Charriere's company later employed the coiled springs in the making of a circular scarificator. The circular scarificators, associated particularly with French manufacture, were the most elegant of nineteenth-century scarificators and a fitting complement to the Charriere cupping sets.[149] They were generally not sold by British and American surgical supply companies, but a number of them appear to have reached the hands of American physicians. In America, there were five patents on scarificators, of which the Smithsonian possesses three patent models. The most significant American patent was that of George Tiemann in 1846. Tiemann's scarificator had a flattened base and an ebony handle, which contained a coiled spring. The blades were moved by a rack and pinion mechanism, and triggered by a knob at the end of the handle. The advantages claimed by the inventor were ease in handling, ease in cleaning, and the diagonal cut of the blades that allowed the blood to flow more freely and the wounds to heal more readily. Tiemann & Co. was still selling their patent scarificator as late as 1889 for a price of $7.00.[150] The Smithsonian possesses a marketed version in addition to the patent model. The two other patent scarificators in the Smithsonian collection were both invented by Frederick M. Leypoldt of Philadelphia. The first, patented in 1847, was similar in external appearance to the common scarificator. The novelty consisted of a new arrangement of the cocking lever and cantilever spring that allowed use of a lighter and cheaper casing. Although the patent model was made of brass, Leypoldt claimed that with his improvements in the internal mechanism, the case could, with safety, be made of tin.[151] Leypoldt's second patent, issued in 1851, was for a scarificator with a greatly simplified inner mechanism allowing for a substantially smaller and lighter case. The cocking lever was placed horizontally in the casing and engaged the blade rods through a rack and pinion mechanism. According to Leypoldt, this scarificator was more convenient, more portable, cheaper, safer, and more reliable than the common scarificator.[152] Leypoldt probably marketed his scarificators, there being in the Smithsonian collection other bloodletting instruments with his name, but he did not form a major surgical supply company as did George Tiemann. [Illustration: FIGURE 16.--Advertisement for phlebotomy and cupping instruments. Note the rubber cups. (From George Tiemann & Co., _American Armamentarium Chirurgicum_, New York, 1889. SI photo 76-13542.)]