on some Chloro-brom-iodides of Silver. 



299 



Volume at 330 = 1*006834 (solid) 

 330 = 1-054867 (liquid) 

 750 = 1-106782 

 This alloy, like the preceding, has obviously two temperatures of 

 maximum density or minimum volume ; the one 133° C, the other at 

 some point far below zero. 



5. ChLOEO-BROM-IODIDE or SILYER having the COMPOSITIOIf Ag^ \ 



Ag Br Ag Ol, or AGg Er Cl. 

 The alloy contains : — 



Agl . . . . 73-9285 Ag . . . . 50-9634 



Ag Br . . 14-7856 I 39-9528 



Ag Cl . . 11-2859 Br ... . 6-2919 



Cl .... 2-7919 



100-0000 100-0000 

 Specific gravity = 5-907. Calculated specific gravity on the assump- 

 tion that no condensation takes place = 5-725, showing a condensation 

 equal 0*291 on the calculated volume. Eusing-point 350° C. Specific 

 gravity of the liquid at the fusing-point = 5-680 ; at 750° C. = 5-340. 

 Euses to a bromine-red liquid, which cools to a mass of the same colour. 

 As the mass cools it becomes bright brick-red, dull brick-red, orange- 

 red, and finally, when cold, a rich orauge-yellow. It turns green both 

 in mass and in powder on exposure to light. It expands in solidifying, 

 and cracks the tube in which it is cast as vigorously as the iodide of 

 silver itself. It forms a brittle solid when cold, and possesses a number 

 of horizontal rifts produced at the moment of expansion. More brittle 

 than any of the preceding compounds, but less so than Ag I. CrystalHne 

 fracture. Lustrous surface. Harsh crystalline noises during cooling. 

 Taken from the parafiine-bath at 250° C, it was so plastic that it could 

 not only be bent upon itself, but twisted like a corkscrew. In the 

 expansion-apparatus the bar expanded up to 124° C. to a less extent than 

 the preceding ; between 124° C. and 133° C. it contracted to a greater 

 extent than the preceding ; at 133° C. it commenced to expand again, and 

 between 133° and 350° C. it expanded to a less extent than the preceding. 

 At the melting-point and at 750° C. the volume was less than that of 

 any of the preceding. 



The following results were obtained : — 



Coefficient of cubical expansion for 1° C. 

 ° 0. ° 0. 



Between and 124 -00005400 



124 and 133 (contraction) -00270000 



133 and 350 -00010800 



Expansion on passing from the solid to the liquid state . -03414100 



Between 350° and 750° C -00014379 



