200 HALL AXJ) SMITH— COLUMBIUM. [May i 9> 



(B) 10 c.c. of (A) diluted to ioo c.c. i c.c. = .000106 Ti0 2 . 



( C) 10 c.c. of (B) diluted to 100 c.c. 1 c.c. = .0000106 Ti0 2 . 



(D) 10 grams of oxalic acid in 100 c.c. 1 c.c. =0.1 gram of 

 oxalic acid. 



(is) 1 gram chromotropic acid in 100 c.c. 



50 c.c. Nessler tubes, one inch in diameter, were used for all of 

 the tests. 



.5 c.c. of (is) in 50 c.c. of water gave a mere trace of color, 

 for which reason the solution to be tested was always compared 

 with another tube containing the same amount of chromotropic 

 acid, thus making allowance for the slight color given by the solu- 

 tion of that reagent. 



.15 c.c. of (C) gave a faint pink color when added to 50 c.c. 

 of water containing .5 c.c. of (is) ; .00000159 gram of Ti0 2 in 

 50 c.c. of water gave a change of color ; .3 c.c. of the same solu- 

 tion gave a very distinct coloration, or .00000318 gram of Ti0 2 in 

 50 c.c. More than 1 c.c. of the chromotropic acid gave so much 

 color'as to interfere with the delicacy of the test. 



EFFECT OF OXALIC ACID. 



i c.c. of (is). 



i c.c. of (-D), or 1 gram of oxalic acid in 50 c.c, required 2.6 

 c.c. of titanium solution (C) to show the characteristic pink color, 

 or .0000275 gram of Ti0 2 . 



1 c.c. of reagent was adopted as the amount best suited to use and 

 was the amount taken in all of the following cases unless otherwise 

 stated. 



With 0.2 gram of oxalic acid, .0000339 gram of Ti02 2 in 50 c.c. 

 gave a pink color. 



With 0.5 gram of oxalic acid, .0000275 gram of Ti0 2 was re- 

 quired to give the test for titanium. 



1.0 gram of oxalic acid required .0000244 gram of Ti0 2 to give 

 the test. 



In the presence of 2.0 grams of oxalic acid, .0000244 gram of 

 Ti0 2 gave a distinct pink color in 50 c.c, while with 5.0 grams of 

 oxalic acid, .0000265 gram of Ti0 2 gave a color. 



The amount of oxalic acid seems to have little effect although the 

 presence of the acid diminishes the delicacy of the test, but this is 

 independent of the amount of the acid present when more than o. 1 

 gram is used. 



