638 
WILLIAM HERBERT LOWE. 
destroy pyogenic organisms, and in this strength the living tis¬ 
sues are affected by it, a zinc albuminate being formed which ap¬ 
pears as a white translucent film covering the surface to which 
it has been applied. Its use is restricted to the disinfection of 
wounds that are already frankly septic. Solutions of from 5 
to 8 per cent, strength should be used. The film of zinc albu¬ 
minate which results is markedly resistant to new bacterial in¬ 
vasion, and further restrains exudation and protects mechani¬ 
cally the underlying tissue. This combination of qualities 
makes it an antiseptic agent of the greatest value in veterinary 
practice in dealing with sores and open infected wounds. 
Among antiseptic agents may be mentioned aluminum 
acetate, acetanilid, hydrogen peroxide, mercuric iodate, naph- 
thalin, beta-naphthol, pyoktanin, formic aldehyde and heat. 
Heat .—The temperature of boiling water, 212° F., is sufficient 
to quickly destroy all known pathogenic bacteria. Most spores 
are also destroyed by this degree of moist heat, but so marked a 
power of resistance inheres in some spores that they are not de¬ 
stroyed by even so long an exposure as two hours. For insur¬ 
ing the absolute destruction of all spore life the method of frac¬ 
tional sterilization is available. 
None of the ordinary pus-forming bacteria are spore bearers, so 
that their destruction,in such dressings and instruments and mate¬ 
rials to be used in wound-treatment as will not be injured by 
moderate heat, is simple and rapid. When micro-organisms in 
a desiccated state are exposed to dry heat, a much higher tem¬ 
perature is required for their destruction than when they are 
moist or when they are exposed to the action of hot water or 
moist steam. For destroying the ordinary pyogenic organisms 
exposure to at least 212° of dry heat for one hour is required, but 
to insure the destruction of spores an exposure of three hours 
or more to a temperature of 284° F. is necessary. 
The possibility of using heat conveniently in the shape of 
boiling water or of steam for the absolute and certain destruc¬ 
tion of bacteria has caused these agents to very largely super¬ 
sede chemicals for the disinfection of instruments, dressings and 
