Sodium carbonate (Na2CO3) can react with acid to generate carbon dioxide gas, but salt cannot react with acid. Then take out a small amount of these two solids in two glasses, label them with labels A and B respectively, and then add some vinegar respectively. It is observed that there are bubbles in A and no bubbles in B, so the original solid in A is soda ash and the original solid in B is salt.

Salt has a salty taste, while soda ash has no salty taste, so it can be tasted alone. Salt is salty, but soda ash is not salty.

So the answer is: soda ash; Salt; Try it.