HYGIENE AND SANITATION 23 
This method of fumigation is not applicable when the temperature 
falls below 65° F. for the gas condenses under such conditions. 
Disinfection may be accomplished by spraying objects with a 
mixture of 5 parts of formalin to 95 parts of water. 
Carbolic acid or phenol. Pure carbolic acid exists at ordinary 
temperatures as needle-like crystals. This substance is frequently 
used in the form of liquefied carbolic acid which consists of 9 parts 
of the crystals mixed with 1 part of water. Carbolic acid is ordi- 
narily employed as a disinfectant in a five per cent solution of the 
crystals. As the crystals dissolve slowly, solution is hastened by the 
use of hot water. The fluid may be applied liberally to surfaces as 
a spray, or fabrics and implements may be immersed in the fluid for 
an hour. Carbolic acid is somewhat expensive, and on this account 
some other cheaper agent may be employed. The substance in ques- 
tion should not be confused with “crude carbolic acid” which is 
quite different in composition. 
Crude carbolic acid. Commercial crude carbolic acid is a by- 
product of the distillation of coal tar. It contains certain insoluble 
oils and a mixture of cresols and similar substances which possess 
disinfectant value. When the content of these is known, an effective 
disinfectant may be made by including these substances in two per 
cent solution. The disinfectant in question should not be confused 
with true carbolic acid (phenol). 
Chloride of lime. Chloride of lime or chlorinated lime consists 
of slaked lime which has been exposed to the action of chlorine. 
It is a white powder which deteriorates in strength rapidly after 
opening the hermetically sealed container in which it is supplied. 
This disinfectant is particularly useful where the action of a de- 
odorant is desired besides a disinfectant. It is commonly employed 
diluted with water in the proportion of six ounces to a gallon of 
water. The presence of organic matter interferes with the effective- 
ness of this agent. 
Various coal-tar creosote disinfectants. Mixtures of various 
coal-tar products, principally creosote oil, with soap in the form of 
emulsions are on the market under a large variety of trade names. 
The disinfecting value of these products varies greatly, but when 
the carbolic acid coefficient is stated, one of these products may be 
used with assurance as to its efficiency. The expression carbolic acid 
coefficient, refers to the relative germicidal value of a product as 
compared with carbolic acid. 
Bichloride of mercury or corrosive sublimate. This agent is 
