150 Proceedmgs of Indiana Academy of Science 



TABLE 3. Effect of ethyl alcohol. TABLE 4. Limit of sensitiveness. 



0.01 mg. Co, Ice. 4 N NH.SCN, 

 0.8 cc. 5N HCl, 1 cc. ether; total 

 voL 5 cc. 



Per cent alcohol Color in ether or 

 in 5 cc. ether-alcohol layer, 



faint blue 



0.0 

 1.0 

 2.0 

 4.0 

 (3.0 

 8.0 

 16.0 

 20.0 



slightly blvier 

 slightly bluer 

 maximum blue 

 maximum blue 

 maximum blue 

 maximum blue 

 maximum blue 



1 cc. 4 N NH.,SCN, 1 cc. 5 N HCl, 

 0.3 cc. alcohol, 1.2 cc. ether: total 

 vol. 5 cc. 



Repetition using KSCN and NaSCN 

 in jilace of NH4SCN gave the same 

 tints for each concn. of Co. 



T.VBLE ."). Comparison of sodium, jxtta.^siuni and nnunonium thiocyanates 



in neutral solution. 



1 cc. 4 X alk. thiocyanatc, 2 cc. etiier, 0..5 cc. C..H.-,(JH; total vol. 5 cc. 

 (The sodium and potassium salts gave identical results). 



mg. Co Color, KSCX or Na.SCX 



acjueous layer ether layer 



0. 1 sky blue none 



1 .0 dec;) blue verj' faint blue 



1 .0 deei) blue pale blue 



0.5.0 itidi'j;() blue deep sky blue 



Color, XH4SCX 

 a(iueous layer ether layer 



sky blue very faint blue 



deep blue deep blue 



deep blue deep blue 



indigo blue slightly paler than 

 acpieous layer 



T.VBLIO n. Comparison of 1:1 aniyl alcohol-ether with 1:1 ethyl alcohol-ct he 



in acid solut ion. 



1 cc. 4 X Xli,SCX, 1 cc. 5 X HCl; total vol. 5 cc. 



rag. Co Color, amyl alcohol-ether 



O.OIl none 



.002 faint blue 



Color, ethyl alcohol-ether 



faint blue 



distinct blue 



T.VBLE 7. Ethyl alcohol in neutral solution as a reagent for co})alt. 

 1 cc. 4 X Xa8CX; total vol. 5 cc. 



