FOLIA DIGITALIS. 469 



The lime, amounting to between a quarter and a half of the entire 

 quantity of ash, is in the leaf combined with organic acids, especially 

 malic, perhaps also citric. The proportion of potash varies greatly, but 

 may amount to about 30 per cent, of the ash. 



Commerce — ^There were imported into the United Kingdom in the 

 year 1^)72, 4o,.549,700 lb. of unmanufactured tobacco, rather more than 

 half of which was derived from the United States of America. The 

 total value of the commodity thus imported was £1,563,382 ; and the 

 duty levied upon the quantity retained for home consumption amounted 

 to £6,694,037. In 1876 the consumption of tobacco had increased to 

 47,000,000 lb., i. e. 1| lb. per head of the population. 



In the United States 559,049 acres of land being in 1875 under 

 cultivation with tobacco yielded a crop of 367,000,000 lb. 



Uses — Tobacco has some reputation in the removal of alvine ob- 

 structions, but it is a medicine of great potency and is very rarely used. 



Substitutes — Of the other species of Nicotiana cultivated as 

 Tobacco, X. rust'ica L. is probably the most extensively grown. It is 

 easily distinguished by its greenish yellow flowers, and its stalked 

 ovate leaves. In spite of their coai-ser texture, the leaves dr}^ more 

 easily than those of X. Tabaciim, and with some care may even be 

 made to retain their green colour. X. I'ustica furnishes East Indian 

 Tobacco, also the kinds known as Lafakia and Turkish Tobacco. 



X. persica Lindl. yields the tobacco of Shiraz. X. quadrivalvis 

 Pui"sh, X iiudtivalvis Lindl. and X. repanda Willd. are also cultivated 

 plants, the last named, a plant of Havana, being used in the manufac- 

 ture of a much valued kind of cigar. 



SCROPHULARIACE^. 



FOLIA DIGITALIS. 



Foxgloi.-e Leaves; F. Feuilles de Digitale; G. Fingerhutbldtter. 



Botanical Origin — Digitalis pui'purea L., an elegant and stately 

 plant, common throughout the gi'eater part of Europe, but preferring 

 siliceous soils and generally absent from limestone districts. It is found 

 on the edges of woods and thickets, on bushy ground and commons, 

 becoming a mountain plant in the warm parts of Europe. It occurs in 

 the island of Madeira, in Portugal, Central and Southern Spain, Nor- 

 thern Italy, France, Germany, the British Isles and Southern. Sweden, 

 and in Norway as far as 63° N. lat.; it is however very unequally dis- 

 tributed, and is altogether wanting in the Swiss Alps and the Jura.^ 

 As a garden plant it is well known. 



History — The Welsh " Physicians of Myddvai " appear to have 

 frequently made use of foxglove for the preparation of external medi- 

 cines.- Fuchs* and Tragus^ figured the plant; the former gave it the 



' Dr. R. Cuuningham found (1868) Di'ji- - Meddygun Myddfai (see Appendix) iu 



f dis purpurea completely naturalized about many places. 

 San Carlos in the Island of Chiloe in * De Hiisl. Stirpium, 1542. 892. 



Southern Chili. ■• De Stirpium . . . nomenclaturis, etc. 



1552— " C«ni;xj«M/a .tylrestris seu Dirjitalig. " 



