Dissolve the picric acid in water, add sufficient sulphuric acid to give the mixture a slightly acidulous taste, and then add carmine of indigo according to the shade of green desired. To dia silk ...

If stored incorrectly, delicate substances can turn into high-risk materials. Explosive picric acid recently caused alarm ...

After visiting the site near Uckfield, Mr Smith said: "The picric acid which we were concerned about is rather too dry for us to be happy with, so we're now adding water to it to moisten it up to ...