110 THE ANALYST. A P PAR ATU S. Apparatus for Parallel Titrations. A. Thilmany. (Chenz. Zeit., 1901, xxv., 115.)--The titrating vessels in this apparatus are glass cylinders with a central tube open at the bottom, and rising to the level of the outer part. Through these central tubes pass m e t a l s p i n d l e s w i t h square heads, on which drop horizontal cross- pieces, and to the latter glass stirrers with metal caps are screwed. These agitators are beht out- wards a t their base so as almost to touch the walls of the glass vessels, while their upper parts revolve c l e a r of t h e 1, burette ends and taps. Z- The central uprights are driven by gearing or belting contained in the box of the stand from any convenient prime motor. As all the stirrers travel at the same speed, the amount of agitation in all the vessels isTHE ANALYST. 111 uniform ; and the whole arrangement becomes specially suitable for comparative experiments in dye-testing, etc. The apparatus is protected as a ‘‘ Gebrauchs- muster. ” F. H. L. A shown Simple Respirator. A. Junghahn. (Chem. Zezt., 1900, xxiv., 1138.)-As by the sketch, this apparatus is made of glass, with two automatic valves, the expired air escaping at the top, and that needed for inspiration being brought from behind the wearer through the rubber tube. The device is equally suitable for laboratory or industrial purposes ; it is stated not to impede the breathing, and, being all glass, is not itself corroded by acidvapours. The respirator is patented in Germany, and may be procured from Kaehler and Martini, Berlin, W. F. H. L. A brass clip closes the nostrils.