J=>A.KT III. 



MINOR J'OREST INDUSTRIES. 



The only minor forest industries that -will be dealt witli in this 

 Part are — 



I. — Charcoal-burning. 

 II. — Manufacture of cutch and kattha. 

 III. — Distillation of sandal-wood oil. 

 IV. — Preparation of turpentine products. 

 V. — Impregnation of timber with antiseptic substances. 

 Several petty industries have already been briefly described in 

 Parts I. and II. ; as, for instance, the manufacture of tar at page 

 69, the distillation of teak and deodar oil at page 170, and so on. 

 In the course of a few years the number and extent of such minor 

 forest industries in this country are certain to undergo an enormous 

 expansion, requiring the employment of hundreds of thousands of 

 the population. 



CHAPTER I.— CHARCOAL-MAKING. 



If wood is burnt with free access of air, there will be nothing 

 left of it but a small quantity of ash varying, for most of our 

 species, from ^ to 2 per cent, of its dry weight. If, on the other 

 hand, air be entirely excluded and the wood subjected to a temper- 

 ature of 300° to 350° C, a number of liquid and gaseous products 

 will be given off, what remains behind being, charcoal. Charcoal- 

 making, or the carbonisation of wood, is thus only a process of 

 destructive distillation. In this process all the moisture, most of 

 the oxygen and hydrogen of the wood, and about half the carbon 

 are expelled, so that the charcoal consists of the remaining carbon, 

 oxygen and hydrogen, and all the ash elements, the carbon constitut- 

 ing about 90 per cent, of the whole. Actually the charcoal-burner 

 uses wood with its bark on, the result being a somewhat larger 

 proportion than 10 per cent, of elements other than carbon. 



As just said, more than half the aggregate quantity of the com- 

 bustible elements, viz., carbon, oxygen, and hydrogen, is lost in car- 

 bonisation. But, on the other hand, the advantages gained are 



