866 SEC. 19. EDUCATIONAL APPLIANCES. 



(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. 



Professor H. Landolt, Aix-la- Chapelle. 



The series consists : 



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

 the galvanic current. 



(2.) An apparatus for decomposing water by means of palladium 

 electrodes with absorption of the hydrogen gas. 



(3.) An apparatus for the electrolysis of saline solutions. 



!4.) Lecture room eudiometer. 

 5.) An apparatus for showing the formation of nitric peroxide 

 by passing electric sparks through air. 



(6.) An apparatus for showing the action of oxygen upon nitric 

 acid. 



(7.) An apparatus for illustrating the absorption of gases by 

 liquids. 



(8.) A condenser for bromine and other coloured vapours. 



(9.) An apparatus for showing the formation of flowers of 

 sulphur. 



(10.) An apparatus for illustrating the manufacture of sulphuric 

 acid, and for showing the decolorising action of sulphurous acid 

 upon nitric peroxide. 



4114. Photographs, illustrative of the chemical lecture-room 

 of the Polytechnic School of Aix-la- Chapelle, and of the contri- 

 vances for throwing experimental illustrations on a screen by means 

 of a Duboscq's lamp. Professor H. Landolt, Aix-la- Chapelle. 



