Cannabis

It is known nowadays that A shipload of bat guano from South America is probably directly responsible for the Irish potato blight and subsequent immigration's from Ireland to the new world during the years 1845-50, It was first used in the south and east of Ireland then winds and wet conditions spread it to the rest of the country. Overshadowed by the Irish plague was the failure also of the potato crop in the Scottish Highlands as well as the spores were wind borne eventually also to the Island of Britain