Thumb Sucking Is Discouraged.  Where a baby sucks its thumb, it may irreparably injure its speaking and singing voice in after years, Dr. Newton C. Thomas of Northwestern University of Chicago, told delegates attending the National Council of Teachers of America which concluded its sessions today.  “This form of relaxation is said to cause malformation of the upper jaws,” said Dr. Thomas, “and destroys some of the overtones that are so vital a part of musical speech.”  The Evening Kansan-Republican, Newton Kansas.  Saturday, November 27, 1915.  Page 1.