To treat a cold sore: as soon as the first symptoms are detected, put honey on the affected part of the lip. To cure toothache: make a plug of cotton wool, soak it in whisky and apply it to the troublesome tooth. For fainting: chop an onion and persuade the patient to inhale the fumes until tears come. ''Grandma's Remedies'' is an endlessly fascinating collection of traditional cures and treatments for everything from acne to wasp stings. Many are surprisingly effective, and all of them paint a vivid picture of the world of our grandparents and great-grandparents, where resourceful and inventive women were the guardians of family health. If you're intrigued by the traditional and natural approach to healthcare, if you've ever wondered how to make a poultice or a tincture, or even if you just want to find out about the more domestic side of history, ''Grandma's Remedies'' is interesting - and enlightening - reading.