PINUS SYLVESTRIS. 
21 
cutaneous diseases of man and animals, and we believe with good 
success.* 
Off. Pp. Aqua Picis Liquidae, D. 
Unguentum Picis Liquidae, L. D. E. 
Pix. Common pitch, Botr/cug of the Greeks, though not officinal, 
requires to be noticed here. If the boiling of tar be continued for a 
sufficient length of time, it is deprived of its volatile ingredients, and 
converted into pitch ; but the most general and economical way of 
obtaining it, is by boiling together the necessary proportions of tar 
and coarse hard resin ; by varying these proportions you may obtain 
the pitch in any degree of hardness and dryness you require. 
Pitch is much less pungent and less bitter than common tar ; it is 
more adhesive, but has not the same overpowering and disagreeable 
smell. It is sometimes used as an ingredient in plasters, and may 
be considered a digestive. 
ExTRACTUM Pint. Extract of pine, or essence of spruce is 
another well known produce of the Pinus Sylvestris : it is prepared 
by decoction from the twigs. This essence fermented with molasses 
and water forms the wholesome beverage known by the name of 
spruce beer. 
Besides these resinous products, necessity has discovered that the 
bark of this tree may be- made subservient to the nourishment of 
man. Linn^us informs that the Laplanders make a kind of bread 
from the inner bark, or alburnum : for this purpose the tallest trees 
are selected, and the external bark, which is dry and scaly, being 
carefully removed, the inner white and succulent matter is collected 
and dried. When required for use, it is slowly baked on the fire, 
by which means it is rendered hard and porous ; it is then pounded 
into flour, kneaded with water, and made into cakes which are 
baked. This bread is eaten by the Laplanders during a great part 
of the year. 
* The most general use to which tar is applied, is in the manufacture of ropes, and 
for other purposes connected with the equipment of shipping. 
