354 



Mr. E. Schunck. 



Action of Acids. — A mixture of 1 part of concentrated hydrochloric 

 acid with 9 parts of absolute alcohol, dissolves phyllocyanin easily. 

 In daylight the solution appears dark blue, green at the edges ; in 

 artificial light it appears purple. It shows a spectrum differing from 

 that of phyllocyanin, and more nearly resembling that of chloro- 

 phyll, especially as regards the fourth aud fifth bands, which are 

 extremely faint, whereas with phyllocyanin they are very intense ; 

 the spectrum is, in fact, that of the hydrochloric acid compound of 

 phyllocyanin. On adding water to the solution, unchanged phyllo- 

 cyanin is precipitated, but if the solution be evaporated, it leaves a 

 residue green by transmitted, blue by reflected light, which is no 

 longer phyllocyanin, for it dissolves in alcohol with a brownish-green 

 colour, and the solution shows a spectrum identical with that of the 

 product formed by the action of alkalis on phyllocyanin, and cha- 

 racterised by two bands in the red, and two fine, but distinct bands 

 in the green, which will be referred to presently. 



Phyllocyanin is soluble in concentrated hydrobromic acid. 



It dissolves in concentrated sulphuric acid, giving a grass-green 

 solution, which shows a spectrum resembling that of the hydrochloric 

 acid compound. On the addition df water, unchanged phyllocyanin 

 is precipitated, but if the solution be left to stand for some time, the 

 phyllocyanin contained in it is changed, and the precipitate with 

 water now consists of several products, one of which shows the same 

 spectrum as that formed by the action of hydrochloric acid. 



Phyllocyanin is not in any way affected by treatment with a boiling 

 w r atery solution of phosphoric acid. On the addition of phosphoric 

 acid to a boiling alcoholic solution of phyllocyanin, the latter acquires 

 a purplish tint, but the spectrum remains the same, and the solution 

 on cooling deposits unchanged phyllocyanin. 



Phyllocyanin shows no tendency to combine with oxalic, tartaric, 

 or citric acid, but these acids do affect it to a certain degree, that is, 

 they induce decomposition at temperatures at which the substance 

 itself remains unchanged. Mixtures of finely powdered phyllocyanin 

 with oxalic, tartaric, and citric acids remain unaltered when heated in 

 the water-bath. After being heated in an air-bath to 130°, the oxalic 

 acid mixture no longer contains phyllocyanin, the latter being com- 

 pletely charred and decomposed, whereas the tartaric and citric acid 

 mixtures show only slight indications of change at that temperature. 

 On being heated to 155°, and kept at that temperature for some time, 

 the tartaric and citric acid mixtures are found to contain products 

 which differ from phyllocyanin, without having properties such as 

 compounds of the latter with acids might be expected to show. 

 Under the conditions described, therefore, phyllocyanin shows no 

 tendency to combine with weak acids. 



Action of Alkalis. — When phyllocyanin is treated with very dilute 



