82 



of Daphne Cannabina, and samples of the papei- prepared from it ; 

 and gave an account of the mode in which the paper is manufactured. 



Hmrsday, February 13, 1841. Professor Balfour, President, in the 

 chair. 



The following papers were read : — 



1. ' On the Composition of the Ash of Armeria maritima, from dif- 

 ferent localities, with Remarks on the Geographical Distribution of 

 the species, and on the presence of Fluorine in plants in general ;' by 

 Dr. Voelcker, Professor of Chemistry, Cirencester. After alluding to 

 the observations made by Dr. Dickie and others as to the presence of 

 iodine in plants growing near the sea, and its absence in the same 

 species when grown inland, the author proceeded to detail the expe- 

 riments which he had made on Armeria maritima. The plants ana- 

 lyzed were procured from four localities, viz., the sea-shore near 

 Edinburgh ; an elevated trap-rock at some distance from the shore 

 near Edinburgh ; light, sandy soil in Mr. Lawson's nursery. Golden 

 Acres; and granitic rocks on the lofty mountains of Braemar, contri- 

 buted by Professor Balfour. Dr. Voelcker was able to detect traces 

 of iodine in the ash of the specimens grown in the first locality, but 

 none in any of the others. He also found in certain cases that soda 

 was replaced by potash. The results of the analyses of the plants 

 from the first-mentioned localities, suggested the following observa- 

 tions : — First, the proportion of alkaline chlorides, as well as that of 

 silica, is considerable. Secondly, the quantity of soda is more abun- 

 dant in the ash of specimens grown near the sea-shore, whilst potash 

 prevails in the ash of plants grown on the solid rock near the shore. 

 Thirdly, soda is entirely re-placed by potash in the ash of the plant 

 grown in the nursery. Fourthly, the quantity of phosphoric acid in 

 specimens from the third locality is considerable, when compared 

 with that in those from the first and second. Fifthly, the proportion 

 of magnesia in the ashes of Armeria in its natural state, is larger than 

 in the ash of specimens grown in the nursery. (The character of the 

 specimens grown in the nursery was somewhat altered, the plants 

 being much raore vigorous, their leaves broader and of a brighter 

 green, and not so rigid as in the wild plant). Dr. Voelcker suggests 

 that the chloride of sodium found in the specimens from Braemar may 

 arise from the spray of the sea, or particles of salt carried inland by 

 the winds and other agencies. He corroborated Dr. G. Wilson's 

 statements as to the existence of fluorine in plants. 



Dr. Balfour, in remarking upon the paper, stated that M. Chatin 



