312 STATE BOARD OF AGRICULTURE. 



The marked increase in soluble content at the higher temperature is un- 

 doubtedly wholly the result of hydrolysis. The high temperature helped 

 the minerals and rocks to decompose and hydrolyze more rapidly. 



The material which went into solution was not analyzed and consequently 

 no discussions will be presented here regarding its composition. This paper 

 will be restricted only to the presentation of the results and to those dis- 

 cussions warranted by the results. The chemical composition of the solu- 

 bility product of the rocks and minerals together with the germain discus- 

 sions and theories will form, it is hoped, the subject matter of a later paper. 



Finally it should be stated that the marked increase in solubility of the 

 rocks and minerals at the higher temperatures throws a new light and fur- 

 nishes a good proof that the large increase in solubility obtained in soils at 

 similar high temperatures, in the previous investigation, was not due wholly 

 to the decomposition of the organic matter content but also to the solubility 

 and hydrolysis of the mineral particles of the soils. 



RATE AND EXTBNiT OF (SOLUBILITY OF HOOKS AND MINERALS TREATED WITH 

 SINGLE SAILT SOLUTIONS AND THEN WASIIIED UNTIL ALL THEIIR (FREE SIOLU- 

 BLE SALTS WERE ELIMINATED. RATIO OF SOLIiD TO DISTILLED WATER 

 WAS 1 TO 0.75 ANID MIXTURES INIAINTAINOSD AT ROOM TBMPERATUiRE. 



In treating soils with salt solutions, then washing them until all the free 

 soluble salts were eliminated and then studying their solubility, it was found 

 that some of the salts greatly increased the rate and extent of solubility of 

 all the different classes of soil except sand, while other salts had very little 

 or no effect upon the solubility. 



Since these results are of considerable theoretical as well as practical in- 

 terest and importance, it was deemed advisable to repeat the investigation 

 also with rocks and minerals. The procedure consisted of mixing about 

 50 grams of powder of rocks or minerals with 250 cc. of N/10 solution of Ca 

 (N03)2, NaNO.,, KNO3, KCl, (NH4)2S04, NaCl, K2SO4, CaH4(P04)2, KH2 

 PO4, and NaC2H302, allowing the mixtures to stand for about 24 hours at 

 room temperature and occasionally stirring and then leaching the soHd ma- 

 terial with distilled water until entirely free from soluble salts. The washed 

 powder was then placed in tubes with a water content of about 1 of solid to 

 0.75 of water and its freezing point depression determined in the usual man- 

 ner. Table 17, 18 and 19 represent typical results obtained. 



