Rather than flushing twice and wasting valuable water, save the planet and your dignity at the same time. Simply place a few drops of the Haeckels courtesy flush into the toilet and flush once. The modern toilet system, originally known as an S-trap type water closet was invented by Alexander Cummings in 1775. This device was preferred throughout history as the standing water in the a ‘S’ pipe below was used to seal the outlet of the bowl therefore preventing any foul odours from entering into the bathroom. Size is 100ml.