462 Composition of Seaweed and Use as Manure, [sept., 



per cent, of water, and even 85 per cent, is recorded ; well- 

 drained weed contains about 60 per cent., while weed dried 

 by exposure to air in a shed contains 10 per cent, or even less. 

 Weed carted by the farmer would probably contain about 

 75 per cent, of water on an average. 



Table L — Percentage Composition of Dry Matter of Various 



Seaweeds. 





Fucus 

 cera- 

 noides. 



Fucus 

 cani- 

 culatus. 











Green weeds. 



Name of weed. 



Fucus 

 serratus. 



Fucus. 



Laminaria. 



Clado- 

 phora 

 and Ulva. 



Ulva. 



Locality 



Croyde, 

 N. Devon 



Croyde, 

 N. Devon 



Thanet, 

 Kent 



Jersey 



Thanet, 

 Kent 



Jersey 



Croyde, 

 N. Devon 



Thanet, 

 Kent 



Date of collection 



July, 

 1908 



July, 

 1908 



Feb., 

 1909 



March, 

 1907 



Feb., 

 1909 



'March, 

 1907 



July, 

 1908 



Feb., 

 1909 



Organic matter ... 

 Nitrogen 



Total ash 



Sand 



Pure ash 



Phosphoric acid... 

 Potash 



6q*8o 

 1 '25 

 30*20 



5'iS 

 25 "05 

 °'°3 

 3-80 



76*00 



1 '53 

 24*00 



2*67 

 21-33 



0*03 



2*52 



75-16 

 2"33 

 24*84 



373 

 2i"n 

 0*05 



3"7Q 



73*86 

 2*25 



26*14 

 1*24 



24*90 

 o*66 

 5*88 



61 *66 

 2*14 

 38-34 

 i3"i5 

 25*19 

 o*c6 

 4'74 



63'59 

 148 



36*41 

 1*14 



35 - 27 

 0*65 

 576 



i-68 



0*03 

 2*16 



2*70 



Composition of Other Substances collected with Seaiveed. 







Mixed growth — 











Salicornia 





Small shells 





Zostera marina. 



herbacea and 



Sea mat. 



and general 







Glyceria 





debris. 1 







maritima. 







Locality 



Jersey 



Thanet, Kent 



Thanet, Kent 



Thanet, Kent 



Organic matter 



76*32 



61*50 



25*80 



21*86 



Nitrogen ... 



o*68 



2*15 



2'37 



0*97 



Ash 



23*68 



38-50 



74' 20 



78-14 



Sand 



3*62 



16 *68 



25*80 



44^5 



Pure ash 



20 06 



21*82 



48 -40 



33-29 



Phosphoric acid 



070 



0*04 



0*04 



002 



Potash 



0*69 



1*28 



1*30 



0*48 



Contained also 21 *8 per cent, of calcium carbonate. 



In Table I. are given the results of analyses by the writer 

 of a number of seaweeds and of materials commonly gathered 

 at the same time. The samples of Fucus from Jersey and 

 from Croyde and the Cladophora were cut from the rock; 

 the Thanet sample of Fucus, the Laminaria, and the Ulva were 

 thrown up by the tide. The other figures refer to materials 

 gathered along with the weeds, but quite different from them. 

 Zostera marina, or eel grass, its German name being " sec- 

 gras," has green grass-like leaves, and grows in shallow 



