BAIRD &.TATLOCK. (LONDON) LTD. 



5937 



5938 



5939-5941 



5937 George's Apparatus, for determining the composition of ammonia, sulphur dioxide, 



water, etc. (See Chemical News, p. 303, vol. Ixxvii.) 



5938 Flask with platinum electrodes, to show decomposition of steam 



5939 Apparatus for the electrolysis of hydrochloric acid, water, and ammonia. 



Consisting of a V tube closed at one end, with two platinum electrodes. On filling the tube with the liquid 

 to be decomposed , and connecting the electrodes with two or more Bunsen's or Grove's cells, the respective gases are 

 evolved from the surface of the platinum, and can be collected and tested over a pneumatic trough. By reversing 

 the poles of the battery the position of the gases is reversed, the gas which was collected in the open tube being 

 now found in the closed limb, and vice versd. 



Price 



5940 Apparatus, as above, with metal stand 



5941 Apparatus, as above, with wooden stand 





 



8 

 13 

 11 



5942 



5942 Apparatus for the volumetric analysis of the mixed gases from the decomposition of hydro- 

 chloric acid consisting of 



Electrolysis jar or cell, with platinum electrodes. 

 Tube with two stopcocks. 

 Absorption cylinder with tubulure. 

 Absorption jar, 2iJ in. by 2 in. 

 Supports for tube. 



Price complete on stand 



The electrolysis jar is filled with strong hydrochloric acid, and the mixed gases are led to tube ; excess being 

 taken up by absorption cylinder, which is filled with pumice stone moistened with a solution of soda. The stop- 

 cocks are closed, and on cooling one end of the tube with ether, a little strong solution of potassium iodide is 

 introduced by suction. The potassium iodide is at once decomposed, and steel-grey iodine deposited. More of the 

 solution is introduced, until it begins to have a brown colour. Shaking the tube carefully hastens the reaction. 

 Finally, the tube is inserted in a weak solution of potassium iodide, and the lower stopcock opened. On adjusting 

 the level of the liquid inside the tube with that in the jar, the residual gas (hydrogen) will be found to occupy 

 one-half the tube. 



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