125 



of southern countries*. Lepra originated in Judea; the elephantiasis 

 rubra of Cayenne, the framboesia of Java, the yaws, elephantiasis, her- 

 petic and psoric eruptions, are more frequent among the inhabitants of 

 southern latitudes than among those who live under the temperate zones. 

 In countries near to the equator, the surface of the body, habitually ex- 

 posed to an ardent atmosphere, is powerfully excited : the skin is irrita- 

 ted, and its secretion increased; perspiration becomes so profuse, thatit 

 weakens, in a short time, those who, coming from distant countries, are 

 not accustomed to so intense a heat. The activity of the cutaneous sys- 

 tem exceeds that of the urinary system, whose action decreases in propor- 

 tion. These differences in the energy of the two systems, account readily 

 for the difference of their diseases: for, it is a law of Nature, that the 

 more an organ, or system of organs, is called into action, the more it is 

 liable to disease, which is but a derangement of its action. 



Calculous affections are more frequent in children and old people than 

 in adults. In old age, the proportionate quantity of the urine exceeds 

 that of the perspiration. Phosphoric salts, the base of a great number 

 of urinany calculi, are more abundant in old men, as is proved in them by 

 the ossification of the arteries, of the ligaments, of the cartilages, of the 

 membranes, ihe solidification, ar.d the almost universal induration of the 

 different parts. In children the activity of the urinary system is propor- 

 tionate to that of the digestive organs. Destined to throw out the resi- 

 due of nutrition, which, at that period, is very active, the organs by 

 which the urine is secreted are likewise endowed with considerable ener- 

 gy. Lastly, it is observed, that the greatest number of calculous patients 

 received into the hospitals of large towns, come from low and damp 

 streets near to rivers; every thing-, therefoie, tends evidently to esta- 

 blish, that the frequency of urinary calculi, depends on an increase of 

 activity, in the organs destined to the secretion and excretion of urine. 



CHAPTER II. 



OF ABSORPTION. 



XL. IN the history of the phenomena of life, a statement of the func- 

 tions of the absorbent system, ought immediately to follow that of the 

 functions of the digestive organs. The vessels, which take up the chyle 

 separated from the food, by the action of the organs of digestion, form a 

 considerable part of the absorbent system, bear a perfect resemblance to 

 the other lymphatics, and differ from them only in their origin. When 

 digestion is not going on, those vessels convey lymph absorbed in the in- 

 testinal canal, the inner part of which, even when in a state of emptiness, 

 is always bedewed by an abundant quantity of serous mucus. 



* It would be more correct to say that cutaneous affections are more frequent among 

 the inhabitants of southern climates. 



