Allen and Clement — Bole of Water in Tremolite. 109 



Table IV. — Total Losses of Water at Different Temperatures. 



Tremolite from 



Ossining, N. Y. 

 2 gr. taken 



Time 



Temper- 



Loss 



Per cent 





ature 



mg. 



loss 



1 \\ hrs. 



500° 



10-9 



•54 



141 " 



840-5° 



16-5 



•82 



29* " 



870-5° 



17*9 



•89 



6H " 



904° 



26*2 



1-31 



95f " 



923° 



37-6 



1-88 



Per cent of 

 total water 



24-7 

 33 3 

 39*4 

 59-2 



85-1 



Gouverneur, N. Y. 



2 gr. taken 





100° 



1-7 





200° 



3*3 





320° 



4-5 





608° 



7-7 





805° 



9-8 





880° 



11-1 





920° 



13-7 





980° 



20-1 



Russell, N. Y. 

 2 gr. taken 



12 



10 



8 



4 



4 



10 



hrs. 



500 c 

 800 c 

 835 c 

 845 c 

 865 c 

 920 c 



7-7 

 9-0 

 9'4 

 9-4 

 9-4 

 14-2 



38 



45 

 47 

 47 

 47 

 71 



22-4 

 26-2 

 27-3 

 27*3 

 27*3 

 41-4 



Edwards, K Y. 



11 



500° 



9-9 



•50 



19-8 



2 gr. taken 



15£ " 



800-5° 



11-9 



•59 



23-8 





16* « 



835° ■ 



12-4 



•62 



24-8 





33 " 



875° 



14-4 



•72 



28-8 





37£ " 



905° 



21-2 



1-06 



42-4 



given off so -very slowly at a temperature of 900°. That it is 

 mechanically held seems entirely improbable, for there is no 

 indication of a spongy structure to be found by microscopic 

 analysis. If capillary pores exist they are submicroscopic. 

 The phenomenon is in all probability molecular ; the water is 

 therefore to be regarded as dissolved, and the mineral as a 

 solid solution. Mineralogists and chemists are wont to regard 

 the retention of water at a high temperature as proof of chem- 

 ical combination, but all ideas agree that a true hydrous com- 

 pound cannot lose water without becoming inhomogeneous. 

 The behavior of tremolite is comparable with that of the zeo- 

 lites in the two essential points above mentioned. In the 

 latter, however, the quantity of water is very much greater, 

 and presumably for this reason the change in birefringence 

 and volume which they undergo when dehydrated is much 

 more noticeable. In the zeolites, as in tremolite, dehydration 

 is very slow and requires in some cases a temperature of 500° 

 for its completion. 



