You can conduct a test to find this answer for yourself. Obtain two identical small containers, such as margarine tubs. Add the same amount of water to each. The water should be allowed to reach room temperature. Dissolve 2 ts of salt in one of the tubs. Add a penny, dime or nickel to each (or test each coin in succession). Observe the results after 24, 48, and 60 hours. Voila!