Much ado about puffing or did Shakespeare smoke cannabis?

There has been renewed interest in the theory considering whether William Shakespeare smoked a pipe with cannabis while he wrote his world-acclaimed works.

In its latest edition, the South African Journal of Science has an article by Francis Thackeray, who conducted a study on pipes found in the garden used by Shakespeare.

The BBC's Milton Nkosi asked him about the residue found in 400-year-old pipes believed to have been used by Shakespeare to smoke.