FIR TREE. 
225 
they make a hole in the ground, eight or nine 
inches deep, which will contain nearly a quart of 
juice, and the earth is previously beat in order to 
render it less permeable ; nevertheless a quantity of 
the juice will ooze through the new-made pits, and 
continue to do so till the resin, mixing with the 
earth, at length forms a mass sufficiently compact 
to resist any further transudation. It may be ob- 
served in this place, that in some countries they 
make a deep gash in the substance of the tree, near 
the ground, from which they collect a much purer 
resin than in the common way ; but as this custom 
proves very injurious to the trees, they prefer the 
use of pits. 
Notwithstanding all the care which is generally 
paid to cleaning the soil contiguous to the pits, 
sand, leaves, and fragments of bark, will inevitably 
collect in the latter, and render a filtering process 
afterwards necessary. When the pits have been 
properly prepared at the foot of the trees, and a 
little time before they make the incisions (which is 
towards the end of May), they strip off about six 
inches of the bark down to the liber. This pre- 
caution, it seems, is highly necessary, that the edge 
of the instrument employed to make the incisions 
may not be injured ; for if any splinters or fila- 
ments should be left in the wounds, the course of 
the juice to the pits would be impeded : besides, in 
taking off the outer bark it is scarcely possible to 
prevent fragments from falling down, and mixing 
VOL. III. Ql 
