EXCRETION 



447 



ti vely narrow limits in health, according to Koranyi, the diet exercising 

 no influence upon it whatever. Thus, in a large number of healthy 



individuals ^ fluctuated only between i'23 and i'6g, while A 



varied from i'26 to 2'35, and the percentage of sodium chloride 

 from 0-85 to i -54. This is illustrated in the table : 



The Urine in Disease. Although, strictly speaking, a truly 

 pathological urine has no place in physiology, the line which 

 separates the urine of health from that of disease is often narrow, 

 sometimes invisible ; while the study of abnormal constituents 

 is not only of great importance in practical medicine, but throws 

 light upon the physiological processes taking place in the kidney, 

 and upon the general problems of metabolism. Even in health 

 the quantity of the urine, its specific gravity, its acidity, may 

 vary within wide limits. A hot day may increase the secretion 

 of sweat, and correspondingly diminish the secretion of urine, 

 and the deficiency of water may lead to a deposit of brick-red 

 urates. A meal rich in fruit or vegetables may render the urine 

 alkaline, and its alkalinity may determine a precipitate of earthy 

 phosphates. But neither the scanty acid urine with its sedi- 

 ment of urates, nor the alkaline urine with its sediment of 

 phosphates, comes into the category of pathological urines ; 

 the deviation from the normal does not amount to disease. 

 The maximum deviation from the line of health is the total 

 suppression of the urine. If this lasts long, a train of symptoms, 

 of which convulsions may be one of the most prominent, and 

 which are grouped under the name of uraemia, appears. At 

 length the patient becomes comatose, and death closes the 

 scene. Suppression of urine may be the consequence of many 

 pathological conditions, but there is one case on record in the 

 human subject which, in effect, though not in intention, belongs 

 to experimental physiology. A surgeon diagnosed a floating 

 kidney "in a woman. With a natural impatience of loose odds 

 and ends of this sort, he offered to remove it, and in an evil 



