306 RECORD OF THE ROYAL SOCIETY 



Station now also receives a grant from the Board of Agriculture from the 

 Research Fund provided by the Development Commissioners. 



The staff now consists of Director, Chemist, Goldsmiths' Soil Investigator, 

 Bacteriologist, Botanist, Organic Chemist, and two assistants. 



The investigations conducted at Rothamsted may be classified as follows : 



1. Field Experiments. On the original experimental fields the treatment of 

 the plots has in many cases been carried on without break or alteration since 

 1843 and in nearly all cases since 1852. One field is devoted to wheat, a 

 second to barley, a third to root crops, a fourth to leguminous crops, and a 

 fifth to hay. The plan of the experiments has been to divide these fields 

 into plots, each of which receives a different manurial treatment which is 

 repeated year by year, and is so arranged as to provide all the possible variations 

 in the supply of nutriment to the plant. On another field the same crop is 

 not grown continuously, but a rotation of crops is followed. The effect of the 

 manures upon the yield of the crops may be considered to have been settled 

 long ago by these experimental plots, but they continue to yield material for 

 the investigation of the part played by the different constituents of the plant 

 upon its general nutrition, and upon the composition of crops grown under 

 various conditions of nutriment. The soil has also become profoundly altered 

 by the long-continued manurial treatment and affords material which throws 

 light upon the behaviour of other soils of naturally abnormal composition. 

 Other experimental fields have since been added to investigate the residue left 

 by different fertilizers, the effect of green crops and other additions of organic 

 matter to the soil, the value of certain new fertilizers, &c., &c. 



2. Feeding Experiments. During the earlier years of the experiments a 

 number of trials with animals were made at Rothamsted in order to determine 

 the composition of oxen, sheep, and pigs and of their increase in fattening. The 

 relation of food to live weight increase, the relative value in the nitrogenous 

 and non-nitrogenous constituents of food, the relation of nitrogenous food to 

 work, and the sources of fat in the animal's body were determined. These 

 investigations were conducted with all the precision that was then obtainable, 

 and though much of the work has since been superseded by more refined 

 methods of research, they provide many of the fundamental data upon which 

 the theory of animal nutrition was built up. 



3. Investigations on the biology of the soil. Much of the earlier work of the 

 Station was concerned with the question of the sources of nitrogen in vege- 

 tation, and the work of Lawes, Gilbert, and Pugh may be taken to have finally 

 settled the question that the higher plants themselves do not assimilate 

 atmospheric nitrogen. After the discovery by Helreigel and Wilfarth in 1866 

 of the nitrogen-fixing bacteria living in symbiosis on the roots of leguminous 

 plants, much of their work was repeated and verified at Rothamsted, and 

 several confirmations of their observations were obtained upon a field 

 scale. Later work has largely been concerned with the effects of the other 



