210 Progress of Agricultural Knowledge 



ment of dung can be greatly improved, though in many districts 

 the quality certainly may be. 



But besides farm -yard dung, we have an infinite variety of 

 artificial manures or hand-tillages ', indeed, it may be said that 

 there is no refuse of any trade, provided it be animal or vegeta- 

 ble, except tanner's bark, which is not or might not be used for 

 this purpose. It would be useless to enumerate all, as they are 

 well known, and the supply of many is very limited. The two 

 principal articles are Bones and Rape-dust, the former suited for 

 light land, and used chiefly for turnips. It is remarkable how 

 very local is the use of both these manures ; that of bones, indeed, 

 is spreading, but rape- dust is not much known in the south ; and 

 certainly where artificial manures are new, there is some unwill- 

 ingness to lay out money upon them, though dung perhaps is 

 bought at 5s. the cart-load, and carted with great labour at a 

 long distance. When bones were first used, it was thought that 

 unboiled bones must be better than those from which the animal 

 oil had been extracted ; but the reverse appears now to be true — • 

 not that animal oil is useless, but that it sheathes probably the 

 bone, and checks its action upon the plant. There remains, how- 

 ever, in the bone another animal compound, gelatine, or the 

 matter of jelly; but Sprengel states he has repeatedly found 

 that bones act as strongly after they have been burnt,* when 

 the jelly of course is removed; and this is well worth remarking, 

 because the body of the bone consists of phosphate of lime, evi- 

 dently another powerful principle, which is found also abundantly 

 in urine, and consequently in dung. But though the character 

 of bones is established upon light land for turnips, even this 

 manure fails on some soils of that quality. I have some light 

 land where it acts very feebly, some where it does not act at all, 

 and on which many hundred bushels of bones have been quite 

 thrown away. There is also some light land near Baldock, on 

 which bones have been proved to be useless. This shows that we 

 cannot be too cautious in prescribing even the most approved 

 remedies for the first time upon land. 



Rape-dust appears to be established chiefly among the farmers 

 of Nottinghamshire, Yorkshire, and Lincolnshire. As it is one of 

 the few hand-tillages which can be applied to clay, and as some 

 of our south-country clays are much in want of assistance, I may 



* Since this was written I find that Mr. Hannam, of North Deighton, 

 near Wetherby, has this year repeated the experiment with the same re- 

 sult. "In order to solve the question," he says, *' we burnt in a pit a quarter 

 of bones and drilled them with turnips (both swedes and white ones); and 

 on two other patches we applied a quarter of unburnt bones from the same 

 stock as the burnt ones were taken. The turnips are now growing, and, 

 as far as can be determined, seem to thrive with the burnt bones as well, if 

 not better, than with the unburnt." 



