Keegan: Chemistry of Lakeland Shrubs and Bushes. 295 



exerts a powerful action over the heart and arteries. The red 

 colouring- matter of the arillus is insoluble in water, and is due 

 to homogeneous plastids tinctured by an ally of carotin. 



Elder. Sambucus nigra. The wood of this shrub is very 

 heavy and hard, difficult to dry, and is specially eminent for its 

 richness in starch and coniferin in all seasons, its freedom from 

 tannin and phloroglucin, and its very slight reducing- properties. 

 The bark is remarkable for the easy and rapid production of 

 true cork (suberin) as distinguished from the hard rhytidome 

 of most of our trees and shrubs ; it contains a very small 

 quantity of an iron-greening- phlobaphenic tannin and some free 

 phloroglucin, also choline and valerianic acid. The leaves 

 contain much chlorophyll, carotin, and wax, but only a little 

 fat, also rutin and tannin, but not much mucilage, and about 

 7 '5 per cent, of ash. The flowers enclose 0*3 to 0*5 per cent, 

 volatile oil, which contains limonene C^'H 16 , also an acrid resin, 

 rutin, mucilage, and malates, but no tannin. The berries con- 

 tain a sudorific substance, gum, sugar, and malic, but no citric, 

 acid ; the deep red pigment is highly developed, yielding blue 

 precipitates with alkalies and with acetate of lead. 



Ivy. tiedera helix. Who has not marked 'the green of 

 ivy, flourishing and thick, that clasps the huge round chimney,' 

 etc., or when round some ancient elm, etc., 'it twines in grisly 

 folds and strictures serpentine!' Let me observe that it is not 

 a vegetable parasite, as it draws nothing from the tree, which, 

 however, it injures both mechanically and physiologically by 

 being utilised as its support. The wood, so remarkable for its 

 numerous vessels and large medullary rays, examined on 15th 

 August was found extremely rich in starch (the rays being 

 packed full with large granules), globules of resin occurred near 



the cambium and in the pith, there was a considerable amount 

 of coniferin, but no tannin or phloroglucin, and but little 

 glucose. The bark contains a small quantity of a tannin 

 (viridinic acid), also a peculiar resinous glucoside (hederine) 

 allied to saponin ; it has an acrid taste, froths when boiled 

 in water and dissolved in sulphuric acid with brown colour 

 passing to a splendid purple. The leaves contain much white 

 wax, some fat, but comparatively little carotin, a large amount 

 of rutin (which is converted into tannin and ervthrophyll during 

 the winter), also hederine, and much oxalate of calcium ; there 

 is not much starch in summer apparently, and none at all in 

 winter; on 16th August I found the amount of ash in dried 

 I leaves which had been growing on a stone wall to be 4*5 per 



' 1900 October i. 



