257 PINUS SYLVESTRIS 



Preparation and Commerce. The official pine- wood tar is 

 procured by the destructive distillation of fir timber in the 

 northern parts of Europe, and in America, and is known in 

 commerce as Archangel tar, Stockholm tar, and American tar. 

 The great bulk of that used in Europe and known as Archangel 

 or Stockholm tar, is prepared in Finland, Sweden, and Northern 

 and Central Russia, and is procured to a large extent from Pinus 

 sylvestris, Linn. ; that used in America is said to be chiefly 

 obtained from Pinus palustris, Mill. (Pinus australis, Mich.). 

 The tar obtained in Europe is generally considered to be superior 

 to American tar. 



The process now usually followed for obtaining tar is essen- 

 tially the same as that practised by the Macedonians, and 

 described by Theophrastus. It is a kind of downward distillation 

 of the roots and lower portions of the trunks of the old pines ; the 

 more valuable parts of the trees being used as timber. The 

 process as carried on in Bothnia has been thus described by Dr. 

 Clarke : The situation most favourable to the process is in a 

 forest near to a marsh or bog, because the roots of the fir, from 

 which tar is principally extracted, are always most productive in 

 such places. A conical cavity is first made in the ground 

 (generally in the side of a bank or sloping hill) ; and the roots of 

 the fir, together with logs and billets of the same, being neatly 

 trussed in a stack of the same conical shape, are let into this 

 cavity. To prevent the volatile parts from being dissipated, the 

 whole is then covered by turf, which, by means of a heavy 

 wooden mallet and wooden stamper, worked separately by two 

 men, is beaten down, and rendered as firm as possible about the 

 wood. The stack of billets is then kindled, and a slow com- 

 bustion of the fir takes place, without flame, as in making 

 charcoal. During this combustion the tar exudes, and a cast- 

 iron pan being at the bottom of the funnel, with a spout which 

 projects through the side of the bank, barrels are placed beneath 

 this spout to collect the fluid as it comes away. As fast as the 

 barrels are filled, they are bunged and ready for immediate exporta- 

 tion. The time required for this slow combustion varies according 



