

UNIVERSITY OF) CALIFORNIA AGRICULTURAL EXPERIMENT STATION 



COLLEGE OF AGRICULTURE ^ou^ons^^J^o^^a D,ECTOR 



BERKELEY c. VAN NORMAN, VICE-DIRECTOR AND DEAN 



CIRCULAR No. Ill 



REVISED 

 OCTOBER, 1917 



THE USE OF LIME AND 



ON CALIFORNIA SOILS . lv OP SJ " / 



BY CHAS. B. LIPMAN 



Much confusion exists in the popular mind with reference to the 

 actual nature 'of lime and its use. The following brief statements 

 are intended to clear up difficulties which exist and to reply to fre- 

 quently recurring questions on the important subjects of lime and 

 its use, and gypsum and its use. 



THE NATURE AND FUNCTIONS OF LIME 



The term "lime," as we may employ it in the agricultural sense, 

 includes the following materials : Burnt lime or quicklime (oxide of 

 calcium), hydrated or waterslaked lime (hydrate of calcium), ground 

 limestone (carbonate of calcium). In addition a form of lime known 

 as air-slaked lime is available, which may approach in chemical com- 

 position the ground limestone. Air-slaked lime results from the 

 action of carbonic acid gas on water-slaked lime or from that of water 

 and carbonic acid gas on burnt lime or quicklime. Either burnt lime, 

 or hydrated or water-slaked lime will change to air-slaked lime if 

 allowed to lie in the open air for a long enough period of time. 

 The action is rather slow in the center of the pile of lime, however, 

 and thus it may frequently happen that so-called air-slaked lime may 

 consist of a considerable proportion of quicklime or of water-slaked 

 lime, as the case may be, and found to be not as fully carbonated as 

 one would expect. The total amount of air-slaked lime of the variety 

 just described, which is available on the market is very smalL . A 

 form of air-slaked lime is available on our market^, however, in con- 

 siderable quantities today, which results from the processes of sugar 

 refining, and which in chemical composition is very much more like 



