on some Chloro-brom-iodides of Silver. 



295 



Coefficient of cubical expansion for 1° C. 



Between and 125*5 



,, 125-5 and 131*5 (contraction) 



131-5 and fusing-point (330° C.) 



Expansion in passing from the solid to the liquid state 

 Between 330° C. and 750° C 



If we take the volume at 0° C. as unity we have — 



•00012216 



•00004902 



•00015882 



•057390 



•0001760 



Yoln 



me at 



°0. 





= 



1-000000 



125^5 = 



1-015331 



131-5 = 



1-015037 



330 = 



1-046666 (solid) 



330 = 



1-104050 (liquid) 



750 = 



1^177979 



The alloy clearly possesses two points of similar density at different 

 temperatures, the one at 131°-5 C, the other at or about 123^ 0. 



2. Chloeo-beom-iodide of silver having the co:mposition Ag I Ag 

 Br Ag Cl, or AG3 I Br Cl. 

 The alloy contains : — 



41-484 Ag . . . . 57-1932 



33^186 1 21^4184 



25-330 Br .... 14-1218 



Cl .... Q'2QQQ 



Agl.. 

 Ag Br 

 Ag Cl 



100-000 



100-0000 



Specific gravity 6*1197. Calculated specific gravity on the assumption 

 that no condensation takes place = 5-801, showing a condensation equal 

 to *0519 on the calculated volume. Fusing-point 295° C. Specific gravity 

 of the liquid at the fusing-point = 5*5673; at 750° C. = 5*118. The 

 mass fuses to a dark bromine-red liquid, becoming a solid of the same 

 colour, which changes to a pink, dull opaque brick-red, and finally 

 when the mass is cold to a dull orange. The powder is bright orange, 

 becoming bright green on exposure to light. The fused mass on expo- 

 sure to light becomes of a dark steel-grey colour. The mass is compact, 

 hard, and homogeneous ; it is semitransparent in thin layers. Semi-i 

 crystalline fracture. Somewhat lustrous at the surface. Gives a clear 

 metallic ring when allowed to fall on an amil, or when short rods of 

 the alloy are shaken together. It is difficult to break, and has more 

 tenacity than any one of its constituents. It does not bend when cold ; 

 and taken from the parafHne-bath at 250° C. it bends slightly, but breaks 

 easilv. 



