Aqueous Solutions of Hydrogen Chloride, &c. 



311 



perature could not be kept down to 18, the loss of heat by radiation 

 not being sufficient. 



The bath was kept stirred by bubbles of air which escaped from an 

 inverted thistle-funnel connected by a rubber tube with a large 

 Woulfe's bottle. A stream of water ran continuously into the bottle, 

 and drove the air out through the rubber tube and thistle funnel. 

 When nearly full of water, the bottle was emptied by a syphon ; thus, 

 by the combined action of a continuous stream of water tending to fill 

 the bottle, and the intermittent action of the syphon which emptied it, 

 the water-bath was kept stirred. 



The normal and semi-normal solutions were prepared by first making 

 up solutions which contained a gram-molecule in about 800 c.c. or 

 900 c.c., then determining the strength of these solutions, running 

 the volume required from a burette into a measuring flask, and making 

 the solution up to a known bulk. Distilled water, which had been 

 freed from air by being boiled and allowed to cool under reduced pres- 

 sure, was used. 



The hydrochloric acid was prepared by redistilling the acid sold as 

 " pure redistilled." 



The potassium and sodium chloride solutions were prepared from 

 salts sold as " pure recrystallised " (solutions A), and also (solutions B) 

 from salts guaranteed as pure by E. Merck (" f iir analytische Zwecke "). 

 The " pure recrystallised " potassium chloride contained a good deal of 

 sodium, whilst that obtained from Merck contained hardly any. 



The lithium and rubidium chlorides were also purchased from 

 E. Merck, but were of ordinary commercial purity. 



The results obtained are given in Table I. 



Table I. 

 Hydrogen Chloride. 



