78 ESSEX SOCIETY. 



supply it with substances which the growth of plants has taken 

 from it. It will be obvious, on a moment's reflection, that the 

 constituent parts of the plant are taken up from the earth and 

 the air, in much the same manner as our food and drink become 

 our bone and flesh. The analogy is still more distinct when 

 we reflect that all our applications for the improvement of the 

 soil, are nothing more than the supply of food for plants. For 

 the food of plants is found in all manures, and the value of 

 these depend upon the quantity they contain. 



The methods of renovating mowing and pasture lands by 

 means of top dressings, do not essentially differ. We have 

 seen an interesting experiment during the present season. On 

 different parts of the same field, simple meadow mud, rich barn 

 manure, and liquid manure impregnated with lime, were used 

 as a top dressing. The mud was hauled out last autumn and 

 thrown in heaps, and there left to the action of the frosts and 

 snows of winter. In spring it was spread nearly at the same 

 time the other manure was applied. Strange as it may seem, 

 the top to which the mud was applied, appeared to far the best 

 advantage. The grass was heavier, and after the crop had 

 been removed, that part of the field on which the mud was 

 applied, came in more quickly and luxuriantly than the rest. 

 This field was a light gravelly soil, which had not been under 

 very high cultivation. A large proportion of the soils of Mas- 

 sachusetts are composed of gravel with a mixture of sand. 

 These soils peculiarly need the constituents of marl and mead- 

 ow mud. Marl and mud contain the carbonate, or in some 

 cases, the sulphate of lime, which is the same as plaster of 

 Paris. They contain a large mixture of clay, which sandy or 

 gravelly soils need. And on these soils clay mud has been 

 found to do the best. Peat mud is a rich vegetable food, and 

 if a small proportion of potash or ashes is added, it is nearly, 

 if not quite as valuable as the best barn manure. Light soils 

 are always improved by any substances which make them firmer 

 and more compact. Stiff clay soils, on the other hand, are 

 benefited by applications which make them lighter and more 

 permeable. No one of the three kinds of earth, the sand, the 

 clay and the lime, when unmixed with the other varieties, 



