31 



Professor Muspratt, a man of genius and industry, whose 

 death within the last few. months we had so deeply to deplore. 



Presented to you here are samples of tar, acetic acid and 

 alcohol, from several of our more common woods; also pieces 

 of pinewood, coated with eucalyptus tar, the black colour with 

 its fine lustre having remained unimpaired for a series of 

 years. Our wood-tar would for many industrial purposes be 

 equal in value to the best kinds of other tar, and may prove 

 in some respects superior to them. 



Among the undeveloped wood-resources we must not pass 

 that referring to Potash, particularly as this alkali can be 

 obtained without sacrifice of any valuable timber, and from 

 localities not accessible to the wood trade. 



For the preparation of potash the wood, bark, branches and 

 foliage are burnt in pits sunk three or four feet in the ground ; 

 the incineration is continued till the pit is almost filled with 

 ashes. Young branches and leaves are usually much richer 

 in potash than the stem-wood; hence they should not be 

 rejected. The ashes thus obtained are placed in tubs or 

 casks on straw, over a false bottom. 



Cold water in moderate quantities is poured over the ash, 

 and the first strong potash-liquid removed for evaporation in 

 flat iron vessels, while the weaker fluid is used for the lixivia- 

 tion of fresh ashes. 



While the evaporation proceeds, fresh portions of strong 

 liquid are added until the concentrated boiling fluid assumes 

 a rather thick consistence. 



At last, with mild heat and final constant stirring, the whole 

 is evaporated to dryness. This dry mass represents crude 

 potash, more or less impure, according to the nature of the 

 wood employed. 



A final heating in rough furnaces is needed, to expel sulphur 

 combinations, water and empyreumatic substances ; also, to 

 decompose colouring principles. Thus pearlash is obtained. 



Pure Carbonate of Potassa in crude potash varies from 40 

 to 80 per cent. Experiments, as far as they were instituted in 

 my laboratory, have given the following approximate results 

 with respect to the contents of potash in some of our most 

 common trees. The wood of our sheoaks (Casuarina suberosa 

 and Casuarina quadrivalvis), as well as that of the black or 

 silver wattle (Acacia decurrens), is somewhat richer than 

 wood of the British oak, but far richer than the ordinary 

 pine woods. 



The stems of the Victorian blue-gum tree (Eucalyptus 



