FORBES: MINERAL ELEMENTS IN NUTRITION 435 



foods from the market; a large number were from the fertilizer 

 plots of the experiment stations of the country; others were 

 from regions of interest because of the extreme prevalence or 

 rarity of goiter; still others were products from an extensive 

 metabolism experiment with milch cows. The method of esti- 

 mation used was accurate to three-millionths of a gram of iodine. 



About one food sample in five contained iodine. The amounts 

 present were usually too small for expression otherwise than as 

 traces. In 18 samples each of cow's milk, urine, and feces no 

 iodine was found. Iodine was found in considerable quantity 

 only in agar and in Irish moss (from which blanc mange is made) . 

 No other seaweeds were examined. No iodine was found in 

 16 samples of table salt or in any one of seven kinds of nuts. 

 It is very rarely present in spices and condiments. 



Among the animal products the only one containing iodine 

 in more than traces was hair and hoof, from swine, a sample 

 prepared in the course of a complete chemical accounting for 

 the bodies of some experimental subjects. Traces were found 

 in butter, in eggs, and in several kinds (but by no means in all 

 samples examined) of meat, fish, and Crustacea (shrimp and 

 lobster) . 



Among the cereals iodine was found as an uncommon con- 

 stituent, usually in traces only. None of the fruits contained 

 more than the smallest recognizable traces of iodine, and very 

 few contained even so much. 



Among the garden vegetables and root crops beets rather 

 commonly contained traces of iodine (9 samples out of 25), 

 and in one case a larger amount. Two out of three samples 

 of cucumber contained iodine; also one out of three samples of 

 celery. Iodine was found in single samples of endive, kohl 

 rabi, and lettuce. Among onions five samples out of 15 contained 

 iodine, and in parsnips two out of six. Six samples of potatoes 

 out of 21 contained iodine; it was also found in spinach and in 

 rhubarb. We found iodine in one sample of turnips out of 11, 

 but none in tomatoes, pumpkin, and squash. 



Of the hays, silage, and forage crops about one sample in 

 four contained iodine. Among leguminous seeds iodine was 



