OAK. 223 
attains. It has, however, been remarked that the 
trunk of the oak seldom increases to a greater propor- 
tionate diameter than about fourteen inches in eighty 
years. As to its dimensions, it is stated that an oak 
belonging to Lord Powis, and growing, in 1764, in 
Bromfield Wood, near Ludlovv, measured sixty-eight 
feet in girth and twenty-three feet in height, and con- 
tained in the whole 14-55 feet of timber. 
Before oak timber is in a state to be used it is requi- 
site that the trees should be barked, and suffered to 
stand uncut for three or four years, that they may 
become perfectly dry. The bark thus obtained is exten- 
sively used in the tanning of leather; and afterwards 
it serves as fuel, and for making hot-beds for the growth 
of pines, and some other plants. The astringent pro- 
perties of oak-bark render it of use for medical pur- 
poses. The saw-dust of this tree, and even the leaves, 
though much inferior to the bark, have been found 
useful in tanning. The former of these is the principal 
vegetable production of this country, which is used in. 
the dyeing of fustian. 
On the leaves and buds of the oak certain excres- 
cences are formed, in consequence of the puncture of 
insects, as the lodgment for their eggs and a habitation 
for their future young. These are termed galls, and 
if, when arrived at a certain state, they are infused in 
a weak solution of vitriol, they impart to it a purple 
or violet tinge; and, after the whole colouring matter 
is extracted, this becomes perfectly black. Consider- 
able quantities of galls are used in dyeing, and for 
other purposes. 
Acornsy or the seeds of the oak, possess an astringent 
quality, and have a bitter taste, both of which may 
be extracted by steeping them, for some time, in cold 
water, or by boiling them. After this simple process, 
they are not an unpalatable fruit. With the ancient 
Britons they were an article in great request, and even 
constituted an important part of their food ; and there 
can be little doubt that, carefully prepared, dried, and 
