Dictionary.net

• So called from the name of the physician who first proposed them. They are formed of sago, in powder; salep, in powder; tragacanth, in powder, each, four parts; prepared oyster-shells, one part, cochineal, half a part, divided into powders of one drachm each; one of which is given three or four times a day as a demulcent in diarrhoea and dysentery. Dorvault makes poudre de Castilhon synonymous with arrow root.

1846 - Medical lexicon: a dictionary of medical science
By Robley Dunglison