SYMPTOMS AND CLINICAL COURSE 113 



The kidneys apparently endeavor to excrete more water; they withdraw 

 fluid from the body approximately at a uniform rate ; if water is not supplied 

 in plentiful amounts, inspissation of the blood occurs more readily than in 

 healthy individuals. Thus, in a case studied by Strubell, in a patient whose 

 thirst was unrelieved by water for several hours, the specific gravity of the 

 blood rose from 1.055 to 1.071. 



Similarly to the condition in contracted kidney (though here the secretion 

 of uriue is increased from other causes) we find in cases of diabetes insipidus 

 a diminution of the excretion of water through the skin and lungs. We are 

 not prone to attribute this condition to disturbance of the functions of the 

 skin and lungs but are rather disposed to assume that most of the water has 

 been discharged through the kidneys, and hence there is not enough left for 

 the skin and the' lungs. Only after the disease has lasted a long time does the 

 diminution in the activity of the skin attain a certain independence in the 

 clinical picture, as it does in nephritis. 



Insensible perspiration, as well as siveat formation, is diminished, and the 

 fact that no sweating occurs in great summer heat has been noted in a number 

 of clinical histories. Stoermer states that one of his patients showed a rise in 

 temperature to 103.9° P. on very hot days ; on account of his inability to sweat, 

 the patient apparently was unable to cool his body in opposition to the high 

 external heat. 



Naturally the increased excretion of water also requires an increased intake 

 of water, and accordingly the normal desire for water is decidedly increased 

 in all cases of diabetes insipidus. Decided thirst may be the first and most 

 troublesome symptom of the disease, but the physician (in typical cases) sees 

 in it only a result of the diabetes. How far a primary and pathological thirst 

 with secondary increase in the amount of urine must be assumed in certain 

 cases will be considered further on. 



That the condition of nutrition' in many cases is not influenced, and in 

 other suffers more or less severely, has been already mentioned. This varia- 

 tion in the condition of the general health bears no direct relation to the 

 amount of the urinary secretion. 



As thirst is uniformly present so also the appetite is often enormous. 

 Ehrhardt relates the case of a patient who consumed 12 beefsteaks for break- 

 fast and 14 portions of meat at his midday meal. It is self-evident that in 

 these individuals the composition of the urine will deviate from the ordinary 

 in that the amount of the dissolved constituents will be decidedly greater 

 than the normal. French authors describe diabete azoturique as an inde- 

 pendent affection differing from the ordinary diabetes by an increase of 

 N-excretion. It is very probable that a large number of cases included in this 

 group represent really such cases of diabetes insipidus as were blessed with an 

 appetite of the variety Just mentioned. At any rate, in recent times, when 

 pathology has not only considered excretion but also metabolism as a whole, 

 no cases of diabetes insipidus have been reported in which albumin decompo- 

 sition was' decidedly greater than the albumin intake. 



Frequently with an improvement in the general condition, the abnor- 

 mally great appetite also disappears. 



