“…Examples of such results may be found in the works of Boyden and Noble (1933), Wilhelmi (1940), and others, using the ring test procedure, and in the reports of Boyden and Gemeroy (1950), Gemeroy (1943), Gemeroy and Boyden (1961), Leone and Wiens (1956), Leone (1949, 1950a andb), Moody (1958), Moody, Cochrane, and Drugg (1949), Moody and Doniger (1956), Stallcup (1954), Wemyss (1953), and others, using the normal titration curve procedure. For the details, the original works should be consulted.…”