22 
BACTERIOLOGY. 
Chemical 
agents 
Dry dis¬ 
infection 
hospitals, quarantine stations, and departments of 
health in cities for disinfecting wearing apparel, bed¬ 
clothing and bedding. 
The number of chemical agents having destruc¬ 
tive action on bacteria is very large. It will suffice to 
mention a few of the common ones, and describe 
the way they may be applied best. Chemical disin¬ 
fectants may be used dry, in solution, or in the form 
of gas. As examples of dry disinfectants, boric acid, 
bismuth, and iodoform may be mentioned. All are 
used in concentrated form as they are obtained com¬ 
mercially. Boric acid and bismuth are weakly bac¬ 
tericidal, and have an antiseptic rather than a disin¬ 
fectant action. Iodoform when iodine is set free is 
disinfectant. Their chief use is on infected wounds. 
Some of the most used disinfectant solutions are 
as follows:— 
Formalin. 10-20%. 
Bichloride of mercury. 1: 500-1: 1000. 
Carbolic acid . 5%. 
Chlorinated lime . 5%. 
Dakin’s solution . . .. 1-4%. 
Hydrogen peroxide. 20%. 
Alcohol . 70%. 
Not all of these solutions are equally efficacious 
for disinfecting and each one has its advantages and 
disadvantages. 
Formalin is an excecllent disinfectant, and, in 
addition, is also a good deodorant. It does not injure 
fabrics, is not poisonous, and does not coagulate albu- 
