes of plants, in respect to chlorophyll yields, 

 viz. those which yield on extraction with alcohol chiefly amor- 

 phous chlorophyll, those yielding a mixture of the two substances, 

 and those which yield principally the crystalline product. 

 Amongst this latter class occur several varieties of galeopsis, 

 which was found the best adapted for the preparation of a 

 crystalline chlorophyll. The dried leaves were mixed with 

 chalk to neutralise the plant acids, then extracted with alcohol, 

 and the alcoholic extract was then thrown into ether. The ether 

 alcohol solution was washed with water several times to remove 

 the alcohol, after shaking the solution in organic solvents with 

 talc to get rid of resinous matter, which impedes the separation 

 into two layers of the water and ether. On evaporation of the 

 ethereal solution thus obtained the crystalline chlorophyll 

 separated. When obtained by this method it was generally 

 mixed with a colourless substance, from which it could be 

 separated by re-solution in ether, in which the foreign body 

 does not readily dissolve. The product obtained in this way 

 crystallised in hexagonal or triangular plates of bluish-black 

 colour, with no melting-point, and was readily soluble in alcohol, 

 wood-spirit and acetone, but soluble only with some difficulty 

 in ether; it was readily soluble also in chloroform, and easily 

 soluble in hot methylal, from which it separated on cooling ; this 

 solvent was found to be a convenient one for the recrystallisa- 

 tion of the substance. Its composition agreed well with the 

 formula C 38 H420 T N 4 Mg. On gentle treatment with alcoholic alkalis, 

 crystalline chlorophyll yielded a chlorophyllin ; by heating with 

 methyl-alcoholic potassium hydroxide at 140 — 200 it yielded 



