Botanical Origin—This wood is furnished by two West Indian species of Guaiacum, namely:—
1. G. officinale L., a middle-sized or low evergreen tree, with light blue flowers, parapinnate leaves having ovate, very obtuse leaflets in 2, less often in 3 pairs, and 2-celled fruits. It grows in Cuba, Jamaica (abundantly on the arid plains of the south side of the island), Les Gonaives in the N.W. of Hayti (plentiful), St. Domingo, Martinique, St. Lucia, St. Vincent, Trinidad, and the northern coast of the South American continent. This tree affords the Lignum Vitæ of Jamaica (of which very little is imported), a portion of that shipped from the ports of Hayti, and probably the small quantity exported by the United States of Colombia.
2. G. sanctum L., a tree much resembling the preceding, but distinguishable by its leaves having 3 to 4 pairs of leaflets which are very obliquely obovate or oblong, passing into rhomboid-ovate, and mucronulate; and a 5-celled fruit. It is found in Southern Florida, the Bahama Islands, Key West, Cuba, St. Domingo (including the part called Hayti) and Puerto Rico, and is certainly the source of the small but excellent Lignum Vitæ exported from the Bahamas as well as of some of that shipped from Hayti.
History—There can be no doubt but that the earliest importations of Lignum Vitæ were obtained from St. Domingo, of which island, Oviedo[403] who landed in America in 1514 mentions the tree, under the name of Guayacan, as a native. He points out its fruits as yellow and resembling two joined lupines, which could only be said with reference to G. officinale, and would not apply to the ovoid five-cornered fruits of G. sanctum. Oviedo appears however to have been aware of two species, one of which he found in Española (St. Domingo) as well as in Nagrando (Nicaragua) and the other in the island of St. John (Puerto Rico), whence it was called Lignum sanctum.
The first edition of Oviedo was printed in 1526; but some years before this the wood must have been known in Germany, as is evident by the treatises written in 1517, 1518, and 1519 by Nicolaus Poll,[404] Leonard Schmaus[405] and Ulrich von Hutten.[406] The last which gives a tolerable description of the tree, its wood, bark, and medicinal properties, was translated into English in 1533 by Thomas Paynel, canon of Merton Abbey, and published in London in 1536 under the title—“Of the wood called Guaiacum that healeth the Frenche Pockes and also helpeth the gout in the feete, the stoone, the palsey, lepree, dropsy, fallynge euyll, and other dyseases.” It was several times reprinted.
In the old pharmacy the products of destructive distillation of guaiacum wood were known as Oleum ligni sancti. It must have consisted of the substances which we mention further on in the following article.
Description—The wood (always known in commerce as Lignum Vitæ) as imported consists of pieces of the stem and thick branches, usually stripped of bark, and often weighing a hundredweight each. It is remarkably heavy and compact. Its sp. gr. which exceeds that of most woods is about 1·3.
Lignum Vitæ is mostly imported for turnery,[407] and the chips, raspings and shavings are the only form in which it is commonly seen in pharmacy. A stem 7 to 8 inches in diameter cut transversely exhibits a light-yellowish zone of sapwood about an inch wide, enclosing a sharply defined heartwood of a dark greenish brown. Both display alternate lighter and darker layers, which especially in the sapwood are further distinguished by groups of vessels. In this manner are formed a large number of circles resembling annual rings, the general form of which is evident, though the individual rings are by no means well defined. More than 20 such rings may be counted in the sapwood of a log such as we have mentioned, and more than 30 in the heartwood. The pithless centre is usually out of the axis. The medullary rays are not visible to the naked eye, but may be seen by a lens to be very numerous and equidistant. The pores of the heartwood may be distinguished as containing a brownish resin, while those of the outermost layer of sapwood are empty.
In the thickest pieces sapwood is wanting, and even in stems of about a foot in diameter it is reduced to ⅕ of an inch. It is of looser texture than the heartwood and floats on water, whereas the latter sinks. Both sapwood and heartwood owe their tenacity to an extremely peculiar zigzag arrangement[408] of the woody bundles. The sapwood is tasteless. The heartwood has a faintly aromatic and slightly irritating taste, and when heated or rubbed emits a weak agreeable odour.
The bark which was formerly officinal but is now almost obsolete, is very rich in oxalate of calcium and affords upon incineration not less than 23 per cent. of ash. It contains a resin distinct from that of the wood, and also a bitter acrid principle.[409]