[3] These are “grains of Paradise,” Guinea grains, or meleguetta pepper. They are the seeds of _Amomum melegueta_ and _A. Granum-Paradisi_, N.O. Zingiberaceae. After this preliminary breaking of the ground little more seems to have been done for some sixty years, but from about 1880 till the present day the association of copper with the vegetable kingdom has been actively investigated in its many aspects. Dieulafait (1880) showed that the quantity of copper present in the vegetation is largely determined by the nature of the soil, which thus affects the ease with which the element can be detected and estimated. Copper was shown to exist in all plants which grow on soils of “primary origin” (“roches de la formation primordiale”), the proportion being sufficient to enable it to be recognised with certainty in one gram of ash, even by means of the ammonia reaction. Samples of white oak from the clay soils, and plants from the dolomitic horizons also gave evidence of copper in one gram of ash, though less was present than in the first case considered, but with plants grown on relatively pure chalk 100 grams of ash had to be examined before copper could be recognised with certainty. E. O. von Lippman found traces of copper in beets, beet leaves, and beet products; Passerini estimated as much as ·082% copper in the stem of chickpea plants, though he regarded this figure as too high; Hattensaur determined ·266% CuO in the total ash of _Molinia cærulea_ (·006% of total plant, air-dried). After this Lehmann (1895, 1896) carried out more exhaustive studies on the subject of detecting and estimating the copper in various articles of food: wheat, rye, barley, oats, maize, buckwheat, and also in various makes of bread; potatoes, beans, linseed, salads, apricots and pears; cocoa and chocolate. He found that only in those plants which are grown on soil rich in copper does the copper reach any considerable value, a value which lies far above the quantity present in an ordinary soil. Plants from the former soils contained as much as 83–560 mg. Cu in 1 kilog. dry substance, whereas ordinarily the plants only contained from a trace to 20 mg. Apparently the species of the plants concerned seems to be of less importance for their copper content than is the copper content of the soil. The deposition of copper (in wheat, buckwheat and paprika) is chiefly in the stems and leaves, little being conveyed to the fruits and seeds, so that a high content of copper in the soil does not necessarily imply the presence of much copper in the grain and seed. The metal is variously distributed among the tissues, the bark of the wood being the richest of the aerial parts in that substance. The form in which the copper exists in the plant is uncertain and it is suggested that an albuminous copper compound possibly exists.