THE 



GARDENER'S MAGAZINE, 



SEPTEMBER, 1840. 



ORIGINAL COMMUNICATIONS. 



Art. I. Remarks and Observations suggested hy the Reading of Dr. 

 Lindleys " Theory oj" Horticulture" By R. Lymburn. 



The late work of Professor Lindley, on the Theory of Horti- 

 culture, is undoubtedly the greatest help that science has hitherto 

 furnished to practice ; the scientific part is so clear and concise, 

 so devoid of ambiguity, and so full of demonstration, that no 

 practical man who wishes to excel in his business should be 

 without it. Practical men have, however, a still further duty 

 to perform ; they should bring the scientific doctrines to the test 

 of experience. They have many opportunities of detecting cir- 

 cumstances which do not come vmder the observation of pro- 

 fessors. Every new appearance which occurs to them should be 

 diligently weighed and examined ; and if any new truth is eli- 

 cited, or any corroboration or refutation of theoretical principles 

 discovered, they should promulgate their observations for the 

 benefit of themselves and others. Impressed with these ideas, I 

 have ventured to send you the fruits of my observations on the 

 different sections of the practical part of the above work ; and 

 hope the example will be followed by others more able to do 

 justice to the subject. 



On the first section, on Bottom Heat, I would remark that the 

 colour of the soil has an effect on bottom heat; the black colour 

 absorbs heat most readily, but it parts with it again most readily, 

 and the brown colour is more uniform in its temperature. A 

 great source of bottom heat is the composition of the soil. Silex, 

 being a bad conductor, retains heat, and soils which abound in 

 siliceous sand are much warmer than those which contain sand 

 in very small proportion. In sandy soils, though within a short 

 distance of clayey, vegetation commences some weeks earlier, 

 and the various plants, according to their times of starting into 

 growth, will be generally a month earlier ; but very sandy soils 

 part with moisture, and the vegetable food, too freely by evapora- 

 tion, unless in very wet seasons. The most beneficial source of 

 bottom heat, in the open ground, is the pulverisation of the 

 soiL All soils have a natural tendency to consolidate ; the action 



1840. Sept. f f 



