EXTRACTION OP OIL OF TURPENTINE. 725 



resin contains many impurities. Earlier in the year, it is passed 

 directly from vat No. 1 to No. 2, a retort in which it is distilled, 

 the arrangement of the vats then being as shown in Fig. 887. 



The resin in the retort is heated to a temperature of about 

 185 F., steam (by the use of which 30 per cent, more turpen- 

 tine is obtained) being admitted through a pipe. From this 

 retort, vapour of the oil of turpentine and water-vapour pass 

 through a coil of tubing into a cooling tank, where they are 

 condensed ; then they are drawn off into a smaller tank, the 

 water remaining below with the turpentine floating on it, owing 

 to the lower specific gravity of the latter. The oil of turpentine 

 is run through an overflow pipe into a zinc vessel mounted 011 

 a truck, and conveyed by means of a tramway to the turpen- 

 tine shed, where it is pumped into large metal tanks, measuring 

 10 feet by 6 feet by 6 feet, from which it is drawn, as required 

 for sale, into old Spanish wine-casks. No system of purifying 

 is in practice, and it is sold just as it issues from the still. 



The water, which is removed by a syphon from bulnw the 

 turpentine, passes after use through a series of shallow open 

 tanks in a court-yard, from which it is pumped by a small 

 steam engine into an elevated reservoir ; it is then used again 

 for cooling the turpentine. The engine also drives steam into 

 the distilling retort. 



The liquid coloprmny, after distillation of the turpentine, is 

 allowed to flow from the base of the retort by removing a 

 wooden plug stamped with clay. It runs into a straining tank, 

 passing over a very fine copper wire sieve, which catches most 

 of the impurities it has still retained ; the rest falls to the 

 base of the straining tank, in the form of a black deposit 

 resembling pitch. The straining tank has a tap placed about 

 half-way down, through which the liquid colophany passes 

 during autumn into another vat, from which it is ladled into 

 large casks containing about 800 Ibs. 



During summer, however, after a sample has been taken 

 out in a tin mould, the rest of the colophany is at once ladled 

 from the straining tank into buckets, then it is carried to an 

 open court-yard, where it is poured into open shallow metal 

 pans about two inches deep and slightly smaller in diameter 

 than the casks in which it is packed finally for sale. It there 



