LIGN-ALOES. : 289 
in a reckless manner, so that they have almost entirely disappeared 
from Cuantla Morelos, where they formerly abounded. He states 
that old trunks afford as much as 10 or 12 per cent. of oil by dis- 
tillation with steam, costing 20 to 25 francs per kilogram; an 
inferior oil prepared by the natives being sold at a lower price. 
The structure of the wood presents the following characters:— “ The 
fibres are of medium length, with the walls only slightly thickened; 
each is divided transversely by numerous thin walls constituting a 
kind of ligneous parenchyma, of which the whole wood is formed. 
On transverse section the fibres are seen to be all of equal thick- 
ness, so that it is not easy to distinguish the zones of growth of 
the wood. The vessels are of large size, with numerous transverse 
trabeculz, which on longitudinal section are seen to give a moni- 
liform appearance to the vessels; they are dotted all over, the 
dots being surrounded with areole. The medullary rays are thin, 
and have two to four courses of cells in thickness. It is chiefly 
im the fibres and medullary rays that the nearly solid odorous 
substance occurs. It is of a yellowish resinoid aspect under the 
microscope, and fills them either wholly or partially. All the 
fibres, however, do not contain it, and it is most abundant where 
the wood is streaked with dark veins. This matter is soluble in 
alcohol, so that the wood treated with spirit becomes transparent 
under the microscope.” 
In the early notice of this wood by Collins, above referred to, 
it is stated that the wood, “and even the twigs, are rich in essential 
oil ;” but in Poisson’s recent paper, here abstracted, he continues 
to say that “in the green and healthy state the wood presents the 
same appearance ”’ (under the microscope) as above detailed, but 
“ without any trace of oil, although at the same time the oil may 
be perceived in the fruits and bark by rubbing them.” In Leon 
Marchand’s memoir on the “ Organization of the Burseriaceex,” a 
somewhat similar occurrence is mentioned. The resinous and 
perfumed matter of Balsamodendron Myrrha, B. Africanum, and 
Protium obtustfolium is localized in the pith of the young branches 
to some degree, but is abundant in the bark and pericarp of the 
fruits of these plants. 
This oil of Lign-aloe has been examined by Verneuil and 
Poisson. Their experiments show that the wood cut mto shavings 
readily yields the oil by distillation with steam, 7 to 9 per cent. 
being thus obtained. Being dried over calcium chloride it distils 
U 
