IV. LABORATORY APPARATUS. 639 



2456b. Apparatus for simultaneous production of hydrogen, 

 carbonic acid, and sulphuretted hydrogen. 



P. Waage, Professor of Chemistry and Director of the 

 Chemical Laboratory at the Royal University of Chris- 

 tiania, Norway. 



The apparatus consists of a reservoir for hydrochloric acid of 10-15 per 

 cent, strength. At the bottom of this reservoir are three apertures through 

 which it is connected in the usual manner by glass tubes and stopcocks with 

 three cylindrical jars, one filled with zinc, the second with marble, and the 

 third Avith sulphide of iron. Beneath each of these, and communicating with 

 the sewers , is another reservoir into which the solutions of chlorides are 

 gathered. The three gases generated are conducted through wash bottles 

 furnished with stopcocks of glass ; when these are turned off the several gases 

 and the solutions of chlorides will pass through the lower reservoirs into 

 the sewers. 



The apparatus once fitted up is always ready for use, and all superfluous 

 gas is completely led away without producing any smell in the room where 

 the apparatus is fixed. 



2523. Stand used in chemistry for the fusion of metals by 

 means of a gas apparatus. 



2593. Stand provided with pincers and air-bath. 



Bally Freiburg, Baden. 



2595. Heat Regulator. C. Kramer, Freiburg, Baden. 



2550. Frerich's filtering Apparatus, made of platinum. 



F. Sartorius, Goltingen. 



2551. Frerich's filtering Apparatus, made of gutta 

 percha. F. Sartorius, Gdttingen. 



2552. Frerich's filtering Apparatus, made of porcelain. 



F. Sartorius, Gdttingen. 



2553. Frerich's Apparatus, for determining specific gravi- 

 ties in scientific investigations. F. Sartorius, Gdttingen. 



2456c. Water Quick Filter Pump for use with a fall of 40 

 feet. E. Cetti $ Co. 



2576. Water Vacuum Pump, constructed for a fall of water 

 of at least 20 feet. F. A. Wolffs? Sons, Heilbronn and Vienna. 



This pump is of simple construction and great solidity. Any desired 

 vacuum may be obtained by making use of a regulator. 



2663. " Water Jet " Pneumatic Pump, for laboratories, 

 &c. ; designed by Professors Arzberger and Zulkowsky, and con- 

 structed by P. Bohme, Mechanician, Briinn. 



Prof. Fred. Arzberger and Chas. Zulkmvsky, of the 

 Polytechnic Institute, Briinn, Austria. 



The effect of this pump is based on the injection principle ; it requires for 

 working it a water supply conveyed by high pressure, but no fall below ; 



