598 PHYSIOLOGICAL CHEMISTRY 



(b) Food Starvation vs. Water Starvation. Place two young guinea pigs 

 (150-200 grams) in separate cages. Give one a diet such as that described on 

 page 585 (c), but permit the animal no water. Give the second pig no food, but 

 permit free access to water. The pig receiving no water will quickly become 

 abnormal, and it will be necessary to give it water to preserve its life. The 

 second pig, which has access to w'ater 1 but receives no food to eat, will live 

 longer than the pig receiving an abundance of dry food. This little experiment 

 impresses the important fact that man can live longer without food than without 

 water. 



n. Metabolism Procedures Involving the Manipulation of the Urine 



8. Collection and Preservation of the Urine. In metabolism tests, 

 such as those given in this chapter the accurate collection of the urine 

 for the exact 24-hour period is of the utmost importance. Proceed as 

 follows: Empty the bladder at a given hour, e.g., 8 a.m. and discard the 

 urine. Prepare a thoroughly clean bottle of proper size, introduce into 

 it sufficient toluene to cover the bottom of the bottle and use this bottle 

 for the collection of all urine voided from 8 a.m. until 8 a.m. the next 

 day. During the day, when not actually in use for the introduction 

 of a urine fraction, the bottle should be kept in a refrigerator or cold 

 room in order that the sample may not deteriorate before it is examined. 

 Measure the volume of the sample and determine its specific gravity 

 (see Chapter XXII) and reaction before proceeding to the quantitative 

 estimation of any specific urinary constituents. 



9. Complete Analysis of Urine. Ingest an ordinary mixed diet (or any special 

 diet) and collect the urine accurately for a 24-hour period (see above). Measure 

 the volume of the sample, determine the specific gravity and preserve the urine 

 (see above) until the following constituents have been determined (for Methods 

 of Analysis, see Chapter XXVH). Total solids, titratable acidity, hydrogen ion 

 concentration, total nitrogen, amino-acid nitrogen, ammonia, urea, uric acid, 

 creatinine, total sulphur, ethereal sulphates, inorganic sulphates, neutral sulphur 

 (by difference) total phosphates and sodium chloride. 



Calculate the nitrogen and sulphur "partitions," i.e., the percentage of the 

 total nitrogen and sulphur which occur in the different forms and tabulate the data 

 from the complete analysis. Compare your results with those listed in the table 

 on pages 388 and 611. 



10. Hyperglycemia Produced by Carbohydrate Ingestion. The 



average glucose content of normal blood is somewhat less than o.i per 

 cent. This is increased (hyperglycemia) on the ingestion of carbo- 

 hydrate food. The increase is noted more quickly after the ingestion of 

 monosaccharides than after the ingestion of the more complex carbo- 

 hydrates. After the ingestion of 100 grams of glucose or starch an 

 increase in the sugar of the blood sometimes occurs in five minutes. 2 

 (See Fig. 1 88.) 



1 In case the pig does not drink the water, the animal should be fed the fluid by a sound. 

 2 Jacobson: Bioch. Zeit., 56, 471, 1913. 



