858
JOURNAL OF CHEMICAL EDUCATION
MAY,1932
F., Ber., 62, 1637 (1929). (6) WEINMANN, (7) HEIDELBERGEE, M., AND KENDALI., F. E., J. Bhl. Chen., 84, 639 (1929). A. D., ibid., 86, 491 (1930). (8) LINK, K. P.,AND DICKSON, A. G., Biochem. J., 23, 524 (1929). ( 9 ) NORMAN, A. G., did., 25, 200 (1931). (10) NORMAN, (11) voN FELLENBERG, T., Biochenr. Z., 85, 44 (1918). B., Bet.., 33,132 (1900); TOLLENS, B., ibid., 34, (12) WIDTSOE,J. A., AND TOLLENS, 1434 (1901); O'SULLIVAN, C., J. Chem. Soc., 79, 1164 (1901). (13) SANDS,L., AND KLAAS,R., J. Am. Chem. Soc., 51,3441 (1929). (14) HEIDELBERGER, M., AND G ~ E B E LW. , F., J . Bid. Ckem., 70, 613 (1926).
Diamonds found in American gravels. A number of diamonds have been found in gravel deposits in Michigan, Wisconsin, and Illinois. While the majority of them are small, many diamonds of considerable value have been discovered. The largest so far r e ~ o r t e dfound weighed 21'12 carats. A great diamond field somewhere in the north is believed t o be the source of these one knows. But undoubtedly a t some time stray diamonds. Where i t is-or wa-no glaciers swept over it, carrying away with them some of the diamonds, and perhaps even sweeping As they moved down over the Great Lakes region - away the entire deposit. they scattered the diamonds among the gravel they left in their wake. Attempts made to find this field have all failed. Probably if still in existence i t is hidden in the great wild and inaccessible areas of Canada, and the search for it is on a par with the hunt for the proverbial needle in the haystack. The diamonds found in the gravel beds, having heen washed by water, are clean and easily seen. They resemble pieces of glass or clear crystal quartz. Usually they will reflect a rainbow of color without polishing. Therefore pebbles showing rainbow colors are worth examining carefully.-Science Senn'ce New type of frozen fruit being developed. Z A new type of frozen fruit, which not only will appeal to the palate but also will offer a new outlet for the fruit grower and packer, is being developed by the Food Research Division of the Bureau of Chemistry and Soils, Department of Agriculture. By pulping the pitted fruit, adding a sugar sirup, mining i t thoroughly and then freezina i t a t vcry low temperatures, Department chemists have developed this frozen fruit product which they claim has a remarkably smooth texture and fully retains the original flavor. The experiments already have been made with excellent results with several varieties of fruit, and it is hoped that later results will measure up t o the promise of these preliminary experiments. If so, ice-cream manufacturers and soda fountain operators will have a new and highly desirable fruit'base, which also will be available for direct consumption in the frozen state.-Science Service Fluorine proved cause of mottled teeth. Dogs with mottled teeth, an endemic condition of the enamel produced by the presence of fluorine in drinking water, have been achieved experimentally by Dr. Margaret Cammack Smith of the home economics department a t the University of Arizona. Six months ago, Dr. Smith completed her experiments with the drinking water a t St. David, Arizona, and determined that fluorine in the drinking water a t that place was responsible for the existence of mottled teeth. .\t first the mottled condition w a only ~ producyd exprrirnent?lly irn ~vhiterats hut nor for the lirit time t h condition ~ has heen given to the largrr nnirnals. Thr mottled condition has been produced after a six months' feeding experiment.-Science Service
