lu dus Helmontii (t as sh), lu dus Paracelsi

[For etym. see def.] Med. & Phar .: A calcareous stone, the precise nature of which is not known, used by the ancients in calculous affections. The term was also applied to every species of calculous concretion occurring in the human body. ( Dunglison .) Para cels us gave the name lud us to a kind of cubical pyrites, from their resemblance in shape to a die, and held them in high esteem as a remedy in calculous affections. Hence the Latin name. Van Helmont was of the same opinion, though he was mistaken as to what really was the lud us of Para cels us.