DYSENTERY. 245 



having half a dozen cases under his charge, save those which have been imported 

 from abroad. In most tropical regions, at certain seasons of the year, it is very 

 pivvalrnt and destructive; but it is in fleets and armies, and more especially 

 among troops on active service, that it most frequently displays its terrible power. 

 In all ages armies and garrisons have been peculiarly liable to suffer from it, and 

 the records of campaigns and military marches are full of accounts of its devastating 

 ravages. It is often said that there is no disease which is so crippling to an army 

 in the field as dysentery. It is the most fatal of all their diseases, and is often 

 spnkcn of as "the scourge of armies." 



What are the causes of this frightful malady ? One of the commonest exciting 

 causes is cold, especially when combined with moisture. It is of frequent 

 occurrence amongst people who are exposed to the cold dampness of night after 

 having been heated during the day. It is very common among the seamen serving 

 on the rivers in the aguish districts in China. We are told that the men, when 

 they lie down on the deck to sleep, pull up their frocks and coarse under-flannel 

 jackets, so as to expose the abdomen. When the cool night wind sets in, the 

 exposed skin of the sleepers, from being bathed in perspiration, becomes dry and 

 finally chilled, and in a very short time they awake to find themselves suffering 

 from the early symptoms of an attack of dysentery. 



Another cause is impure water. For example, nearly every person, native or 

 European, who visits Calcutta, suffers from some kind of bowel complaint. The 

 seafaring men who obtain their supply of drinking water by buckets let down over 

 the sides of their ships are said to be the greatest sufferers. We are not surprised 

 to hear this when we learn that opposite the town the water is frightfully impure, 

 and that it receives every day some 40 tons of excreta, besides a multitude of 

 dead cattle, and about 15,000 corpses yearly. 



Substances which act as direct irritants to the bowels may act as exciting causes. 

 All kinds of indigestible foods are credited with this power, as are also acid and 

 imperfectly fermented alcoholic drinks, such as cider, weak wines, and malt liquors. 



By some eminent authorities it is considered that dysentery is due to the 

 entrance into the system of a marsh poison similar to that which causes ague. 

 They urge in favour of this view that although the ordinarily accepted causes are 

 in constant operation in this country, yet we never suffer from the disease. They 

 believe that the disappearance, both of ague and dysentery, from the metropolis is 

 the result of the improvement in our sanitary conditions. 



Dysentery attacks indiscriminately persons of both sexes and all ages, and if 

 one class of individuals is affected more than another it is probably owing to their 

 greater exposure to the cause of the disease. It is more prevalent in summer and 

 autumn than in winter, and in hot than in temperate climates. It is frequently 

 found in those countries in which ague is prevalent ; and strangers are more likely 

 to be attacked than natives. 



Dysentery is not contagious, or at all events its contagiousness is very slight. 

 When once established, it is propagated by the effluvia from the evacuations of 

 those affected. Sometimes it occurs as an epidemic, but more frequently it is confined 

 within small and often very accurately defined limits. 



