While speaking on this subject, it will be as well to bear in mind that there are nine different kinds of plants of a similar kind, of which we have already made mention[741] as being employed for the purpose of imitating Indian nard; so abundant are the materials that are afforded for adulteration. All these perfumes are rendered still more pungent by the addition of costus and amomum, which have a particularly powerful effect on the olfactory organs; while myrrh gives them greater consistency and additional sweetness, and saffron makes them better adapted for medicinal purposes. They are most pungent, however, when mixed with amomum alone, which will often produce head-ache even. There are some persons who content themselves with sprinkling the more precious ingredients upon the others after boiling them down, for the purpose of economy; but the strength of the unguent is not so great as when the ingredients have been boiled together. Myrrh used by itself, and without the mixture of oil, forms an unguent, but it is stacte[742] only that must be used, for otherwise it will be productive of too great bitterness. Unguent of cyprus turns other unguents green, while lily unguent[743] makes them more unctuous: the unguent of Mendes turns them black, rose unguent makes them white, and that of myrrh of a pallid hue. Such are the particulars of the ancient inventions, and the various falsifications of the shops in later times; we will now pass on to make mention of what is the very height of refinement in these articles of luxury, indeed, I may say, the beau ideal[744] of them all. (2.) This is what is called the “regal” unguent, from the fact that it is composed in these proportions for the kings of the Parthians. It consists of myrobalanus,[745] costus, amomum, cinnamon, comacum,[746] cardamum, spikenard, marum, myrrh, cassia, storax,[747] ladanum,[748] opobalsamum, Syrian calamus[749] and Syrian sweet-rush,[750] œnanthe, malobathrum, serichatum,[751] cyprus, aspralathus, panax, saffron, cypirus, sweet marjoram, lotus,[752] honey, and wine. Not one of the ingredients in this compound is produced either in Italy, that conqueror of the world, or, indeed, in all Europe, with the exception of the iris, which grows in Illyricum, and the nard, which is to be found in Gaul: as to the wine, the rose, the leaves of myrtle, and the olive-oil, they are possessed by pretty nearly all countries in common. CHAP. 3.—DIAPASMA, MAGMA; THE MODE OF TESTING UNGUENTS.