THE FARMER'S MAGAZINE. 



223 



the incrustation of seeds, must live or die by that great 

 test. A French gentleman has recently come to this 

 country, to submit his invention of a machine for pre- 

 paring the seed, and the formulas regulating the nature, 

 proportions, and quantities of the mineral substances to 

 be used, to the verdict of English practical farmers ; 

 and I am in a position to state that his appeal has been 

 favourably received, and experiments are being made in 

 various parts of England with the view of testing the 

 value of that gentleman's discoveries. Messrs. Burgess 

 and Key have been entrusted with the construction of 

 the simple machine for the incrustation of the seed. 

 This machine consists in a hollow cylinder, suspended by 

 two leather straps from a pulley, to which a rotary 

 motion o f about forty revolutions in^a minute is imparted , 

 either from a steam-engine or any other motive- 

 power. In the cylinder the seed is introduced mixed 

 with an agglutinous mixture, itself rich in nitrogen ; 

 and then the mineral substances, reduced to a fine 



powder, are added, and from the rotary motion of the 

 cylinder adhere to tho seed in a regular coating ; this 

 is repeated until the entire quantity has been fixed. In 

 order to prevent the humidity of the agglutinous mixture 

 from acting upon the seed, and causing it to germinate 

 before it is put into the soil, an hygrometric substance 

 is mixed with the mineral powders, which abstracts 

 all the excess of humidity from the glue, and besides 

 dries up the crusted seeds almost immediately. 



Previous to his coming to this country, Mons. D'llliers 

 has satisfied himself by numerous experiments of the 

 value of his discovery ; and at the late sowing season, a 

 large area has been sown with his prepared seed in 

 various parts of France, so that at the time of next 

 harvest I shall be enabled to give au authentic account 

 of experiments tried both in France and in England, 

 under every variety of local circumstances of soil, cli- 

 mate, and modes of husbandry. 



Norwood, Jan. 8, 1858. 



LAND DRAINAGE — ITS ACTION AND EFFECT. 



In a former article we pointed out the discrepancy of 

 opinion that existed upon the practice of draining, 

 and we concluded our observations by stating a few 

 leading principles that appertain to the subject. We 

 may pursue these with advantage a little further. 



As a surcharge of water in any description of cul- 

 tivable soil must at all times be injurious, it becomes 

 absolutely necessary that it be discharged as quickly as 

 possible ; and as the amount of rainfall is different in 

 different portions of the kingdom, the means applied 

 must have relation to the quantity to be discharged by 

 the drains. Consequently, in districts where the rain- 

 fall exceeds 30 inches annually, the means resorted to 

 for its removal must be in relation. The permeability 

 of the soil also forms a strong consideration ; the more 

 retentive it is, the nearer together must the drains be 

 placed ; and vice versa the greater the porosity of the 

 subsoil. The depth of the drains will depend upon the 

 nature of the upper soil and substratum : if exceedingly 

 retentive, and only slightly permeable, then the depth 

 of the drains must be compensated by the distance be- 

 twixt them. On such soils drains of 30 to 36 inches in 

 depth will be found sufficient, the distance between 

 varying from 15 to 20 feet; but when the substrata 

 become more permeable, the depth of the drains should 

 be increased, and the space between them extended. 

 It rarely happens, however, that any soil affected by 

 surface water requires drains more than 48 inches in 

 depth, or will allow a distance of more than 30 feet 

 apart. This may be accepted as a principle necessary 

 in application, upon soils affected only by what is termed 

 top toater, or such water only as is supplied from 

 above. Upon the pei-nieability or impermeability of 

 the substratum the apj/lication must invariably depend; 

 but as many drainers contend that all soils are more or 

 less permeable, it may be well at once to advert to 

 that point. To a certain depth it undoubtedly is the 

 case; but frequently at a depth of 18 inches some of our 

 strongest clays become impermeable, unless for short 

 periods after excessive drought, when, by their having 

 shrunk, fissures have been formed by which water 

 becomes freely admitted, but which, when again 

 saturated, become impervious to the further admission 

 of water. Or, as is the case in many tenacious clays, 

 small veins of silt exist in stratified order, and accom- 

 plish the object of allowing the water to pass off slowly 

 by theii- assistance. Professor Ansted, in speaking of 

 the London clay, says, '^ It is tougb, and of course 



impermeable ;" and this has been proved over and over 

 again to be correct. 



Much of late has been advanced upon the benefit to 

 be derived by not allowing any of the rain water to be 

 carried off by surface drains, but that the whole of it 

 should be admitted, and pass through the soil to the 

 drains below. The argument advanced in favour 

 of such a practice is assuredly carried too far. It 

 is true that rain water contains some fertilizing 

 properties, more especially as regards the ammonia 

 and^nitric acid that become combined with it, but 

 which, at all times minute in quantity, during very 

 rainy seasons exist in the smallest perceptible propor- 

 tions. Whenever these enter into and become com- 

 bined with the soil, they are by their affinity immediately 

 taken up by it, and retained to be given out to plants 

 vegetating upon its surface. The greatest amount 

 of injury sustained by soils surcharged with water 

 arises from the exclusion of air and the lowering 

 of its temperature, as well as by the admixture 

 of mineral ingredients with it, which become injurious 

 to vegetation. Air contains substances equally be- 

 neficial to vegetation as those contained by rain 

 water; those properties in the latter, before referred 

 to, being taken up in its passage through the air 

 as the rain-water descends to the earth. After long 

 periods of drought, when the air has become highly 

 charged with those substances, the quantity brought 

 down by the first shower that falls is far greater in 

 amount than what is brought down by the next and 

 succeeding showers. In long continuous seasons of 

 rain it ceases altogether. As it is during such seasons 

 that a surcharge of water to the soil becomes most 

 injurious, it is at once apparent that, if a large portion 

 of this matter can at once be carried off from the sur- 

 face, the necessity of an increased area of drainage below 

 may be dispensed with, especially in districts where the 

 amount of annual rainfall is greHtest. 



Water in a state of evaporation from a surface dis- 

 charges the heat also; and, therelore, if no other 

 means exist whereby water can be discharged from tlie 

 soil, it must remain until sufficient heat is produced by 

 the rays of the sun, or by increased temperature of the 

 atmosphere upon tho surface to again convert it into 

 vapour. During this process the heat of the soil be- 

 comes diminished, especially at the immediate surface; 

 and a soil of a district of naturally higher tem- 

 perature is reduced to tho temperature of one of 



