By J. C. LOUDON, F.L.S. H.S. &c.

AUTHOR OF THE ENCYCLOPEDIAS OF GARDENING AND OF AGRICULTURE, AND
EDITOR OF THE ENCYCLOPEDIA OF PLANTS.

LONDON:

PRINTED FOR

LONGMAN, REES, ORME, BROWN, AND GREEN,

PATERNOSTER-ROW.

PREFACE.

THE most original professional facts recorded in this Volume are, the perfecting of the system of heating by hot water (p. 554.), and a new application of the mode of heating pine-pits by steam (p. 443.). The permanently useful subject of Horticultural Chemistry has been continued (p. 11. 127. and 404.), and commenced in connection with vegetable physiology and the operations of culture (p. 394.). The very complete forcing structures erected in the Duke of Northumberland's kitchen-garden at Syon have been described in detail (p. 502.); and a variety of other improvements in gardens, foreign and domestic, are noticed in the Tours of the Conductor on the Continent (p. 1. 113. 241. 369. 497. and 641.), and through different counties in England (p. 93. 222. 464. 557. and 671.). The subject of improving the condition of the labouring classes, at present in a most lamentable condition for want of employment, has been taken up by Mr. Spence (p. 125. 209.), by Captain Pole (p. 79.), by Variegata (p. 218.), by Y. (p. 390.), by R. S. (p. 550.); and by the Conductor, in a number of minor articles among the Miscellaneous Intelligence. Convinced as we are that the only effectual and permanent mode of benefiting the lowest classes of society is by raising their intellectual character; rendering every man, who has a wife and family, above absolute want, by a garden or piece of ground of at least a quarter of an acre attached to his cottage; and preventing early marriages by a prohibitory law; we would most earnestly recommend attention to what has incidentally dropped from us on these subjects (p. 69. 84. 94. 216. 223. 226. 328. 451. 540. 549. 556. 650. 659. 662.), and in the articles on Education (p. 692.), the Labouring Population (p. 706.), the Cultivation of Waste Lands (p. 704.), Parish Gardens (p. 714.), and in our different Tours. We wish it to be distinctly borne in mind, that all that we have recommended in the above passages has been for upwards of thirty years carried into execution in Wurtemberg, Bavaria, Baden, Silesia, Sweden, and other parts of the Continent, with the happiest effects. Whatever may be the general poverty of Germany and Sweden, and however