14 Ingvar Jorgensen and Walter Stiles. 
The phase test also applies to the chlorophyllides and phaeo- 
phytin and to the phaeophorbides. It is not given with allomerised 
chlorophyll. 
This allomerisation takes place in alcoholic solution particularly 
when water-free (see Section B of this chapter). The chlorophyll¬ 
ides are also very easily allomerised and lose thereby their power 
of crystallisation. Small quantities of water and of acids protect 
the substances against allomerisation, while alkalis increase the 
velocity of the reaction. 
Experiment 5. Allomerised chlorophyll does not give the brown 
phase test. 
Dissolve a little crude chlorophyll, obtained by evaporating an 
ether solution, in absolute alcohol. Add a little alkali, and perform 
the phase test from time to time till at last the brown phase no 
longer appears. 
Experiment 6. Separation of the green and yellow pigments. 
Required: 5 c.c. ether solution of pigments; 2 c.c. 30% potassium 
hydrate in methyl alcohol; 5 c.c. ether. 
Shake 5 c.c. of the ether solution of the pigments with 2 c.c. 
of the strong alkali. After the green colour has reappeared, slowly 
add 10 c.c. water and then add a little more ether. On shaking the 
test-tube two layers are produced of which the lower watery- 
alkaline one contains the saponified green pigments, while the 
carotin and xanthophyll are contained in the upper ethereal layer. 
This test is employed in the examination of the purity of a 
chlorophyll preparation. If all the yellow pigments have been 
removed, the ethereal layer in this experiment should remain 
colourless after saponification of the chlorophyll. 
Experiment 7. Separation of the two yellow pigments. 
Required : The ethereal solution of yellow pigments from Experi¬ 
ment 6; 10 c.c. petrol ether; 30-50 c.c. 90% methyl alcohol; 1 
separating funnel. 
The ether layer obtained in the last experiment is washed with 
water in a separating funnel and evaporated down to 1 c.c. It is 
then diluted with 10 c.c. petrol ether and next mixed with 10 c.c. 
90% methyl alcohol. The methyl alcoholic layer is removed and 
the petrol ether layer is again treated with methyl alcohol and the 
methyl alcoholic layer again removed. This process is repeated 
until the methyl alcohol is no longer coloured. The methyl alcohol 
contains the xanthophyll, the petrol ether the carotin. 
