The British Library has published advice on the use of white gloves. Essentially, we recommend that it is preferable to handle manuscripts with clean dry hands. Wearing cotton gloves to hold or turn the pages of a book or manuscript actually reduces manual dexterity, and increases the likelihood of causing damage. Gloves also have a tendency to transfer dirt to the object being consulted, and to dislodge pigments or inks from the surface of pages.
This short video demonstrates how not to handle a manuscript wearing white gloves (or, indeed, gloves of any colour).