mth Methods for various Soils. 247 



which are frequently loaded with minerals and acids, not only 

 proves injurious to vegetation, but also, from the evaporation of 

 their aqueous particles, tend to corrupt the atmosphere. Some 

 plants require a greater, and some a less, proportion of water 

 in their food. Those in general cultivation are of the latter 

 description, and are easily injured by an excess of moisture. 

 Hence water may be regarded as an impediment to vegetation ; 

 and therefore it becomes a matter of importance, to consider the 

 most proper methods of conveying it off all soils where it is 

 superabundant. 



No regular system of draining can be given, as our plans 

 and operations must be regulated by the circumstances we are 

 placed in ; for it is not with the earth, as with the animal body, 

 whose component parts form a regular system, and whose fluids 

 circulate in known channels. The circulaiing fluids in the 

 earth are conducted by circumstances altogether different, and 

 frequently in channels the most complex and intricate; the va- 

 riety of cases may be said to be innumerable, no two pieces of 

 land being perfectly alike. 



The first consideration should be the nature of the soil and 

 subsoil, whether it is of a retentive nature or not ; and also the 

 surface to be operated upon, even or uneven. When those 

 principles have been thoroughly investigated and the cause made 

 clearly apparent, the operator will readily see that no general 

 rule can be applied to all cases, but that the grand and leading 

 feature of this, as well as of most of our operations, is in making 

 them subservient to the end in view. A principal point is, to 

 ascertain the best and most convenient place for the drains' dis- 

 charging their water, and to mark out the lines before the 

 operation commences. In drainings of every description, two 

 considerations should constantly be kept in view ; these are, drain- 

 ing effectually, and at the least expense. These should be the 

 objects of all who engage in this and every other improvement, 

 and cannot be obtained when the work is executed without 

 investigating the cause from which the wetness proceeds, as is 

 evidently too often practised ; and proofs are not wanting to 

 show that to this may be attributed the failures we so often see. 

 Not unfrequently has land to be drained a second time, from 

 the operator not taking into consideration the nature of the soil, 

 nor yet the cause of the water. 



A wet soil may proceed from one or all of the following 

 causes : — an undersoil of close texture, which will prevent the 

 surface-water from soaking through it; springs bursting out of 

 the earth, and wanting a free current; and frequently low ground 

 becomes saturated with water from the high grounds, through 

 veins of sand, gravel, or fissures of rock ; also from want of 

 a sufficient descent, or by an impervious stratum of retentive clay. 



