On the Physiological Behaviour of Maleic 
and Fumaric acids. 
BY 
T. Ishizuka, Nôgakushi 
The stereo-isomeric fumaric and maleic acids, 
HOOC-CH CH-COOH 
II and II show not only in chemical, 
CH-COOH CH-COOH, 
but also in physiological respects highly interesting differences. 
Mould fungi can easily utilize fumaric acid as source of carbon for 
building up their protoplasm, but not maleic acid. (1) Lcezv (2) found 
a similiar difference for bacteria ; fumaric acid is an excellent 
nutrient, while maleic acid an exceedingly poor one.~ 
Moreover, Pfeffer found that maleic acid exerts an attracting 
influence upon spermatozoids of ferns, while fumaric acid shows no 
such action. 
Again, recent investigations show that maleic acid is more 
poisonous for the higher animals than fumaric ; if per kilo body- 
weight of a dog are injected 1.94 grams of maleic acid in the form 
of the sodium salt into the veins it suffices to kill the dog, while 
with fumaric acid it will not. (3) 
It appeared to me of some interest, to investigate, whether 
analogous physiological differences exist in regard to chlorophyll¬ 
bearing plants and the lower aquatic animals. 
Preliminary trials showed that highly diluted solutions of the 
neutral sodium salts of both acids did not exert any noxious in¬ 
fluence upon plants ; but it may be possible that maleic acid is 
transformed by the vital activity into fumaric, before it can 
exert a noxious action. The fact that there is never found in 
the vegetable kingdom maleic, but fumaric acid is, (4) renders this 
supposition indeed admissible. Therefore, the neutral sodium 
salts of maleic and fumaric acids were applied in higher concen¬ 
trations, and here indeed it became evident that maleic acid acts 
more noxiously than fumaric acid. 
(1) E . Buchner . Ber. D. Chem. Ges. 24 , 1163. 
(2) Central-Bl. f. Bact ; 12 , 361. 
(3) F oder a , Chem. Ztg., Dec. 1895. 
(4) Fumaric acid was found in Fumaria officinalis , Corydalis bnlbosa , Glaticium 
luteum , further in different hinds of Agaric us and in Cetraria islandica . 
