Four 19th-century books suspected of being harmful to humans have been quarantined at France's National Library.
The volumes, which include The Ballads of Ireland by Edward Hayes, an anthology of Romanian poetry by Henry Stanley, and a Royal Horticultural Society book, could contain arsenic-laced colorants, popular in the Victorian Era.
According to a British scientist: "While the threat of arsenic exposure is very real, we must not neglect the harmful effects of being exposed to Irish Ballads."