Dr Davy's Jgricultural Discourse. 345 



higher level, discharged by the drains, might be made applicable to 

 partial irrigation in fields of a lower level. Such water, no doubt, 

 would have a fertilising effect, and, perhaps, even more than ordi- 

 nary rain-water, as it would contain certain saline substances and 

 other compounds which are soluble, derived from the soil, and, it may 

 be, from the manure in the soil, whilst the water is in the act of pass- 

 ing through it, and thus partaking of the quality of spring-water, 

 which is always more or less impregnated with foreign matter, from 

 a like cause, spring-water being rain-water that has passed through 

 the natural filters of the earth's surface. Could this water be so ap- 

 plied to irrigation, it would remove an objection which may be started 

 on the score of economy against thorough-draining, — an objection, 

 however, I believe, of no great weight, if we place, as we should, 

 against the loss by percolation, the gain by active vegetation kept 

 vigorously so by moisture ; and the gain to the soil, through the 

 influence of thorough-draining of a decomposing and ameliorating 

 kind, thereby adding to and deepening and improving it. The sol- 

 vent power, however, of the percolating water is well worthy of 

 being kept in mind ; and it may raise a question of the propriety of 

 applying largely manures to the soil at one time, and whether it 

 would not be better, in the instances of the use of guano, nitrate of 

 soda, and the like, to adopt the method said to be followed by the 

 Peruvians, and make the applications in different stages of the crop, 

 using smaller quantities. 



Barbadoes in many respects resembles Malta ; I am speaking of 

 them now in their agricultural relations. In Malta, as I have al- 

 ready observed, there is a thin soil, which is of excellent quality, 

 resting on a porous freestone. That island has a regular dry season, 

 extending through the hot months of summer, and sometimes longer. 

 Water there is a great want. To collect and store it, attention is 

 constantly given, and immense labour has been expended. Not 

 only every house has its tank, quarried in the rock, but also the 

 majority of the fields — fields of terrace-construction called made- 

 fields — " Campi artificiali." When the rains set in, even the pub- 

 lic roads are made water-channels, and gutters from them convey 

 the water into the field-tanks, some of which are excavated under 

 the roads, and have mouths usually covered with large stones, even 

 in the roads. When the dry season arrives, these tanks are brought 

 into use. Water is raised from them by the lever and bucket, the 

 bimplcst of all mechanical contrivances for the purpose, and applied 

 to the watering of certain crops, as the cotton crop at a particular 

 stage, and to various vegetables and fruit-trees. Could such reser- 

 voirs of water be introduced into Barbadoes, they would unquestion- 

 ably be very useful, especially for the minor crops, and for garden 

 cultivation. Of the happy elfccts of water applied to the latter, an 

 instance offers, close to the garrison of St Ann's, where an intelli- 

 gent and active Italian ironi Tuscany, has brought a piece of lui.d, 



