The above video demonstrates the workings of an assassin's teapot. It has multiple chambers and can be used to covertly pour different liquids, one of which is presumably poison so's you can eliminate your rivals in a civilized manner. He built a transparent model of one to demonstrate its functioning.
I did like his verbal disclaimer, 'Don't try to poison people', added for legal reasons. That got me thinking... I should add some declaimers to this post to assist my regular readers as they go about their daily business. Take heed, following them will lead to a more prosperous and happy life.