Schunck . — The Chemistry of Chlorophyll. 89 
leaves of the common thorn, and from the fronds of Pteris 
aquilina , as well as from grass ; no difference could be dis- 
covered between the various specimens obtained. 
Phyllocyanin is one of the most important of the derivatives 
of chlorophyll ; its properties moreover are very interesting. 
When dry it has the appearance of a dark blue mass, which 
may easily be reduced to a fine powder resembling pounded 
indigo, but without the coppery lustre exhibited by the 
latter substance when rubbed with a hard body. Examined 
under the microscope it is found to consist almost entirely 
of elongated rhomboidal or irregularly six-sided crystalline 
plates, which are generally opaque, but when very thin are 
translucent, and then appear olive-coloured by transmitted 
light. Phyllocyanin is insoluble in water ; it dissolves in 
boiling alcohol, but a great part separates out on the 
solution cooling in microscopic crystals ; it is more soluble 
in ether, benzol, glacial acetic acid, and carbon disulphide 
than in alcohol, but the best solvent is chloroform, which 
takes up large quantities of it, even in the cold. A minute 
quantity of substance imparts an intense colour to most of 
these solvents ; it is only on diluting largely that the solutions 
lose their opacity; they then appear of a dull green or olive 
colour, and show the well-known spectrum of ‘ acid chloro- 
phyll, 5 consisting of five absorption-bands ; they fluoresce, 
but not so strongly as solutions of chlorophyll. Phyllocyanin 
is soluble in aniline, but insoluble in petroleum, ether and 
ligroin ; it contains nitrogen, but is free from sulphur. Phyllo- 
cyanin may be heated to 160° C. without change ; between 
160 0 and 180° it is, however, completely decomposed, leaving 
a charred mass of the same volume as the substance taken, 
which, when further heated, burns away leaving a hardly 
visible trace of ash, differing in this respect from chloro- 
phyllan, which after burning leaves a quantity of incombustible 
matter. 
Phyllocyanin is soluble in concentrated hydrochloric and 
sulphuric acids. The solution in hydrochloric acid appears 
dark blue by day-light, purple in artificial light, and shows a 
