150 THE PRINCIPLES OF 



known manure, dam's blood manure, ought to have most 

 of the characters of a general manure. The refuse from glue- 

 works, refuse from fisheries, refuse from tanneries, from 

 woollen factories, the refuse which is brought over from South 

 America, as the small bones with flesh adhering to them of 

 slaughtered animals and the list no doubt could be prolonged. 

 Any substance which is the refuse of either animal or vege- 

 table life will be general in its composition. Compost heaps, or 

 collections of rubbish of all kinds, including occasionally the 

 bodies of animals, mixed with earth, give a rich compost, 

 which owes its value to the fact that it is a substance con- 

 taining all the requisite materials. Another instance is that 

 of seaweed, which during its life collects its nitrogenous 

 matter, its alkalies, its phosphates, its chlorine, its magnesia, 

 and other substances from the surrounding water. Finally, 

 it is torn up in stormy weather and stranded upon the coast, 

 and forms a very excellent general manure. River weeds 

 also may be employed as a fertilizing agent. 



In treating of these general manures, I shall take farmyard 

 dung as the type, as there is no substance that has been 

 introduced to the notice of agriculturists which has super- 

 seded it in their estimation. Farmyard dung in this country 

 at least holds its own, in spite of M. Ville, who has written 

 severely against its use, and who considers that it is the most 

 expensive of fertilizers ; in spite also of certain results which 

 have been obtained in this country, and which are certainly 

 very extraordinary. Any inquirer may, I feel sure, enjoy the 

 opportunity of verifying what I am now about to state at 

 Rotharnsted or Woburn, where a valuable set of experiments 

 are being carried out on the Duke of Bedford's farms. At 

 Woburn, during the last eleven years, farmyard manure 

 does not contrast in its effects very favourably with certain 

 combinations of artificial manures. It is a startling sight to 

 see a definitely heavier crop of corn growing at Rotharnsted 



