398 Kccgtiii : The Chemistry of sonic Common Phints. 



the wing^s of butterflies. The scarlet pij^-meiit is similar or 

 analoi^ous to that in beetroot ; its alcoholic solution absorbs 

 the blue-violet portion of the spectrum. The ash of this brilliant 

 fungus contains about 41 per cent, potassium (as phosphate, 

 sulphate, and chloride), 7.7 phosphorus, the other constituents 

 varying" from 6.7 to 0.12. 



EvEBRumx {Euphrasia officinalis). — This plant is recog'nised 

 as a semi-parasite, i.e., in the early stains of its growth certain 

 cells of its roots undergo a modification whereby they elongate 

 and penetrate into the roots of grasses in their neighbourhood, 

 and absorb therefrom a portion of their organic nutriment. 

 It is chiefly in luscious grassy pastures that ' the trembling 

 Eyebright shows her sapphire blue.' Its stem is copiously 

 branched, and varies in height from one to eighteen inches. 

 The leaf chloroplasts are easily rendered inactive by injurious 

 external agencies, so much so that at times no evolution of 

 oxvgen therefrom can be detected. In July the whole contains 

 62 per cent, of water, and the dried substance 1.5 per cent, of 

 wax with only a little carotin and some fat-oil, but no resin, 

 very little sugar, some mannite, cinnamic acid apparently, little 

 starch, mucilage, or oxalate of calcium, and a considerable 

 quantity of an iron-greening, non-phlobaphenic tannin or tannoid 

 which precipitates bromine water but not gelatine, and turns 

 brown in the presence of alkalis and perchloride of tin ; the ash 

 amounts to 10. i per cent, and had 37.7 per cent, soluble salts, 

 19.5 lime, 9.8 silica, 10.2 P^O^, 8.4 SO^ and 7.3 chlorine. It 

 would seem that, owing to the small size of this very dainty- 

 plant, some of the chemical principles contained therein never 

 attain a very high degree of development. Gathered quite 

 fresh and instantly extracted, a small quantity of the remarkable 

 acrid and bitter glucoside rhinanthin can be obtained. 



Corn-Mint [Mentha arvensis). — This is a plant so highly 

 variable in external aspect that for a long time it threw the 

 ' lumping and splitting ' systematists into a very great embar- 

 rassment. Damp localities, with plenty of sun, seem eminently 

 favourable to many of its characteristic proclivities. The over- 

 ground parts yield 1.7 per cent, wax, resin, and volatile oil, but 

 little carotin, also considerable mucilage, some tannoid and 

 iron-greening quinol tannin, which precipitates gelatine and 

 bromine water and evolves quinone on oxidation ; the resin 

 dissolves in sulphuric acid with a brown colour, passing to a 

 splendid red, and with a solution of bromine in chloroform it 

 yields a greenish-Ncllow coloui-. llu' ash contains 50 per cent. 



Naturalist, 



