|Alternative reference number||NLB/51 p257|
|Title||Copy letter from Robert William Frederick Harrison, Assistant Secretary of the Royal Society to the Secretary, the War Office|
|Date||12 March 1915|
|Description||'With respect to yhe question submitted by you to the Royal Society I now beg to report as follows:|
"Nitre Cake remaining as residue in the manufacture of nitric acid has hitherto been worked up into "salt cake" by fusing it with common salt. The excess of sulphuric acid in the nitre cake is thus utilized for the production of a further quantity of sodium sulphate and hydrolic acid. Salt cake is used in the manufacture of glass but the demand for it has fallen off very seriously, glassmakers in France, Belgium and Germany noo longer being able to import it.
The excess of sulphuric acid in the nitre cake might be utilized by manufacturers of superphosphate fertilizers. It would be quite worth while to offer it to these manufacturers though they would probably not care to pay more than a fraction of its free acid value".'