THEORIES AND EXPERIMENTS IN ANTISEPSIS. 
551 
The matter of oxidation is, by no means, an unimportant 
part of the subject Certain of the organisms are anaerobic and 
cannot live in the presence of oxygen ; others are aerobic and 
require oxygen in order to exist, and a third class, the facultative 
organisms may live either in the presence or absence of oxygen. 
Antiseptics which cause any change with respect to the amount 
of oxygen supplied to the organisms, or to the tissues surround¬ 
ing them, act upon, at least, one of the above classes. 
The proper oxidation of the somatic cells undoubtedly has 
much to do with protecting the body from the harmful effects 
of certain germs. If, for example, a Cell be surrounded by a 
fluid containing oxygen, the external portion of the cell will 
get the most oxygen, and will become more or less oxidized, 
while in the region of the centre of the cell a reducing power 
will be exerted and oxygen will be readily taken up from the 
external layer. From this condition of affairs, we may differ¬ 
entiate the central portion of the cell as chiefly of a reducing 
character and the external portion of the cell as chiefly of an 
oxidizing nature ; between these two fairly well differentiated 
layers, we may distinguish an intermediate layer partaking 
somewhat of the characters of the other two ; a portion of the 
time it is oxidizing in function and a portion of the time re¬ 
ducing. 
Oxidizing portion. 
Variable portion. 
Reducing portion. 
(Nucleus.) 
MODIFIED FROM DANDER BRUNTON. 
The limiting membrane of the cell, or the medium sur¬ 
rounding the cell, influences the degree of oxidation. A thick 
