Born in Kalamazoo, Derek Yonkerman (1859-1923) moved to Cleveland with his family seven years later. He eventually became a veterinarian, returning to Kalamazoo in 1890 to practice. Eleven years later, an article in the Kalamazoo Gazette reported that Yonkerman had a cure for tuberculosis in cattle which he hoped to market for humans. In 1902, the Yonkerman Chemical Company organized with Yonkerman as President and William Shakespeare as Secretary-Treasurer. The company, located in the Lawrence and Chapin building on North Rose Street, produced Tuberculozyne touted to be a cure for tuberculosis. His first book called Tuberculozyne A Cure for Consumption came out in 1905. The book in this collection, Tuberculosis was written by Dr. Freeman Hall (1834-1918) a Civil War surgeon who came to Kalamazoo in 1883. About three-quarters of the book covers what the disease is with the rest promoting Tuberculozyne. The appendix gives glowing recommendations from those who have tried the product and were now cured or improved. Newspapers advertised the book which could be acquired for free. Tuberculozyne was primarily glycerine, water, burnt sugar and almond oil. It cost $10.00 per bottle and was marketed in other countries like Great Britain and Australia. The Yonkerman Company ceased to exist after 1916. Dr. Yonkerman continued to practice as a veterinarian until his death in 1923.