93 
ALDEHYDASE (SALICYLASE). 
We have seen that Schoenbein ( 384 ), especially as the result of his 
work on the oxygen-carrying power of blood, recognized the im- 
portance of oxygen carriers for oxidation processes occurring in the 
animal organism. Traube ( 427 ) also believed that a complete analogy 
exists between the respiratory changes occurring in muscle and 
the process of slow combustion. His theory of muscular activity 
was based upon the assumption that the muscle fiber contains a 
vital, oxidizing ( verwesungs ) ferment (see Traube ( 425 ), p. 107), 
which carries oxygen from the blood to the oxidizable substances 
contained in the muscle fluids, without the ferment itself suffering 
any destruction. These or similar views were also shared by other 
distinguished observers. Thus, according to Claud Bernard ( 47 ) the 
respiration of tissue is not a direct combustion, but an indirect oxi- 
dation accomplished by chemical agents of the nature of ferments. 
Some few observations were made by Schutzenberger ( 393 ) on the 
oxidation of certain substances in the animal organism. It remained 
for Schmiedeberg to greatly extend our earlier knowledge of such 
processes. Thus, as the result of their investigation of the forma- 
tion of hippuric acid in the animal organism, Bunge and Schmiede- 
berg ( 106 ) came to the conclusion that the red blood corpuscles play 
an essential role in the formation of hippuric acid in the living kid- 
ney, for the reason, possibly, as these observers surmised, that it 
plays the part of an oxygen carrier. From these observations 
Schmiedeberg himself ( 366 ) was naturally led to the study of those 
oxidations which in the animal organism might result in the forma- 
tion of hippuric acid. He arrived at the conclusion that the princi- 
pal changes occurring in the animal organism are splittings (hydroly- 
sis), oxidation, and synthesis, and, as he proved in these researches, 
the two latter processes frequently go hand in hand. It was shown 
that benzyl alcohol was oxidized by blood to only a slight extent, 
and almost equally well by a solution of sodium carbonate, but not 
at all in pure water. Similar results were obtained with salicylic 
aldehyde. On the other hand, by the action of oxygenated blood in 
the tissue of the kidney and lung both of these compounds are oxi- 
dized a thousand times more rapidly than they are by blood alone 
or by a solution of sodium carbonate. From this it follows that 
conditions exist in the tissues whereby an increased activity is con- 
ferred on the oxygen of the blood, in that it is rendered active or gotten 
into the nascent state, or some change is effected in the oxidizable sub- 
I stance, whereby it becomes more easily oxidizable. This increased 
activity on the part of the oxygen may be explained as a result of the 
action of (1) an exciter analogous to platinum-black, or (2) of readily 
combustible substances in the tissues which have the power of 
