EPIDEMICS. 



extremes of temperatures, hence the rationale of baking clothes and boiling linen 

 which has been in use in the fever-room, and the explanation of the disappearance 

 of many epidemics during the colder months of the year. Many of these poisons are 

 also destroyed by disinfectants, such as chlorine, and the vapour of burning sulphur, 

 Their intensity seems to increase with overcrowding, as in those horrible " fever 

 dens " of which we hear so much. 



We have mentioned the term epidemic. By an epidemic disease we mean one 

 that travels from place to place. Cholera is a striking example of an epidemic 

 disease. It is always present on the banks of the Ganges, but at times it breaks 

 its bounds, and travels all over the civilised world. It usually travels along the 

 lines of human intercourse, and its rate of progress varies considerably in different 

 epidemics. It may take two or three years to spread from India to America, or 

 may do so in as many months. It is said that epidemics travel very much faster 

 than they used to, but that even now in Russia, where in many places human inter- 

 course is very limited, their progress is comparatively slow. Epidemics usually make 

 their entry in this country either at Southampton, London, or Hull. Sometimes an 

 epidemic of cholera will miss certain places apparently on its direct line of march, 

 and then go back and invade them later. Sometimes an epidemic of cholera dis- 

 appears abruptly after a high wind, just as if it were blown away : but generally it 

 departs slowly and gradually, and in a manner more compatible with its dignity. 

 Cycles of epidemics are sometimes observed, one disease being after a time followed 

 by another, this by a third, and so on. 



Some diseases are not epidemic at all, but are what is called endemic that is, 

 they confine their attention solely to their place of origin. If you want ague you 

 will have to go to it, it will not come to you. Endemic diseases never spread from 

 one person to another, and never go away from the locality except in the person of 

 the individual. 



We have shown that for the maintenance of health it is necessary that certain 

 things should be taken into the body, and it is equally essential that certain other 

 things should be given off from it. All waste materials must be got rid of, for if 

 retained they would soon interfere with the working of the delicate mechanism of our 

 organisms. The non-elimination of the urine for even twenty-four hours would be 

 attended with the most serious results. Many people neglect their bowels, and the 

 result is that the health always suffers sooner or later. We all know the untoward 

 symptoms occasionally following a " sudden chill," or in other words, following 

 arrest of the functions of the skin. Illness is occasionally produced by the abrupt 

 cessation of some long-accustomed discharge. Women whose periods have been 

 arrested by cold or exposure often suffer severely for some days subsequently. It 

 is the rule in animal life that a certain amount of work must be done in return for 

 the crude force taken into the system in the shape of food and drink. 

 If a man were to take his accustomed quantum of food, but instead of 

 working were to remain in bed all day, and do nothing, he would quickly suffer for 

 it. The muscles of the limbs, if not used, very soon waste away, or get converted 

 into fat. People who, although they may not remain in bed all day, take too little 

 exercise, are seldom in really good health. They get fat and bloated, the extremities 



