soap was known to mankind since 2800 BC . it is even mentioned in the bible. in ancient times soap was made using animal or vegetable fat , ash and sometimes other materials were added to give it scent .
this process was expensive.
In 1791 , Nicolas Leblanc succeeded in producing sodium carbonate from salt by a 2- step process . In the first step , sodiom chloride is mixed with concentrated sulfuruc acid at temprature of 800°C , then hydrogen chloride gas is evolved , leaving solid sodium sulfate. in the second step the sodium sulfate is crushed and mixed with charcoal and limestone and the mixture is heated again.
this process was much cheaper , and therefore revolutionized the soap industry . today soaps are made in a different process , using synthetic materials instead of the natural fats , giving better results , as these materials make stronger and better connections between the oil and water than the classic natural version of soap.