DENTAL CARIES IN THE COTTON EAT(15)

of acid or base. An aqueous solution of 1 X HC1 or l NNaOH was dispersed by pipette through the cereal in suchquantity as to provide an excess of 0.1 equivalent of acid orbase per 100 gm of cereal. The treated cereals were then driedand reground before being mixed in the diet. These dietswere fed for from 10 to 12 weeks.The caries scores given in table 1 showed that the cario-genic activities of potatoes, rice, wheat and dextrin weresimilar. Under the conditions of these experiments, oatmealproduced less caries than the other foods. It is of interestto point out and emphasize that oatmeal was the only foodwhich was not reduced to a flour, and therefore was of coarserparticle size. The destructive effect of the basal diet, whoselargest particles were provided by the casein, is shown infigu