708 PROPERTIES, HARVESTING AND DISPOSAL OF RESIN. 



of a groove (carrc) near the base of the tree and where the 

 bark has already been trimmed, about 10 centimeters wide, 

 3 centimeters high, and 1 centimeter deep (4 inches by 1 inch 

 by f inch). From this groove the resin flows in viscous trans- 

 parent drops, which thicken on contact with the air : part of 

 the resin solidifies, becoming attached to the surface of the 

 groove ; the remainder, being more liquid, flows into a recep- 

 tacle which has been placed on the ground to receive it. Kain- 

 water, which may fill the pots, always remains above the resin, 

 the specific gravity of which is slightly higher than that of water. 



Once a week, and once every five days during the season 

 when most resin flows, the groove is cut by slicing off a thin 

 shaving of the wood at its upper extremity. The groove thus 

 becomes gradually longer, its breadth remaining constant or 

 being gradually reduced. As the groove becomes older, the 

 resin ceases to flow ; in freshly cutting it, the resin-tapper 

 slices the surface of the top of the groove for a length of 10 to 

 12 centimeters (4 to 4f inches), his chief skill being shown in 

 removing only a very fine shaving of the sapwood, so that the 

 operation may be resumed several times without cutting 

 deeper than 1 centimeter. This operation is effected forty to 

 forty-five times during a season, but ceases after the 15th of 

 October. The groove is cut in successive years up to a height 

 of 3 or 4 meters (9| to 13 feet). 



Formerly, the resin which ran from a groove was collected 

 in a hole dug in the sand at the foot of the tapped tree. This 

 method, which now is abandoned nearly everywhere, had many 

 disadvantages. The sand in which the hole was dug absorbed 

 much resin ; besides this, when the groove became elongated, 

 the resin had to traverse its whole length before reaching the 

 ground. In flowing over the groove, therefore, the resin lost 

 much volatile matter, and became hard ; needles, pieces of 

 bark and particles of sand were blown on to it by the wind, 

 and water or other impurities mingled with it. 



In order to prevent the consequent waste of resin, Hugues, 

 in 1860, devised a method for catching the resin immediately 

 below the points of exudation by means of a little zinc collar 

 which was fixed across the groove, and for collecting it in a 

 glazed, conically-shaped pot, 14 centimeters wide at the top, 



