112 Phenomenon of Ah^oi'ptlon hi its Relation to Soils 



A more definitely agricultural observation was made by Gazzeri^ 

 who observed that soil and especially clay take up soluble substances 

 which he considered an advantage inasmuch as they may become 

 available later as the plants need them. 



Lambruschini^ suggests a special kind of combination {incorpora- 

 mento) between plant nutrients and soil which was neither so weak as to 

 allow them to be washed out nor yet so strong as to interfere with 

 their absorption by the plant. 



J. P. Bronner^ observed that when river sand was shaken in a bottle 

 with liquid manure both the smell and the colour were largely removed. 

 This was confirmed independently by Huxtable in 1848. Liquid 

 manure filtered through a loamy soil lost smell and colour'*, "it went 

 in manure and came out water." 



The first quantitative experiments were made by H. S. Thompson 

 in 1845^. Soils were mixed with a solution of ammonium sulphate 

 and washed through with water. Analysis showed that considerable 

 quantities of ammonia had disappeared from the solution while 

 calcium and magnesium sulphates were present. The sulphuric acid 

 radical was not absorbed. 



Way^s chemical hypothesis. 



J. T. Way followed up this work^ and extended it to other bases: 

 he showed that ammonia was absorbed from all its salts, so also -were 

 potassium, sodium and magnesium from their salts. Lime was also 

 found to be absorbed from caustic lime and from bicarbonate solutions, 

 but other salts were not tried because Way assumed that it was useless, 

 there being no provision in the soil for the decomposition that would 

 be first necessary. Burning a soil was found to diminish the absorption 

 by about one-half and thoroughly ignited clays showed no absorption 

 whatever. Absorption both of ammonia and potash increased with 

 the strength of the solution but not proportionately. Way supposed 

 the phenomena to be chemical. Matteucci' had already explained 

 the absorption of salts by sand by assuming that the particles 

 of sand have a. greater attraction for salts than they have for water, 



1 1819 Text Book of Manuring, quoted by A. Orth, Landw. Versuchs-Stat. 1873, 16, 56. 

 - Atti dei Georgofili di Firenze. 1830, 9, 330, quoted by F. Sostini, Landw. Versuchs- 

 Stat. )873, 16, 409. 



3 Der Weinbau in Suddeutschland, 1836. * Quoted by Way. 



6 Journ. Roy. Ag. Soc. 1850, 11, 68. « Ibid. 313. 



' Sur les pMnomenes physiques des corps virants, 184.7. 



