210 Flint — Researches uj)07i the Complexity of Tellurium. 



atomic weight estimations made upon the telhiriuni in them. 

 In the second part will be given an account of an experiment 

 upon a fractionation by nitric acid, and of a preliminary 

 investigation of the less easily hydrolyzed fraction. 



Part I. 



As a check upon the whole work, one hundred and fifty 

 grams of the purified product were dissolved in nitric acid 

 (sp. gr. 1"25) and crystallized out as basic nitrate by evapora- 

 tion of the solution at about 85° C. After being washed with 

 concentrated nitric acid, the basic nitrate was dried by heating 

 at 110° to 120° C. in speciall}^ constructed electric drying 

 ovens through which was passed a cui'rent of air dried by 

 sulphuric acid. The air was bubbled lirst through a solution 

 of potassium hydroxide, then through concentrated sulphuric 

 acid, and finally filtered by passing through a tower containing 

 cotton wool. 



Portions of this preparation were then weighed out in 

 platinum and brought to constant weight by heating, for 

 periods of about twelve hours each, at 140° C. in air dried as 

 just stated, in the electric heaters. The temperature was next 

 raised, and the nitric acid expelled from tlie compound by 

 ignition up to 425° to 450° for twenty to twenty-four hours. 

 The experiments were finally completed by a short ignition 

 over a bunsen burner at such a temperature as would ensure 

 a glassy condition of the fused dioxide. 



In all the basic nitrate experiments detailed in this paper, 

 the weighings were made by the method of oscillations, a 

 standardized set of weights employed, and a correction for the 

 inequality of the balance arms applied. Lastly, the weights 

 were reduced to a vacuum. The corrected results of the 

 determinations made upon the unfractionated material, which, 

 excepting number 5, were performed in pairs, are given in 

 Table I. It should be added that in no case was there evidence 

 of the escape of traces of dioxide by volatilization. 



Table I. 



Unfraction atecl Material. 



Exp. 



1 . 



2 . 



3 . 



4 . 



5 . 



jOs.HNOs taken 



2Te02 found 



Atomic weight 



gims. 



gi-ms. 



of tellurium 



4-26930 



3-56471 



127-41 



3-66863 



3-06339 



127-48 



3-17350 



2-64983 



127-46 



3-43498 



2-86827 



127-48 



5-47269 



4-56963 



127-44 



20-01910 



16-71583 



127-45 (Mean) 



