112 SEA BAMBOO AS A SOURCE OF POTASH. 



The following figures are taken from the publications of the 

 Board of Agriculture and Fisheries (Leaflet No. 254, " Use 

 of Seaweed as Manure," p. 4) : — 



Table XL — Fkesh and Dried Sea Weed. 



Organic Nitro- 

 Water. Matter. gen. Potash. 

 Per cent. Per cent. Per cent. Per cent. 

 Fresh Seaweed — 



Laminaria digitata, stems 



("Driftweed," "Tangle,"' etc.) 82.37 12.31 0.23 1.83 



Laminaria digitata fronds 74-75 19-59 0.34 1.28 



Fucus ■z'csiculosus | ("Wrack," | 68.17 25.29 0,38 .97 



Fucus nodosus \ "Bladder 1-70.52 23.13 0.33 .78 



Fucus serratus ( wrack," etc.)) 75.40 19.08 0.36 1.02 



Dried Seaweed — 



Laminaria digitata, stems — 64.03 1.31 10.49 



Laminaria digitata, fronds — 77-28 1.30 5.25 



Fucus vesiculosus — 79-71 i - 18 3.07 



Fucus nodosus — 78.39 1.13 2.52 



Fucus serratus — 77-56 1.50 4.18 



Average Potash Content of Ash. 



L. digitata. L. digitata. F. vesi- F. F. 



(stems), (fronds), culosus. nodosus. serratus. 



Per cent. Per cent. Per cent. Per cent. Per cent. 



Potash in Ash 28.71 20.99 ^5-29 12.22 t8.6o 



It will be seen by comparison with the tables above given 

 of seaweeds from the coast of America and those of the British 

 Isles that while our South African bamboo (Ecklonia buccinalis) 

 is on the whole lower in its potash content than the American 

 weeds, it is decidedly better in composition than any of the 

 analyses quoted from the leaflet of the Board of Agriculture and 

 Fisheries, especially as concerns the stem. The most noticeable 

 feature of the investigation has been the very marked contrast 

 between the constitution of the salts obtained from the stems of 

 the plant and the leaves, but this is not a matter for surprise, as 

 a similar result was obtained in the United States of America. 

 The principal plants of the American Pacific littoral are Macro- 

 cystis pyrifera and N&reocystis Inetkeana ; both of these grow 

 in huge groves sometimes hundreds of feet in length. The Eck- 

 lonia Inicc'malis, on the other hand, though not very much inferior 

 as a source of potash, is not at all similar to the American 

 weeds in appearance. At the present moment I am not aware 

 of any statistics being available as to the distribution of this 

 particular species of algae ; it is reported that it occurs at intervals 

 for some hundreds oi miles north of Capetown, but whether 

 this is so can be a.scertained only by a proper marine surv'ey 

 of our coasts. 



Undoubtedly the chief use for the seaweed at the present 

 time would be as a fertiliser, and it is quite within the range 



