Again, glibness of speech sometimes awakens our distrust.

The once goodly row of quartos looks now like a set of mineral teeth that have essayed too closely to simulate Nature by assaulting a Boston cracker; and the intervals of vacuity among the books, as among the incisors, deprive the owner of his accustomed glibness in pronouncing himself on certain topics.

Perhaps that accounts for the glibness with which language slips off your tongue.