AIR AS A DISTRIBUTER OF DISEASE 231 



distributed by the air, and a person can take them with- 

 out coming in actual contact with the patient, when no 

 other means of infection is known save that of air cur- 

 rents. The distribution of disease bacteria by means of 

 air, however, does not extend very far from the patient. 

 If bacteria are thrown off into the air, a second person in 

 the same room and in the immediate vicinity may become 

 affected by them. But the danger is confined chiefly to 

 the room occupied by the patient. It is true that the 

 germs may pass into other rooms or out of doors, but 

 they usually cease to be dangerous, partly because they 

 become mixed with such large amounts of pure air, and 

 partly because they soon settle to the floor or ground 

 and are destroyed by sunlight. The danger of taking 

 such diseases decreases rapidly as we pass from the 

 immediate vicinity of the patient. The danger may be 

 much decreased if the skin of the patient be kept moist 

 by a mixture of glycerine and water, or by a little oil 

 rubbed on the skin. This may be done in scarlet fever, 

 during the later stage, when the skin is peeling, and the 

 danger of contagion will thereby be lessened. 



From these facts we can conceive that the dust and 

 dirt collecting on the floor of the sick room will be likely 

 to become a source of trouble. The dust that accumu- 

 lates on the floors, walls, or ceilings, on the window sills or 

 the doors, or on any article of furniture in the room occu- 

 pied by a patient, is likely to contain the living disease 

 bacteria. Such material is therefore a source of con- 

 tagion, and in protecting a family from attacks of conta- 

 gious diseases the dust accumulations of the sick room 

 must be looked upon as a special source of danger. 



