Fulgurite or lightning tube; thunder stone. / sagitta fulguris. / pierre detonnerre (title on object); a tube of molten sand or rock created during a lightning strike. Here referred to as a 'thunder stone'. Top right the Latin name; numbered top left: 27. Part of the seventh album with drawings of reptiles; amphibians and natural history ensembles. The seventh of twelve albums with watercolors of animals; birds and plants; known around 1600; commissioned by Emperor Rudolf II. With explanations in Dutch; Latin and French; minerals and metals; Anselmus Boetius de Boodt; Praag; 1596 - 1610; paper; watercolor (paint); deck paint; ink; pen; h 110 mm x w 116 mm