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XV. — Agricultural Chemistry — Sheep- Feeding and Manure. 

 Part I. By J. B. Lawes. 



A prominent feature in the best agriculture of Great Britain is 

 the concentration of produce on the land, by means of the purchase 

 of cattle-food or direct manures ; and it may safely be affirmed 

 that, with a rapidly increasing population and a limited area of land, 

 this system must become more and more general if the enhanced 

 demand for human food is to be in any degree adequately met 

 by the supplies of the British farmer. The importance to him, 

 therefore, of a clear conception of the nature and sources of value 

 of manuring substances generally, as well as of the characteristic 

 differences or identity of those derived from the various resources 

 at his command, will at once be obvious ; yet, it will be admitted 

 that even the most intelligent and observant practical farmer is 

 far from possessing that clear and definite conception of the 

 rationale of the practices he adopts, which alone can prove an 

 unerring guide in his operations, and ensure such conduct of 

 them in detail as is consistent with true economv, and calculated 

 to yield the full advantages which a perfect application of their 

 inherent principle must attain. Much has, however, been done 

 of late years, both by societies and individuals, towards providing 

 that basis of facts without which fixed principles in agriculture, 

 and a right understanding of the practices already approved by 

 experience, cannot be attained ; yet, much remains to be done 

 before even the more general and fundamental usages can be 

 satisfactorily explained, whilst the circumstances of their local 

 adaptation may be said to constitute a distinct and not less 

 important, and at the same time more extensive and permanent, 

 field of inquiry. 



The growth of green and fodder crops, to be consumed by 

 animals upon the farm, is recognised as a most important source 

 of manure, and it is decided, by the practice of the best farmers, 

 that the full advantages which such a course is competent to yield 

 are only attainable when it is aided by the purchase of foreign 

 food for home consumption, or by the direct supply of purchased 

 manure, and it is indeed probable that increased production at 

 home is far more necessarily dependent on the accumulation 

 of material from external resources than is usually supposed. 

 Before, however, the exact economical effects of alternate cropping, 

 the consumption upon the farm of roots or other home produc- 

 tions, or of purchased food, or the supply of foreign manure, can 

 be clearly appreciated or explained, much precise information has 

 yet to be provided, as to the chemical circumstances connected 

 with the growth and appropriation of the more important plants 

 which enter into rotation, and the employment of food and manure 



