Book IV Sulphur, amber, Pliny's gems, jet, bitumen, naphtha, camphor, maltha, Samothracian gem, thracius stone, obsidianus stone

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	BOOK IV	63

	Indian usage, called camphora. We know this to be true because Averroes writes that amber is a species of camphor; because Serapio writes that it forms abundantly when the earth is shattered with earthquakes and then, commonly, both sulphur and bitumen pour forth with great force; because certain springs of warm water along the Aemilia Road smell of camphor; because merchants say that they have seen a place in India that exudes camphor. Since the native camphor from India is colorless and, in part, tenuous and finely fibrous, it differs from the white naphtha of Babylonia. That which is brought to us in the small cakes is artificial. It is prepared in the following manner. Indian bitumen which effloresces from native camphor is placed in earthenware vessels and heated over burning coals. The more tenuous portions of the bitumen, having been changed to a white color, are carried upward to the lid. It is then collected and given the form we see. For this reason it happens that merchants sometimes bring us pieces of bitumen along with the camphor from India. But this association, in itself, is of little value. Actually if a cotton cloth is moistened with water and placed in the lid of the vessel in which oil is being extracted from amber, the cloth will have the odor of camphor.²Not without cause has Avicenna said that amber has a strong camphor odor. It catches fire and burns with the same ease as all other bitumens. Nevertheless the Moors and the younger Greek writers who follow them have another theory regarding the origin of camphor. They say it is the gum or the tears of a tree with such wide-spreading branches that it is able to shade an area large enough to accommodate a hundred men with ease. The wood of the tree is said to be white, ferulaceous, light, and with the camphor contained in the porous heart of the tree. Obviously a dream. The tree is said to grow in mountains near the ocean. When they think camphor to be either tears, resin or gum, the Moors do not consider why it is that the Indians would have any cause to extract the more tenuous parts from it over a fire. No matter from what kind of a tree a juice may come, if it is very pleasing and useful, it is used in the form in which it occurs naturally. For example, myrrh, bdellium, benzoin and other similar tears are brought to us in the same form as that in which they are exuded from the tree. Similarly, frankincense, storax, and other resins and even the gums of ivy, juniper, peach, and other trees are not altered. But, on the other hand, we often extract the more tenuous portions of other mineral substances in this manner, for example, from mercury and calamine. Therefore it is very probable, as certain merchants relate, that camphor is made from a certain genus of bitumen by distillation.³ ⁸ Although camphor and amber have the same general composition, C₁₀H₁₆O, they are only distantly related, chemically. There are many organic compounds that have an odor similar to camphor. When heated amber yields succinic acid, often called oil of amber and a bituminous residue. Agricola refers here to this acid * Several closely related terpenes can be produced from bitumen but they were probably not being produced in the time of Agricola. Today these compounds are called camphors.

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