34 



changed to carbonate, would become augmented by nearly one- 

 half more. It is fixed chiefly to silicic acid in felspar, and 

 thus only tardily set free through disintegration, partly by the 

 chemic action of air, water and various salts, partly through 

 the mechanic force of vegetation.* The importation of potash 

 into Victoria during 1870 was only 170 tons, but with the 

 increase of chemic factories we shall require much more. 



It has justly been argued, that the chemic analysis affords a 

 very unsafe guidance to the artisan, as regards the quantity 

 of potash obtainable from any kind of tree or other plant, 

 inasmuch as necessarily the percentage must fluctuate accord- 

 ing to the nature of the soil, this again depending on geologic 

 structure and the quality and quantity of decaying foliage on 

 any particular spot. It should, however, not be quite for- 

 gotten, that most plants have a predilection for that soil 

 which contains, in regions otherwise favourable to them, also 

 due proportions of such mineral particles as are essentially 

 necessary for the normal nutrition of the peculiar species ; for, 

 otherwise, in the wild combat for space it would succumb or 

 cede before the more legitimate occupant of such soil. Hence, 

 at a glance, even from long distances, we may recognise in 

 many of our forest-regions an almost abrupt line of demar- 

 cation between the gregarious trees, where one geologic forma- 

 tion meets or replaces the other. Thus, trees richer in potash, 

 or oils, or any other product, may often be traced with ease 

 over their geologic area, for which purpose the admirable maps 

 of Mr. Selwyn and his collaborators afford us here in Victoria 

 also in this respect already so very much facility. 



I have often been led to think, that many an indigent 

 person might find employment by collecting the wood-ashes, 

 which, as a powerful manure, or as material for a local potash 

 factory, ought to realise a fair price. Such an employment 

 would be probably as lucrative as collecting glass, or bones, or 

 substances for paper-mills; while the ashes, now largely wasted, 

 would be fully utilised. 



It may be assumed, that at an average the ash of our ordi- 

 nary eucalypts contains 10 per cent, of crude potash, equal 

 to about 5 per cent, pure potash. A bucketful of wood-ash 

 such as we daily remove from our domestic fire-places, con- 

 tains about 25 Ibs., from which accordingly about 2| Ibs. of 

 inferior, or 1J Ib. of superior potash, may be obtained; the 



* The proverb of chemistry " Corpora non agunt, nisi fluida" is 

 here also applicable. 



