Xyster

(zis'tür.) [Gr.] (Surg.) An instrument used for scraping bones. uhadbeenpreviously represented by the same letter in lien of y. Certain proper names interchange with this letter as regards the initial, the latter sometimes being indifferently I, J, or Y.-Y-SHAFT. (Mach.) In steam engines, the name of the shaft which sets the valve in motion:-so called because formerly the lever used for working the regulator in atmospheric engines was ofa forked shape, after the manner of the letter Y. [s. 972]