SEA BAMBOO AS A SOURCE OF POTASH. I 1 5 



Another method of utilisation would be to destructively 

 distil the dried kelp in iron retorts on a large scale, the products 

 of distillation being acetic acid, acetone and ammonia, eventually 

 calcium acetate and sulphate of ammonia ; the charred residue 

 could then be lixiviated with hot water, and the salts obtained 

 by solar evaporation. This would have the advantage, too, of 

 rendering ^XDSsible the recovery of iodine from the mother liquor, 

 and would conserve the products of combustion, for which there 

 would be a market in South Africa. 



The scope of this paper is purely that of a ])reliminary 

 investigation ; originally it was started from the point of view 

 of utility, but it has gone beyond that to the question of recog- 

 nising that the subject is one of intense interest from a scientihc 

 standpoint, and that the field for investigation is practically un- 

 limited. We have bordering on our coasts hundreds of different 

 varieties of seaweed about the composition of which we know 

 little or nothing. I have made no attempt in this paper to go 

 into the question oif the presence of iodine in sea bamboo, nor 

 have I made any determinations of the amount of protein. These, 

 with the problem of the composition of the organic matter — the 

 alguloses, etc., are sufficient to provide for a separate investiga- 

 tion, and I sincerely hope that I have said sufficient to induce 

 someone to take up this question and carry out the necessary 

 analyses. 



Reverting to the subject of jxitash and its use as a manure, 

 1 need hardly remind you that, prior to the commencement of 

 hostilities, the potash market was practically controlled by Ger- 

 many, through her huge deposits at Stassfurt, and that the 

 United States of America found it beyond the question of 

 practical politics to utilise its extensive seaweed groves as a 

 .source of supply for its own needs, owing to the prohibitive 

 competitive prices at which Germany could supply pure salts. 

 Since then America has hopes of succeeding in exploiting its 

 own resources. New Zealand has also taken up the question, and 

 is at present carrying out experiments on the same subject. 

 Here in South Africa we have at our very doors large quantities 

 of a seaweed which yields fairly satisfactory quantities of potash. 

 Tt should be possible on a commercial basis to obtain from the 

 trunk iwrtion an ash containing not less than 33 per cent, of 

 potash, and from the leaves an ash containing not less 

 than 22 per cent, of jjotash. On the pre-war basis these 

 would be worth at least £8 a ton and £5 los. a ton 

 respectively. The most urgent need is first of all for 

 an exhaustive Marine Survey to ascertain the extent of 

 occurrence of the seaweed. The opportunity for making 

 the question a success comes at a moment when we are at the 

 parting of the ways ; iif we seize the opportunity now. we may 

 be successful ; if we wait until after the war. it may be too late. 

 .Shall we succeed? 



In conclusion, I wish to express my thanks to the Govern- 

 ment Analyst at Cape Town for i)ermission to carry out the 

 analvtical work here recorded. 



