The leather is then folded in the centre, smoothed with a paper-knife, put under a weight, and allowed to dry. The dried leather forms the so-called perfume skin which retains its fine odor for years. Instead of the above alcoholic liquids any desired alcoholic perfume may be used; especially suitable are those containing oils of lemon grass, lavender, and rose, since they are not very volatile, and when combined with musk and civet remain fragrant for a long time. A sufficiently large piece of perfume skin inserted in a desk pad or placed among the paper will make the latter very fragrant. Spanish skin is chiefly used for this purpose, as well as for work, glove, and handkerchief boxes, etc. It is generally inclosed in a heavy silk cover. If leather be thought too expensive, four to six layers of blotting-paper may be perfumed in the same way and properly inclosed. Thin layers of cotton wadding between paper can also be thus perfumed and used for filling pin cushions, etc. SPANISH PASTE. Mix the following substances intimately in a porcelain mortar, and add water drop by drop until a doughy mass results. Ambergris ¾ oz. Benzoin 1½ oz. Musk ¾ oz. Vanilla ¾ oz. Orris root ¾ oz. Cinnamon ¾ oz. Oil of bergamot 1½ oz. Oil of rose ¾ oz. Gum acacia 1½ oz. Glycerin 1½ oz. This paste, divided into pieces about the size of a hazelnut, is used for filling the so-called cassolettes or scent boxes which are carried in the pocket, etc., like smelling bottles. Owing to its pasty consistence this preparation can be used for perfuming jewelry (small quantities are inserted within the diamond settings), fine leather goods, belts, and other articles. It is unnecessary to lengthen the list; every practical perfumer will know what objects need perfuming. CHAPTER XIX. HYGIENIC AND COSMETIC PERFUMERY. Perfumery is not merely called upon to act in an æsthetic direction and gladden the senses; it has another and more important aim, that is, to aid in some respects the practice of medicine. It is not necessary to point out that in this sense, too, it acts in an æsthetic way; for health and beauty are one and inseparable. The field relegated to perfumery with reference to hygiene is extensive, comprising the care of the skin, the hair, and the mouth. But we also find in commercial perfumery articles which possess no medicinal effect and serve merely for beautifying some parts of the body, for instance, paints and hair dyes. As it is not possible to separate perfumes with hygienic effects from cosmetics, we shall describe the latter in connection with the former.