360 Some Photochemical Experiments with Pure Chlorophyll. 



Ewar,t, as to the chemical changes occurring in the process of carbon 

 assimilation by green plants, are not supported by experimental evidence. 



In conclusion, we would thank Mr. W. Stiles for his co-operation in the 

 work of extraction and purification of the pigments, and we should like 

 to express our indebtedness to Prof. Y. H. Blackman for the facilities he has 

 given us, and for his continued advice and criticism. 



[Note added October 12, 1916. — Of Willstatter's three papers on chloro- 

 phyll which appeared in 1915, only that in the ' Berichte der deutschen 

 chemischen Gesellschaft ' (1915, No. 13, p. 1540) was available at the time 

 the manuscript of this paper was completed ; the other two (' Sitzungsber. d. 

 kgl. preuss. Akad. der Wissen.,' 1915, p. 322 and p. 544) were only accessible 

 in the form of very brief abstracts. We were thus unaware that Willstatter 

 had made experiments on the behaviour of a chlorophyll solution exposed to 

 carbon dioxide. Now that copies of the journal containing the other two 

 papers are available in this country, we find that Willstatter has made such 

 experiments, and arrives at the conclusion put forward above, that phaeo- 

 phytin is produced under these conditions.] 



LITERATURE CITED. 



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