he action of alkalies:

[Illustration: Decomposition of Chlorophyll a and Chlorophyll b]

=Decomposition of Chlorophylls by Acids.=--The first action of dilute acids
upon chlorophylls is to remove the magnesium, without otherwise changing
the molecule. Two hydrogens go in in the place of the magnesium. Dilute
acids act in precisely the same way upon each of the "phyllins" shown in
the above scheme. In this way, a whole series of compounds, corresponding
to each of the chlorophylls and their alkali-decomposition products, but
with the magnesium lacking in each case, has been prepared. Thus,

COO.C_{20}H_{39}
/
Chlorophyll _a_, MgC_{31}H_{29}N_{3}-COO.CH_{3},
\\
(NHCO)

COO.C_{20}H_{39}
/
becomes Phaeophytin _a_, C_{31}H_{31}N_{3}-COO.CH_{3},
\\
(NHCO)

COO.C_{20}H_{39}
/
Chlorophyll _b_, MgC_{31}H_{29}O_{2}N_{4}
\
COO.CH_{3}

COO.C_{20}H_{39}
/
becomes Phaeophytin _b_, C_{32}H_{30}O_{2}N_{4}
\
COO.CH_{3}

Similarly,

Isochlorophyllin _a_, becomes Phytochlorin _e_,

Chlorophyllin _a_, becomes Phytochlorin _f_, and _g_,
COOH
/
C_{32}H_{32}ON_{4}
\
COOH

Isochlorophyllin _b_, becomes Phytorhodin _g_

Chlorophyllin _b_, becomes Phytorhodin _i_ and _k_,
COOH
/
C_{32}H_{30}O_{2}N_{