286 



Scientific Proceedings (129) 



and rate of flow in proportion to the weight of the animal was 

 held to be important, if satisfactory results were to be obtained. 

 The use of the cat was held to possess distinct advantages in 

 that it afforded the analyst the opportunity of recording the 

 exact action of the preparation upon the heart. It was held 

 to be a possibility that further work might result in a method 

 for measuring the total therapeutic activity, as well as the 

 toxicity. 



Results were submitted showing that the first year's growth 

 digitalis leaves as produced at the University of Minnesota 

 during 1922 were the equal in every way with respect to thera- 

 peutic value to leaves collected from second year's growth, pro- 

 vided the long petioles which frequently develop during the 

 first year's growth were not included in the drug. The petioles, 

 it was pointed out, represented 40 per cent, of the weight of 

 the entire dried leaf. The general practice is not to collect these 

 long leaf stalks. The leaf stalks or petioles were stated to be 

 only about one-quarter as rich in therapeutic constituents as the 

 lamina. 



138 (2098) 



Experimental goitre and iodin in natural waters in relation to 

 distribution of goitre. 



By J. F. McCLENDON and AGNES WILLIAMS. 



[From the Laboratory of Physiological Chemistry, University of 

 Minnesota, Minneapolis, Minnesota.] 



White rats of 30 gram weight were placed on a diet containing 

 about or less than .006 milligram of iodin in 50 grams of dry 

 foodstuff in addition to distilled water. Controls were placed 

 on the same diet except for one day a week when they drank 

 water containing .01 per cent, iodin. At the end of about three 

 months those receiving the iodin had thyroid glands one-half 

 to two-thirds the weight of those receiving no iodin. 



The United States is divided into four zones based on the 



