According to the use made of them, perfumes for fumigation may be divided into two groups: those which develop their fragrance on being burned, and those which do so on being merely heated. The former group includes pastils and ribbons, the latter fumigating powders and waters.
Fumigating Pastils.
French—Pastilles fumigatoires; German—Räucherkerzen.
Pastils consist in the main of charcoal to which enough saltpetre is added to make the lighted mass glow continuously and leave a pure white ash. To this mass are added various aromatic substances which are gradually volatilized by the heat and fill the surrounding air with their perfume. It is important to observe that only ordinary saltpetre (nitrate of potassium) is to be used for this purpose, and not the so-called Chili saltpetre (nitrate of sodium) which becomes moist in the air. For ordinary pastils finely rasped fragrant woods such as cedar or santal are frequently employed. During the slow combustion, however, the wood gives off products of a pungent or disagreeable odor such as acetic acid and empyreumatic products, which lessen the fragrance. Fine pastils are composed of resins and essential oils and are usually formed into cones two-fifths to four-fifths of an inch high, by being pressed in metal moulds.
Fumigating pastils are manufactured as follows. Each solid ingredient is finely powdered by itself, and the necessary quantities are then put into a wide porcelain dish and intimately mixed with a flat spatula. In order to confine the dust, the dish is covered with a cloth during this operation. The mixture being completed, the essential oils are added, together with enough mucilage of acacia to form a plastic mass to be kneaded with the pestle, and which after drying will have a sufficiently firm consistence.
Pastilles Orientales.
| Charcoal | 1½ lb. |
| Saltpetre | 3½ oz. |
| Benzoin | ½ lb. |
| Powdered amber | 3½ oz. |
| Tolu balsam | 2¾ oz. |
The charcoal for this and all other pastils should be made from soft woods (willow, poplar, etc.). The characteristic of these pastils is the amber they contain (the offal from manufactories is used) and which on ignition gives off a peculiar odor much prized in the Orient, rather than in Europe or America.
Pastilles du Sérail.
| Charcoal | 1½ lb. |
| Saltpetre | 3½ oz. |
| Benzoin | ½ lb. |
| Santal wood | 5½ oz. |
| Opium | 1¾ oz. |
| Tolu balsam | 2¾ oz. |
This formula is here given as usually quoted. It may be stated, however, that the opium may be omitted entirely, as it neither contributes to the fragrance, nor produces, by being burned in this manner, any of the supposed exhilarating or intoxicating effects which it may produce when used in other forms or employed in other ways.