XXIV. | GREENHEART. 153 
regard it when appropriating this timber to works of 
construction. 
Owing to the difficulty of distinguishing the sap, 
many either dispute its presence altogether, or assert that 
if it exists it may be safely employed the same as the sap 
of Lignum Vite ; this is, however, by no means certain, 
as I have found that if it is placed in any damp or im- 
perfectly ventilated situation, it decays much sooner than 
the heartwood; but, if used under more favourable 
circumstances, its durability is very great. 
In connection with this question, a merchant and 
importer of Greenheart timber said upon one occasion, 
when we had a parcel under survey, that he was confident 
a certain log had no sapwood upon it, for if it had, it 
would be liable to the attack of a small worm, but that 
the worm would not touch the heartwood. The log 
referred to was accordingly tested by cutting off a thin 
cross section, and upon examination of the piece, there 
were found in it several marks or traces of the worm, 
which had penetrated to the depth of 2 to 3 inches; 
the heartwood, or duramen, had not, however, been 
touched. The gentleman at once admitted that, with 
such evidence, he would take it as conclusive that there 
was sap to the depth of 3 inches on the log, but that its 
appearance had entirely deceived him. 
The case was no doubt exceptional, as the worm is 
very seldom seen in this wood. 
Greenheart is extensively employed in ship-building 
for keelsons, engine-bearers, beams, shelf-pieces, &c., and 
for planking. It is also used for piles, and many other 
purposes, but its application to the domestic arts is some- 
what limited by its great weight. 
The strength of this wood exceeds that of most 
others, whether it be tried by the transverse or tensile 
