1889.] On Salts of a Base Containing Chromium and Urea. 335 



Calculated. Observed. 



........ 71 13'4 



p ........ 52 10-3 52 6 



j ........ 56 36-3 56 42 



pi\ ........ 40 14-5 40 21-5 



The striations on the planes a and I were parallel to th^ir intersec- 

 tions, and rendered the readings obtained from them in the zone 

 [aim'} valueless, except for the sake of identification. No distinct 

 cleavage was observed. 



No. 2. 



The foregoing experiment having failed to give the pure oxalate, 

 recourse was had to the decomposition of the pure chloride with 

 silver oxalate. The two substances warmed together with water 

 for some time and filtered gave an abundant crop of dark-green 

 crystals belonging to the anorthic system. Examination showed, 

 however, that the salt differed from the preceding one only in con- 

 taining more water of crystallisation, and that it readily parts with 

 the latter even in a corked tube, becoming less soluble and possibly 

 forming the preceding compound. This substance, which has the 

 composition (CON 2 H 4 ) 12 Cr2(C 2 4 ) 3 Cr2(Cr 2 4 ) 3 29H 2 0, gave the follow- 

 ing results on analysis : 



1. 0*5113 gram lost in vacuo 0'1347 gram H 2 0, and suffered no 

 further loss at 100 C. The dry salt ignited left 0'0788 gram 

 O 2 3 . 



Calculated. Found. 

 H 2 in 100 parts ...... 26'36 26*34 



Cr 2 3 ...... 15*43 15-41 



The crystals are dark-green in colour, and have bright and for the 

 most part well- developed faces. They seem to have no good cleavage. 

 They crystallise in the anorthic system, and the zones [raw], [cbdl~\ 

 are those most largely developed, and give the habit of the crystals. 



