Comparative Stiidy of Chlorophyll. 401 



Spectrum 5, an alcoholic extract after boiling the material 

 for ten minutes : — 



Band 1. \ 690 [centre = X 643] - X 635. 

 „ 2. X 618 [centre = X 607] - X 596. 

 „ 3. centre at X 570. 

 „ 4. X 542 [centre = X 538] - X 530. 

 „ 5. absorption commences at X 517. 



Spectrum 6 same as extract of spectrum 5, but after treat- 

 ment with liquor ammonia : — 



Spectrum 7 same as extract of spectrum 5, after treatment 

 with nitric acid : — 



Band 1. X 682 -X 635. 

 „ 2. X 618 -X 596. 

 „ 3. centre at X 570. 

 „ 4. centre at X 538. 

 „ 5. commences at X 517. 



Spectrum 8 shows the absorption-spectrum of an extract 

 made with benzol, freshly prepared. The two bands in the 

 blue end are drawn in such a way that the left half of each 

 band shows the intensity of absorption, while the right half is 

 drawn darker to bring out the centre of the baud : — 



Band 1. X 674 - X 632. 



„ 2. centre of band — X 486. 

 „ 3. centre of band — X 453. 



The extract was got by triturating purified Spirogyra-msiteT'ial 

 with benzol ; after ten mmutes a yellow extract with a 

 slightly greenish tint was obtained, which showed very slight 

 fluorescence. 



Spectrum 9 represents the absorption-spectrum of an extract 

 made with xylol from fresh material. At first the light was 

 allowed to shine through a thin layer to define, the two 



TRANS. BOT. SOC. VOL. XVIII. 2 R 



