so 
PINUS SYLVESTRIS. 
where they are condensed, and pass along with the matter liqaefied 
into the receiver: this is the tar of commerce, the greater part of 
which we import from the Baltic. 
Sensible and Chemical Properties of Tar. Tar differs 
from the native resinous juice of the tree, in containing the saline 
and mucilaginous parts as well as the extractive and the oily, and in 
having acquired an empyreumatic quality from the action of fire ; it 
may therefore be considered a mixture of resin, eujpyreumatic oil, 
charcoal, and acetous acid. This acid is not only soluble in water, 
but also renders the empyreumatic oil mor^ soluble. Tar has a hot, 
pungent, disagreeable taste, and a penetrating, overpowering smell, 
particularly when heated ; its consistence depends a good deal upon 
the temperature of the weather: in an ordinary temperature it is 
somewhat thicker than common turpentine, but becomes much more 
fluid under a hot sun ; its colonr in a mass is of a dark brown, ap- 
proaching to black, but when spread thin upon any surface it is of a 
reddish brown, with something of a shining golden hue; by exposure 
to the air, and as it dries upon the surface, it becomes nearly black, 
but not permanently so, recovering its bright hue if sufficiently 
heated to drop off; it is adhesive and clammy to the touch, and very 
inflammable. 
Medical Properties and Uses. Tar was at one time so 
much in vogue, that Bishop Berkeley thought it worthy of a treatise, 
in which he extolled and recommended the use of tar watfr; and by 
many of the physicians of his time extraordinary virtues were 
ascribed to it. According to Dr. Cullen, it strengthens the tone of 
the stomach, f?xcites appetite, promotes digestion, and relieves 
dyspeptic symptoms. At the present day it is but little used, not 
perhaps from being altogether devoid of the qualities M'hich have 
been ascribed to it, but because there are other less nauseous reme- 
dies which can be resorted to. Dr. Crichton and Mr. Ward, of 
Maidenhead, have recommended tar vapour in phthisis pulmonalis, 
and asthma; and we have ourselves seen two or three instances of 
consumptive patients being much benefited by remaining a few hours 
daily in a plantation of pines while the sun was shining, and when 
the surrounding air must have been in some degree impregnated with 
the vapours of the exuding resins ; how far regular exercise, pure 
air, and the imagination may have tended to produce the effect we 
shall not pretend to decide. Tar water has also been considered as 
a heating diuretic and sudorific, and has been sometimes recom- 
mended in diseases of the urinary organs. As an external applica- 
tion tar has been much used in the cure of tinea capitis, and other 
