T H E J O U R N A L O F I N D r S T R I A L AlVD E N G I N E E R I N G C H E M I S T R I ’
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greater r a t e t h a n t h e other, or of selectively adsorbing t o a n extent easily deterrniried quantitatively. T h e nature of t h e surface of t h e constituents of a soil is such t h a t t h e cation is adsorbed a t a much greater r a t e t h a n t h e anion. T h e presence of bases of t h e soil (Ca, Mg, etc.) in solution. after contact of certain salt solutions with a soil, is not d u e t o a direct chemical reaction of t h e salt i n solution with t h e silicates of t h e soil, b u t t o a seco n d a r y reaction of free acid, resulting from t h e selective adsorption of t h e cation, with t h e mineral cons t i t u e n t s of t h e soil. I n general, t h e smaller t h e soil particles, t h e greater t h e selective adsorption of t h e cation. T h e selective adsorption of t h e cation from a solut i o n of a n electrolyte by a soil increases with t h e c o n centration up t o a certain point, a n d t h e n remains practically constant, t h e surface of t h e soil particles having t a k e n up all t h a t i t is able at this point. At very low concentrations t h e adsorption of t h e cation is practically complete. T h e presence of other. substances m a y or m a y not affect t h e selective adsorption b y a soil. SOILS WAWIWTOW
B U R E A U OF
THE ESTIMATION O F THE LIME REQUIREMENT O F SOILS BY MEANS OF THE HYDROXIDE OF THE ALKALIN EARTHS’ By C . R . ~ I O U L T O K A S D P. F.
TROWDRIDGE
The methods which are in use for estimating t h e acidity of soils are not proving t o be entirely satisfactory a n d this gives rise t o new methods a n d proposals for new methods. T h e old provisional method of t h e Association of Official Agricultural Chemists-shaking o u t t h e acids a n d acid salts with normal potassium nitrate-is open t o criticism both on t h e score of t h e length of time needed for t h e determination a n d because t h e process does not bear a n y direct relation t o t h e practice of liming soils. T h e method in use now, t h a t of Yeitch,? is not open to t h e last objection b u t is t o t h e first-according t o some critics-as i t frequently takes a large number of determinations t o fix t h e lime-absorbing power of t h e soil. I n order t o cut domn t h e length of time involved in t h e Veitch method, Bizzell a n d Lyon3 have proposed a modification of R . Albert’s method. T h e essential points of t h e new method are boiling t h e soil with a n excess of N / I O barium hydroxide solution a n d measuring t h e excess by means of ammonia set free from a d d e d ammonium chloride. The ammonia is distilled off a n d caught in N/IOacid. T h e barium hydroxide is standardized b y direct titration against t h e acid a n d a correction is made for t h e pon-er of t h e soil t o set free ammonia from ammonium chloride. Fifty cc. of barium hydroxide are used a n d 2 j g. of soil. A fixed a m o u n t is consequently always present which m a y greatly exceed t h e a m o u n t needed b y t h e soil or m a y not exceed i t materially. 1 Read before the University of Missouri Section of the American Chemical Society, March 6, 1914. 2 J . Amer. Chem. SOL.,24, 1 120. a THISJOURNAr 6, 101 I .
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Now in t h e Veitch method it is tacitly admitted t h a t a n excess of lime water will cause more calcium oxide t o be absorbed b y t h e soil, a n d so t h e least amount t h a t will show a n excess is used as t h e lime requirement. Some of t h e effects of this mass reaction have been studied i n t h e laboratories here in t h e past when a n a t t e m p t was made t o modify t h e Veitch method by titrating back t h e excess of lime water. T h e lime requirement was determined by t h e Veitch method. T h e n t o fresh samples of soil various amounts of lime watek were added, as 5 , I O , 15, 20, 2 j a n d 30 cc. T h u s in some cases there was a n excess of lime water amounting t o I O cc. a n d in other cases t h e same deficiency. It was found t h a t when evaporating t h e solution with phenolphthalein a considerable deficiency required b u t a very few cc. more lime water t o give a color t h a n did a slight deficiency. Likewise, a great excess required b u t little more acid t o neutralize t h a n did a small excess. I n some cases b u t z or 4 drops of acid or lime water represented a difference of I O cc. of lime water. An a t t e m p t was made t o determine what ingredients of t h e soil were using this excess of lime water. I t was found t h a t thoroughly washed a n d ignited sea sand when used in place of soil with t h e Veitch method used up considerable lime water a s shown by t h e few drops of tenth-normal acid needed t o destroy t h e color when 5 j I O , or even 1 5 cc. of lime water were used. Sand treated once with lime water would use up considerable amounts of lime water added subsequently after decanting a n d washing free of t h e previous addition. Enough of this unpublished work has been quoted t o show t h a t in this laboratory i t was considered t o be demonstrated t h a t a n excess of calcium hydroxide increased t h e lime requirements of soils. It was t h e results of this work t h a t led us t o investigate t h e work of Bizzell a n d Lyon t o determine if barium hydroxide acted a n y differently t h a n did calcium hydroxide. Lime requirements were determined on a sample of soil by t h e method of Bizzell a n d Lyon, using jo and I O O cc. of barium hydroxide. K O blanks were r u n on t h e soil as t h e y would not effect t h e results found. Table I shows t h e results of this soil. T h e Veitch method gave a lime requirement of 1 0 , 4 2 0 pounds of lime per acre foot. T h e Bizzell a n d Lyon method accurately followed gave only 8 j per cent G. soil No. 7b 25
25 25 25 25 25 25 25
TABLEI Cc. Cc. Ba(OH)1 G. Parts per Pounds per acre foot CaO million B a ( O H ) % used b y soil 8,350 0.06958 2783 30.40 50 9,036 0,07530 3012 50 32.90 50 27.29 0,06246 2498 7,495 5494 16,481 60.00 0,13734 100 5415 16,244 59.14 0,13537 100 16,811 0.14008 5604 61.20 100 896 2,688 9.80 0,02243 35 580 1,741 6.34 0,01451 35
of this a m o u n t , varying from 7 , j o o t o 9,000 lbs. When double t h e a m o u n t of barium hydroxide called for by t h e Bizzell a n d Lyon method was used t h e lime requirement was increased t o over 16,000 Ibs., t h u s doubling t h e lime requirement. Since about 30 cc. of hydroxide were sufficient t o satisfy t h e soil when t h e determination was made as directed b y t h e Bizzell a n d Lyon method, duplicate samples were r u n , using 3 j cc. of hydroxide. I n this
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case t h e lime requirement fell t o about one-fourth of t h e first value. The method was further tested with a different soil a n d b y different chemists, using various amounts of barium hydroxide water, t h e treatment otherwise being t h e same as in t h e Bizzell a n d Lyon method. Table I1 shows t h e results on this second soil. A blank was r u n on this soil in order t o be able t o make a better comparison with t h e Veitch method. Enough ammonia was freed b y t h e soil t o represent 1.0; cc. of Ba(OH)2 solution a n d this correction was made on t h e following determinations: TABLE11 G. soil iYo. 3b
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
Cc. Cc. Ba(OH)z G . Parts per Ba(OH)> used by soil CaO million CHEMISTA 00 1 . 0 5 blank .. 00 5 3.16 0,00858 343 5 3.49 0,00947 379 25 11.18 0,03035 1214 25 8.86 0,02405 962 50 14.11 0.03811 1523 50 10.41 0.02831 1130 CHEMIST B .~ 50 13.41 0,03641 1456 50 12.59 0.03418 1367 75 15.15 0.04113 1645 75 15.50 0.04208 1683 9.23 0.02506 100 1002 16.66 0,04523 100 1809 21.05 0.05715 100 2286 100 22.15 0,06014 2406
Pounds per acre foot
A:;]
.. 1,030 1,136 3,642 2,866 4,597 3,391 4,369 4,102
4,936 5,050 3,007 5,428 6.858 7:217
T h e Veitch method gave 6 , 8 5 j lbs. of lime per acre foot, whereas t h e method of Bizzell a n d Lyon gave various amounts according t o t h e a m o u n t of barium hydroxide used. I n some cases t h e lime requirement found was n o t a t all proportional t o t h e barium hydroxide used b u t in general i t increased as t h e hydroxide increased a n d frequently i n strict proportion t o t h e hydroxide. I n t h e third table t h e following variation of t h e method was used. T h e first t w o duplicates were treated as per t h e regular Bizzell a n d Lyon method until t h e digestion was complete when t h e soils were decanted upon a filter a n d washed three times b y decantation with hot water. These washings were distilled with ammonium chloride as usual with t h e result t h a t from 3 8 t o 39 cc. of t h e 5 0 cc. of hydroxide added h a d n o t been washed out of t h e soil. T h e soil residue was again treated with 50 cc. of lime water as above a n d this time a further 3 j t o 36 cc. of t h e second j o cc. of hydroxide remained with t h e soil. T h e soil residue holding about 7 5 cc. of barium hydroxide was t h e n distilled a n d all b u t 13.90 cc. recovered b y distillation, t h u s making t h e lime requirem e n t comparable t o t h a t found when 7 j cc. h a d been used in Table 11. TABLEI11 Soil 3b 1st washing.. . . . . . 1st washing. . . . . . . 2nd washing.. . . . . 2nd washing.. , . , .
Soil . . . . . . . . . . . . . . Soil . . . . . . . . . . . . . .
Cc. Cc. Ba(OH)? G. Ba(0H)z used b y so11 CaO 50 39.30 .. 50 38.21 .. 50 35.59 .. 50 36.04 residue 15.34 0.04i65 residue 13.90 0.03774
Pounds Parts per per million acre foot
..
..
.. 1666 1510
.. , .
.. 4,998 4,529
I n Table I1 a n d all following work t h e barium hydroxide solutions used were standardized not b y direct titration b u t by distillation exactly a s in t h e determination b u t omitting t h e soil. I t seems t o t h e authors t h a t this is t h e only logical method of standardization,
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for t h e n conditions are all alike in all cases. Any effect t h a t boiling in t h e flasks has upon t h e barium hydroxide will have a n influence upon both t h e standardization a n d t h e determination. A4nextremely acid soil was selected for further study. I n this case as t h e barium hydroxide was increased, t h e water added before distillation was decreased b y t h e same volume so t h a t t h e same amount of distillate would represent t h e same p a r t of t h e whole. Otherwise t h e determination was carried o u t as usual. TABLEIV G. soil 14-4-16 25 25
25 25 25 25 25 25
Cc. Cc. Ba(OH)z Ba(OH)* by soil 10 -2.20 -2.09 10 25 0.60 25 4.46 50 11.43 50 10.86 100 30.14 100 Lost
G . CaO
..
0.00i20 0.00892 0.02286 0.02172 0.06028
..
Parts per Pounds per million acre foot
..
..
.. 48 357 914 869 2411
..
i44 1,071 2,742 2,607 ,233 I
..
Table I V gives t h e results on this soil. The Treitch method gave a lime requirement of I j , 2 jo lbs. per acre foot. When I O cc. of hydroxide were used more ammonia was recovered in t h e distillate t h a n corresponded H a d a blank been run on this soil t o t h e hydroxide. i t might account for t h e difference. The sample of soil was exhausted, a n d so no blank could be run. T h e lime requirement increases much more rapidly t h a n does t h e barium hydroxide used, b u t not even with I O O cc. does t h e lime requirement reach more t h a n a third of t h a t found b y t h e Veitch method. Exactly similar results were obtained from another strongly acid soil. The Veitch method gave 18,630 lbs. of lime needed per acre foot a n d t h e Bizzell a n d Lyon method gave 681 a n d 1,032 lbs. per acre foot. A soil which was alkaline b y t h e Veitch method a t n o cc. of lime water was next studied. The blank b y t h e Bizzell a n d Lyon method was 56.05 cc. of acid used b y t h e ammonia freed by t h e soil. Table V gives t h e results of this work. I n all cases t h e soil showed a lime requirement, t h a t is, in no case was sufficient ammonia recovered in t h e distillate t o represent t h e power of G. soil 14-1-109 25 25 25 25 25 25 25 25 25 25
TABLEV Cc. Cc. Ba(0H)a G. Ba(0H)Z used b y soil CaO 10 10 25 25 50 50 50 ( b ) 50 ( b ) 100 100
Parts per million 1,164 1,664 1,722 1,326 2,261 1,980 821 1,133 3,100 3,342
Pounds per acre foot 3,492 4,992 5,166 3,978 6,783 5,940 2,463 3,399 9,300 10,026
( a ) The cc. of Ba(OH)? used by the soil is expressed in terms of a tenthnormal acid which is weaker than the Ba(0H)p solution. ( b ) These two determinations were run by a chemist other than the on e making the others.
both t h e Ba(OH)2 and t h e soil t o free ammonia from ammonium chloride. Consequently when t h e soil blank was accounted for there remained some of t h e B a ( O H ) ? which was held back b y t h e soil. So even with a n alkaline soil some of t h e added hydroxide solution will be held back on distillation a n d will not free a m m o n i a from ammonium chloride. T h e socalled lime requirement we find b y this method is considerably greater for this alkaline soil t h a n i t was for t h e other strongly acid soils. T h e behavior of some of t h e determinations above
Oct., 1914
T H E J O U R N A L O F I N D C ' S T R I A L A N D ENGILVEERING C H E M I S T R Y
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eastern p a r t of Pennsylvania a n d is included between t h e parallels of 40' 30' a n d 40' 45' a n d t h e meridians 7 5 ' I j' a n d 7 5 ' 30' west, covering a n area of about 2 2 6 square miles. I t lies in Lehigh a n d Northampton counties with its southeastern corner in Bucks county. Most of t h e rocks in this section are more or less crystalline, being either sediments which have changed t o slates, quartzites, schists a n d gneisses by varying degrees of metamorphism, or igneous rocks, such as granite a n d diabase which have solidified from a molten magma. T h e basal complex1 of t h e region consists chiefly of gneisses a n d schists. Following t h e formation of these deep-seated rocks occurred a long period of erosion, after which a portion of t h e land was submerged beneath t h e sea, a n d s a n d , gravel, mud a n d TABLEVI so11 Time Cc. B a ( 0 H ) z G. Parts per Pounds per calcareous ooze were laid down in t h e form of marine 14-4-16 Minutes. used bv soil CaO million acre foot sediments. I n these deposits, now hardened t o sand1,946 5,838 20 24.32 0.04864 25 g. 1,063 3,189 0.02658 13.29 and stone, conglomerate, shale a n d limestone, are t o be 590 1,770 7.38 0.01476 50 cc. 318 954 3.97 0.00794 seen fragments of waste from t h e igneous a n d metaBa(OHh 63 189 0.00158 0.79 J 90 morphic rocks of t h e adjacent land. Those s t r a t a are 20 2,870 8,610 0.07172 35.86 40 1,705 5,115 0,04262 21.31 not continuous sheets, for portions of t h e sea bottom 1,060 3,180 60 0,02648 13.24 75 6.99 560 1,680 0.01398 were, a t times, uplifted into land a n d t h e sediments 3.12 250 750 0,00624 90 14-1-109 0.10833 4,333 12,999 t h a t h a d been deposited were subjected t o erosion, 39.90 2,639 7,919 0.06597 25 g. soil 24.30 while other portions were still submerged. The sea and 0.037466 1,499 4,497 13.80 1 8 7.41 50 cc. 805 2,415 0.02012 in which these sediments were laid down was a body 503 1,509 4.63 0.01257 Ba(OH)z 20 0,092005 3,680 11,040 33.89 of water occupying t h e interior of t h e American con0.04447 1,779 5,337 35 16.38 7.46 tinent a n d its eastern shore oscillated back a n d forth 810 2,430 50 0.020254 0.42 0.001140 46 138 65 across what is known as t h e Appalachian province. in 29 87 0.27 80 0.000733 t h e eastern part of which the Allentown Quadrangle is T h e figures shown are for t h e t o t a l time given. As more ammonia was freed t h e barium hydroxide held situated. Submergence began a t least as early as t h e by t h e soil was decreased until a t t h e e n d of 80 or 90 Cambrian, probably as early as t h e Algonkian, a n d minutes i t h a d been decreased t o a n insignificant continued t o t h e close of Carboniferous Time. Several great cycles of sedimentation are recorded a m o u n t which in t h e acid soil might have been reduced t o nothing if a blank h a d been run on this soil. T h e in t h e rocks of this region. The first sedimentary t o t a l volume of distillate was a b o u t 450 cc. a n d was r o cks-c on gl o mer a t e s , sa n ds t o ne s an d sh a1e s- we re distributed among t h e aliquots a b o u t in proportion laid down early in Cambrian time along the eastern border of t h e interior sea as it encroached on t h e sinking t o t h e time of each separate collection. A brief survey of t h e d a t a presented seems t o es- land. As the land was worn down and erosion became tablish t h e fact t h a t t h e lime requirement found b y t h e less active, t h e sediments became finer until in late method of Bizzell a n d Lyon is proportionate t o t h e Cambrian time very little mechanical detritus reached barium hydroxide used a n d not t o t h e acidity of t h e t h e sea a n d t h e deposits were mainly carbonates of soil. T h e lime requirement is considerably lower t h a n lime and magnesia. This condition continued into when t h e Veitch method is used. T h e lime require- Ordovician time with no marked break in sedimenment varies with t h e length of time of t h e distillation tation. During Silurian time, however, great beds a n d volume of distillate until a zero lime requirement of quartz sand a n d pebbles were laid down over t h e limestones of t h e preceding age. The Carboniferous is obtained. No consideration of t h e speed of a method is worth began with t h e formation of marine deposits, in large while when i t s performance is such as is indicated b y p a r t limestone, which, in t h e southern p a r t of t h e this s t u d y . However, t h e experience in this laboratory province, are of great thickness. T h e sedimentary rocks of t h e Quadrangle are those shows t h a t a t least as much attention on t h e p a r t of laid down in pre-Cambrian, Cambrian a n d Ordovician t h e operator is needed for t h e method of Bizzell a n d Lyon as for t h e Yeitch method. T h e time consumed time. The pre-Cambrian formations of t h e Quadrangle are in evaporating, a n d so forth, does not enter i n t o conknown as t h e Shimer graphite schist a n d t h e Franklin sideration when a chemist has other work in progress. limestone a n d are of no importance in this investigation. DEPARTMENT O F AGRICULTURAL CHEMISTRY T h e Cambrian formations are known as t h e HardyUNIVERSITY OF MISSOL-RI, COLUHBIA -ston quartzite, t h e Leithsville limestone a n d t h e BllenA STUDY OF THE DOLOMITIC LIMESTONES OF THE town limestone. ALLENTOWN QUADRANGLE Of t h e Ordovician formations, t h e only one of imBy SAMUELH SALISBURY, J R , AND GEORGEC. BECK portance t o us is t h e Coplay limestone. was such a s t o raise t h e question whether t h e lime requirement could not be varied b y t h e length of distillation of t h e ammonia. Some of t h e samples a t t h e end of 2 0 minutes h a d used up all t h e hydrochloric acid in t h e receiving flask, showing a n alkaline reaction. Five cc. more of acid were added a n d again t h e solution in t h e flask turned alkaline a t t h e end of 2 5 minutes, necessitating a second addition of acid which was largely used up. To f u r t h e r test this continued freeing of ammonia, some determinations were made a n d t h e distillate was caught in different receiving flasks b y means of a n a d a p t e r having a two-way stopcock between condenser a n d receiving flask. About 450 cc. of water were used a n d a n 800 cc. Kjeldahl. Table V I gives results on both t h e acid and alkaline soil.
1 ;!
Received June 16, 1914
T h e Allentown Quadrangle is located in t h e extreme
1 G. W. Stose, ~ ~ e r c e r s b u r g - C h a m b e r s b u rFolio, g Geofogiral Allac of the United Stales, No 170.
