412 



R. W. CHALLINOR. 



Solution of Standard Tint. 



4 cc. Oo solution = "012 grams = 24°/° Co 

 required 3*8 cc. Ni „ - *038 „ = 76"/° Ni 



•050 



Diluted to 50 cc. 



SECOND SERIES. 







NI or Co added 



Total 











)IH-t.ll.-, 



grains 



Colour 





metals in 

 50 cc. 

 grams 



Given 



Found 



Error 



cc. 



Grams 



05 



pink 









Ni -032 



•03152 



- -00048 



.', taken 





L-86 



0135 Ni 



0385 



Co -018 



•01S48 



+ 



00048 



•05 



light 



25 



0075 Co 



•0575 



Ni -044 



•0437 



- 



0003 





green 









Co -066 



•0063 



+ 



0003 



•0501 



green 



8*9 



•00S7 Co 



•0588 



Ni -045 

 Co 0051 



•04469 

 00541 



+ 



0003 

 0003 



•05035 



green 



4-05 



01395 Co 



06430 



Ni -0490 

 Co -00135 



•04887 

 •0014S 



+ 



00013 

 00013 



•05 



pink 









Ni 0i4 



01352 



- 



00048 



] taken 





2-55 



0255 Ni 



•0380 



Co -036 



03648 



+ 



00048 



•042 



pink 



■97 



•0097 Ni 



0517 



Ni -03 

 Co -012 



0296 

 •0124 



+ 



0004 

 0004 



•044 



green 



1-75 



00525 Co 



04925 



Ni -038 



0374 



- 



0006 













Co -006 



•0066 



+ -0006 



Tercent- 

 age error 

 on weight 

 of mixed 



metals 



•96 

 •6 

 •6 

 •26 

 •96 

 95 



\ • 



Maximum error (No. 7) = '0006 gm. in '044 gm. = 1'36% 



Effect of free HNO s on the Colour. 

 A number of experiments showed that the presence of 

 much free HN0 3 had a decided influence on the colour of 

 solution. The results of those given below show the maxi- 

 mum amount which may be present without affecting the 

 colour. 



Ni and Co solutions were mixed in the same proportion 

 as that required to produce standard tint, diluted to 20 cc. 

 with distilled water and compared with each other, then 

 to one was added 16 E. HNO s , 1 cc. at a time, to the other 

 the same quantity of distilled water and again compared 

 after each addition, with the following results : — 



