CURRENT LITERATURE 
NOTES FOR STUDENTS 
Photosynthesis.—We are indebted to WirtsTATTeR and his co-workers? 
for a series of contributions on the chemistry of the chloroplast and the mech- 
anism and behavior of the rennet! apparatus. It is a promising sign 
that so eminent a chemist as WILLSTATTER recognizes that the chemistry of 
the cell is not the chemistry of he test tube and flask of the ‘‘true chemist,” 
but rather the chemistry of a highly complex colloidal substrate with its 
enzymes. Physiologists can well look forward with keen anticipation to fur- 
. ther notes from his laboratory, since we have this statement concerning his 
future work: “Analyse physiologisch Mapenierae ngs ist nicht Selbstzweck, 
sondern Vorbereitung fiir physiologische Fo 
The leaf pigment chlorophyll is a mixture iv te green pigments, a blue- 
green (chlorophyll a) and a yellow-green (chlorophyll b), and two yellow pig- 
ments, carotin and xanthophyll. In the Phaeophyceae a third carotinoid 
(fucoxanthin) is found. The chlorophylls of all plants investigated (almost 
200) are neutral substances carrying a complex magnesium compound whose 
molecule is built up of 4 freely substituting pyrrol nuclei and are of the following 
compositions eu oe (C3:H»N;Mg) (CONH) (COOCH;) (COOC..H;,) 
and (C;;H2,ON;Mg) (CONH) (COOCH;) (COOCH;,,). These compositions 
were determined by a judicious and cautious treatment of chlorophyll eee 
with proper alkalies and acids in proper concentrations. It was found 
_ Splitting with acid made it possible to preserve and find in the products of 
hydrolysis that compound which is separated by alkalies, and, conversely, 
that the alkali derivatives exhibited a characteristic group which is destroyed 
with extraordinary ease by acids. Saponification of the pigment with alkali 
yields green, water soluble salts, the chlorophyllins. Progressive removal of 
*WictstArrer, R., and Srott, A., Untersuchungen iiber Chlorophyll. 8vo. 
pp. Vili-+424. pis. 11. Besfin: Julius Sasinger: 1913; see review of recent work on 
the pigments of the green leaf and the processes connected with them in New Phytol. 
14:281-204. 1915. 
———., Uber die chemischen emtoaietet des Assimilationsapparates. Sitzb. 
Kgl. Preuss, Akad. Wiss. 20:322. rors. 
———., Uher die Kakatiaton ergriinender Blatter. Sitzb. Kgl. Preuss. Akad. 
Wiss. 36: bok: Ae 
———, Untersuchungen iiber die Assimilation der Kohlensiure. Ber. Chem. 
Gesells. 48: 46-4664: IgI5s. 
Wusratter, R., Sitzb. Kgl. Preuss. Akad. Wiss. 32:484. 1915. 
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