340 Dr Davy's Agricultural Discourse. 



most active portion of nicany valuable manures, and is probably 

 essential to the production in plants of all these albuminous sub- 

 stances which are of the nature of animal matter, from which even 

 animals themselves — those feeding on vegetables, are supposed to 

 be formed, the vegetable being the generator, and the animal only 

 the recipient. 



There are other good and important effects resulting from thorough- 

 draining, which I have scarcely time to mention, as its tending to 

 counteract the evils of drought, as well as of excessive moisture, 

 thereby favouring vegetation, and at the same time benefiting the 

 climate, as it conduces equally to prevent either extreme, — a parched 

 state of the atmosphere, or excessive humidity and fog ; and as it 

 tends also to promote an equable temperature of atmosphere. In 

 brief, it is difficult, I believe, to appreciate too highly the advan- 

 tages of thorough-draining to land that requires it. Mr Smith of 

 Deanston, who may be considered as the inventor of the process, 

 has well said, that it requires faith to admit all the good it is ca- 

 pable of accomplishing, — that good is so much beyond what the in- 

 experienced in its efficacy would expect. 



I consider it, I may remark, a circumstance of good fortune to 

 have witnessed the results of the first trial made of it at Deanston 

 by this gentleman, and also the first attempt, I believe, of the kind 

 made within the tropics, viz., in this island, by your talented coun- 

 tryman Dr Phillips, on his estate of Lamberts, and in Demerara by 

 Dr Schier, the able agricultural chemist of that colony, on an estate 

 in the neighbourhood of George Town. At Deanston, when I was 

 there six years ago, the condition of the land and of the pastures was 

 such as to excite admiration. Though the season was unusually dry, 

 and fields adjoining the property were parched, in which rushes were 

 growing, the Deanston meadows, similarly situated, were beautifully 

 green, and in them not a rush was to be seen or a weed. The har- 

 vest was over, but the farmyard, in the numerous stacks of corn, 

 bore ample proof of the great fertility of the arable land. The in- 

 creased value of the estate, the result of its improvement from tho- 

 rough-draining and good farming, I am afraid to mention, lest I 

 should lay myself open to the charge of exaggeration. Mr Smith, 

 who was my conductor and informant on the occasion, kindly had a 

 hole dug through the soil and subsoil, to shew the deepening of the 

 soil from the decom josition and disintegration of the subjacent stony 

 matter from the action on it of air and moisture. In Demerara, the 

 result of Dr Shier's experiment, making allowance for the shortness 

 of time, appears to be no less satisfactory. When I saw the field, 

 in the latter end of May last, after a heavy fall of rain, water was 

 flowing abundantly fi'om the mouths of the drains, whilst the sur- 

 face soil was merely moist, and in a fit state for tillage ; and having 

 no open drains, such as are generally used in the colony, it was in a 

 condition to admit of the plough and harrow, and the use of any 



