T. KiBK. — On the neglected Forest Products of yew Zealand. 189 



visable to try different methods of extraction with the same kind of tree, 

 giving the jn-eference to those which cause the least injury to the timber. 



The Westland pine appears to merit particular attention — in common 

 with the red silver pine it would probably afford turpentine of special value 

 for certain purposes, although the yield of either would, in all likelihood, be 

 comparatively small. 



Oil of Turpentine. 



This is manufactm'ed by distillation on a large scale in the Southern 

 States of America. The turpentine is placed in copper stills of large ca- 

 pacity, and is distilled without water ; the volatile oil is received into barrels 

 direct from the still, and is ready for market. 



The resin remaining after the oil has been extracted is drawn off into a 

 vat containing water, which separates it from all impurities, when it is 

 packed for export. 



Potash. 



This is extensively prepared from wood-ashes in the forest districts of 

 Germany, Eussia, and other Eiu'opean countries, also in Canada and the 

 United States of North America, where it enables the settler to defray a 

 large proportion of the heavy cost of clearing forest land. 



Potash salts are found in varying proportions in all plants, and are most 

 abundant in the young branches and leaves. 



The process of extraction is simple and inexpensive. All parts of the 

 plant, including the leaves, are burnt in diy pits dug in the earth from 

 three to five feet in depth, and of any convenient size. The ashes are placed 

 in tubs or vats, each having an orifice near the bottom secured by a plug, and 

 a false bottom covered with straw or rushes. The ashes are saturated with 

 water, and, after standing about twelve hours, the potash-liquor is drawn off 

 and taken to the evaporating pans, usually shallow iron vessels, sometimes 

 with corrugated bottoms. 



It is now kept in a boiling condition and constantly stirred, fresh liquor 

 being added from time to time as required, until the whole becomes of a 

 pasty consistence, when the heat is gradually reduced and the dry residuum 

 allowed to cool. 



In Canada the crude potash thus obtained is usually sold to the nearest 

 storekeeper, but it requires to undergo a process of calcination to free it 

 from certain organic matter before it becomes the potash of commerce. 



After the first potash-liquor has been drawn off, water is again poured 

 over the ash in order to remove all soluble matter, and the weak solution 

 thus afforded is used to lixiviate a fresh supply of ashes. 



The insoluble portion of the ash is used in the manufacture of certain 

 kinds of glass, and is of great value as manure on account of the phosphates 

 which it contains, 



