DENTAL CARIES IN THE COTTON EAT(12)

alkaline-ashfood. These were cooked, peeled, dried, and then reduced to aflour in a ball mill. "NVheat flour, rice flour, and finely g'roundoatmeal were used as representative acid-ash foods. Theash character of some of these foods was altered by the addition 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.