Abstract: Fume generated by roasting speiss is contacted with an oxygen-containing gas at an elevated temperature for a sufficient time to product arsenic and antimony products which may be separated from each other by means such as condensation. Further, in the roasting of antimony-containing phases (such as speiss) the presence of arsenic can enhance the volatility of the antimony.

Abstract: A medical device valving mechanism comprising a molded plastic, one-piece, elongated valve body molded to have a longitudinally extending body shaped to be gripped and securely held in either hand leaving the hand's thumb free for valve operational movement. The body has at least one fluid passageway extending longitudinally therethrough and a cylindrical opening extending transversely therethrough to intercept the at least one passageway. A cylindrical molded plastic, one-piece rotor for snug slidable and rotational insertion into the cylindrical opening to block the at least one passageway is provided. The rotor has at least one transaxial passageway which opens the at least one fluid passageway through the valve body when the rotor is in its valve opening position and which closes the at least one fluid passageway when the rotor is in its valve closing position.

Abstract: A biopsy needle instrument has selectable locking means to permit or prevent the projection of a cannula and a stylet and separate loading members allowing the cannula and stylet to be loaded separately and yet fired sequentially using a single button. Another embodiment of the invention permits the independent firing of the stylet and the cannula.

Abstract: Arsenic and antimony are separated from speiss by a roasting operation employing pyrite and coke and the arsenic is separated from the resultant product by a water pressure leaching operation.

Abstract: Fume generated by roasting speiss is contacted with an oxygen-containing gas at an elevated temperature for a sufficient time to produce arsenic and antimony products which may be separated from each other by means such as condensation. Further, in the roasting of antimony-containing phases (such as speiss) the presence of arsenic can enhance the volatility of the antimony.

Abstract: An aspiration syringe suitable for one-handed operation has a barrel defining a bore, a plunger consisting of a small cross-section plunger shaft extending into the bore and a first seal within the bore, carried by the distal end of the shaft for axial movement within the bore, and an end closure across the bore proximal of the first seal, the plunger shaft extending in sliding, sealed engagement therethrough. The first seal engages the wall defining the bore in vacuum-tight sealing engagement. The transverse cross-sectional area of the shaft is much less than the transverse cross-sectional area of the bore to provide a syringe-actuating vacuum chamber of substantial volume within the bore between the seal and the end closure.