I love Annie Gregory's 1902 jewel of a book titled 'The Woman's Favorite Cook Book' where she states on the 1st page that she was assisted by 1000 housewives in compiling all of the recipes and tips in this very hefty book. (Wow) I especially love this little (and still useful) article called The Varied Uses of Lemon, It goes on to say:
" Every toilet table should be liberally supplied with lemons. The uses are so varied and so valuable that no one can overlook them. Among them is the fact that a teaspoon of lemon juice in a cupful of black coffee will drive away a headache. But if, on rising, the juice one half of a lemon be squeezed into a cupful of very hot water and drank with no sugar there will be no headache to drive away. A slice of lemon rubbed on the temples and back of the neck will also cure the
headache. A solution of lemon juice should always be at hand. A little rubbed on the skin at night will whiten and soften it's texture. A fine manicure acid is made from a teaspoonful of lemon juice in a cupful of warm soft water. It will whiten discolored and stained fingernails. Lemon Juice in water will loosen the tartar that accumulates on the teeth. It makes the breath sweet. A slice of lemon rubbed over tan shoes which are then wped off with a soft cloth will remove black stains from their 
surface." Bessie Hill Porter
" Every toilet table should be liberally supplied with lemons. The uses are so varied and so valuable that no one can overlook them. Among them is the fact that a teaspoon of lemon juice in a cupful of black coffee will drive away a headache. But if, on rising, the juice one half of a lemon be squeezed into a cupful of very hot water and drank with no sugar there will be no headache to drive away. A slice of lemon rubbed on the temples and back of the neck will also cure the
headache. A solution of lemon juice should always be at hand. A little rubbed on the skin at night will whiten and soften it's texture. A fine manicure acid is made from a teaspoonful of lemon juice in a cupful of warm soft water. It will whiten discolored and stained fingernails. Lemon Juice in water will loosen the tartar that accumulates on the teeth. It makes the breath sweet. A slice of lemon rubbed over tan shoes which are then wped off with a soft cloth will remove black stains from their 
surface." Bessie Hill Porter 
