APPARATUS FOR TEACHING CHEMISTRY. 1041 



4112. Hofmann's Apparatus (No. 1-16). 



Warmbrunn, Quilitz, fy Co., Berlin. 



(1.) Apparatus for the electrolysis of hydrochloric acid, of water, 

 and ammonia. 



(2.) Apparatus for illustrating the synthesis of hydrochloric 

 acid. 



(3.) Apparatus for showing that hydrogen and chlorine when 

 united suffer no contraction of volume. 



(4.) Apparatus for showing that two volumes of water-gas 

 (steam) are formed when two volumes of hydrogen unite with one 

 volume of oxygen. 



(5.) Apparatus for showing that ammonia consists of three 

 volumes of hydrogen and one volume of nitrogen. 



(6.) Apparatus for the simultaneous electrolysis of water, hydro- 

 chloric acid, and ammonia. 



(7.) Apparatus for showing that the composition of hydrochloric 

 acid does not vary. 



(8.) Apparatus for showing that hydrogen and oxygen unite 

 with each other only in the proportions in which they are obtained 

 by the electrolysis of water. 



(9.) Apparatus for illustrating the deportment of simple and 

 compound gases under the influence of changes of temperature 

 and pressure. Of novel construction. 



(10.) Eudiometer for the lecture-room table with stand. 



(11.) Apparatus for experimenting with liquid sulphurous acid. 



(12.) Apparatus for illustrating the phenomena of combustion. 



(13.) Vapour density apparatus complete. 



(14.) Apparatus for proving that the volumes of carbonic and 

 sulphurous anhydride equal the volumes of oxygen which enter 

 into them. 



(15.) Apparatus for the electrolysis of phosphide of hydrogen. 



(16.) Sodium apparatus, 



4113. Series of small Apparatus, for illustrating in the 

 lecture room projections on a screen by means of Duboscq's lamp. 

 Manufactured by Dr. Geissler of Bonn. 



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



The series consists of: 



(1.) An apparatus for showing the decomposition of water by 

 the galvanic current. 



(2.) Apparatus for decomposing water by means of palladium 

 electrodes with absorption of the hydrogen gas. 



(3.) Apparatus for the electrolysis of saline solutions. 



!4.) Lecture room eudiometer. 

 5.) Apparatus for showing the formation of nitric peroxide by 

 passing electric sparks through air. 



40075. 3 U 



