( 604 ) 
amine. But on th^ other hand many objections have been raised to 
the position assigned to tellurium: for instance, the different consti¬ 
tution of telluric acid which, probably, must be looked upon as 
H 6 feO B and the totally different hydration of tellurates in comparison 
with sulphates and selenates. However this may be, it is highly 
desirable to obtain more data as to the position of tellurium among 
the other elements and for this reason, the relation to sulphur had 
to be ascertained in the first place. 
§ 3. The tellurium was obtained from l l / a kilo of crude tellurium 
probably derived from American ore. It appeared to contain the 
following elements: tellurium, selenium, sulphur, lead, copper, 
bismuth, iron, silicon and traces of antimony, zinc and a few other 
metals. 
The first purification was carried out by oxidation with aqua regia, 
evaporation of the filtrate to dryness, and repeated extraction of the 
residue with strong hydrochloric acid. The boiling filtrate was then 
precipitated by sulphur-dioxide; the first portions of the precipitate 
being rich in selenium were each time rejected. This operation was 
repeated three times. The amorphous tellurium was divided into two 
parts; one portion was converted, by the process given by Norris, 
Fay and Edgerley 1 ), into basic tellurium nitrate Te,0,(0H)(N0 s ) 
and by repeating the process five times, which operation lasted 
many weeks, it was finally obtained quite pure in the form of the 
said salt: from this, pure TeO, was then obtained by gentle ignition 
and this, dissolved in pure hydrochloric acid was precipitated by 
SO,. The other portion was converted into telluric acid by means of 
CrO„ according to Staudenm ayer’s process as modified by Gutbier-): 
this was purified by precipitating twelve times with nitric acid and 
then crystallising from water. It is necessary to reduce the adhering 
CrO, with alcohol, otherwise the telluric acid crystals retain a yellow 
colour which is caused by occluded solid CrO,; this matter I hope 
to refer to shortly. 
The pure telluric acid was then reduced completely by hydrazine 
hydrate. 
The crystalline form of the basic nitrate has not been described 
up to the present. The following data have been obtained from the 
substance crystallised from nitric acid. 
l ) Norris, Fay and Edgerley, Americ, Chem. Journ. 23. 105. 
3) Gutbier, Z. f. anorg. Chem. 29. 22. (1901); 32. 96. (1902). 
