INSTRUCTIONS GIVEN IN SCHOOL OP FORESTRY. 151 



Hcing vines. In both these cases it is therefore impossible to know 

 accurately the qualities of this tree. 



" The process employed in order to extract the resinous juice of 

 this tree will give an idea of the injury thus inflicted, Gemmage is 

 usually begun when the tree is twenty-five years old, and goes on 

 from April till September. The first thing is to remove a strip of 

 bark from 12 to 16 centimetres in breadth, extending from the foot 

 of the tree to a height of from 33 to 50 centimetres. The incision is 

 deep enough to cut through the alburnum, for the resinous juice 

 issues chiefly from the ligneous trunk, and from between the bark 

 and the wood. Every week the wound is re-opened. These incisions 

 in following years are carried upward to a height of from 4 to 5 

 metres. A new incision at the root of the same tree is then begun. 

 It is parallel to the first, from which it is separated only by a width 

 of from 5 to 6 centimetres ; it, as well as later incisions, extends to 

 the same height. These incisions are carried all round the tree, and 

 are called qiiarres. 



" This method of gemmage is the most gentle ; it is called gemmage 

 d, vie. When it is wished to go to greater lengths two incisions are 

 made simultaneously, one at the top the other at the foot, the first 

 is called quarre haute, the second hasson. Sometimes incisions are 

 made all round the tree at the same time. This operation is called 

 gemmer d, mort, or ct pin, perdu. Up to the present time the maritime 

 pine is chiefly cultivated for its resinous juice, which furnishes 

 articles of undoubted value, consisting of turpentine, pitch, tar, and 

 lamp-black. As a source of revenue there is no doubt that the 

 present mode of exploitation is the most profitable, and is therefore 

 quite justifiable. But in the departments of Gironde and the Landes 

 they go further, and assert that the maritime pine, if it is to be of 

 any use at all, ought to bo resine. It is even affirmed, despite of 

 examples quoted to the contrary, that the extraction of the resin is 

 indispensable for its prosperity and even its existence. 



" We may easily see that gemmage must interfere injuriously with 

 the growth of the tree. Nature has not given it a resinous juice for 

 nothing, and this juice, independent of the sap, seems, in combination 

 with the latter, to promote nutrition and growth. As a proof of this 

 when pines which have been gemme are felled, they exhibit very 

 narrow annual layers, which bear witness to a retarded growth, whilst 

 the opposite has been seen in pines which, without having been 

 gemmi, have grown in precisely similar conditions ; but it has been 

 ascertained that the timber of resinous trees is more solid, and has 



