432 Keegaii : The Chemistry of some Common Plants. 



by the solid wax from the attack of external agencies. The 

 wax also serves to ' protect ' the leaf from the withering effects 

 of excessive transpiration. The chlorophyll itself is of extra- 

 ordinary depth, and richness of tint, notwithstanding the enor- 

 mous amount of silicia in the ash. which is indicative of im- 

 perfect and exhausted vegetative power. There are no mycor- 

 hiza in or on the roots, and there is a strong excretion of water 

 from the leaves, and with it silica and salts of lime. The 

 process of deassimilation does not seem to surpass the tannoid 

 and resin stage, no true tannin being produced, except perhaps 

 a little in the floral parts. The soluble carbohydrates pass to 

 lignin with considerable facility, and the absence of acids in- 

 dicates the comparative immobility of the albumenoids. 



Ti'FTED Vetch [Vicia cracca). — This tall conspicuous plant, 

 crowned with a rich purplish blue raceme of flowers, springs 

 up in hedges, waste places, and amid the grassy herbage of 

 open sunny tields and pastures. The chemistry is com- 

 paratively tame and uninteresting. The official analysis of 

 the dried plant reports 27.4 per cent, albumenoids, 1.4 fatty 

 matter, 20 fibre, and 6.8 ash. On i8th July, the dried over- 

 groimd parts contained 1.7 per cent, of carotin and wax, with 

 no glyceride. The alcoholic extract seemed to have traces of 

 a tannoid like luteolin, and also some alkaloidal substance, 

 a resinous matter, and a little cane-sugar and citric acid ; 

 there was no tannin, glucose, or bitter principle. There was 

 much mucilage, and oxalate of calcium, but no extractible pro- 

 teid or starch. The ash amounted to 6.8 per cent., and con- 

 tained 19 per cent soluble salts, 2.2 silica, 40.6 lime, 4P-0^, 

 2.51 S0'^. and 2.2 chlorine ; there was a little manganese and 

 very much insoluble carbonate. Altogether the analysis is 

 tame and bald ; the chief feature being the paucity or absence 

 of benzene derivatives, and the presence of an abundance of 

 lime. It would seem that the totality of the tannic chromogen 

 was concentrated in the floral parts, but the pigment thereof 

 is by no means pure ; it cannot be compared with that of the 

 Cranesbills, for instance, although like the latter, it forms 

 remarkable pure blue compounds with the organic salts of 

 manganese. The black or olive shade of the seeds seems to be 

 due to tyrosin. 



Garlic Hedge-Mustard {Alliaria officinalis) — This fine 

 plant flourishes under hedges and in shady waste places. In the 

 first year the stem is very short, and the root becomes fleshy 



Nat\iralisti 



