of Chlorophyll, 239 
out. They constitute his hypochlorin. I have repeated 
Pringsheim’s experiments with the leaves of various plants and 
found the phenomena under the microscope exactly such as 
he describes. On examining the properties of the hypo- 
chlorin obtained, more especially the absorption-spectrum of its 
solution, I arrived at the conclusion that they do not differ 
from those of phylloxanthin, that the two substances are in 
fact identical. 
The memoirs recently published relating to the action of 
alkalis on chlorophyll are of more interest than those treating 
of the action of acids. In a memoir entitled £ Extraction de 
la Matiere Verte des Feuilles 1 ,’ Guignet describes a method 
of obtaining the sodium-compound of chlorophyll in dark 
green crystalline needles, of which he says that its solutions 
show exactly the same absorption-bands as those of ordinary 
chlorophyll. Following the directions given by him, I ob- 
tained a product which was quite amorphous, and I doubt 
whether it is possible to get any crystalline compound by the 
direct action of alkalis on chlorophyll. 
Hansen, in his work on the colouring-matters of chloro- 
phyll already referred to, proceeds on the assumption that 
chlorophyll is not altered by treatment with caustic alkalis, 
and he accordingly submits his crude product to a process of 
saponification. The colouring-matter of chlorophyll — that 
which by French and English chemists is called simply chloro- 
phyll — consists according to him of a green colouring-matter 
and a yellow colouring-matter. To separate these from each 
other and from the fatty matters with which they are as- 
sociated was his main object. Taking green leaves, preferably 
grass, he first extracts them with boiling water, which removes 
yellow colouring-matters and other impurities. The leaves, 
after pouring off the extract, are dried in the air, when they 
appear blackish-green. The dry material is then extracted 
with strong boiling alcohol, by which a solution of a splendid 
green colour is obtained. This, after some deposited fatty 
matter has been filtered off, is mixed with caustic soda lye 
1 Comptes Rendus, c. p. 434. 
