366 HIGH FAEMING, 1837-1874 



owes the origin of its most striking development. In 1840 his 

 Chemistry in its applications to Agriculture and Physiology * clearly 

 traced the relations between the nutrition of plants and the com- 

 position of the soil. In his mineral theory he was proved to be 

 mistaken ; but his book revolutionised the attitude which agri- 

 culturists had maintained towards chemistry. So great was the 

 enthusiasm of country gentlemen for Liebig and his discoveries, as 

 popularised by men like Johnston and Voelcker, that the Royal 

 Chemical Society of 1845 was in large measure founded by their 

 efforts. But if the new agriculture was born in the laboratory of 

 Giessen, it grew into strength at the experimental station of Rotham- 

 sted. To Sir John Lawes and his colleague Sir Henry Gilbert 

 (himself a pupil of Liebig) farmers of to-day owe an incalculable 

 debt. By their experiments, continued for more than half a 

 century, the main principles of agricultural science were established ; 

 the objects, method, and effects of manuring were ascertained ; the 

 scientific bases for the rotation of crops were explained ; and the 

 results of food upon animals in producing meat, milk, or manure 

 were tested and denned. On their work has been built the modern 

 fabric of British agriculture. 



With increased knowledge of the wants of plant or animal lif e 

 came the supply of new means to meet those requirements. Arti- 

 ficial manure may be roughly distinguished from dung as purchased 

 manures. Of these fertilising agencies, farmers in 1837 already 

 knew soot, bones, salt, saltpetre, hoofs and horns, shoddy, and such 

 substances as marl, clay, lime and chalk. But they knew little or 

 nothing of nitrate of soda, of Peruvian guano, of superphosphates, 

 kainit, muriate of potash, rape-dust, sulphate of ammonia, or basic 

 slag. Though nitrate of soda was introduced in 1835, and ex- 

 perimentally employed in small quantities, it was in 1850 still a 

 novelty. The first cargo of Peruvian guano was consigned to a 

 Liverpool merchant in 1835 ; but in 1841 it was still so little known 

 that only 1,700 tons were imported ; six years later (1847) the im- 

 portation amounted to 220,000 tons. Bones were beginning to be 

 extensively used. Their import value rose from 14,395 hi 1823 to 

 254,600 in 1837. As originally broken in small pieces with a 

 hammer, they were slow in producing their effect ; but the rapidity 



1 Organic Chemistry in its applications to Agriculture and Physiology. By 

 Justus Liebig : edited from the manuscript of the author by Lyon Playfair, 

 1840. 



