Gooch and McClenahan — Typical Hydrous Chlorides. 375 



chloride at the temperature of incipient decomposition would 

 be to reverse the action of decomposition and to hold the 

 hydrous salt in a condition of greater stability. In the case of a 

 salt which when heated evolves all its chlorine this inhibitive 

 action would be the only effect observed. In the case of salts 

 which give in the decomposition hydroxides or oxides capable 

 of reacting with hydrogen chloride under the conditions with 

 the formation of an anhydrous chloride, the effect of heating in 

 an atmosphere of hydrogen chloride might also be increased 

 stability for a certain range of temperature, but this limit of 

 stability once passed, a second effect of the hydrogen chloride 

 tending to increase the rapidity of the formation of the anhy- 

 drous chloride and so to produce a more rapid evolution of 

 water from the salt as compared with the amount of water set 

 free from the salt heated per se at the same temperature might 

 become prominent. It is to be expected that one and the same 

 salt might exhibit each of these effects, the one restraining 

 dehydration and the other aiding it, at appropriate tempera- 

 tures. 



Now, returning to the salts under investigation, we find that 

 the experimental results fall very well into line with the assign- 

 ment of symbols according to Cushman's hypothesis. 



The symbol 



Ba/ H 



C1 = 0< 



X H 



suggests the observed easy detachment of water and the absence 

 of all effect of decomposition of the chloride when the water 

 is removed at 100°, and suggests no reason why any special 

 effect should be anticipated when hydrogen chloride is made 

 the medium in which dehydration takes place. 

 The symbol 



II H 



/ 



O — O —CI 



/li ri 



H H 



— 6 — o_ci 



\ H H 



\ H H 



\ i i 



o — o— CI 



4 A 



