TITANIUM. 97 



acid cannot be completely freed from iron by 

 acids. Now, 6'134 is very near 6*1 64, the weight 

 deduced from a mean of all the other experi- 

 ments related in this section ; but we are cer- 

 tain that 6*134 is a little too high. Conse- True ato- 



. . mic weight 



quently, the true atomic weight of titanic acid of titanic 

 must be 6, and not 6*25, or any intermediate ac 

 number. 



It is obvious that menaccanite is a simple ti- 

 taniate of iron, or a compound of 1 atom titanic 

 acid and 1 atom protoxide of iron. Hence the 

 true constitution of the ore is 



1 atom titanic acid 6-0 or 57-143 



1 atom protoxide of iron 4-5 - 42-857 



10-5 100 



If any confidence can be put in the analysis o 

 Klaproth, nigrine is a compound of 4 atoms ti 

 tanic acid and 1 atom protoxide of iron ; or, nu 

 merically, 



4 atoms titanic acid . 24 



1 atom protoxide of iron 4-5 



28-5 



I do not notice the manganese, because its ato- 

 mic weight agrees with that of iron. 



Iserine is probably identical in its composition ferine. 

 with menaccane ; but no analysis of it hitherto 

 made can be depended on ; for it is much mix- 



VOL. II. G 



