284 



PHILIP B. HAWK 



other observers (Bogen, Honiborg, Kaznelson, Sick, Umber) claim, as 

 the result of experiments on man, that the latent period varies from 3 to 

 10 minutes. Carlson says: 



"The latent, period of the appetite secretion varies indirectly with the 

 rate of continuous secretion so that when the continuous secretion is 

 abundant, the appetite secretion shows no latent period at all, while with 

 the lowest rate of the continuous secretion, the latent period varies from 

 2 to 4 minutes." 



That this latent period does not exist in certain human stomachs after 

 water stimulation is evident from our data. 



/OO cc. distilled uscl-lrer -then added 



Fig. 4. Curves showing immediate stimulation by water and rapid emptying of the 

 stomach. (Bergeim, Rehfuss and Hawk; Jour. Biol. Chem., 1914, XIX, 345.) 



It has also been claimed that, the gastric glands exhibit a pronounced 

 fatigue when subjected to repeated stimulation (Foster and Lambert). 

 That this pronounced glandular fatigue is not always inevidenco is illus- 

 trated in Fig. 5. A normal man was given 500 c.c. city water (10-12 

 C.) at 1 p. m., five hours after breakfast, and samples of juice were 

 collected at ten-minute intervals until the stomach was approximately 

 empty. After an intermission of ten minutes the experiment was re- 

 peated. It will be observed that the stimulation was almost as great in the 

 repeated test as in the initial one. A similar absence of glandular fatigue, 

 in the dog, has also been observed by Ivy(&) after the injection of gastrin 

 evei'y two hours over a period of twenty-six hours. 



When gastric stimulants ^ are under discussion, much emphasis is in- 

 variably placed upon the stimulatory power of meat extract. The com- 

 parative stimulatory power of water and meat extract in the same normal 



