A. J. Moses — JV'ew Mercury Minerals from Texas. 261 



although two evident faces Avere foiirid their signals were very 

 faint and their angles not sure. 



The comparison between the measured angles and the angles 

 calculated to the determined indices and axial elements is as 

 follows : 





Faces 



Eeflect- 



ing. 











P 



Form. 



Measured. 



Calculated. 



Measured. 



Calculated. 



a{100[ 



2 



90° 





90° 





^>joio} 



2 



0° 





90° 





mjllOf 



4 



57° 32' 



57° 28' 



90° 



90° 



d\\0\] 



1 



89° 56' 



90° 



61° 58' 



61° 52' 



o\\l\\ 



3 



57° 30' 



57° 28' 



65° 44' 



65° 44' 



£c|331j 



4 



57° 29' 



57° 28' 



81° 26' 



81° 27' 



s{112i 



2 



58° 20' 



57° 28' 



48° 53' 



47° 54' 



r|211| 



1 



72° 16' 



72° 18' 



75° 4b' 



75° 42' 



e|132} 



3 



27° 38' 



27° 25' 



63° 41' 



63° 37' 



Also, 













wjSllj 



2 



l-,<~0 fro' 



7 / d6 



77° 59' 



80° 02' 



80° 06' 



^{122} 



2 



38° 07' 



38° 05' 



56° 43' 



56° 35' 



Chemical Analysis of Montr oydite. — With great difficulty, 

 picking crystal \)\] crystal, '0506 grams of pure material was 

 obtained and very carefully heated alone in one of the small 

 closed tubes described under eglestonite. The sublimate 

 formed appeared to be entirely metallic. The dissolved sub- 

 limate gave ]io test for chlorine. It was therefore assumed, 

 for want of further material, that the sublimate was mercury 

 and the loss oxygen. The percentages are very close to those 

 of mercuric oxide HgO. 



Percentages Percentages 



Analysis. HgO. 



Loss on beating 7*13 O 7*408 



Sublimate 92-87 Hg 92-592 



Other Characters of Montroyclite. — Luster, adamantine to 

 vitreous. Transparent. Color of larger crystals, a red darker 

 than crocoite and nearer realgar ; minute crystals orange- 

 red. Color of the powder a little lighter than color of 

 crystals. E^ot noticeably affected by sunlight. Brittle. 

 Hardness less than 2. Specific gravity not determined. 



Under the microscope there are indications of cleavage 

 oblique to the length and with crossed nicols there is extinc- 

 tion parallel to the length. 



Heated in the closed tube volatilizes completely and forms 

 a sublimate of metallic mercury. 



Dissolves easily and quietly in cold nitric or cold hydrochloric 

 acid. 



