366 HIGH FARMING, 1837-1874 



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

 Chemistry in its applications to Agriculture and Physiology ^ clearly 

 trace d the re lations between the rLutrition joLplants^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 Hke Johnston and Voelcker, that the Royal 

 Chemical Society of 1845 was in large measure founded by their 

 efiforts. 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) farrq ^s of to-day owe an incalculable 

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

 century, the main principles of agricultural science were estabHshed ; 

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

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

 results of foqcFupon animals in producing meat, milk, or manure 

 were tested and defined. On their work has been built the modem 

 fabric of BritisTi^aQ-riculture . 



With increased knowledge of the wants of plant or animal life 

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

 ficial manure may be roughly distmguished from dung as purchased 

 manures. Of these fertihsing agencies, farmers in 1837 already 

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

 substances as marl, clay, Hme and chalk. But they knew httle 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 smaU quantities, it was in 1850 stUl a 

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

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

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

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

 extensively used. Then- import value rose from £14,395 in 1823 to 

 £254,600 in 1837. As originally broken in small pieces mth 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. 



