452 



Dr. E. Schunck. 



phyllocyanin, which dissolves in ether and in acetic acid, both 

 solutions having a dull green colour, and showing the same spectrum. 

 It is also soluble in concentrated hydrochloric acid, the solution 

 having a bright bluish-green colour. 



In contact with acids phyllotaonin undergoes a series of changes, 

 accompanied by corresponding changes in the absorption spectrum. 

 If to an ethereal or alcoholic solution of phyllotaonin a small quantity 

 of an acid, such as hydrochloric, sulphuric, oxalic, tartaric or acetic 

 acid be added, the colour of the solution changes slowly from green to 

 brown, and now shows the spectrum frequently referred to in which 

 two bands, that in the red and that in the green, are seen split up into 

 two (see fig. 11 of the Plate previously referred to). A further change 

 takes place on standing, one of the bands in the green becoming 

 darker, the other lighter (see spectrum, fig. 12). Here the action 

 stops with all the acids named except acetic acid. On treating 

 phyllotaonin with boiling glacial acetic acid it dissolves, and the 

 dark purple solution if sufficiently concentrated deposits on cooling 

 crystalline needles, arranged in fan-shaped masses. These collected 

 on a filter and dried show a fine purple colour, and closely resemble 

 the supposed ethyl-compound of phyllotaonin ; its solutions show the 

 same absorption spectrum as the latter. This product is doubtless 

 a compound with acetic acid; stronger acids such as sulphuric or 

 hydrochloric acid yield no similar compounds. The products 

 formed by the action of acids may in all cases be re-converted into 

 phyllotaonin by means of alkali. The process of re-conversion may 

 be traced in its course with the crystallised acetate. If the latter be 

 treated with aqueous potash in the cold it dissolves ; acetic acid 

 added gives a green precipitate which dissolves in ether, the solution 

 showing the spectrum of fig. 11, but if boiling alcoholic potash be 

 employed, the corresponding ethereal solution shows the spectrum of 

 phyllotaonin. Under the influence of acetic acid the latter again 

 passes through the series of changes previously described. That 

 the changes induced on the one hand by acids, and on the other by 

 alkalis, are due in one case to hydration and in the other to dehydra- 

 tion, seems probable. After being heated to the melting point, 

 phyllotaonin gives solutions showing the spectrum, fig. 12, but by 

 treatment of the fused substance with alcoholic potash it returns to 

 its original state. It is difficult to attribute the change in this case 

 to anything but loss of water, the latter being taken up again on 

 treatment with alkali. 



A potassium compound of phyllotaonin is obtained on adding 

 potash to an alcoholic solution of the substance ; it crystallises in 

 needles which are purple by reflected light. The sodium compound 

 obtained in the same way is hardly crystalline. A boiling alcoholic 

 solution of phyllotaonin to which cupric .acetate and acetic acid have 



