To be absolutely brutal and honest with you, nobody cares about I look forward to hearing from you.. The practical reason is that it's one of the various standard and conventionally polite ways to end the body of the letter. It's just a standard exit.
1 In some cases, liver failure causes this taste to occur. 2  Gastroesophogal reflux disease can cause the salty taste (even when no pain is present). 3  Some medicines can make everything taste odd. for example the drug enalapril, which is a drug used to prevent heart failure.
Sodium chloride is readily water-soluble, so if this crude salt were exposed to condensation or rain water, the sodium chloride could be dissolved and removed, and the salt could in effect lose its saltiness. Also, the salty flavour is detected by our sense of taste. If there were a physiological change in the functioning of our taste buds, salt consumed may no longer taste the same, but this would not be due to any inherent change in the salt itself. In summary, salt, i.e. sodium chloride, is a very stable material which retains its properties when stored dry.