DYSENTERY. 



tcstinal canal only. The anomalies observed in other organs, and in 

 the blood, during dysentery, as well as the more or less severe fever 

 accompanying the disease, are secondary symptoms, induced by the 

 intestinal affection. Dysentery is thus closely allied to cholera, where 

 the infection also causes, first, a severe disease of the intestinal mucous 

 membrane, and, secondarily, as a result of this primary disease, changes 

 in the composition of the blood, in the circulation, and in the nutrition 

 of the various organs. Of course, the intestinal affection is not the 

 same in dysentery as in cholera, and consequently its influence on the 

 blood differs from that of cholera. 



Dysentery poison cannot be directly observed, as an organic, living 

 substance, any more than the poisons inducing other infectious diseases 

 can, but the reasons so often repeated, especially when speaking of 

 typhus, induce us to refer dysentery also to an infection of the body 

 by a certain species of low vegetable organism, and to speak of a 

 "dysentery germ," as we have already spoken of a "typhus germ" 

 and a " cholera germ." From this point of view, we may, to some 

 extent, understand the facts which have been determined by thorough 

 observation concerning the spread of the disease. . 



Dysentery results, although not exclusively, from a miasm ; or, in 

 other words, the dysentery germ grows, flourishes, and increases, out- 

 side of the human body, and persons staying near its locality are in 

 danger of being attacked by it. The circumstances favorable to the 

 increase and propagation of dysentery poison, among which a high 

 temperature and a certain amount of moisture are prominent, exist in 

 the tropical regions ; there the disease is endemic through large por- 

 tions of country. According to the classical work of Hirsch, in Europe 

 only the peninsulas, as the south of the continent, and the islands 

 about them, constantly offer such favorable conditions for the increase 

 of the dysentery germ as to cause the disease to be endemic there. 

 But, through almost all Europe, the conditions for the increase and 

 propagation of dysentery, which is endemic with us also, are occasion- 

 ally so favorable, especially late in the summer, that the disease be- 

 comes epidemic. The circumstance that dysentery is not endemic or 

 epidemic in all regions where high temperature and moisture con- 

 stantly exist, justifies the conclusion that these are not the only things 

 necessary for the growth of the germ, or else that it is not so widely 

 spread as to be found everywhere that conditions favorable to its de 

 velopment exist. The coincident epidemic or endemic occurrence ol 

 dysentery and intermittent is frequent, but not at all constant, accord- 

 ing to the recent observations of Hirsch. Dysentery exists where the 

 requirements for malaria, marshes, etc., are not present. It attacks 

 the open country oftener than the city. 



