TELLURIUM. 237 



it possesses at once the characters of an acid and 

 an alkali. Davy discovered that it forms a gas 

 with hydrogen, similar in its properties to sul- 

 phuretted, phosphuretted, selenietted, and arse- 

 nietted hydrogen gases. But no experiments 

 have been made to determine the specific gra- 

 vity or composition of this gas. 



1. Berzelius made two analytical experiments, 

 from which the atomic weight of tellurium may 

 be deduced. 



(1.) He found that 100 parts of tellurium be- Composi- 

 tion of ox- 

 came 124*8 parts of oxide ; hence, oxide of tel- ide of teiiu- 



lurium is a compound of 



Tellurium 100 or 4-032 

 Oxygen 24-8 - 1 



We see that the oxide of tellurium is a com- 

 pound of one atom tellurium, and one atom ox- 

 ygen. The atomic weight of tellurium by this 

 experiment is 4*032, or rather less than one per 

 cent, more than 4. Now, it is exceedingly dif- 

 ficult to make an experiment similar to the one 

 by which Berzelius determined the composition 

 of oxide of tellurium, without some loss. If the 

 loss amounted to 0*2, which is no more than 

 Trijth part of the whole, then the oxide of tel- 

 lurium is composed as 1 follows : 



Tellurium 100 or 4 



Oxygen 25 - 1 



