Determination of Iodine 



101 



greater. The diversification of the flora became greater in some 

 of the subjects as lower levels of the jejunum were reached; in 

 the majority of them bacilli of the colon group assumed greater 

 prominence. The Streptocci persist in Sub. II and the question 

 arises whether their continued presence indicates a definite local- 

 ization (infection) in the alimentary tract. 



Abstracts of Communications 

 Special June meeting. 

 Minneapolis, Minnesota, June 12, 1922. 

 49 (2009) 



The determination of iodine in large samples of foodstuffs. 

 By J. F. McCLENDON and O. S. RASK (by invitation). 



[From the Laboratory of Physiological Chemistry, University 

 of Minnesota Medical School, Minneapolis, Minnesota.] 



The method of Kendall was found satisfactory for estimating 

 small amounts of iodine as low as 0.02 mg. where destruction of 

 large amounts of organic matter was not involved. If, however, 

 the size of the sample is increased there is a corresponding de- 

 crease in accuracy. In order to reduce the bulk of material the 

 following processes were carried out : Cereal grains were made 

 into beer without removal of any solid matter and the alcohol 

 volatilized after making the beer alkaline. In the combustion, 

 the fumes were passed through an alkaline solution to catch the 

 iodine. After the iodine was in the form of I 2 it was shaken out 

 with carbon tetrachloride and then this carbon tetrachloride 

 shaken with a dilute solution of S0 2 to get the iodine into water 

 solution again as iodine. By these processes both organic and 

 inorganic inert constituents may be eliminated. 



