Put the salt and sand in some water.
the salt will not be visible but the sand will
now strain the the sand from the water
now boil the water and now the water will boil away and now you will just have salt left.
this is the formula and answer of this question
One of the greatest technology advancement that made a huge impact in the field of crime investigation were the Closed Circuit Televisions (CCTV). The camera would just be simply mounted at an establishment wherein it remains to be monitored 24 hours a day, and crime would be simply investigated just by looking at its video feeds.