In a message dated 6/23/2002 2:58:28 PM Eastern Daylight Time, firstname.lastname@example.org writes:
If the vinegar trick works on sand....will it also work on rocks to see
if they will change your Ph? I also don't have a supply of car batteries
like Dave does. Rich
Yes,... that is where I first heard of it being used was to test a rock. Maybe one of the resident chemist will explain why vinegar can be used to tell if the rock has a pH raising quality. The only test I remember from school was adding vinegar and baking soda would actually blow out a fire.