COMPOSITION OF THE ASH OF A N.S.W. SEA-WEED. 95 



On the COMPOSITION of the ASH of a NEW SOUTH 



WALES SEA-WEED ECKLONIA EXASPERATA, 



and the PERCENTAGE OF IODINE PRESENT. 



By C. J. White, b.sc, Caird Scholar, University of Sydney. 

 (Communicated by Prof. Liversidge. ll.d., f.r.s.) 



[Read before the Royal Society of N. S. Wales. December 5, 1906~\ 



This analysis of the ash of a New South Wales sea weed, 

 the first of an intended series, was made in the Cliemicai 

 Laboratory of the University of Sydney, at the suggestion 

 of Professor Liversidge, to be used in connection with his 

 investigation upon the occurrence of gold in sea- water. It 

 was also intended to test for and estimate the amounts of 

 any of the rarer elements which might be present, but 

 this portion of the work has had to be postponed. 



Eeklonia exasperata (Family Laminariacese, Sub-class 

 Phaeophycese) is a very characteristic New South Wales 

 Alga — being in fact one of the commonest of our brown 

 sea- weeds. It is found adhering to the rocks below low 

 tide mark, and like the Laminarise in general, has a large 

 stalked thallus resembling a huge leaf. It is attached to 

 the substratum by means of branched root-like hold fasts 

 developed from the base of the stalk. The leaf-like expan- 

 sion of the thallus in the case of Eeklonia is further marked 

 by spinose projections and undulating edge. It belongs to 

 the same family, and is closely allied to the weeds, that 

 are, or rather were, used by the kelp makers of North-west 

 Europe (i.e., Laminaria digitata and L. stenophylla) and 

 like them contains a high percentage of potassium salts 

 and an appreciable quantity of iodine. This latter element 

 is not found in Eeklonia to the same extent as in L. digitata 



