THE WATER HYACINTH. 
light-coloured stalks, red ash, 15 per cent.; well developed roots, 21 per cent. 
Other plants seldom exceed 20 per cent. of ash,’e.g., tobacco, 12 to 16 per cent.; 
grasses, 7 per cent.; oak, 1.3 per cent.; beech, .6 per cent. ‘It was found that 
the whole of the potash of the stalks was present in an easily soluble form— 
probably as a chloride—an important fact for the potash recovery on a com- 
mercial scale. If the soluble potash is expressed as a chloride (KC1), the per- 
centage so obtained is equal to the percentage of readily soluble ash, i.e., the bulk 
of the potassium is present as the chloride. (See second table, last column.) 
Whien plants are freed from roots and all extraneous matter, there is from 
10 to’ 15 per cent. of ash, and more than three-quarters of this ash is readily 
soluble in water. 
Nearly all the phosphate present is in a soluble form. The percentage of 
potash in the ash is not high. Few uncultivated plants yield large.amounts of 
ash rich in potash. As a comparison, the percentage of K,O derived from ashes 
of various plants is as follows:— : : 
Tobacco, 30 to 40 per cent.; bamboo (a source of potash in Burmah), 30 
to 40 per cent.; banana, 40 to 50 per cent.; beech tree, 25 per cent.; 
oak, 11 per cent.; coconut husks, 15 to 20 per cent. 
The preparation of commercially pure soluble salts of potassium merely 
requires burning, lixiviation, and fractional crystallization—three simple opera- 
tions particularly adapted to our climate. 
When we consider that the bulk of the world’s supply of potash salts is 
located in Germany, and that many countries are experimenting with expensive 
chemical processes for the preparation of potash from felspars and felspathic 
rocks, the preparation of potash salts from water hyacinth seems an attractive 
commercial prospect. In the Journal of Agriculture of India, July, 1917, the 
position is summed up thus: “The value of the green plant as a nitrogenous, 
phosphatic, and potassic manure is apparent—its use as such resolves itself 
into a question of transport, as 95 per cent. consists of water.” An inventor of 
a process for extracting potash from water hyacinth has already made applica- 
tion for a patent in New South Wales to exploit the weed on the Richmond 
and Clarence Rivers and tributaries. The inventor claims the - following 
results :— : 
Air-dried plants. yield 17.37 per cent. ash. This 17.37. per cent. ash 
contains 13.71 per cent. total potash; or 17.37 per cent. ash contains 
10.60 per cent. soluble potash. : 
30,000 tons air-dried water hyacinth yield about 1,500 tons of 30 per cent. 
potash (K30), which is a marketable commodity, and was valued at 
about £11 per ton before the war. 
These results are rather less than the mean of the Malay results, e.g— 
Ash, mean, from sun-dried plants, 27 per cent. (10 to 15 per cent. from 
plants freed from roots). This 27 per cent. contains 15 per cent. total 
potash; or 27 per cent. contains 12.7 per cent. soluble potash. 
We may take it that about 3 per cent. of the dried ‘plant is potash (K:O). 
We must beware, however, of basing all calculations and preparations on labora- 
tory determinations. The ash obtained by a complete burn on a small scale 
may differ somewhat from that likely to be obtained in an actual pit burn on a 
much larger scale; and there is bound to be loss owing to imperfect means of 
extraction and preparation. «A large percentage of the costs will be due to 
the collection and. preparation of material before burning. This will have to 
be satisfactorily solved by the introduction of mechanical methods of cutting up 
the weed in thick extensive areas, collecting, crushing, and delivering it in 
sufficient quantities in proper condition at the place for burning. Further, 
as the roots contain very little potash, but a large amount of ash and extraneous 
matter, some method of cutting the plant, or if pulled from the mud, of cutting 
off the roots, would reduce the after-handling charges. In all probability, in 
small plants, some kind of power engine—possibly the alcohol type—might be 
used for the operation of travelling conveyors and rollers for crushing, ‘&e., and 
the exhaust heat be used in the processes of drying and evaporating. be 
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