This section is from the book "The Gardener's Monthly And Horticulturist V18", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
Bleaching: Put a number of flowers, which have previously been placed in a warm chamber to cause them to open, in a vessel containing a solution of chloride of lime, 1/2 oz. of soda, and 2 quarts of water. Cover the vessel and leave it as it is in a moderate temperature for four or five days. During this period the flowers first change, to an orange color, and afterwards to a blueish white. As soon as these changes show themselves take the flowers out and pour off the fluid, and fill it up again, using this time only 1 oz. of chloride of lime and no soda. Let the flowers remain in this until quite white, subsequently drying them in a warm oven.