METABOLISM 



577 



diacetic acid) is particularly pronounced. The following table shows 

 the data obtained in an actual case of the withdrawal of carbohydrate 

 food from the diet of a normal man (von Noorden). 



ACIDOSIS ACCOMPANYING CARBOHYDRATE WITHDRAWAL 



Experiment. Ingest an ordinary mixed diet for one day. Follow this by a 

 period of two to four days in which no digestible carbohydrate is eaten. (A diet 

 of meat, eggs, butter, agar-agar and water has a very low digestible carbohydrate 

 value.) Collect the urine for each day of the experiment, examine it qualitatively 

 for acetone bodies (see tests in Chapter XXIII). If present, determine the total 

 acetone bodies quantitatively (for methods see Chapter XXVI). The blood may 

 also be examined (see Chapter XVI). Did the withdrawal of carbohydrate food 

 cause an acidosis or ketonuria? How did it compare with the acidosis in the 

 above table? 



16. "Alkaline Tide." For a time after a meal the normal acid 

 reaction of the urine may be changed to neutral or alkaline. This 

 has been explained as due to the withdrawal of hydrogen ions to manu- 

 facture the hydrochloric acid of the gastric juice. 



Experiment. Ingest an ordinary mixed diet. Urinate just before dinner and 

 note the reaction of the urine to litmus. If acid, determine the hydrogen ion 

 concentration by the method given in Chapter XXVI. (If alkaline, discard the 

 urine and make the test on another day.) After eating a heavy dinner (meats) 

 collect the urine at intervals of a half -hour and take the reaction to litmus and 

 determine the hydrogen ion concentration as before. Did your urine change in 

 reaction after the meal and if so how long a period elapsed between the meal and 

 the occurrence of the maximum change in reaction? 



17. The "Partition" of Urinary Nitrogen and Sulphur as Influenced 

 by Diet. It was first shown by Folin 1 that the percentage of the total 

 nitrogen and total sulphur of the urine which appeared in the form of 

 any particular nitrogenous constituent or in any particular form of 



1 Folin: Amer. Jour. PhysioL, 13, 118, 1905. 

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