"cataplasm" - Translation from English to Arabic

I bought an unction of a mountebank so mortal that, but dip a knife in it where it draws blood no cataplasm so rare collected from all simples that have virtue under the moon can save the thing from death that is but scratched withal.
لقد أحضرت معـي سمــا من أحد التجار إنه سم مميت جدا ولو بكمية قليلة حتى أن المصاب بــه ، لا يمكن شفاؤه