44 ANALYSIS OF DISTURBANCES OF METABOLISM 



faulty absorption of food— and this is to be especially discussed here— they 

 can be well controlled and have in fact been thoroughly investigated. 



The loss in material which the body suffers from profuse sweating is rela- 

 tively slight. But the heat equivalent that corresponds to the evaporation 

 of one liter of sweat amounts to no less than 580 calories. We are Justified, 

 therefore, in speaking of " exhausting sweats." 



The food requirement of the patient is decidedly increased by muscular 

 work. We know that even simple muscular tension, without any accompany- 

 ing effort, is expressed in an increase of the respiratory metabolism. It is not 

 essential, therefore, that there should be a pathologic tendency to movement 

 which constantly keeps the entire musculature in action, as in many insane 

 patients, or that severe convulsions should produce such shock. On the con- 

 trary, even the restlessness of a patient in bed with increased respiration and 

 cardiac action and mild tremor, as frequently occurs in the susceptible 

 patient, will bring about an increase of oxidation. The degree of such in- 

 crease in metabolism cannot, however, be determined quantitatively. 



The conditions are still more difficult if we attempt to estimate the loss 

 of substance which the diseased body suffers in the discharge of transudates, 

 in suppurating wounds, in profuse expectoration^ in severe albuminuria, in 

 long-continued hemorrhage, and the like. There can be no doubt that, in all 

 cases in which there is loss of the body albumin, the diet must be arranged 

 to compensate for it if loss of weight is to be prevented. 



The conditions are much plainer when, in consequence of qualitative dis- 

 turbances of metabolism, the affected organism suffers loss because the food 

 products are not oxidized to their normal end products, and, in consequence, 

 material which is still capable of oxidation is present in the blood, and is 

 excreted unoxidized or imperfectly oxidized in the urine. 



The sugar which the diabetic excretes in the urine is lost to the body as a 

 source of power. If we fail to take account of this we overestimate the actual 

 food-requirement and energy-interchange of the diabetic. With a suitable 

 diet, in fact with a diet of the same calory values, we can produce equilibrium 

 of metabolism in the diabetic as in the healthy. Only the food must be given 

 to him in such a form that he can utilize it. 



By other products also, which, in disturbances of metabolism, are found 

 in the urine (acetone, aceto-acetic acid, /8-oxybutyric acid, cystin, homogen- 

 tisic acid, etc.) energy is occasionally lost to the body. 



The organism always loses energy when there is insufficient assimilation 

 of food in the intestines. This occurs in the healthy, but is frequently 

 and decidedly increased in the sick. Its amount may be accurately deter- 

 mined. 



In the healthy estimation of the calory value of feces such as are dis- 

 charged by those on a mixed diet has led Rubner to assume a reduction of 

 8 per cent, from the raw calory value of the ingested food as the average 

 amount of energy thus lost. This calculation, however, is valid only under 

 conditions in which the feces are made up chiefly of the unabsorbed" residue 



