JOHm OF AGRICClTIIAl RESEARCH 



Vol. XVI Washington, D. C, March io, 1919 No. 10 



SOLUBILITY OF LIME, MAGNESIA, AND POTASH IN 

 SUCH MINERALS AS EPIDOTE, CHRYSOLITE, AND 

 MUSCOVITE, ESPECIALLY IN REGARD TO SOIL 

 RELATIONSHIPS 



By R. F. Gardiner 

 Soil Scientist, Bureau of Soils, United States Department of Agriculture 



While experiments relating to the solubility of lime, magnesia, and 

 potash in various silicates have frequently been carried out,^ especially 

 with those minerals in contact with a saturated solution of carbon dioxid, 

 there seems to have been relatively little work done upon the degree of 

 action of soil extracts upon the lime, magnesia, and potash present in 

 epidote, chrysolite, and muscovite, all of which minerals are commonly 

 found in soils. 



A knowledge of the solubility of the lime, magnesia, and potash in 

 epidote, chrysolite, and muscovite would also be a means of roughly 

 estimating their availability, so far as a soil extract is concerned, for the 

 soil solution is acting continuously upon the neighboring minerals. 



The individual factors involved in the experimental work were as 

 follows: The production of a very slightly acid soil extract by the addi- 

 tion of 500 cc. of distilled water every 24 hours to an acid soil from 

 Auxvasse, Missouri, and the extracts combined. The combined ex- 

 tracts were then analyzed. The next steps were the grinding of selected 

 samples of epidote, chrysolite, and muscovite to pass a screen of 100 

 meshes to the inch and the analysis of the finely ground minerals. 

 Then two 25 cc. blank solutions of the soil extracts, together with 24 

 nursing bottles with 25 cc. of the soil extract in each in contact with from 

 o.i to i.ogm. of epidote, 0.1 to i.ogm. of chrysolite, and fromo.i too.4gm. 

 of muscovite, were placed in a thermostat and kept at a temperature of 

 25° C. for a period of two months. At the end of the period the soluble 

 material filtered from the minerals by Pasteur-Chamberland filters was 

 analyzed, and a correction made for the composite blank solutions, for 

 lime, magnesia, and potash with the results given in Table I. Prelimi- 

 nary to the results given in Table I, an analysis was made of the water 



• Storer says that silicates of alumina, lime, magnesia, and potash are "decomposed and dissolved to a 

 certain extent by carbonic acid-water, and also even by pure water." (Storer, Frank H. first out- 

 UNEs OF A dictionary of solubilities of chemical substances, p. 549. SSI- Cambridjie, [Mass.], 1864.) 



Journal of Agricultural Research, Vol. XVI, No. 10 



Washington, D. C. Mar. 10, 1919 



m (259) Key No. H-6 



