426 APPLIED PHYSIOLOGY 



extermination of house flies. It is not carried by the air or the dust 

 of the sick room, and so quarantine of the sick room is not necessary. 

 But it may be carried by soiled bedclothes, or on the hands of the 

 nurse. It is necessary to be careful in the cleanliness of everything in 

 the sick room, and to dispose of all slops and sewage in such a way that 

 the germs in them cannot escape. 



Cholera is an intestinal disease which is spread in the same way as 

 typhoid fever. It is seldom seen in civilized lands, but is common 

 among people who drink river water which is full of sewage. 



740. Mumps. Mumps is caused by the growth of a 

 kind of microbe in the salivary glands, producing swellings 

 around the lower jaw. It seldom causes a severe illness. 

 Its germs are not long-lived and do not readily spread. 

 The disease may be suppressed by keeping the sick away 

 from well persons, and by washing their dishes and towels 

 and handkerchiefs separately from those used by other 

 persons. 



741. Eruptive diseases. There are a number of infec- 

 tious diseases in which spots appear on the skin. For this 

 reason they are called eruptive diseases. The common 

 eruptive diseases are measles, scarlet fever, chicken pox, 

 and smallpox. A person who has had one of these dis- 

 eases is usually immune to it for the rest of his lifetime. 



The eruptive diseases are caused by germs whose exact nature has 

 not been discovered. The germs may live in clothing, or carpets, or 

 other things which are laid away in a dark, close room, but they soon 

 die when they are exposed to the sunlight and fresh air. The dis- 

 eases are usually spread by well persons living in the same room or 

 house with the sick, or by using some article which the sick have 

 handled. They may be suppressed by closely quarantining the sick, 

 thoroughly cleansing everything in the sick room, and properly dis- 

 posing of all slops and sewage from the sick. The chief obstacle in 

 the way of entirely stamping out the diseases is the great difficulty of 

 recognizing extremely mild cases of the diseases in which few or no 

 spots are seen. 



