Pentahalides, with their Crystallography. 



47 



The crystals gave good reflections of the signal on the 

 goniometer. In the following tables the measurements which 

 were chosen as fundamental are indicated bv an asterisk. 



Measured. Calculated. 



Measured. Calculated 



a 



a c. 



100a001=*90° 



2' 







c a to, 001 a 110 = 85° 



8' 



85° 



9' 



m 



aM, 



•110 a!10=*89 



47 







c aM, 001 ^ 110 = 85 



7 



85 



n 



a 



a m. 



100 a 110 — *44 



43 







e a TO, 021 a 110 = 65 



9 



65 



3 



c] 



" e > 



001 a 021 =*43 



26 







e aM, 021 ^ 110 = 65 



8 



65 



18 



e 



a d. 



021 ^ 011 =*65 



25 







d~m, 011 ^ 110 = 70 



Q 



70 



2 



a 



a if, 



100 a 110 = 45 



4 



45° 



4' 



ds-.ll, Oil a 110 = 70 



6 



70 



4 



a 



a e, 



100a021 = 90 



6 



90 



16 



JAW, 311 a 110 = 40 



41 



40 



41 



a 



a d, 



100 a 011 = 89 



57 



89 



54 



f AfZ, 041 a 011 = 32 



30 



32 



37| 



a 



*P, 



100^311 = 41 



18 



41 



19 



a; a to, 341 a 110 = 25 



46 



25 



44| 



a 



A 0. 



100 .v 311 = 41 



31 



41 



25 



y*M, 341 a 110 = 25 



56 



25 



52 



The form of CsCl . C1 3 I is monoclinic. From a 

 number of crystallizations this salt was always ob- 

 tained in needles, sometimes over 20 mm in length 

 and having the habit shown in fig. 4. 



The forms which were observed are : 



6, 010, i-i 



p, 212, 



— 1-2 



s, 211, 2-2 



1, 210, i-2 



q, 211, 



-2-2 



d, 041, 4.-1 



The axial ratio is as follows : 

 d:b:c — 0-9423: 1 : 0-4277, /? = 100^001 = 86° 20' 



Measured. Calculated. 



I a?, 210 a 210= *50° 22' 

 Up, 210 a 212= *44° 51 

 jj'aJ, 212 a 211 =*106 35 

 l^q, 210 a 211 = 27 3 



27° r 



Measured, Calculated. 



?aS, 210 a 211 = 28° 35' 28° 34' 



p*p, 212 a 212 = 32° 59 33 2 



p A 6. 212a<)10 = 73 31 73 29 



6a<£ 010 a 041 = 31 30 21 



The crystallization of RbCl.Cl 3 I is 

 monoclinic This salt was crystallized a 

 great many times and was always ob- 

 tained in plates, sometimes over 20 mra 

 broad, but seldom l mm thick. The habit 

 is shown in fig. 5. 



The forms which were observed are : 



I, 010, i-i 

 c, 001, O 



m, 110, I 

 p, 111,-1 



s, 111, 1 



The axial ratio is as follows : 



${1:6 = 1-1390: 1: 1-975, fi = 100*001 .-=67° 6f 



