What is it? Soot produced by burning organic material such as wood, bone or oil. Like ochre, it was used in the earliest cave paintings. Used as the main ink up until Classical times. Pliny's Natural Histories explains the collection process, indicating an organised manufacturing process.
How is the pigment made? Collect the soot from a fire. Mull the soot thoroughly with a binder (such as animal fat or gum arabic) and water.
Was it used in English manuscripts? Yes. Although most medieval manuscripts were written in iron gall ink, there is still evidence of carbon ink being used, particularly in paintings. It's also possible carbon ink was used for more ephemeral writing.
Is is safe? Yes, provided you don't set yourself on fire. And always take care to wash hands after touching and avoid inhaling raw pigment.
What is it? Oak galls are produced by oak trees when a gall wasp lays her egg on a branch. The tree reacts by growing a shell around the larva, which grows inside. The developed gall wasp then chews its way out, leaving the empty gall behind on the tree. Although Dioscorides (40–90 CE) knew of its use as a black hair dye, it did not start being used as an ink until about the fourth century. It became the most common ink for manuscripts during the medieval period and up to the nineteenth century.
How is the pigment made? Collect the empty galls from young oak trees. Crush the galls and add water. Heat the liquid and strain. Add ferrous sulphate and gum arabic to the mixture.
Was it used in English manuscripts? Yes, although it is difficult to say for certain whether they used the native apple oak galls or imported marble or Aleppo galls. Possibly a mixture of both, depending on availability and finances. They were certainly imported in large numbers by the early modern period.
Is is safe? Yes and no. Galls were actually recommended for stomach complaints, so would not hurt you on their own, but the added iron would probably not do you much good.