104 Green. — On Vegetable Ferments. 
It has quite recently been claimed by Sigmund 1 that these 
enzymes have also the power of splitting up fats into glycerine 
and free fatty acids. He says that he caused myrosin and 
emulsin to act upon olive-oil in closed glass vessels at a tem- 
perature of 38° to 40° C., and that gradually and continuously 
free fatty acid was developed in the mixture, its presence 
being demonstrated both by litmus and phenol-phthalein. 
His mode of preparing the enzymes is, however, open to 
criticism. He bruised seeds of the mustard in one case, and 
of the almond in the other, with excess of water, and allowed 
them to extract for twelve or fourteen hours. He then 
decanted the supernatant fluid and added excess of alcohol, 
throwing down a precipitate which he removed by filtration, 
washed and dried at about 40° C. This method is hardly 
likely to prepare either myrosin or emulsin pure ; if any other 
ferment, e. g. a fat-splitting one, were present in the seeds as 
well as the former, it would certainly be present in his dried 
residue. Though hitherto no one has attempted to isolate 
a fat-splitting enzyme from these seeds, there seems to 
be ground for suspecting its presence, as both mustard-seeds 
and almonds contain oil. Sigmund further states 2 that cer- 
tain fat-splitting enzymes which he detected in various seeds, 
as will be mentioned in connection with other researches on 
this point 3 , were able to split up amygdalin and salicin. The 
same criticism may be applied to this statement. The mode of 
extraction was similar and it is at least possible that his residue 
contained two ferments, rather than one as he supposes. 
Proteo-hydrolytic Enzymes. 
The ferments or enzymes which effect the decomposi- 
tion of proteids, and to which therefore the name proteo- 
hydrolytic may be applied, have been the subjects of obser- 
vation and experiment by many writers since 1875. The 
1 Sigmund, Beziehungen zwischen fettspaltenden und glycosidspaltenden Fer- 
menten. Sitzungsberichte d. k. Akad. der Wissenschaften in Wien, Math.-Nat. 
Classe, Bd. 101, May 1892. 
2 loc. cit. 
Vide infra, p. 116. 
