Contributions to the Chemistry of Chlorophyll. 



187 



bright bluish-green colour, which, changes to a dull olive-green. The 

 addition of water to the solution produces a brown precipitate, which 

 being filtered off and washed to remove the acid, dissolves much more 

 easily in boiling alcohol than phyllocyanin, giving a dark olive- 

 coloured solution. This solution leaves on evaporation a brown 

 amorphous residue, which treated with ether dissolves for the most 

 part. The ethereal solution has a green colour with a tinge of red, 

 and shows a spectrum consisting of eight bands; it leaves on evapo- 

 ration a semi- crystalline residue, which is green by transmitted, 

 purple by reflected light. On the addition of concentrated hydro- 

 chloric acid it separates into two distinct layers, the upper one being- 

 colourless, while the lower one is green, and shows four bands. 



By the prolonged action of tin on the solution of phyllocyanin in 

 hydrochloric acid, a further and more complete change is effected, the 

 solution acquiring a bright red colour without the least tinge of green. 

 On adding water the solution gives a red flocculent precipitate, which 

 filtered off and washed appears dark red, the filtrate retaining an 

 orange colour, and showing a broad ill-defined band, covering part of 

 the green and blue. The precipitate dissolves almost entirely in 

 warm alcohol, giving a bright red solution. This solution, on adding 

 a little caustic alkali, acquires a bright lemon-yellow colour, but the 

 red colour is restored by an excess of hydrochloric acid ; the alkaline 

 solution shows a broad band between the green and blue, but on 

 standing a short time exposed to the air it changes, becoming of a 

 deeper yellow, and it now shows a spectrum of three bands, one in 

 the yellow, one in the green, both pale, with a dark band between the 

 green and blue. The red alcoholic solution leaves on spontaneous 

 evaporation a reddish-brown amorphous residue, which dissolves only 

 in part in boiling ether, giving a reddish-brown solution, which shows 

 a peculiar spectrum of six bands, The body showing this spectrum is 

 probably a product of oxidation of the red substance. The acid liquid 

 filtered from the red precipitate, after removing the tin with sul- 

 phuretted hydrogen, is found to contain a mere trace of organic 

 matter. 



The colouring matter formed by the action of tin and hydrochloric 

 acid on phyllocyanin resembles in some respects those contained in 

 the petals of red flowers. Hitherto, however, I have not succeeded in 

 finding among the latter any one exactly like it. 



Examination of the Mother-liquors of Phyllocyanin. — Having some 

 reason to suspect that the acetic acid mother- liquors of phyllocyanin 

 contained some other substance similar to it of definite character, I 

 added water to a portion of these liquors, so as to throw down the 

 whole of the colouring matter contained in it. The flocculent pre- 

 cipitate was filtered off and dissolved in boiling alcohol. The solu- 

 tion on cooling gave a crystalline deposit which was found to possess 



