This section is from the book "Mrs. Rorer's Vegetable Cookery And Meat Substitutes", by Sarah Tyson Rorer. Also available from Amazon: Mrs. Rorer's Vegetable Cookery And Meat Substitutes.......
During the summer, when herbs are in their highest state of perfection, full of juice, just before the flowering, they should be gathered for drying. The gathering should be done on a perfectly dry day, about two days after a rain, early in the morning or after sundown. Take the leaves from the stems and spread them out on boards covered with brown paper. Stand the boards in a warm oven, and dry quickly to preserve the flavor. When dry, put them into glass jars, screw down the tops and stand them at once in the kitchen closet. The bottles must be perfectly dry and the herbs cold when they are put in, or they will sweat and spoil. Mark the jars plainly on the outside to avoid confusion.