Regarding the posting about the acid in baby's saliva causing sore nipples: from "Principles of Biochemistry" by White, Handler & Smith: pH of saliva ranges from 6.4 - 7.0, where 7.0 is neutral. This means that saliva is an extremely weak acid in the chemical sense. For comparison: sweat: pH 4.5 to 7.5 (generally more acidic than saliva) tears: pH 5.2 to 8.3 tapwater generally about pH 5.5 because of dissolved carbon dioxide Remembering basic chemistry - below 7.0 is acid, above 7.0 is basic. Sarah Friend Barnett, LLLL, IBCLC Bronx (New York City), New York [log in to unmask]