I n t h e course of some recent studies of Iowa soils, it became necessary t o ascertain their reaction or need of lime a n d inasmuch as previous tests. h a d been carried out b y t h e Veitch method a n d comparisons h a d indicated it t o be quite satisfactory, it was decided t o use t h e same method in this work. I t mas soon noted, however, t h a t t h e results which were being secured were in most cases t h e direct opposite of those obtained b y previous tests of samples of t h e same

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... oil types taken from approximately t h e same localities. For instance, practically all t h e samples from Bremer County were found t o be basic in reaction, whereas previous tests of t h e soils of t h a t county h a d shown t h a t almost all were acid. The test had been carried out in exactly t h e same way in both cases. El-ery step in t h e operation a n d every detail in manipulation was carefully checked b u t no difficulties were encountered with t h e method. T h e soil samples were taken in t h e same way, a n d both lots were chosen as representative of soil types. Furthermore t h e y were t a k e n b y t h e s a m e man so t h a t there was every reason t o expect t h a t t h e reaction of t h e samples would be very similar. d t least i t w a s felt t h a t t h e same tendency of t h e soils t o react acid or basic should h a r e been observed with both lots of samples. There was only one difference in t h e two lots of samples: t h e first was secured especially for acidity tests a n d t h e soils were tested in a n unground condition: while t h e second lot was obtained in connection with t h e soil survey of t h e county a n d t h e samples were finely ground before being tested. This grinding was necessary in order t o prepare t h e samples for t h e chemical analysis which was t o be made of t h e soils. I t seemed probable, therefore, t h a t t h e difference in t h e reaction of t h e two lots of samples was due t o t h e grinding. The questions then arose-Does t h e grinding of soils increase their basicity according t o t h e T'eitch t e s t ? If so: what causes t h e production of a basic reaction? I n a critical study of t h e method which he devised. T-eitch' observed t h a t t h e length of time t h e treated a n d dried soil was allowed t o stand in contact with water h a d a considerable effect on t h e apparent acidity as determined b y t h e method. He noted t h a t when solution was allowed t o go on from qS t o i z hours t h e pink color with phenolphthalein was developed with less added lime water t h a n when t h e solution was allowed t o stand 16 hours or less. T h e increase in basicity was so pronounced in some cases t h a t soils which were acid when allowed t o s t a n d 16 hours gal-e a basic reaction upon standing 24 t o 48 hours longer. I n discussing t h e cause of this increase in basicity, T'eitch concluded t h a t it was not due t o t h e failure of 1 J . .am. Chem. SOC., 26, 637. C a C 0 3 t o go into solution in partially carbonated water in t h e shorter time a n d he suggested t h a t t h e cause might probably be found in t h e slower solubility a n d hydrolyzation of t h e neutral lime compounds t h a t are formed with t h e added lime water or t o t h e solution a n d hydrolyzation of neutral compounds already present in t h e soil. He called attention t o t h e fact t h a t in 1S4j, Rogers Brothers' showed t h a t many of t h e common minerals, "particularly t h e zeolites a n d feldspars when reduced t o fine powder a n d treated with carbon dioxide-free water, gave a more or less strong reaction with phenolphthalein." Since t h a t time t h e solution of minerals in water has been studied b y a large number of investigators* and it has come t o be quite generally accepted t h a t t h e observations of Rogers Brothers were correct. 1Iinerals are known t o be present in soils in considerable amounts, and their solution t o proceed very slowly. T h e development of a basic reaction when soils are subjected t o long standing in t h e lime-water test may? therefore, be due t o t h e solution of silicates. T h e directions for carrying out t h e Yeitch test based on these experiments by t h e author of t h e method and numerous other investigators prescribe, therefore, t h a t t h e samples shall stand only over night in contact with t h e water. I n this way i t is deemed t h a t there is not sufficient time for t h e solution of a n y of t h e silicates in t h e soil t o occur a n d make t h e test basic. I t seemed probable t h a t the same reason which T'eitch advanced for t h e development of a basic reaction b y soil upon long standing with water might account for t h e production of basicity in a ground soil, t h a t is, t h e solution and hydrolyzation of silicates. As t h e point raised is of some interest a n d t h e question of t h e condition in which t h e soil should be when tested for acidity is of considerable importance, some tests have been carried out along this line. X o previous investigations, as far as t h e authors are aware. have specified what t h e condition of t h e soil should be when t h e 1-eitch test is applied, a n d these results indicate t h a t it is of importance because of t h e development of a basic reaction when soils are ground before being tested. In order t o determine definitely n7hetht.r grinding occasioned a development of basicity in soils. four samples of soil from Bremer County were secured a n d each sample was thoroughly mixed and divided into four portions. T h e first portion was unground and unsieved, t h e second was put through a 2 0 mesh siei-e, t h e third through a 40 mesh sie\-e a n d the fourth portion through a n 80 mesh sieve: grinding was done wherever necessary. I n t h e case of t h e Bremer fine sandy loam a n d t h e Carrington sandy loam very little grinding was necessary t o p u t t h e soils through t h e 20 mesh sieve b u t considerable grinding was needed t o p u t t h e m I A m .