554 
PIERRE A. FISH. 
causes a kind of tanning with extraction of water, which con¬ 
stricts the tissues and restrains putrefacation. Upon the same 
principle they form coagulums in which the organisms are re¬ 
tained, or which protect the surfaces against ulterior contami¬ 
nations. Some agents used as antiseptics act only as desiccators 
and prevent development in this manner. When gelatin, 
covered with dermatol, is inoculated with bacillus coli, bacillus 
pyocyaneus or pyogenic bacteria, the growth of the cultures is 
impeded, due to the desiccating action of the agent which drys 
the surface of the gelatin (Cadeac and Guinard). The con¬ 
clusion reached is that dermatol is not a true inicrobicide, but 
hinders the evolution of the germs by modifying the medium 
upon which they grow. The feeble changes in the chemical 
composition of a medium, resulting from the presence of an 
antiseptic even in very small amount, can prevent the mi¬ 
crobes from performing their function and restrains their evolu¬ 
tion. 
Guinard asks why certain medicinal agents may not excite 
the cellular elements in such a way as to cause a defensive 
action, either by causing a bactericidal action of the medium, 
01 by an elaboration of organic secretions, which may neutralize 
the toxic substances. He believes that such an hypothesis will 
assist in explaining the curative action of antitoxic serum and 
in serum therapy. 
Experiments .—The following experiments have differed 
from most others, in that no especial attention has been devoted 
to determining the exact death point of the organisms ; but to 
put aitificial conditions upon as natural a basis as possible, as 
found in open wounds. The experiments were confined entirely 
to such organisms as are usually found in such wounds. In the 
two cases examined (one in 1897 and the other in 1898), the 
mieioscope showed numerous micrococci and some bacilli. In 
older to simulate the conditions of a wound, plates of gelatin 
and in some cases, of agar were prepared. A gash was cut in 
the medium and the organisms planted by drawing two loops 
of the culture prepared from the wound, through it. The dry 
