By the mid-19th century metallic molds were introduced to accept a molten liquid to produce formed suppositories. The earliest form consisting of a tin tray and perforated removable lid to accommodate individual pewter molds. In 1865 Wm. Chapman, a pharmacist, constructed the first solid metal mold. Suppositories formed in these molds were very difficult to remove. Charles Bullock and Edmund Crenshaw solved this problem in 1867 with the introduction of a two-part, brass mold, hinged at one end and held together by a metallic band. By 1875 about twenty different forms became available that employed this so-called fusion method of production whereby a molten mass was poured into molds a process suitable only for heat-stable ingredients. Thus, heat intolerant ingredients required the hand made method prior to the development of cold compression suppositories formed by a machine.