272 On the Composition of the Ash of Xvmeria maritima. 

 No. IV. Ash of Armerin maritima sri'own on Little Graisrindal 



100-00 10000 



The composition of this ash differs from that of plants grown 

 in other localities, particularly with respect to the lime, which 

 appears to replace in part the alkaline salts. However, silica and 

 chloride of sodium, two substances which are essential to the 

 healthy growth of Armeria, are present in considerable quantity. 



The circumstances connected with the occurrence of Armeria 

 maritima, Plantago maritima, Cochlearia officinalis, and some other 

 marine plants in the Scottish Highlands, deserve to be well in- 

 vestigated. Not having had an opportunity of examining myself 

 the localities in which Armeria, Plantago, and other marine jilants 

 ai'e found in the Highlands, it does not become me to offer an 

 explanation of this curious fact. I may however be allowed to 

 ui-ge those interested in this subject to pay attention to the me- 

 teorological condition of those places in the Highlands where 

 maritime plants are said to occur. It is a well-ascertained fact, 

 that the spray of the sea is carried into the air to a considerable 

 height, from which the salt in it is sent down again to the earth 

 with the rain. The quantity of rain in mountainous districts 

 being generally much greater than in the lowlands, it appears to 

 me not unreasonable to suppose, that particularly those sides of 

 elevated points in the Highlands which are exposed to frequent 

 sea-winds will be pro\ided with a quantity of salt, sufficiently 

 large to supply the wants of the sea-pink, which plant, as indi- 

 cated above, always contains a notable quantity of common salt. 



In conclusion, I beg to offer a few observations respecting the 

 occiu-rence of fluorine in plants. Dr. Will of Giessen has the * 

 merit of having first discovered fluorine in plants. Comparatively 

 few examinations of plants have been made in reference to the 

 occm*rence of fluorine in them. Most examiners have confirmed 



