IN the ordinary methods for the preparation of tartaric acid dinitrate, a mixture of fuming nitric acid with concentrated sulphuric acid is used as a nitrating agent.

The product is treated with iced water to remove the sulphuric and nitric acids.

As the dinitrate is decomposed by water, even at 0° C, it is impossible to avoid some loss in this process.

By using nitric anhydride as a nitrating agent this difficulty is avoided. Nitric acid, which is the only other product of the reaction, can be removed by evaporation in vacuo.