432 Remarks and Observations suggested 



moisture than sandy soils from the latter; manures and decompos- 

 ing substances retain and give out moisture: but to the capillary 

 attraction of the narrow apertures of a well-pulverised soil, as the 

 professor remarks, we should look as the most beneficial source ; 

 if contained in greater quantity, it is prejudicial ; and if the clayey 

 composition of the soil or subsoil, or the inequality of its levels, 

 presents an obstruction to the outlet of the superfluous water, 

 draining must be had recourse to. In the work before us the bad 

 effects of too much water are clearly pointed out, and the periods 

 of the growth when most water is required detailed ; as also the 

 little good to be got by watering in dry weathei", owing to the 

 dry and heated state of the atmosphere. On this account, any 

 water we give should be given in the evening, when the soil has 

 time to imbibe the water in the cool of the night; but, unless the 

 waterings are copious indeed, they are generally evaporated by 

 the next day's sun, and the water diluting the soil into the con- 

 sistence of soft puddle or paste, it is hardened by the sun of 

 next day into a crust or cake, the bad effects of which have 

 before been noticed in the section Bottom Heat : by degrees, as 

 the operation is repeated, the crust gets thicker, and thus often 

 to small seedlings and other plants more harm than good is done 

 by watering without covering. To prevent these bad effects and 

 lessen the evaporation, a covering should be spread above 

 through the day to shade from the sun, and removed at night 

 at the time of watering. If the seedlings are in small patches, as 

 annual flowers, they should be covered with an inverted flower- 

 pot a little raised from the ground to admit air, or a piece of 

 bast mat or thin cloth is better, to screen the heat and allow 

 as much as possible of the light to pass; and they should be ele- 

 vated on sticks to allow the air to circulate freely. When the 

 seedlings are in beds, the surface should be hooped over, and 

 bast mats tied above the bed, not reaching quite to the ground, 

 but so as to screen the heat, allow a little of the light to pass, 

 and the air to circulate freely below ; the mats should be re- 

 moved, and the bed watered regularly every evening, so as to 

 get the benefit of the dews and night air, and replaced in the 

 morning before the sun gets hot. This is troublesome and ex- 

 pensive, but when the seedlings are valuable will be found to 

 repay both. In the dry summer of 1826, we preserved a bed of 

 seedling black spruce (Pinus nigra) by this means, which got 

 no rain from the time they were sown till about 10 or 12 

 weeks afterwards ; but by this treatment they grew stronger and 

 better than usual, and their value was many times the amount 

 of the expense. When plants cannot be deferred planting 

 during the time of a drought, if small, such as vegetables or 

 herbaceous plants, a good plan is, after watering, to invert a 

 flower-pot over them; the plants, however, generally suffer so 



