116 Allen and Clement — Role of Water in Tremolite. 







Table IX 











Charge, 



2 



grams 









Temper- 







Total loss 



Loss per 



Time 



ature 







in mg. 



day in mg. 



6 



hours 



800 







14-2 



11-1 



H 



a 



a 



• 





180 



3-8 



6 



a 



a 







214 



3-4 



6 



a 



a 







23-8 



2-4 



H 



u 



a 







24-8 



1-0 



H 



a 



a 







26-2 



1-4 



H 



a 



a 







27*9 



1-7 



6 



a 



a 







29-1 



1-2 



4 



a 



a 







30*4 



1-3 



4 



a 



a 







31-1 



•7 



8* 



a 



a 







31-4 



•3 



7 



a 



a 







32-2 



•8 



6* 



a 



a 







33-0 



•8 



"2 



6* 



" 33-6 



" 34-3 



" 34-6 



34*9 



35-4 

 " 36-3 



6 " " 36-9 



The loss of water at 800° was so slow that it was suspected 

 that in dry air it might be indefinite ; in other words, that the 

 vapor pressure never would fall to zero. It seemed worth 

 while in this case to try another series of experiments in which 

 the furnace was traversed by a current of air saturated with 

 water at the room temperature, — about 25°. The case was 

 like that of kupfferite, except that beryl undergoes no second- 

 ary change when heated in air to 800°, and work with it there- 

 fore seemed more promising. After continuing the dehydration 

 for eight days, it was found that the loss during that time was 

 almost identical with the loss in dry air during the same time. 



Table X. 





Temper- 



Total loss 



Loss per 



Time 



ature 



in mg. 



day in mg 



6 hours 



800° 



15*4 



15 4 



7 



a 



193 



3*9 



64 " 



a 



21-6 



23 



6 



tt 



23-8 



2-2 



7 



a 



27'1 



3-3 



6i " 



a 



27*6 



•5 



H " 



a 



295 



1-9 



6* " 



a 



30-7 



1-2 





Total loss in 50 h. = 30*7 mg . 



A reference to the previous table will show that the same 

 weight of beryl lost in dry air during a period of nine days, or 

 The tendency for the reaction to reverse 



51 hours, 30'4 mg . 



