“Portions of walls and ceiling not readily accessible may be disinfected by chlorine gas liberated from chloride of lime by crude carbolic acid. This is accomplished by making a cone of 5 or 6 pounds of chloride of lime in the top of which a deep crater is made for the placement of from 1 to 2 pints of crude carbolic acid. The edge of the crater is thereupon pushed into the fluid, when a lively reaction follows. Owing to the heat generated, it is advisable to place the chloride of lime in an iron crucible (pot), and to have nothing inflammable within a radius of two feet. The number and location of these cones of chloride of lime depend on the size and structure of the building to be disinfected. As a rule it may be stated that chlorine gas liberated from the above sized cone will be sufficient for disinfecting 5200 cubic feet of air space.” _Liquid manure_, _leachings_, etc., where collected are thoroughly disinfected by chloride of lime applied in the proportion of 2 parts to 1000 of fluid. [Illustration: FIG. 113.--Chamber used in government work for formaldehyde disinfection. The small cylinder at the side is the generator.] _Vehicles_ may be thoroughly washed with 2 per cent. formalin solution, or if closed space is available, subjected to formaldehyde gas disinfection, after cushions, hangings, etc., have been removed and washed with the disinfectant. _Harness_, _brushes_, _combs_ should be washed with a solution of formalin, carbolic acid, or creolin as given under these topics. _Washable articles_ should be boiled, dropped into disinfectant, solutions as soon as soiled, and then boiled or steamed. _Unwashable articles_--burn all possible. Use formaldehyde gas method in a closed receptacle (Fig. 113). _Stock cars_--the method described for stables is applicable here. _Animals, large and small_, may have the coat and surface of the body disinfected by washing with 1 to 1000 bichloride or strong hot soapsuds to which carbolic acid has been added to make a 5 per cent. solution; they should then be given a good warm bath. Frequently time and money are saved by a combination of steam and formaldehyde disinfection. This is a regular practice in municipal and quarantine disinfection (Fig. 114). [Illustration: FIG. 114.--Chamber in actual use at government quarantine station for disinfecting baggage and dunnage with steam or formaldehyde or both. The small cylinder at the side is the steam formaldehyde generator.] Persons engaged in disinfection work should wear rubber boots, coats and caps which should be washed in a disinfectant solution and the change to ordinary clothing made in a special room so that no infective material will be taken away. PART III. THE STUDY OF BACTERIA. CHAPTER XVI. CULTURE MEDIA.