on Green Leaves and other Parts of Plants . 169 
A few simple experiments sufficed to verify this supposition. 
The effect of strong oxidisers on aniline being well-known, 
and the products to which they give rise having been minutely 
examined by chemists, it became necessary to employ less 
energetic oxidisers for our purpose. On passing a current of 
air through a solution of aniline in acetic acid very little effect 
is produced. Hydrogen peroxide and ozone act, however, 
very differently. On adding a solution of hydrogen peroxide 
to a solution of aniline in acetic acid and heating, there is an 
immediate formation of a crystalline deposit, which when the 
action is completed forms a mass of garnet-coloured needles. 
These being filtered off and crystallised from benzol are found 
to have properties identical with those of anilophyll from 
leaves. A specimen thus prepared yielded in 100 parts C 78*84, 
H 5*88, N ii‘37, O 3*9 1. On passing a current of ozonised 
air through a solution of aniline in acetic acid a similar effect 
is produced ; a crystalline deposit is formed, which after being 
purified is found to consist of anilophyll. It is necessary that 
acid should be present at the same time, for neutral or alkaline 
solutions of aniline yield no trace of anilophyll with hydrogen 
peroxide. The conditions for the formation of anilophyll 
from aniline seem therefore to be the simultaneous presence 
of an excess of acid and some form of active oxygen, such as 
ozone or hydrogen peroxide. It is not a matter of indifference 
however, what particular acid is taken ; with hydrochloric 
or nitric acid the process results in the formation of colouring 
matters belonging to the class of indulines b In place of 
acetic acid any one of the following acids maybe employed — 
carbonic, formic, propionic, butyric, valerianic, palmitic, suc- 
cinic, malic, tartaric, citric, tannic, or phthalic acid. Oxalic 
acid, singular to say, completely hinders the reaction, possibly 
because it is itself more readily oxidised than aniline ; 
binoxalates hinder it to a certain extent, but neutral oxalates 
do not interfere with the formation of anilophyll. It is 
1 Very dilute nitric acid does, however, produce anilophyll, and there is reason 
to suppose that the brown colour acquired by aniline on standing, especially on 
exposure to light, is due to the same substance. 
