332 



THE ROTHAMSTED EXPERIMENTS. 



No litter 

 used. 



Experi- 

 ments at 

 Woburn 

 Park. 



Nitrogen 

 not ac- 

 counted 

 for. 



over the third. That is to say, Ox No. 1, with more or less 

 gain over each of the three-day periods — which may perhaps 

 be interpreted as retention in the alimentary canal or bladder 

 rather than increase in the substance of the body — showed a 

 considerable deficit of nitrogen in the excrements compared 

 with that in the food. Ox No. 2, on the other hand, with 

 loss of weight — which probably only represented more com- 

 plete evacuation in relation to the food consumed — indicated 

 more of tendency to excess of nitrogen in the excrements 

 compared with that in the food. In experiments in 1860-61, 

 also with two bullocks, Henneberg found — this time over six- 

 day instead of three-day periods — deficits of nitrogen in the 

 excrements corresponding to the following percentages of the 

 amounts supplied in the food — 35, 37, 21, 12, 10, 0. It may 

 be observed that the percentage of loss was, upon the whole, 

 the greater with the larger amounts of nitrogen in the food. 

 Later results of Henneberg will be referred to further on. 



In none of the foregoing experiments, either by Bous- 

 singault, at Eothamsted, or by Henneberg, was any litter 

 used, the excrements being collected and analysed by them- 

 selves. 



In 1851, we made experiments with oxen, at Woburn Park 

 Farm, by the permission of the Duke of Bedford. In the 

 experiment, the results of which are given below, there were 

 five Herefords, each in a separate box, and the experimental 

 period extended over thirty-five days. Liberal fattening food 

 was given, consisting of a cooked mixture of equal parts of 

 ground oil-cake, barley, and beans, besides clover-hay-chaff, 

 and swedes. The litter consisted of wheat-straw ; and an 

 absorbent, composed of 2 parts sawdust and 1 part sulphuric 

 acid, was used ; a small quantity being daily sprinkled over 

 the manure in the boxes just before spreading the fresh 

 litter. At the end of the experiment the whole of the dung 

 was got out, put into a large shed, turned over by men, 

 pulled to pieces by boys, and thoroughly mixed ; and in 

 that state it was weighed, and several separate 100 lb. 

 samples were taken, each being put into a clean cask, in 

 which state the samples were sent to Eothamsted for 

 analysis. In the preparation for analysis, the whole of the 

 100 lb. sample was coarsely ground, then divided into por- 

 tions, one or more of which was finely ground for analysis, 

 and in the sample so prepared the nitrogen was determined 

 by the soda-lime method. It was so determined separately 

 in samples from two of the 100 lb. casks. Deducting the 

 amount of nitrogen in the increase (reckoning it to contain 

 1.27 per cent), there was a deficiency of nitrogen in the dung, 

 compared with that in the food and litter — according to one 



