44 



plaster of Paris or of zinc paint. This is mounted on brass and 

 fitted over the frame of the ordinary silvered mirror, thus not requiring 

 the latter to be removed. The advantage gained by this mirror he 

 stated to be, that the whole of the rays reflected from the surface of 

 the plaster of Paris were brought into one focus, together with those 

 reflected from the surface of the glass, and thus a more equal and 

 also a more briUiant light is produced than by any of the means 

 heretofore employed for the purpose of getting a perfectly white light. 

 —J. W. 



Botanical Society of Edinburgh. 



Thursdaij, November 14, 1850. Professor Fleming, President, in 



the chair. 



The Curator gave in a report on the state of the herbarium, 

 noticing that considerable progress had recently been made in the 

 arrangement of the collections, and that four additional cases had 

 been obtained. Several important additions of foreign plants were 

 likewise noticed. 



The following papers were read : — 



1. 'On the British species of Carex;' by John M'Laren. The 

 author stated that the substance of this paper was contained in an 

 essay written last summer for Dr. Balfour's class. He had since 

 re-examined all the species, with the view of improving the descrip- 

 tions and was happy to acknowledge his obligations to Dr. Arnott's 

 edition of the ' British Flora,' recently published, for some important 

 particulars which he had not previously observed. Among the more 

 important works which he had consulted were also Goodenough's 

 ' Monograph of the British Carices,' in the ' Linnean Transactions,' 

 Schkuhr's ' Monograph' (the French edition), Kunth's ' Enumeratio 

 Plantarum,' Fries' ' Summa Flora Scandinaviae,' Babington's 'Manual,' 

 and the figures in the ' English Botany ' and its Supplement. Some 

 others are quoted along with the synonyms. The author stated that, 

 in the present state of the science, unanimity could hardly be expected 

 amono' naturalists with regard to the true limits of species; but as it 

 was necessary, in describing the Carices, to adopt an opinion on this 

 subiect, he thought it better to lean to the side of simplicity, and 

 rather to unite two plants whose identity might be doubtful, than to 

 retain them as ambiguous and ill-defined species. The result of these 



