Re: Who invented liquid soap and why ?

Hello, A.L.  As far as I can tell, Liquid Soap was invented by  Hendrik Willem Brouwer of  Holland, working for Lever Brothers. He received patent number US4065398: Liquid soap 
composition. You can read more about this invention at this webpage.

As for why - I can only guess that Lever Brothers saw the potential to increase sales and profits due to the convenience of a soap that could easily be dispensed in public places like public 
restrooms, as a better alternative than providing a community bar of soap (do you really want to wash your hands with  a bar of soap covered with some stranger's dirt and germs?), and as 
a more comfortable alternative to providing powdered soap (I have used it in public restrooms in the past...feels like you are washing your hands with  Ajax or Comet. Uncomfortable).

In fact, since the invention of liquid soap, there have been a whole lot of patents for equipment that  dispenses liquid soap, so the market is obviously there!