144 ON THE ARTIFICIAL MODES 



Caroline. I should have thought that this abundance 

 of water would have been favorable to the culture of ma- 

 ny species of plants. 



Mrs. B. It is true that marshes cannot be said to be 

 inimical to vegetation in general ; for these spots abound 

 with plants, but they are of an aqueous nature, which are 

 good neither for man nor cattle. They afford, however, 

 an ample repast for the creeping things of the earth ; 

 and when we condemn noxious weeds and stagnant 

 marshes, we should remember that, though man is lord 

 of the creation, this world was not made for him alone, 

 and that the reptile and the worm have also their share 

 of its enjoyments. When it is required to drain a marsh 

 of small extent, it may be done by planting it with wil- 

 lows, alders, and poplars. These trees being of very 

 rapid growth absorb a considerable quantity of water, the 

 greater part of which they evaporate into the atmosphere. 

 The poplar has also the advantage of affording very 

 - little shade ; it does not, therefore, interfere with the ac- 

 tion of the sun and air, agents which perform very 

 prominent parts in the operation of draining. 



Very extensive marshes will not admit of being drain- 

 ed merely by planting. In this case, the mode resorted 

 to is to raise a bank of earth around the marsh, which 

 answers the purpose of a dam, and prevents the water 

 from running into it ; for, if once you accomplish this, 

 the marsh is soon dried by the mere process of evapora- 

 tion. If the marsh be occasioned by a clay soil, the ar- 

 gillaceous earth, which does so much harm by retaining 

 the water after it has entered the marsh, will do as much 

 good by its impermeability when raised in the form of a 

 bank to prevent the water from entering. In digging for 

 this purpose, the earth must be thrown up towards the 

 marsh, so as to leave the trench or ditch external ; the 

 water will then run off by this ditch instead of filtering 

 through the dam raised on the other side. The dam 

 should be formed in the shape of a hog's back, and press- 

 ed down hard towards the base, in order to prevent the 

 water in the ditch oozing through. The dam or dyke 



799. Of the plants of marshes what is said 1 800. For what may 

 they be serviceable'? 801. How may a small marsh be drained 1 

 802. How may a large one 1 ? 803. If the marsh is occasioned by a 

 clay soil, what is said of the argillaceous earth 1 ? 804. In what form 

 should be the dam 1 ? 



