Allotelluric acid

By very cautious heating at 140° C. the dihydrate very gradually loses a bimolccular proportion of water, forming allotelluric acid, H2Te04, which is a loose powder of density 3-43 at 19° C. 3 on further heating it passes successively into tellurium trioxide and tellurium dioxide. 

That the foregoing classes of salts may be derived from different acids is quite feasible, for the second form of telluric acid described, allotelluric acid, obtained by heating the crystalline acid II6Te06 (p. 885), differs from the ortho-acid not only in its greater acidity but in its precipitation reactions.2... 

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