52 CHLOROPHYLL. [CH. II 



(59) Action of copper salts. 



By the addition of a little 10 % CUSO4 solution^ a 

 copper compound is produced, which has the general 

 appearance of chlorophyll, but differs notably in not being 

 fluorescent-. To observe this point compare it with 

 unaltered chlorophyll extract ; fluorescence is most easily 

 visible with a strong solution in a narrow test-tube. 



(60) Stability of the coppei^ compound^. 



Fill two test-tubes A, B, with the copper compound 

 and two others C, D, with unaltered leaf-extract : place A 

 and G in sunlight, B and D in the dark. After some 

 hours note by comparison with B and D that the copper 

 compound is not destroyed while C is affected. 



(61) Spectroscopic examination. 



To see the characteristic chlorophyll band / in the 

 red, a small direct-vision spectroscope may be used : the 

 solution may be in a test-tube, and ordinary daylight will 

 suffice. In Detmer's Praktikum, p. 17, a convenient 

 holder for test-tubes is figured and described. For the 

 other bands direct sunlight is needed, the solution, which 

 must be a weak one, should be placed in a parallel- 

 sided vessel, and a more elaborate spectroscoj)e should be 

 used. 



(62) Other pigments (Anthocyan). 



The red varieties of Ricimis and Amaranthus may be 



1 Or of strong solution of copper acetate and strong HCl. 



2 Tschirch, Deut. Bot. Ges. Bd. v. 1887, p. 135. 



3 See Schunck, Annals of Botany, iii. p. 94. 



