J. L. Kreider — Behavior of Typical Hydrous Bromides. 105 

 Thus the symbol 



for hydrous barium bromide, showing two molecules of water 

 externally attached, suggests the observed easy removal of all 

 water without simultaneous loss of hydrogen bromide, and 

 indicates, as was observed, that concentration of hydrogen 

 bromide in the system is not likely to affect the course of 

 dehydration. 

 The symbol 



H H 

 I 



/O - O -Br = o/S 



Mg 



/ I I 



/ H H 

 \ H H 



\H 



\ i 

 \ O- O -Br = 0< S 



II XH 



H H 



for hydrous magnesium bromide, in which two molecules of 

 water are externally attached and four internally, shows why 

 one-third of the water may be removed at a moderate temper- 

 ature, without much loss of hydrogen bromide; why the 

 remaining two-thirds of the water require a higher tempera- 

 ture for their removal with simultaneous evolution of hydro- 

 gen bromide; and why increase in the concentration of 

 hydrogen bromide in the system retards both the loss of water 

 and hydrogen bromide, after the first third of the water has 

 been expelled. 



The symbol 



H H 



I I 



/O _ O -Br 



/ I I 



/ H H 



/ H H 



/ I I 



Al - O - O - Br 



\ k L 



\ H H 



\ I I 



\0 _ O -Br 



i I 



H H 



