274 Flora — Estimation of Cadmium taken as the Sulphate. 



to give a soluble double oxalate, gave results much too high. 

 The dissolving of the precipitated oxalates in various reagents 

 furnished no solution to the problem. 



The results in the following table will show the scope of the 

 work done : 



No. 



CM. 



tkn. 



Am. 

 oxalate. 



Pot. 

 oxalate. 



Solvent. 



Cur't = 



N.D a0 o 



fe rA 



. DC 





Cd. 

 fd. 



Error. 





grm. 



grm. 



grm. 





amp. 



amp. 



H 



grm. 



grm. 



1. 



0-1491 



excess 



none 



none 



3-0 



9-0 



12 



1 



0-1558 



+ 0-006 r 



2. 



0-1491 



sit. excess 



none 



u 



2-5 



7-5 



12 ' 



30 



0-1506 



+ 0-001* 



3. 



0-1491 



2-0 



0-5 



it 



2-0 -2-5 



6-0 - 7-5 



8 



25 



01531 



+ 0-004C 



4. 



0-1491 



none 



0-5 



j H 2 S0 4 



( 15 dps. 



none 



2-5 



7-5 



8 



30 



01476 



-0-001f 



5. 



0-1491 



" 



8-0 



2-0 



6-0 



6-2 



20 



0-1507 



+ 0-001 ( 



6. 



0-1118 



4-0 



none 



a 



1-5 



4-5 



61 



20 



0-1272 



+ 0-015^ 



7. 



% 



none 



5-0 



j NH 4 OH 3 

 ( few cm. 

 none 



2-0 -3-5 



6-0 -10-5 



6-8 



18 



2 



? 



8. 



0-1118 



a 



5-0 



1-5 



4-5 



6-0 



15 



0-1129 



+ 0-0011 



9. 



0-1019 



i< 



4-0 



< i 



2-0 -3-0 



6-0 - 9-0 



8 



20 



0-0995 



-0-0024 



10. 



0-1019 



" 



6-0 



a 



0-5 -1-5 



1-5 - 4-5 



4-6 



35 



0-0982 



-0-003" 



11. 



0-1019 



a 



5-0 



" 



1-0 



3-0 



5-5 



55 



01033 



+0-001^ 



12. 



0-1019 



it 



7-0 



1 1 



0-5 



1-5 



4 



55 



0-1030 



+ 0-0011 



13. 



0-1223 



2-0 



8-0 



a 



0-1 -0-15 



0-3 -0-45 



4 



60 



01236 



+ 0-00U 



14. 



0-1223 



2-0 



8-0 



. 



0-02-0-10 



•06- 0-3 



4 



76 



0-1229 



+ 0-0006 



15. 



01223 



(KOH 

 \ 1 grm. 



j H 2 S0 4 dil. 



"j 10 cm 



j oxalic acid 

 . \ 5 grm. 



3-0 



9-0 



8 



40 



0-0876 



-0-034'] 



16. 



0-1223 



j KOH 



I 0-25 grm. 



...„ 



j oxalic acid 

 \ 10 grm. 











-- 



• -- 











17. 



0-1019 











j oxalic acid 

 \ 1 grm. 



1-2 



3-6 



8 



35 



0-1033 



+ 0-0014 



18. 



0-1019 



---- 



.... 



j oxalic acid 

 1 3 5 grm. 



3 



9 



8 



60 



0-1018 



-o-oooi 



Of these, numbers 1, 2, 3, 6, 8, 9, 14, 15, 17, and 18 gave 

 very spongy precipitates, while No. 7 was so spongy that it 

 could not be satisfactorily dried, and so was not weighed. In 

 experiments numbered 4, 9, 10, 14, 15, and 18 the cadmium 

 was not all precipitated in the time allowed. Jn No. 10, also 

 the precipitate was non-adherent. In No. 16, the oxalate was 

 precipitated and was not broken up by the current. 



VII. In Solutions containing Urea, etc. 



Balachowsky* obtained good results by the electrolysis of 

 solutions containing, in addition to cadmium salts, area and 

 various aldehydes. These solutions were found to offer no 

 difficulties with the rotating cathode, when cadmium sulphate 

 is taken, as may be seen from the following results. The 

 deposits were gray, compact, and quickly dried. The solution 

 was diluted to about 60 cra3 or 70 cm3 , and the best current poten- 

 tial was found to be that given by six storage cells connected 

 in series — approximately 11 -8 volts. 



*Compt. rend., cxxxi, 385 (1900). 



