On Agricultural Mechanics. 125 



It has been customary to trample and roll, and by every means firm 

 the land after wheat-sowing, to hinder the frost from throwing the young 

 plants out. On this account, when my father stated his intention to a 

 party of farmers who were walking over Whitfield Example farm, of sowing 

 wheat on a field which had been subsoil-ploughed in the spring, and had 

 borne an excellent crop of swedes, and which was then, after having been 

 cultivated with Secular's implement, in as loose a state as possible, they 

 tried to dissuade him, and foretold that the young plants would, on the 

 first frost, be thrown out. The plants certainly sustained some severe 

 frosts, but the result showed the fears expressed to have been unfounded. 

 The Norfolk farmers, I believe, are very careful, in ploughing for wheat, 

 to break the furrow-slice as little as possible, and to firm the land as 

 much as possible, before sowing their wheat. They find that this tends 

 to hinder the frost from throwing out the plant. May not this throwing 

 out by the frost, upon wet land at least, be explained in this way ? The 

 rain falls on such land, and sinks in till it comes to an impervious bot- 

 tom, at no great depth, where the land has never been stirred by the 

 plough or otherwise. It remains there, and, on freezing in winter, it of 

 course forces open the land, and the plants are thrown out and killed. 

 There are two ways of hindering this : one is to trample and roll the 

 land, and make a hard surface, so that the rain, on falling, flows over 

 the surface and is carried away by the open furrows. It thus does not 

 sink in. This is the plan generally followed, but it often fails, as I be- 

 lieve the experience of many would testify. Would not the better plan 

 be to drain the land and put in the subsoil-plough and work it with the 

 scarifier? The rain, on falling, will certainly sink in, but it will sink 

 far beyond the reach of the frost, and will be carried away by the drains, 

 the plants at the same time deriving all the advantages of a free and 

 open soil. 



[To he continued.'] 



XI. — On the ^' Tchornoi Zem,^' or Black Earth of the Central 

 Regions of Russia. By Roderick Impey Murchison, 

 F.R.S., President of the Geological Society. 



[Since the accompanying sketch was read before the Geological Society 

 of Londjn, I have added to it the valuable analysis of the black earth by 

 M. Payen, and have willmgly acceded to the request of my friend Mr. Pusey 

 to publish it in the volumes of the Agricultural Society.] 



In previous communications respecting the geological structure of 

 Russia in Europe, M. de Verneuil and myself gave a sketch of 

 the superficial accumulations which are apparent in the northern 

 governments of that empire. In conjunction with our associate. 

 Count Keyserling, we shall revert to this subject, both with the 

 view of adding to our former stock of knowledge that which has 

 resulted from recent researches, and also to show in one con- 

 nected memoir the relations of all the varied superficial demtus 



