122 PHOSPHATIC MANURES [chap. 



book and Lawes' patent, Liebig has generally been 

 regarded as the inventor of superphosphate, and even 

 though Lawes was able to take out a patent for making 

 it from mineral phosphates instead of from bones, the 

 idea is generally set down to Liebig. Owing, however, 

 to actions for infringement of his patent brought by 

 Lawes in 1853, the steps leading up to Lawes' patent 

 are on record, and it is seen that he arrived at the idea 

 of making superphosphate and had tried it experi- 

 mentally on a considerable scale, prior to Liebig's 

 publication. 



In his proof of evidence, Lawes, after describing his 

 fitting up of a laboratory and taking over the Rothamsted 

 estate in 1834, stated that during 1836, 1837, and 1838, 

 he used considerable quantities of bone dust on his 

 farm for the purpose of manuring his turnip crops, and 

 finding that it produced no good effects, and knowing 

 that upon other soils its properties as a manure were 

 very great, he commenced a series of experiments 

 with bones and mineral phosphate of lime decomposed 

 by sulphuric and other acids, applied to the most 

 important agricultural plants of the farm. These 

 experiments were in 1839 conducted on a small scale 

 by plants in pots and by manuring a certain number 

 of plants in a field. The result of these small experi- 

 ments was most remarkable with turnips, and he 

 in 1840 used the superphosphate on half an acre or 

 more of that crop. In 1841 the results were so far 

 advanced that he used about 20 tons of superphosphate. 

 He was prepared to have taken out a patent in 1841, 

 but was persuaded by his friends not to do so, as they 

 objected to his embarking in any mercantile or business 

 occupation (Lawes was then only twenty-six years of 

 age). Lawes further stated that he had not noticed 

 Liebig's recommendation until after the date of his 



