450 Browning and Palmer — Ferrocyanides, etc. 



The method is especially recommended for the detection of 

 small amounts of ferrocyanides and ferricyanides in the pres- 

 ence of each other. The following table gives some results 

 obtained : 



K 4 FeC 6 N 6 K 3 FeC 6 N 6 KSCN 

 present present present 



Indication 



grm. 



o-ooio 



0-0005 

 0-0002 

 0-0001 



0-1 



o-i 



0-1 

 0-1 



o-i 

 o-i 



0-1 



o-i 



0-0100 

 0-0050 

 0-0010 



o-ooio 

 o-ooio 

 o-ooio 



o-i 

 o-i 

 o-i 

 o-i 



o-ooio 



0-0005 

 0-0002 



o-oooi 



o-i 

 o-i 

 o-i 

 o-i 



grm. 



Tests for K 4 FeC 6 N 6 only 



0-1 Distinct 



0-1 Distinct 



0*1 Distinct 



0-1 Distinct 



Tests for K 3 FeC 6 N, 



0-1 

 0-1 



o-i 

 o-i 



only* 



Distinct 

 Fairly distinct 

 Faint 

 Very faint 



Tests for KSCN only 



0-0010 Distinct 



0-0005 Distinct 



0-0002 Distinct 



0-0001 Distinct 



Tests for K 4 FeC 6 N 6 , K 3 FeC 6 N 6 and KSCN 



0-0100 0-0100 Good tests for K 4 FeC 6 N 6 , K 3 FeC 6 N 6 , KSCN 

 0-0050 0-0050 Good tests for K 4 FeC 6 N 6 , K 3 FeC 6 N 6 , KSCN 

 0-0010 0-0010 Good tests for K 4 FeC 6 N 6 , K 3 FeC 6 N 6 , KSCN 



Tests of mixtures unknown to analyst 

 0-0010 Found K 4 FeC 6 N 6 , K 3 FeC 6 N 6 



o-ooio 



0-0010 Found K 4 FeC 6 N , KSCN 



0-0010 Found K 4 FeC 6 N 6 , K 3 FeC 6 N 6 , KSCN 



* These tests were made without waiting to wash the ferrocyanide pre- 

 cipitate thoroughly. 



