244 * HE FARMER AT HOME. 



us how fast their roots absorh, or their leaves exhale ; and in cultivat- 

 ing rare plants, this simple experiment will enable us to determine 

 what quantity of water they require. 



LEAVES FOR MANURE. The dead leaves of the forest con- 

 stitute an admirable manure when rotted in the barn-yard, pig-stalls, 

 or in composts ; they have precisely the value of straw, being very 

 similar in their action. The leaves of oaks and plants growing on a 

 rich soil are better than those of pine, or such as grow on poor lands. 

 They should be collected as early as possible in the fall. They might 

 be gathered with rakes and put into stacks of several hundred each in 

 the forest, to remain till the snow falls, when they could be removed 

 to their places of deposit with more convenience than at the period of 

 collecting them, or as they may be needed for litter. If they were to 

 be at once ploughed into the soil, they would form an excellent 

 amendment ; but in that case, require rather more time to yield veg- 

 etable food. In this case, lime should be applied with the leaves. 



LEECHES. The traffic in leeches is a remarkable one, alike for 

 the gatherer and the dealer. The leech is met with more abundantly 

 in the south than in the north of Europe. The country about La 

 Brienne, in France, is famous for its supply of leeches; and here is 

 exhibited the wretched nature of the employment of a leech-gatherer. 

 He has his arms and legs bare, and walks about in the marshes where 

 the leeches abound. They attach themselves to his legs as he moves 

 along, and he picks them off from time to time ; he seeks for them 

 also about the roots of bulrushes and sea- weeds. He can on some 

 days gather a groce in three or four hours : and he puts them into a 

 small bag suspended round his neck. Such is the leech-fishery in 

 spring ; but in summer it is still worse. The leeches then go into 

 deeper water, and the gatherer strips naked to go after them. These 

 poor fellows are exposed to fogs, mists, and fetid vapors, and are sub- 

 ject to agues, catarrhs, and rheumatisms ; but the trade is tolerably 

 lucrative, and thus there is no scarcity of leech-gatherers. They are 

 sometimes imported in bags, but more usually in small barrels contain- 

 ing about two thousand each : theJiead being made of stout canvas, 

 to admit the air. It has been estimated that the annual consumption 

 of leeches in Paris is about three millions ; and that not less than 

 seven millions are annually carried to London, either for use there or 

 for shipment to other places. 



LENS. Is a glass ground into such a form as to collect or dis- 

 perse the rays of light which pass through it. They are of different 

 shapes, from which they take their names. If rays proceed from a 

 radiant point distant as far as the sun, their divergency is so trifling 

 that they may be considered as parallel. When parallel rays fall on 

 a piece of glass having a double convex surface, that ray only, which 

 falls in the direction of the axis of the lens, is perpendicular to the 

 surface; the other rays falling obliquefy, are refracted towards the 



