Part 2 — Substitutes for True Lignum-vitae

Woods of the Lignum-vitae Family

“Maracaibo lignum-vitae,” or vera.—The properties which especially adapt lignum-vitae to its most exacting uses are extreme density, durability and toughness, combined with self-lubrication. All of the woods of the family possess these properties to a degree but, as already shown, that of Guaiacum alone, and apparently only certain kinds of it, meet the full requirements of the trade. The wood of Porlieria is not upon the market because the trees are too small. Bulnesia, however, is of comparatively good timber form and can be had in considerable quantity. It is sometimes used as a substitute for the genuine lignum-vitae, but its principal use is said to be for steps and collars for water turbines. (See page 31.)

This “Maracaibo lignum-vitae” or vera-wood is not considered suitable for propeller shaft bushings and certain other purposes. The objections that have been made to it are that it does not wear well and that the grain is less interwoven than in the best of the genuine wood and accordingly there is more liability to cup-shakes, radial cracks, and similar defects. One New York dealer states that 75 per cent of the vera logs he has seen showed bad ring-shakes. The lower resistance to wear may be due, in part at least, to the large number of crystals present in the wood of this genus since they would act in the nature of a very fine, sharp and hard sand or grit.

The writer has been unable to determine the extent to which these objections are justifiable. The fact remains that the wood is less used now than it was a few years ago and is in little demand at a price from one-third to one-half that of the Cuban. The only figures available on the amount of vera exported are for transshipments from Curaçao during the fiscal years 1912, 1913, 1914, 1915, the values being $4,822, $3,431, $4,361, and $1,941 respectively. These values include an unknown amount of Haitian wood of the same name.

“Paraguay lignum-vitae.”—This is the wood of Bulnesia Sarmienti locally known as “palo santo” on account of its use for incense in churches. As previously stated, this wood has a place on the market in the manufacture of the “oil of guaiac wood” used by perfumers. It is also used to a small extent in Argentina for chucks and bearings and for various purposes such as small articles of furniture, utensils, and ornaments (31, p. 122).

In Paraguay it occurs scattered among the quebracho trees, and owners of timberlands there are seeking a market for their wood under the name of “Paraguay lignum-vitae.” Unless the wood should prove of much better quality than the vera (described above), which is unlikely, the much higher cost of transportation will probably prevent its exploitation.

Woods of Other Families

“Philippine lignum-vitae.”—There is no wood on the market which is recognized by the trade as a satisfactory substitute for lignum-vitae. A few have been proposed and advertised. Among these may be mentioned the “mancono,” sometimes called “Philippine lignum-vitae” (41, p. 19). The botanical name of this tree is Xanthostemon verdugianus Naves, and it belongs to the Myrtaceae or eucalypt family.

The heartwood of mancono is brownish, turning purple when exposed to the air; the sapwood is very narrow and of a pale reddish color. The wood is very heavy and hard, the specific gravity of the oven-dry material being about 1.24. The grain is fine and twisted. The wood checks badly upon exposure to the air, though most of the cracks are said to be superficial (26, pp. 3-4). The writer is informed that the experimental use of this wood for bowling balls proved its unsuitability for that purpose. There are no records of it having been tested for bushing blocks for steamships.

“Red lignum-vitae.”—The term “red lignum-vitae” is sometimes used in the trade to designate quebracho when used for articles of turnery. This is an extremely hard reddish wood, becoming claret-red upon exposure, chiefly used as a source of tannin extract. There are two species, Schinopsis Lorentzii Engl. (= Quebrachia Lorentzii Griseb.) and Schinopsis Balansae Engl. The principal sources of supply at present are Argentina and Paraguay.

The wood is used for some of the purposes for which true lignum-vitae is employed, for example bowling balls and other turned articles, but is unsuited for bearings. The wood has no resemblance to Guaiacum except in density, which is given by Mell and Brush (33, p. 6) as 1.2 to 1.4. It lacks odor, is not oily, has a reddish color, is without ripple marks, and some of the rays contain intercellular canals.

“Indian lignum-vitae.”—The true lignum-vitae does not grow naturally in the Old World but Guaiacum officinale is occasionally cultivated in the tropical regions, as in Calcutta and Madras (15, p. 132). An Indian wood sometimes known as “lignum-vitae of Pegu” (29, p. 35), the “varnish tree” of Burma, is Melanorrhoea usitata Wall. of the Anacardiaceae or sumac family. The description of this wood as given by Gamble (16, p. 217) suggests lignum-vitae in that it is highly resinous, fine-textured, very hard and heavy, though the latter statement is hardly consistent with the given weight per cubic foot, namely, 54 pounds. Some authorities give the weight as 59 pounds. A writer in Hardwood Record (29, p. 35) says that this wood’s “extreme closeness of grain and density of structure suggests a relationship with the true lignum-vitae” but there is no evidence that it is suitable for, or has ever been used as, a substitute for the latter.

“African lignum-vitae.”—A New York dealer informs the writer that he has been offered 100 tons of “African lignum-vitae,” but the nature of this wood and the species producing it were not known. According to one writer (29, p. 35), “the ‘African lignum-vitae’ (Combretum truncatum) is a large tree which is abundant in lower Guinea and the Mosambique districts. The wood is very hard, heavy, close-grained, and with a deep reddish-brown heartwood and light-colored sapwood.” This wood belongs to the family Combretaceae, is not closely related to the true lignum-vitae and, so far as known to the writer, has not been used in bearings.

“Australian lignum-vitae.”—Boulger (5) describes six Australian woods which are sometimes called “lignum-vitae,” namely, (1) Acacia falcata Willd. (Leguminosae), (2) Myrtus semenoides F.v.M. (Myrtaceae), (3) Eucalyptus polyanthena Schau. (Myrtaceae), (4) Phyllanthus Ferdinandi Müll. Arg. (Euphorbiaceae), (5) Vitex lignum-vitae A. Cunn. (Verbenaceae), (6) Dodonoea viscosa L. (Sapindaceae). He says that the last mentioned, which is found throughout the Tropics, is “suited for all the uses of the true lignum-vitae.” In India, according to Gamble (16, p. 132), this species is only a shrub, the wood of which is used for engraving, turning, tool-handles, and walking sticks.

Baker (2, pp. 49, 57, 232, 375) mentions four Australian woods as possible substitutes for lignum-vitae, namely, Elaeocarpus Bancroftii F. M. & B. (Tiliaceae), Geijera parviflora Lindl. (Rutaceae), Eucalyptus Thozetiana F. Muell. (Myrtaceae), and Casuarina Cambagei Baker (Casuarineae). Of the third he says (p. 232): “The timber of this tree is probably harder than that of any Eucalyptus tree. It is very heavy, close-grained and interlocked, has a chocolate color, and much resembles in texture, color, and hardness, lignum-vitae, Guaiacum officinale, Linn., of Central America. In fact it is more deserving the title of Australian ‘lignum-vitae’ than other trees of the continent passing under that name, and it is so named in the museum specimens.” As to the wood of Casuarina Cambagei (p. 375): “It is very dark chocolate in color, hard, close-grained, without a figure, ... dresses to hard, firm, even surface, takes a good polish, and ... is the most suitable of all Australian timbers for shaft bearings, being the nearest substitute for lignum-vitae so extensively used for this purpose.” There is no evidence that any Australian wood has actually been used for such a substitute.

Other woods called lignum-vitae.—Boulger (5) also reports that the name lignum-vitae is applied to the following additional woods: Metrosideros scandens B. & S. (Myrtaceae), a tall creeper in New Zealand; Ixora ferrea Benth. or Siderodendron triflorum Vahl. (Rubiaceae) of British Guiana, also known as “hackia,” “West Indian ironwood” and “Martinique ironwood”;⁠[15] also to an unknown species shipped from Guayaquil and called “Guayaquil lignum-vitae,” though “having nothing in common with the true lignum-vitae, to which it is inferior.” Further this author (5, p. 289) states that “among the ancients and in France the name (lignum-vitae) has been applied to Tetraclinis articulata Vahl.”

“Guayacan.”—The generic name Guaiacum (also spelled Guayacum) is derived from the vernacular name “guayacan.” The latter, or some variant of it, is applied by Spanish-speaking people not only to all the woods of the lignum-vitae family (Zygophyllaceae) but to many others as well. It seems to be the equivalent of the English term “ironwood” and is likely to be used to designate any hard and heavy timber, particularly one which is not well known by some other name.

In Argentina, the names “guayacan” or “guayakan,” and “guayacan negro” are applied to Caesalpinia melanocarpa Griseb. of the Leguminosae or pea family. This tree reaches a height of 65 feet and a diameter of 20 inches (44, p. 354). The wood varies in color from chocolate-brown to nearly black, is very hard, heavy,⁠[16] durable, and more or less cross-grained. It is in local demand for turnery but apparently is not exported.

“Yellow guayacan.”—The fallaceous contention that because true lignum-vitae is called “guayacan,” any wood called “guayacan” is true lignum-vitae, has resulted in much confusion and in the substitution of inferior material for the genuine.

A most conspicuous instance of this is described in Hardwood Record (28, p. 22). It appears that in 1918 the Navy Department accepted the bid of the officials of the Panama Railroad, Canal Zone, for over 300,000 pounds of lignum-vitae logs. A specimen of the wood supplied was examined by the writer and found to be (as reported) a species of Tecoma (or Tabebuia) of the Bignoniaceae or catalpa family, though locally known as “yellow guayacan” or “yellow guayacum.” (See “Uses of lignum-vitae; Railroad cross-ties.”) It is also reported that considerable of this wood was purchased by the Emergency Fleet Corporation, and used for stern bearings but with what success the writer is unable to determine. In order to prevent checking the logs were stored under water, shipped in wet sawdust kept wet while cutting and fitting into the tubes, a practice which might be followed with the more refractory kinds of genuine material with success. The wood in question seems to be lacking in the essential properties of the genuine and it will be very surprising if it proves to be a satisfactory substitute.

“Yellow guayacan has never been used anywhere for bearings,” says a writer in Hardwood Record (28, p. 22), “and only the slightest knowledge of the structure of the wood is required to convince anyone that it is not suitable for any part of a vessel coming in contact with water and subjected at the same time to great wear and tear, as in the case of bushing blocks.”

The Bureau of Construction and Repair of the Navy Department advises the writer in a letter dated March 29, 1919, that it “made one purchase of Tabebuia with the expectation that this material would be suitable for the same uses for which the genuine lignum-vitae is required. Tests have proven that this material has sufficient strength and hardness but is lacking in oil content which prohibits its use for stern tube bearings which require wood of self-lubricating properties.”

The writer found some of this material in the New York Navy Yard and was informed that it has been used to a small extent for stern bearings either alone or in connection with genuine lignum-vitae. In the latter case the lower half of the tube would be lined with the genuine wood, the upper, where wear is less, with the substitute. The workmen had no difficulty whatever in recognizing this substitute and were outspoken against its employment where the genuine could be had.

The “yellow guayacan” grows also in Mexico and is sometimes called “Mexican lignum-vitae.” The writer saw about 200 tons of it in New York where it had been stored for several months owing to the inability of the owners to dispose of it profitably. A wood of the same or, more likely, a closely related species grows in Colombia and is called “guayacan polvillo.” One in British Guiana is, as stated elsewhere in this paper, called “hackia” or “lignum-vitae.” These woods are hard and heavy and more or less cross-grained, sometimes decidedly so. They are of a yellow color due to the deposits of a crystalline substance called “lapachol.” They bear so little resemblance to the true lignum-vitae that there is no occasion for confusing them with it.

The writer was recently informed by a person familiar with the timbers of Central America that at least 40 different kinds were locally called “guayacan.” While this may be an exaggeration it serves to emphasize the need for discrimination on the part of the buyers and users of lignum-vitae if they would avoid being imposed upon, whether intentionally or otherwise.

“Palo santo” or “páo santo.”—The woods of the Zygophyllaceae are often called “palo santo” in Spanish America. The equivalent Portuguese term is “páo santo.” The wood of Zollernia paraënsis Huber (Leguminosae) of Brazil is known by this name and, presumably on this account, it has been exported as a substitute for the wood of Guaiacum officinale which, according to Huber (24, pp. 179-181), it resembles in its physical properties. He describes the tree as tall with a cylindrical trunk and light gray and scaly bark. The heartwood, which is relatively large and distinctly differentiated from the light yellow sapwood, varies in color from light gray or greenish to almost black. Sometimes it is spotted like “snakewood” (Brosimum Aublettii P. & E.) and is then called “muirapinima preta.” A specimen, said to have been a part of the Huber collection, was examined by the writer and found to be hard, heavy, and fine-textured, but perfectly straight-grained, fissile, and non-resinous.