328 TJie Management and Diseases of the Dog. 



" Now it is well ascertained that when the excretion of 

 aqueous fluid of one such surface is checked, the exhalation 

 from some other surface becomes more copious. 



" It is probable that the aggregate quantity of water thus 

 expelled from the system in a given time, cannot vary 

 muck, in either direction, without deranging the whole 

 economy. But we are sure that the amount furnished by 

 any excreting surface may vary and oscillate within certain 

 limits consistent with health, provided that the defect or 

 excess be compensated by an increase or diminution of the 

 ordinary expenditure of watery liquid through some other 

 channel. Sound health admits and requires this shifting 

 and counterpoise of work between the organs destined to 

 remove aqueous fluid from the body. This supplemental 

 or compensating relation is more conspicuous in regard to 

 some parts than to others. The reciprocal but inverse 

 accommodation of function that subsists between the skin 

 and the kidneys affords the strongest and the most familiar 

 example. 



" In the warm weather of summer, when the perspiration 

 is abundant, the urine is proportionately concentrated and 

 scanty. On the other hand, during winter, when the 

 cutaneous transpiration is checked by the agency of 

 external cold, the flow of dilute water from the kidneys is 

 strikingly augmented.* All this is well known to be com 

 patible with the maintenance of the most perfect health. 

 But supposing the exhalation from one of these surfaces to 

 be much diminished, or to cease, without a corresponding 

 increase of function in the exterior, then dropsy, in some 

 form or degree, is very apt to arise. The aqueous liquid 

 thus detained in the blood-vessels seeks, and at length 

 finds, some unnatural and inward vent, and is poured forth 

 into the areolar tissue, or into the cavities bounded by the 

 serous membranes. 



* This is especially noticeable after bathing. 



