Note 1640 — I.—PHÆNOGAMOUS OR FLOWERING PLANTS. (continued 13)

Guibourt obtained of it 17 per cent., Umney 21·5, Squibb 11 to 16, T. and H. Smith “not more than 15,” D. Hanbury 11 to 15·8. Jalap grown in Bonn afforded to Marquart 12 per cent.; a root cultivated at Münich gave Widnmann 22 per cent.; from plants produced in Dublin W. G. Smith got 9 to 12 per cent.; and fine tubers from Ootacamund in India yielded to one of us 18 per cent. of resin. Broughton is of opinion that exposure of the sliced tuber to the air in the process of drying, favours the formation of resin, by the oxidation of a hydrocarbon.