98 
whereas Abelous and Biarnes ( 5 ) arranged the tissues in the follow- 
ing order with regard to their activity toward salicylic aldehyde: 
1. Spleen. 
2. Lung. 
3. Liver. 
4. Thyroid. 
5. Kidney. 
6. Thymus. 
7. Suprarenal. 
8. Testicle. 
According to these authors muscle, pancreas, and brain are inca- 
pable of oxidizing salicylic aldehyde. Medwedew ( 291 ) studied the 
kinetics of the oxidation of salicylic aldehyde by extracts of various 
organs and has found that the quantity of salicylic aldehyde oxidized 
is proportional to the square of the concentration of the ferment, and 
inversely proportional to the square root of the concentration of the 
aldehyde. 
One of the most interesting facts disclosed by these investigations 
is that the oxidation of the aldehyde by aldehydase is independent 
of the presence of atmospheric ox}^gen. Thus in certain of his experi- 
ments Medwedew ( 292 ) found the following amounts of salicylic acid 
to be produced (1) during aeration, and (2) in the absence of air: 
No. of experiment. 
Amount of salicylic acid 
found, in milligrams. 
(1) Aerated. 
(2) In absence 
of air. 
1 
85 
83 
2 
118 
115 
3 
80 
78 
It will be observed that the differences between the several amounts 
of salicylic acid formed in the two cases are very small and are probably 
within the limits of experimental error, and yet in experiment No. 3 
(1) was subject to a continuous current of air for 16 hours, whereas 
(2) remained without aeration, and portion (2) of experiment No. 2 
was kept in a hermetically sealed vessel. Similarly it has been shown 
by Abelous and Aloy ( 4 ) that the oxidation of salicylic acid by various 
organs proceeds more rapidly in a vacuum than in the presence of air. 
In fact, according to these authors, liberal supplies of free oxygen - 3 
diminish the rate of oxidation very considerably and may even sup- 
press it altogether. These authors are of the opinion, therefore, that in 
such oxidations as take place in a vacuum the oxygen necessary for 
the oxidation is furnished by certain oxygen compounds which are 
dissociated by the oxidizing ferment. In other words 7 such processes - 
