Scope and Contents From the Collection: The Northwestern University G.V. Black digitized collection contains 43 manuscripts, 100 letters and several photographs covering the period between 1867 and 1915. Some of the more important items in the collection are: correspondence between Dr. Black and Dr. Frederick S. McKay from the turn of the century that focus on mottled enamel of teeth and early hypotheses on water and fluoridation; correspondence, program announcements and other memorabilia from the World Dental Congress held in...