130 PRINCIPLES OF BACTERIOLOGY 



more expensive than sulphur dioxide viz., fifteen to twenty cents per 

 1000 cubic feet against ten cents with sulphur. Therefore, we believe 

 that formaldehyde gas is the best disinfectant at present known for 

 the surface disinfection of infected dwellings. For heavy goods it is 

 far inferior in penetrative power to steam; but for the disinfection of 

 fine wearing apparel, furs, leather, upholstery, books, and the like, 

 which are injured by great heat, it is, when properly employed, better 

 adapted than any other disinfectant now in use. 



Sulphur Dioxide in House Disinfection. Four pounds of sulphur 

 should be burned for every 1000 cubic feet. The sulphur should be 

 broken into small pieces and put in a pan sufficiently large not to allow 

 the melted sulphur to overflow. This pan is placed in a much larger 

 pan holding a little water. The cracks of the room should be carefully 

 pasted up and the door, after closing, also sealed. Upon the broken 

 sulphur is poured three to four ounces of alcohol and the whole lighted 

 by a match. The alcohol is not only for the purpose of aiding the 

 sulphur to ignite, but also to add moisture to the air. An exposure 

 of eight to twelve hours should be given. 



Sulphur fumigation carried out as above indicated is not as efficient 

 as formaldehyde fumigation, but seems to suffice for surface disinfec- 

 tion for diphtheria and the exanthemata. All heavy goods should be 

 removed for steam disinfection if there is any possibility of the infection 

 having penetrated beneath their surface. If there is no place for steam 

 disinfection their surfaces should be thoroughly exposed to fumigation 

 and then to the air and sunlight. In many cases when cleanliness has 

 been observed, surface disinfection of halls, bedding, and furniture 

 may be all that will be required. 



There is always a very slight possibility of a deeper penetration of 

 infection than that believed to have occurred; it is, therefore, better 

 to be more thorough than is considered necessary rather than less. 



Sulphur dioxide without the addition of moisture has, as already 

 stated under the consideration of disinfectants, very little germicidal 

 value upon dry bacteria. 



Public Steam Disinfecting Chambers. These should be of sufficient 

 size to receive all necessary goods, and may be either cylindrical or 

 rectangular in shape, and are provided with steam-tight doors opening 

 at either end, so that the goods put in at one door may be removed at 

 the other. When large the doors are handled by convenient cranes 

 and drawn tight by drop-forged steel eye-bolts swinging in and out of 

 slots in the door frames. The chambers should be able to withstand a 

 steam pressure of at least one-half an atmosphere, and should be con- 

 structed with an inside jacket, either in the form of an inner and outer 

 shell or of a coil of pipes. This jacket is filled with steam during the 

 entire operation, and is so used as to bring the goods in the disinfecting 

 chamber up to the neighborhood of 220 F. before allowing the steam 

 to pass in. ^ This heats the goods, so that the steam does not condense 

 on coming in contact with them. It is an advantage to displace the air 

 in the chamber before throwing in the steam, as hot air has far less 



