DECEMBER 29, 1899. ] 
gesting agent of the pineapple to be of the 
same nature. Pelkelharing* found that 
the activity of pepsin is intimately con- 
nected with a nucleoproteid and the same 
author as well as Halliburton declare throm- 
base (the clotting enzyme of the blood) to 
be a nucleoproteid. + Spitzer declared also 
the peroxidase of the animals to be a nucleo- 
proteid, | which however, the writer found 
not to be the case with the vegetal per- 
oxidase, which in all probability has an 
albumose-like nature. Seegen and Kratsch- 
mer § inferred from their investigations an 
albuminous nature of the diastase of the 
liver, while the writer found the trypsin 
and diastase of the pancreas gland to be of 
peptone character; that is to say, when 
transformed to the inactive state, they behave 
towards the usual reagents like a peptone, 
while in regard to their activity they differ 
essentially from them (see on this point 
further below). As to the diastase of 
malt, Osborne as well as the writer, || has 
inferred its protein character. In the purest 
state it was prepared by Wroblewski, who 
showed that it was a proteose and was form- 
erly obtained with an admixture of a car- 
bohydrate, araban. This author recently 
also proved invertase to be of a proteose or 
peptone-like nature. Certain authors failed 
to obtain with their enzyme preparations 
either the reactions or the composition of 
protein matters, which may have been due 
in some cases to imperfect purification, 
while in others the enzyme might really be 
no protein at all, which is probably the 
case with the rennet, investigated by 
Hammarsten. The active character of an 
enzyme is not necessarily connected with a 
protein nature, since the ordinary soluble 
* Zeitschrift physiol. Chem., Vol. 22, p. 233. 
t Arch. fiir Physiol., 1895, p. 213, and Journal of 
Physiol., Vol. 9, p. 265. 
{ Jahresbericht f. Thierchemie, 1897. 
@ Jahresbericht f. Thierchemie, 1877. 
|| Pfhig. Arch., Vol. 27, p. 206. 
SCIENCE. 
957 
proteins have no such activity atall. In 
analyzing enzymes we can only find the 
composition of the killed* enzyme, which 
in fact is no longer a real enzyme. This 
brings us to the second of the above ques- 
tions, the cause of their chemical powers. 
The question how it is to be explained 
that a small amount of enzyme can trans- 
form a relatively very large amount of 
another substance has been answered in 
various ways, none of which have proved 
satisfactory. We shall not enter here on a 
critical review of all these hypotheses, 
which the reader will find treated in Green’s 
recent work: ‘The Soluble Ferments and 
Fermentation,’ (chapter 24).} Only a few 
points, especially regarding recent views 
may be mentioned, before the view of the 
writer is discussed. 
One author declared that enzymes are not 
bodies, but properties of bodies (which non- 
sense was called by several authors an 
‘ingenious,’ hypothesis! ); another said that 
small quantities of enzymes are merely at- 
tached to proteins, but are not proteins them- 
selves; another declared that the enzymes 
act by repeatedly causing oxidation and re- 
duction.{ But even if this last mentioned 
view were correct (which cannot be, since 
most enzymes can be active also in the 
absence of oxygen), it does not explain 
the power that would cause the supposed 
oxidations and reductions. Saccharoff, who 
advanced this hypothesis, made experiments 
with papayotin only, in which he assumes 
a small quantity of ‘bionuclein,’ an ac- 
tive principle, containing iron, and as- 
sociated with it a larger amount of 
another substance that has a mere _ pro- 
moting action. From some very vague 
* The word ‘killed’ is used here as a short term 
for ‘ transformed to an inactive state.’ 
t Recently a review of this work was published in 
this JOURNAL. 
{ Saccharoff, Centralbl. f. Bakteriologie, Vols. 24. 
and 26. 
