260 Scientific Intelligence. 



of the point of the agglomeration into a mass of powder such as : 

 chrysolite, kaolin, zircon. 



There are great differences between these various points. 

 Between a and b there can be several hundred degrees of dif- 

 ference." 



The following may serve as illustrations of the numerical 

 results obtained. 



For anorthite from Miyake Idsu, Japan, a crystal remained for 

 a long time unaltered at 1350° ; at 1425° it still preserved its 

 cleavage, and 1490° was obtained as the most probable point of 

 the destruction of the crystalline structure. With anorthite of 

 absolute purity, prepared for the purpose, the following values 

 were obtained : 



delation 

 of^ 



Temp, of destruction 



Capacity in calories of 



c 



of the crystal 



1 kilo of the fused mineral 



7-07 



1544° 



451-2 



7-1 



1547° 



453-6 



7-128 



1550° 



455-9 



7-19 



1562° 



456-8 



For anorthite glass the following points were also obtained : 



No. 2, Minimum temperature of the deformation of the glass, 

 1083°, 1110°. 



No. 3, Temperature at which the glass begins to be clouded, 

 1144°. 



No. 3 bis, Temperature at which the glass becomes crystalline, 

 labile point, 1210°. 



Temperature at which the crystallization has the appearance of 

 being rapid, 1250°. 



With leucite, at a temperature of 1430° the edges of the crys- 

 tal were rounded and the faces vitrified though, as a whole, it 

 did not lose its shape. At 1470°, though still preserving its 

 form, it was softened so that it could be easily flattened out by 

 the pincers. At 1500° the glass commenced to form and was 

 complete at 1600°. 



For chrysolite the point of fusion was too high to allow of 

 being determined accurately but was estimated to be about 50° 

 below that of platinum ; 1730° was taken as the probable tem- 

 perature. Wollastonite from Auerbach (monoclinic in crystalli- 

 zation) was liquified at 1366° to a glass which quickly assumed a 

 hexagonal crystalline structure. The artificial hexagonal min- 

 eral fused to a fluid, transparent glass at 1515°. 



9. Mineral Resources of tlie United States. Calendar year 

 1903. David T. Day, Chief of Division of Mining and Min- 

 eral Resources. 1204 pp. 8vo. Washington, 1904 (IT. S. Geo- 

 logical Survey, Charles D. Walcott, Director). — This annual 

 volume of the Geological Survey devoted to the Mineral Re- 

 sources of the United States, like its predecessors, contains a vast 

 amount of useful and important information. This is made the 

 more valuable from the fact of the admirable promptness with 



