on some Chloro-brom-iodides of Silver. 297 

 3. Chloeo-beom-iodide oe silyee having the composition AGj \ Aq 



Be Ag Cl, oe Ag^ \ Be Cl. 

 The alloy contains : — 



Ag I .... 58-6404 Ag .... 53-8989 



AgBr .. 23-4557 1 31-6905 



Ag 01 . . . . 17-9039 Br ... . 9-9813 



Cl .... 4-4293 



100-0000 100-0000 



Specific gravity 6-503 ; after annealing by slow cooling in paraffine 

 6*997. Calculated specific gravity on the assumption that no condensa- 

 tion takes place = 5-762, showing a condensation equal to -0487 on the 

 calculated volume. Eusing-point 320° C. Specific gravity of the liquid 

 at the fusing-point = 5-6971 ; at 750° C. = 5-3749. Fused to a dark 

 bromine-red liquid, which, after passing through the different changes of 

 colour as No. 2 alloy, finally cooled to a dark orange-coloured opaque 

 solid. Both the exterior of the fused mass and the bright orange- 

 coloured powdered substance turned green on exposure to diffused light. 

 The mass contracted on cooling. Taken from the paraffine-bath at 250° 

 C. it was found to be flexible, and it could be bent through an angle of 

 40° before breaking ; when somewhat cooler it was brittle and easily 

 broken, but when cold it was tenacious and difficult to break. It was 

 compact and homogeneous, and gave a clear metallic ring when allowed 

 to fall on an anvil. In the expansion-apparatus the bar expanded 

 regularly, but much less rapidly than Nos. 1 and 2, up to 124° C. 

 Between 124° C. and 133° C. it contracted considerably more than No. 2 

 alloy ; at 133° C. it began to expand, and between 133° C. and 320° C. 

 it expanded at the same rate as No. 2. At the melting-point and at 

 750° C. the volume was less than that of either of the preceding. 

 The following results were obtained : — 



Coefficient of cubical expansion for 1° C. 

 ° C. ° C. 



Between and 124 = -00008307 



„ 124 and 133 (contracting) = -00189999 



133 and fusing-point (320° C.) = -00020250 



Expansion in passing from the solid to the liquid state = -02771500 



Between 320° C. and 750° C = -00012390 



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



°0. 



Volume at = 1-000000 

 124 = 1-010301 

 133 = -993201 



-320 = 1-031068 (solid) 

 320 = 1-058783 (liquid) 

 750 = 1-112020 



