1908-9.] The Action of Nitric Anhydride on Mucic Acid. 97 
analyses confirm this conclusion. Tire figures vary with each new 
preparation, but correspond more closely with the tetranitrate than with 
the trinitrate. 
Pure tetranitrate, free from ether, has not yet been obtained. On 
evaporating the ethereal solution, the substance crystallises in well-defined 
colourless needles, hut on standing in air or in vacuo over concentrated 
sulphuric acid, these soon fall to a white powder. This change is appar- 
ently due to partial decomposition. The substance behaves in a similar 
manner when crystallised from alcohol. 
The white powder thus obtained does not decompose further if kept 
perfectly dry, but in the air it soon begins to decompose, with evolution of 
nitric acid and oxides of nitrogen. Mucic acid is one of the products of this 
decomposition. Tartaric acid dinitrate behaves in a similar manner when 
exposed to moist air, tartaric acid being the chief product of decomposition. 
Mucic acid tetranitrate is, in many other respects, very similar to tartaric 
acid dinitrate. It is readily soluble in water, alcohol, and ether, but not in 
chloroform or benzene. 
Treated with ammonium sulphydrate, crystals of the sparingly soluble 
ammonium mucate are obtained. 
On heating the nitrate it decomposes violently. 
When an ethereal solution of the nitrate is allowed to stand in contact 
with a little water, drops of a syrupy substance, which is soluble in water, 
separate from the ethereal layer. In the course of a few days crystals of 
oxalic acid separate from the aqueous layer. 
On the analogy of tartaric acid dinitrate, tartaric acid and tetraketo 
adipic acid should be formed as intermediate products of decomposition. 
As yet, neither of these acids has been detected. 
(. Issued separately February 19 , 1909 .) 
