The Sixteenth Edition (October 1905) was edited by J. C. DaCosta, and the Seventeenth (September 1908) by DaCosta and E. A. Spitzka. Spitzka edited the Eighteenth (Oct. 1910) and Nineteenth (July 1913) editions, and in October 1913, R. Howden edited the New American from the Eighteenth English Edition. The “American” editions then continued with consecutive numbering from the Twentieth onwards, with W. H. Lewis editing the 20th (September. 1918), 21st (August 1924), 22nd (August 1930), 23rd (July 1936), and 24th (May 1942). C. M. Gross edited the 25th (August 1948), 26th (July 1954), 27th (August 1959), 28th (August 1966), and 29th (January 1973). Carmine D. Clemente edited and extensively revised the 30th edition (October 1984). With the sale of Lea & Febiger in 1990, the 30th edition was the last American Edition.