by ingenious physiologists. Their theoretical spe- 

 culations, however, have been pursued with much 

 abstruseness and uncertainty, and it was left for the 

 present age to exhibit, with somewhat like precision, 

 the laboratory of nature in the vegetable kingdom. 

 Mr. Knight, the president of the Horticultural So- 

 ciety, from thirty years' intense application to this 

 subject, has determined, by ingenious and satisfac- 

 tory experiments, many of the phenomena of vege- 

 tation, particularly such as are connected with the 

 circulation of the sap, the perspiration of plants, &c. 



These subjects, perhaps, some of our readers may 

 not have had occasion to examine. As they cannot 

 fail to prove of peculiar interest to many enquiring 

 minds, we shall have pleasure, as opportunity offers, 

 in giving the opinions of eminent botanists, and the 

 result of various experiments connected with this 

 department of vegetable physiology. 



This species of verbascum is particularly hand- 

 some, and we have observed that the flowers of a 

 plant which has remained in its present situation four 

 or five years, are now produced of a darker hue 

 than when it was first planted. This possibly may 

 have arisen from the presence of a portion of peat 

 soil, which, from an alkaline quality that exists in it, 

 is sometimes found to change pinks into purples; 

 perhaps from the neutralization of acids, which pro- 

 duce effects directly opposite. 



It never has perfected seeds with us, nor does it 

 increase very much at the root, but it may be pro- 

 pagated by cuttings of the young flowering stems, 

 which strike root readily under bell glasses. It 

 does not require any peculiar soil or situation. 

 Hort. Kew. 2, v. 1, 385. 



