134 
without giving the peroxidase reaction with guaiaeum. Thus it 
often happens that samples of cured tobacco have the power of de- 
composing hydrogen peroxide, ofttimes very actively, and yet have 
no power to blue guaiaeum either alone or in the presence of hydro- 
gen peroxide. On the other hand, an aqueous extract of the fresh 
green leaves of tobacco, containing one-fifth of its volume of absolute 
alcohol, showed both the oxidase and peroxidase reactions with guaia- 
cum, whereas such extracts had no power to decompose hydrogen 
peroxide. It would seem, therefore, that the power to decompose 
hydrogen peroxide and the oxidase and peroxidase reactions ordi- 
narily exhibited by plant and animal tissues and secretions are dis- 
tinctly different properties. According to Loew ( 278 ), therefore, the 
decomposition of hydrogen peroxide by plant and animal tissues is 
due to a special enzyme, to which he gave the name “catalase.” a 
Still other observations point to the specific nature of catalase. 
Thus in 1902 , Pozzi-Escot ( 333 ) observed that catalase did not give 
the guaiaeum reaction nor oxidize hydroquinon. Somewhat later 
a The name “catalase” (spelled by these authors “katalase”), together with the 
names “oxygenase” and “peroxidase,” has recently been objected to by Moore and 
'Whitley ( 306 ) as being ill chosen. According to these authors “there is no reliable 
evidence of this destruction of hydrogen peroxide being due to an enzyme at all.” 
They point out that it is not specific, and that the decomposition can be accomplished 
by every ferment solution of whatever type, by nearly all animal and vegetable 
fluids, and by means of numberless inorganic catalysts. “In any case it is absurd, ” 
according to these authors, “to give it a name which belongs to or includes the whole 
vast range of catalytic actions.” Every true enzyme is a catalase in the sense that 
it acts catalytically, and why a catalytic agent which happens to act upon hydrogen 
peroxide and which furthermore has never been shown to be a specific enzyme 
should be dignified by the name “catalase” is difficult to conceive. Every investi- 
gator in this field will no doubt appreciate the force of some of these objections. At 
the same time there are doubtless many who would be inclined to question the 
exclusion of catalase from the group of soluble ferments. The mere fact that innu- 
merable substances decompose hydrogen peroxide has nothing to do with the ques- 
tion. One might as well object to our looking upon invertase as an enzyme for the 
reason that innumerable acids can hydrolyze cane sugar, and while many names 
in science are ofttimes nothing more than apt and striking catchwords, they have 
taken such a firm hold in the minds of those dealing with the subject that it is prac- 
tically impossible to replace them. An instance of this kind is met with in the term 
“catalysis” itself, which in its original meaning simply begs the question as to the 
inherent causes of all phenomena of this kind. To say that an agent simply acts by 
its presence is merely emphasizing the most obvious phase of the whole phenomenon, 
and conveys no insight into the causes thereof, which after all are the things which 
we are chiefly concerned in discovering, and yet it is quite likely, from the present 
drift of things, that the term “catalysis” will remain long after contemporary chem- 
ists have ceased to have a voice in the shaping of chemical thought. If a committee 
of chemists, philologists, and advocates of the simple spelling were all to get to- 
gether with the express purpose of introducing new names for the oxidases, peroxi- 
dases, and catalases it is more than likely that the result would be something far less 
euphonious and suggestive and of less real meaning than the names which these 
substances now bear. 
