XVI INTRODUCTION. 



How often has it been repeated, that he who 

 causes an ear of wheat to grow where it never grew 

 before, is one of the greatest benefactors to mankind ! 

 If this be true, must we not also regard as a bene- 

 factor the man who has introduced the loveliest 

 scenery of nature into the most crowded streets of 

 our sooty and muddy metropolis ! who has clothed 

 our courtyards, aye, even our windows, with a per- 

 petual summer! who has realized that sweet land of a 

 poet's imagination 



" Where a leaf never dies on the still blooming bowers." 



It is MR. WARD who has effected this. His plan, 

 although improved, I may perhaps say perfected, by 

 various accessories, depends primarily and funda- 

 mentally on protecting the plants from too free com- 

 munication with the outer air. This end is obtained 

 by the use of glass, the light so essential to vegeta- 

 tion being thus freely admitted. The most ready 

 way to try the experiment is, to procure a glass 

 vessel, for instance, one of those jars used by druggists 

 and confectioners; introduce some soft sandstone, or 

 some light soil, filling one-sixth of the jar with it, 

 and taking care that the earth be very moist, yet 

 allowing no water to settle at the bottom of the jar ; 

 plant a fern in the earth, and then cover the jar with 

 its glass lid, first supplying a slip of wash-leather 

 round the rim of the jar, which will pretty nearly cut 

 off the communication between the internal and 

 external air ; no farther attention will be required : 



