1073. Directions for Distilling Perfumed Waters

1073.    Directions for Distilling Perfumed Waters. The following directions are, in the main, those given by the thoroughly practical chemist, Mr. Arnold J. Cooley. In the distillation of odoriferous waters, manufacturing perfumers employ their utmost care, in order to produce a highly fragrant article, free from any contamination that can vitiate the purity of their odor, or lessen their keeping qualities. The still may be of copper, but the head and worm should be formed of solid tin. It should be furnished with a high and narrow neck to prevent the liquor in it spirting over into the neck and condensing-worm. A still furnished with a steam-jacket is the most convenient for the purpose, as the heat of steam, or of a salt-water bath, can alone be safely employed. The common plan is to reject the first 2 or 3 fluid ounces that pass over, and to collect the remainder of the runnings until the proper quantity be obtained. The whole product is then agitated together, and stored, loosely covered, in a cool cellar for some weeks, or even months, in order that it may lose its herbaceous odor and the rawness from recent stillage. It is a common practice to separate any volatile oil floating on waters after distillation, but Mr. Haselden, of England, recommends the excess of oil to be well shaken with the water and the whole transferred to the stock vessel, where the oil will separate; it keeps better thus treated, and full strength is ensured. Ho prefers the stock vessel to be of stoneware, furnished with a tap about 2 inches from the bottom, whereby the water can be drawn out clear, the oil either rising to the top or sinking to the bottom, according to its specific gravity. As soon as it has acquired its full odor, or reached maturity, it is carefully decanted into bottles, which are then well corked or stopped, and stored in a moderately cool place. Some of the leading manufacturing perfumers keep a separate still for each of their more delicate distilled waters, and thoroughly clean them out and dry them after each distillation, as it is extremely difficult to remove any odor or taint that adheres to the still, still-head, and worm. Even blowing steam through them for some hours will not always sufficiently purify them for this species of distillation. In the preparation of distilled waters for medicinal purposes, a clean, sweet still, still-head, and worm, must also be employed. The two last should be of tin or glazed stoneware; and the receivers should be of glass or stoneware. The utmost care should be taken to prevent contamination of distilled waters by contact with copper, lead or zinc, since they slowly oxidize and dissolve these metals. In almost all cases, salted or pickled flowers, herbs, etc., are greatly superior to the fresh vegetables for the preparation of fragrant distilled waters. When the former are employed the product has little or none of the herbaceous and raw odor which is always present when the latter are used, besides which they keep better, and reach maturity, or the full development of their odor, in a much shorter time. (See No. 1349 (Preserved Flowers and Herbs).) Carefully prepared distilled waters keep well, and are not liable to any change, but when the reverse is the case, particularly when the liquor in the still has spirted over the neck of the still-head into the condensing worm, they are apt to acetify, and even to become ropy and viscid. A common, but very objectionable plan, in such cases, is to agitate them with a little carbonate of magnesia, and to filter them through paper. The only safe remedy is to re-distill them on the first indication of such change, for magnesia weakens them. Indeed, all their essential oil and fragrance may be removed by increasing the quantity of it. If magnesia, in any form, be used for filtering distilled waters, it should be the carbonate; but a little of even that will be dissolved if the water be ever so slightly acidulous.