620 SEC. 13. - CHEMISTRY. 



32. lodure of acetylene C 2 H 2 I 2 . "| 



33. Bibromure of acetylene. I Ann. der Ch. u. Ph., B. 178, par 



34. Tetrabromure of acetylene. A. Sabanejeff. 



35. Acetylene triphenyltriamine. 



Journ. de la Soc. Russe, par A. Sabanejeff. 

 37. Isodibroniantracene C 6 H 4 C 2 H 2 C 6 H 2 Br 2 . 



2536r. Chemical Reagents, &c. A series of 835 speci- 

 mens of those employed in scientific research. Not specially 

 prepared for exhibition. Hopkins fy Williams. 



2678. Digester, made of cast-steel, for digesting under 

 pressure. It holds 4 litres, is silvered inside and coppered outside. 

 Manufactured by Fr. Krupp, of Essen. 



Prof. H. Landolt, Aix-la-Chapelle. 



2588. Diagram, showing elevation, section, and plan of a 

 " digestorium " (iron closet constructed for effecting dangerous 

 digesting operations). 



Chemical Institute of the University of Strasslurg, 

 Elsass. 



2584. Instrument for Calculating Atomic and Volu- 

 metrical combinations, to 4 places of logarithms. 



Rudolph Weber, Aschaffenburg. 



2156s. Bunsen's explosion Eudiometer, with the wire 

 cut off, and ground flush with the external surface of the tube in 

 order to prevent straining of the glass by the bending of the wires. 



Prof. H. McLcod. 



When an explosion lias to be made the wires are connected to an induction 

 coil by the help of a wooden paper-clip with strips of platinum foil fastened 

 inside it, each strip being provided with a wire loop to which the conducting 

 wires from the coil may be attached. 



24561. Hegnault's Eudiometer. 



Golaz, 22 Rue des Fosses, St. Jacques, Paris. 



This apparatus is made of a triangular iron stand, and is furnished with 

 a set screw for fixing to the upright a slide moved by rackwork ; a vessel of 

 mercury is fixed upon the slide, and can consequently be raised or lowered to 

 the height required. On the opposite side of the iron upright is fixed a plate 

 provided with an iron stop-cock and two tubes. In one of these tubes is 

 cemented a straight tube, open at its ends, and divided into millimetres 

 throughout its length. In the other tube is cemented a tube, terminating at 

 its upper extremity by a capillary glass tube, and bent horizontally ; this tube 

 is divided into millimetres, and is traversed at its upper part by two platinum- 

 wires, through which the electric spark is made to pass. The whole of 

 this manometer apparatus is surrounded with a glass cylinder 1 5 centimetres 

 in diameter to be filled with water, in order to keep the manometer at a 

 uniform temperature. The second portion of the apparatus consists of the 

 experimental tube in which the gases are submitted to the various absorbents ; 

 this eudiometer is thus composed of two distinct parts : 1. The measuring 



