Experiments on Staining Wood . 129 
labours of Dufay in tliis respect are well known ; and it 
appears by some papers of liis among the Memoirs of 
the Academy of Sciences, that rock crystal, when ex- 
posed to the vapour of arsenic and antimony, assumes a 
red colour. Count de Borch’s description of the me- 
thod of staining marble in Italy may also be mentioned ; 
and the process by means of the smoke of oak chips, 
which is employed by the Dutch for colouring their tiles 
and earthen ware. Canes are prepared for use in India, 
by dipping them in quicklime. That hard compact wood 
brought from America, and particularly Guiana, which, 
on account of its variegated and spotted appearance, is 
called Bois de Lettres , and which Aublet, who gives it 
the name of Piratinera Guianensis , much admired, has 
its whole surface stained by the Indians with the 
blackest and most durable colours.— As the art of stain- 
ing wood seems at present to be nearly lost, the following 
experiments may be of some utility to artists : 
1, By Means of Oils and Acids . 
Experiment I. — A square piece of plane-tree wood, 
a line in thickness, was put into pounded dragon's blood 
from the Canaries* mixed with oil of turpentine, and 
placed over the fire in a glass vessel. The wood slowly 
assumed the colour, even before the spirit was volati- 
lized. After more than an hour the vessel was taken 
from the fire and suffered to stand the whole night, when 
the wood appeared of a mahogany colour, not merely on 
the surface, but also in the interior parts. The denser 
fibres were somewhat less coloured, but this, instead of 
injuring the beauty of the wood, rather added to it. The 
red dye can be made stronger or weaker by taking a 
greater or less quantity of dragon’s blood, and by a greater 
i 1 - - ' ■■ 
* That from Madagascar is of an inferior quality. 
VOL. II. Q 
