512 
PREVENTION OF DISEASE 
following the discovery of the diphtheria antitoxin the lives 
of a million children were saved in France alone. State 
boards of health usually furnish antitoxin for diphtheria and 
lockjaw. 
LABORATORY STUDY 
It takes five pounds of sulphur to disinfect a room which contains 
1000 cubic feet of air. Three ounces of forty per cent formalin, to 
which is added two and one tenth ounces of potassium permanganate, 
will also disinfect the same sized room. Compare the cost and ease 
with which each is used. 
392. Disinfection and Disinfectants. — The time when 
disinfectants shall be used and the manner of disinfection 
have been considered important factors in preventing the 
spread of communicable diseases. The purpose of disin¬ 
fection is to destroy the germs lodging on clothes, floors, 
carpets, and curtains. People who care for the sick should 
know where the germs are likely to be and how to disinfect 
places where they have found lodgment. The term disin¬ 
fectant is sometimes incorrectly applied to deodorizers, sub¬ 
stances which are used to destroy odors, but the word should 
be applied only to substances which destroy germs or bac¬ 
teria. 
Disinfectants are not expensive, and few of the patented 
preparations are as satisfactory as the common ones used 
by boards of health. Weak solutions of carbolic acid and 
bichloride of mercury are chiefly used for killing the germs 
on the hands and clothing, or for cleaning the woodwork in 
the sick room. Chloride of lime is used to kill the germs 
in the discharges of the body, and sulphur dioxide and 
formaldehyde gas for the final killing of the germs in the 
room or the whole house before it is occupied again. 
Never use any methods of disinfection unless they have 
been personally recommended to you by a physician or an 
expert in the details of room disinfection. Do not rely 
