Agricultural Chemistry — Sheep- Feeding and Manure. 307 



these substances in them, though in the instances now before us 

 the sources of insufficiency will be found to be opposite in their 

 character to those already referred to. 



The special object of this series was to trace the relative 

 feeding and manuring values of turnips grown by different ma- 

 nures, by which, as we have shown in our paper on ' Turnip 

 Culture' in this Journal, the composition of the produce, espe- 

 cially so far as the per-centage of nitrogen is concerned, may be 

 materially influenced. 



The turnips selected for the four pens were Norfolk-whites, 

 grown in the season of 1848, in continuation of the experiments 

 detailed in the paper above referred to. Those consumed in pen 

 1 were grown by mineral manures alone ; those in pen 2 by the 

 same manures, with sulphate and muriate of ammonia added ; 

 those in the 3rd, by the mineral manures, with rape-cake added ; 

 and in the 4th, with both rape-cake and ammoniacal salt, in addi- 

 tion to the mineral manures. These conditions, it will be re- 

 membered, are in kind the same as those supplied in the experi- 

 ments of the season of 1845; the quantities have, however, been 

 considerably varied, the amount of rape-cake being much in- 

 creased, and that of ammoniacal salt diminished, by which, as 

 will be explained on some future occasion, the progress of the 

 plots relatively to each other has been somewhat altered. 



In order that the amount of food consumed in each pen, and 

 the effects produced, might fairly be taken to be attributable to 

 the qualities of the different lots of turnips, and to their com- 

 petency or insufficiency to supply the wants of the system, it was 

 decided that the turnips should themselves constitute, almost ex- 

 clusively, the supply of food to the animals. It was thought, 

 however, that cut straw would interfere but little with the results 

 in this respect, and that it would assist in providing the bulk of 

 dry substance, which, independently of matters of more directly 

 nutritive quality, seems to be essential to healthy digestion in 

 ruminant animals more especially. It was found, however, that 

 although both straw and turnips were finely cut and mixed to- 

 gether for some time before being given to the animals, the former 

 was almost entirely refused, in consequence of which its use was 

 abandoned after a sufficient trial, and the turnips were given alone. 

 It could not be expected that the animals would do well upon such 

 food, but as the composition of the turnips was supposed to vary 

 very greatly, especially as regarded the per-centage of nitrogen, 

 which is generally believed to determine, to a great extent, the 

 value of produce for feeding purposes, it was thought, that what- 

 ever the results might be, they would not be without their lesson. 

 It happened, indeed, that many of the animals lost weight, yet 

 the results, thus negative in their character, are found to provide 



