Bore of the smoking pipe and how each smoke is drawn

The bore of the pipes should let an urad grain through (a footnote: this is at the tip; at the root the hole is as thick as the thumb). The oleating and prayogika smokes are drawn through mouth and nose (a footnote: some say the prayogika through the nose only), the purgative smoke through the nose, and the emetic and cough-relieving smokes through the mouth only.