996
T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y Vol.
IO,
No.
12
ARE USED
................ ...............
IO cc. Caa(POa)z,
Cc.
Cc. Cc.
500 500 500 500 500 500
500 500 485 475 478 475
50 50 50 50 50 50
Gram
Gram
0.0304 0.0611 0.0279 0.0537 0.0279 0.0549
0.0304 0.0611 0.0288 0.0565 0.0292 0.0578
Gram
....
0:0066 0.0020 0.0009 0.0022
Gram
..... ...
0.0002 0.0009 0.0006 0.0008
Gram
0:OObl 0.0001 0.0002 0.0003
Gram
Gram
0:01%4 0.0007 0.0004 0.0005
0.0304 0.0611 0.0285 0.0557 0,0288 0.0571
....
Gram
Gram
Gram
0.0017 0.0012 0.0016
0.0304 0.0611 0.0292 0.0574 0.0300 0.0587
0.0311 0.0621 0.0311 0.0621 0.0311 0.0621
.... .... 0.0007
Gram Gram 0.07
0.07
0.19 0.47 0.11 0.34
0.26 0.64 0.23 0.50
o.io o i i o
500
475
50
0.0263
0.0277
0.0006
0.0019
0.0003
0.0005
0,0269
0.0027
0.0296
0.0311
0.15
0.42
500
468
50
0.0521
0.0557
0.0006
0.0008
0.0002
0.0005
0.1529
0.0015
0.0544
0.0621
0.77
0.92
Solution 4 contained potassium chloride, iron, tricalcium phosphate, and aluminum sulfate equivalent t o 5 .gg per cent KzO, 10.31 per cent FezOs, I O per cent Cas(PO&, and I O per cent AlrOs.
These solutions were intentionally exaggerated as t o content of impurities and were analyzed in the same manner as already described for the mixed fertilizers. The determinations shown are the first and only results obtained, emphasizing the ease and accuracy of the method of determination. Table I V shows t h a t the precipitate formed b y the addition of ammonia and ammonium oxalate in the flask considerably diminishes the volume when tricalcium phosphate, ferric hydroxide, or a combination of the two are present. I t further shows t h a t some of the retained potash may be washed out with hot water, but t h a t a considerable amount cannot be removed in this manner. Three successive reprecipitations in large volumes, dissolving the precipit a t e each time in hydrochloric acid and reprecipitating with ammonia, show a small amount of potash recovered. I n the case of the potash, a larger amount was recovered in the third reprecipitation t h a n in the second, indicating t h a t a continuation of these reprecipitations might have shown a greater recovery. A comparison of the theoretical potash content with the amount determined shows slightly more occlusion by the amount of iron used than by the tricalcium phosphate, although the latter showed marked properties in this respect; a combination of the two increases the occlusion. CONCLUSlONS
This work proves t h a t there are two sources of error in the Lindo-Gladding method for determining potash: ( I ) t h e volume of the solution is decreased by the bulk of the precipitate formed on addition of ammonia and ammonium oxalate, which makes a plus error, and ( 2 ) the potash in solution is decreased by occlusion of potash by the heavy gelatinous precipit a t e formed. These two sources of error are partially compensating. I t is impossible t o wash o u t with hot water the potash occluded within the precipitate. The occluded potash may be separated t o a certain extent by repeatedly dissolving the precipitate in hydrochloric acid, diluting t o a large volume, precipitating with ammonia and ammonium oxalate, filter-
ing, and determining potash in t h e filtrates and washings. The use of pure salts for making known strength solutions shows t h a t both iron and calcium phosphate, when precipitated with ammonia, occlude potash, and t h a t a combination of the two is even more effective in producing occlusion. L A B O R A T OOF R YTHE SOUTHCAROLINA EXPERIMENT STATION S. C. CLBMSON COLLEOB,
DETERMINATION OF THE VALUE OF AGRICULTURAL LIME By S. D. CONNER Received M a y 23, 1918
Three analytical methods are commonly used f o r determining the value of agricultural limes and limestones. I-The making of a n analysis and calculating the value of the material from the percentages of calcium and magnesium found. 2-The determination of carbon dioxide and calculating the value of the limestone from this alone. Quite a number of devices have been introduced in late years t o make it possible t o carry out this estimation quickly and easily. 3-The determination of t h e acid-neutralizing power of the material b y digesting in a slight excess of standard acid, then titrating the excess acid with standard alkali. The titration method has been used during the past five years on many samples of limestone, burned lime, hydrated lime, gas lime, marl, shells, various by-products from beet sugar factories, acetylene generators, refuse from water-softening plants, etc. I t has in all cases been found very accurate and rapid. TITRATION METHOD
The procedure used by the author follows: Pulverize a sample of the stone in an iron mortar until it feels free from grit. Weigh out exactly one gram and place it in a 2 j o cc. beaker, cover with a watch glass and introduce, a t the lip, without removing the cover, 6 cc. of 4 N hydrochloric acid. When the effervescence nearly ceases add 7j cc. distilled water and boil gently in the covered beaker for 1 0 or I j min., in which time the reaction is completed and the carbon dioxide driven off. Cool and titrate to faint pink with N I P sodium hydroxide, using phenolphthalein as indicator.
The results are calculated t o .the equivalent of calcium carbonate and the acid-neutralizing power
Dec.,
1918
T H E JOL'RArAL O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
of t h e limestone is reported in terms of per cent of calcium carbonate. With pure calcium carbonate a t one hundred, some magnesites and dolomites will show a calcium carbonate equivalent of over one hundred. P R E C A U T I O N S T O B E OBSERVED-It is best t o COO1 the solution before titrating, as phenolphthalein is more sensitive in the cold and also because some limestones contain enough soluble iron t o destroy the indicator. This destructive action is very much greater in a hot solution t h a n it is in a cold one. Solutions which give much ferrous hydroxide on neutralization should be titrated slowly and with the addition of new portions of indicator when nearing t h e end-point. With materials high in magnesium, such as magnesite, i t is advisable t o titrate slowly, as the color change of the indicator is slow. If t h e end-point is passed the solution can be titrated back with astandard acid, By running a blank determination on t h e acid i t will be found t h a t boiling does not cause appreciable loss of acid and does not materially affect the determination.
997
containing 0.73 per cent humus before and 0.70 per cent humus after extraction with acid. These soils were selected because Soil W represents a type predominating in organic acidity and Soil D represents a typical inorganic acid soil with very little organic acidity. I n view of the fact t h a t the results obtained on the two types of soil agree very closely it seems logical t o conclude t h a t like results would be obtained on other soils of an equal degree of acidity. Both soils used are very acid and it is quite probable t h a t somewhat different relative results would be obtained if similar tests were conducted with soils of slight or medium acidity.
POT TESTS
Pot tests on two types of acid soil with several calcium and magnesium stones have been conducted. The crops grown were wheat and red clover. Each treatment was conducted in duplicate in paraffined galvanized iron pots g1/4 in. in diameter and 1 1 in. deep. The pots were subwatered by means of a tube connected t o an arch a t the bottom of the pot. Both the wheat and clover were sown February 2 7 , 1917. After germination t h e seedlings were thinned so t h a t only three plants of wheat and three of clover were left per pot. The pots were weighed a t regular intervals and kept a t one-half t h e water holding capacity of the soils throughout the experiment. The wheat was harvested September I, 1917, and t h e clover January 15, 1918.
FIG. 1-POT TESTSWITH W H E A T AND CLOVER ON ACID BLACKS A N D Y SOILTREATED WITH VARIOUSMINERALS.SEE TABLE I1
Two radically different types of acid soils were used in the tests. Soil W is a peaty sand high in organic matter, containing j.7 2 per cent ammonia-soluble humus before extracting with dilute HC1 and 4.96 per cent humus after extracting with acid. Soil D is a yellow silty clay very low in organic matter,
FIG. Z-POT TESTSWITH WHEATAND CLOVERON ACID YELLOW SILTY C L A Y SOIL TREATED WITH VARIOUS MINERALS. S E E TABLE11
In addition t o pure cleavable calcite (calcium carbonate) the following high-grade minerals, pulverized t o pass a one-half millimeter sieve, were used t o test their values in neutralizing soil acidity and increasing crop growth: Wollastonite (calcium silicate), raw rock phosphate (commercial), gypsum (calcium sulfate), dolomite (calcium magnesium carbonate) , magnesite (magnesium carbonate), enstatite (magnesium silicate) , serpentine (magnesium silicate). The comparative test of the different minerals was made in addition t o a basic application of nitrogen, phosphate, and potash fertilizer. This basic fertilizer was applied a t the following rates per million pounds soil: 9 1 lbs. ammonium nitrate, one-third applied a t the start and the remainder a t intervals of two months; 73 lbs. di-ammonium phosphate all at, the s t a r t ; I O O lbs. di-potassium phosphate all a t the start. The basic fertilizer was prepared from neutral chemicals of t h e highest purity free from calcium or magnesium. I t is approximately equivalent t o a field application of 1000 lbs. per acre of a formula conand 8 per cent taining 6 per cent N,8 per cent PzO~, K20. All treatments were thoroughly mixed with the proper weight of soil before the pots were filled. A t the end of the experiment soil samples from each pot were taken the full depth of the pots by means of a soil tube and tested for acidity. Table I shows the CaO, MgO, and COz in the minerals used, also the calculated calcium carbonate equivalent as determined by three methods.
T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
998
MINERAL Calcite. Wollastonite. Rock Phosphate.. Gypsum. Dolomite Magnesite Enstatite Serpentine
................... .............. .......... .................. .................. ................. .................. .................
Theoretical Formula CaCOs CaSiOs Caa(P0i)z CaSOi.2HzO CaMg(C0a)z MgCOa MgSiOa Mg3Siz07.2HzO
TABLEI-ANALYSIS OF MINERALSUSED -PER CENT SOLUBLE IN DILUTE HClCaO Per cent 56.00 38.65 25.65 33.25 30.40 0.12 0.08 0.05
Per cent Mgo 0.10 0.12 0.20 0.22 20.50 46.20 0.28 19.11
COz Per cent 43.65 0.13 1.20 0.22 47.04 51.00 0.16 0.25
CaCOa By CaO and MgO Per cent 100.1 68.8 46.3 59.3 105.6 115.6 0.8 47.9
Vol.
IO, No. I P
EQUIVALENBy COS Per cent 99.2 0.3 2.7 0.5 106.9 115'.9 0.4 0.6
B y Titration Per cent 99.5 68.6 12.3 0.0 106.0 116.2 0.3 45.4
TABLB11-SOIL ACIDITYAND CROP RETURNSWITH DIFFERENTTREATMENTS IN POT TEST ACIDITYOF SOIL AFTER CROPPING) AVERAGE YIELDS PER POT Wanatah soil Dupont soil Wanatah soil Dupont soil Pot Wheat Clover H J Wheat Clover J3 H3 TREATMENTI NO. Lbs. Lbs. Grams Grams Lbs. Lbs. Grams Grams 1 None 1800 6750 2460 4000 0.5 0.0 0.7 0.0 Calcite 2 80 3500 20 750 17.0 9.5 10.5 11.0 No Mineral 3 1760 6750 2800 4125 1.5 3.5 44.0 2.0 l/z Calcite 4 520 400 1750 4500 27.5 8.0 54.5 12.5 Calcite 5. 20 40 3000 750 35.0 12.5 65.5 18.5 Wollastonite 6 180 3250 260 1625 33.5 8.5 65.5 3.0 Rock Phosphlate 7... 1160 5250 1780 3500 18.5 8.5 54.5 8.0 Gypsum 8 1420 5500 1980 3500 1.5 0.5 50.5 0.5 Dolomite 9 80 2750 40 750 35.0 11.5 62.5 20.0 Magnesite 10 60 2500 20 625 34.0 8.5 64.0 16.0 Enstatite 11.. 1780 6000 2260 3500 3.5 3.0 49.5 2.0 Seroentine 12 1160 1700 2750 5250 21.5 8.5 54.5 3.0 1 ( N P K) = 91 lbs. ammonium nitrate 73 lbs. di-ammonium phosphate, and 100 lbs. di-potassium phosphate per million pounds soil. All minerals were used a t rate of 2 tons per million pounds soi!, except Pot 4 which had one-half quantity of calcite. 2 All acidity figures are in terms of CaCOs requirement per million pounds soil. 8 H = By Hopkins potassium nitrate method, U. S. Dept. Agr., Bur. of Chem., Bull. 107 (revised). J = C. H. Jones calcium acetate method, PYOC. Off.Agr. Chem., 1914.
...........
.......... .......... .......... ......... .......... ....... ..........
.......... .......... ......... ..........
TABLE111-SOIL ACIDITYDECREASESAND CROP INCREASES B Y TREATMENTS A N D SOILS DRCREASE I N ACIDITY PER 1,000,000 LSS. S O I L ----AVBRAGE CROPINCREASES PER POT Treatment Wanatah soil Dupont soil Average soils Wanatah soil Dupont soil Average soils Wheat and in addition Clover Pot J1 Clover Wheat HI Wheat Clover Clover Wheat H J H J Lbs. Grams Grams Grams Lbs. Grams to N P K Lbs. Lbs. Lbs. Lbs. Grams Grams Grams No. 1240 2250 2400 1320 2312 26.0 10.5 10.5 18.2 4 ' / a Calcite 2375 4.5 7.5 25.7 1720 2780 21.5 16.5 Calcite 12.7 3750 3375 9.0 40.2 2250 3562 33.5 27.5 5 1580 2540 21 .o Wollastonite 3500 32.0 2500 5.0 29.5 2060 3000 1.0 26.5 3.0 6 600 1020 Rock Phosphate 1500 10.5 625 5.0 19.2 1062 6.0 13.7 5.5 810 17.0 7 340 1250 -1.5 820 -2.2 625 580 93 7 0.0 -3.0 6.5 3.2 1.o 8 Gypsum 1680 4000 18.5 13.0 3375 2220 18.0 33.5 8.0 26.0 Dolomite 3687 39.0 2760 9 1700 4250 3500 2240 14.0 32.5 5.0 26.2 Magnesite 3875 35.7 2780 20.0 9.5 10 -20 750 625 260 Enstatite 5.5 540 68 7 2.0 -0.5 0.0 3.7 -0.2 3.5 11 10.5 1500 600 1375 850 Seroentine 20.0 5.0 3.0 18.2 1100 1437 1.0 15.2 12 J = C. H. Jones calcium acetate method. 1 H = Hopkins potassium nitrate method.
Table I1 gives the arrangement and treatment of the pots, together with the soil acidities found a t the end of the test, also the yields in grams of air-dry wheat (grain and straw) and of clover hay. The widely divergent figures obtained in determining the acidity of the two soils with the various treatments illustrates the fact t h a t the acidity of Soil W is largely organic in nature while the acidity of Soil D is almost all inorganic. The results obtained with the potassium nitrate method are not affected t o any great degree by organic acidity, while the results obtained with t h e calcium acetate method are very largely affected b y organic acidity.l Figs. I and 2 show the appearance of the wheat and clover crops on each soil series just before harvesting. Table I11 gives the relative decreases in soil acidity for each treatment as shown by the Hopkins potassium nitrate method and by the C. H. Jones calcium acetate method. The relative crop increases over the basic fertilizer treatment, as well as the average wheat increases, the average clover increases, and the total increases of wheat and clover, are shown for each treatment. Fig. 3 gives the calcium carbonate equivalents of the different minerals used by the titration method in comparison with the relative crop increases and the soil acidity decreases as shown b y the Hopkins and Jones methods. The full application of calcite was taken as one hundred in each case. The acid-neu1
S. D. Conner, J . Assoc. O f f . A g r . Chem., 3 (1917), 139.
tralizing power of the minerals used, as determined by titration. correlates with the crop increases and acidity decreases except in two cases. The high crop yield in the case of the rock phosphate may be partly due t o n phosphate action in addition t o t h a t of the neutralizing value of the calcium. The relatively'lower crop increase with magnesite is probably due t o the fact t h a t magnesia has a n injurious action under certain conditions. When calcium and rnignesium were determined by means of dilute hydrochloric acid t h e calculated CaCOs equivalent is a good indicator of the value of carbonates and silicates of either calcium or magnesium and of raw rock phosphate. This method fails entirely in the case of calcium sulfate. It should be noted here t h a t if an analysis of the total calcium and magnesium is made, b y fusion or otherwise, t h e results obtained for enstatite or other more or less insoluble silicates will be too high. The results obtained b y means of the COZ method are in accordance with t h e crop results only in the case of the carbonates and gypsum. This method fails entirely with silicates and raw rock phosphate. It is only with boiling acid t h a t the COZ method will indicate the value of magnesite and some dolomitic limestones, as such minerals are not completely dissolved by cold hydrochloric acid. The COZ method, of course, would not indicate the value of burned or hydrated lime or of many waste products which might be used for correcting soil acidity.
Dec., 1918
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
999
VI-The treatments decreased the soil acidity in the following order: Magnesite, dolomite, calcite, wollastonite, serpentine, rock phosphate, gypsum, and enstatite. VII-The results obtained in these experiments indicate t h a t the value of agricultural lime is in accordance with its acid-neutralizing power, rather t h a n with the CaO, MgO, or C o t contained, and t h a t the titration method is t h e most accurate and reliable method for determining the value of agricultural limes. S o a s AND CROPSDEPARTMENT PURDUEUNIVERSITY AGRICULTURE EXPERIMENT STATION
1: LAFAYETTE. INDIANA
F I G . 3--RELATIVE EFFECTOF DIFFERENT MINERALSAS S H O W N B Y AVERAGE INCREASE OF WHEATAND CLOVER AND DECREASE IN SOILACIDITY B Y THE HOPKINSAND JONES METHODS COMPARED WITH ACID-NEUTRALIZING POWER OF THE MINERALS DETERMINED B Y TITRATION. FULL CALCITEAPPLICATION TAKEN AS 100
It is a well-established fact t h a t certain silicates of calcium and magnesium compare favorably with calcium and magnesium carbonates in neutralizing acidity and in their beneficial action upon soils.’ Dana2 states t h a t gypsum occurs intermingled with limestone. Clarke3 says, “Wollastonite is commonly found as a product of contact metamorphism, especially in limestones;’’ also, “In many localities serpentine is associated with dolomite or dolomitic limestones.” Taking all these factors into consideration i t would appear that the acid-neutralizing power of the limestone as determined by titration is the best method t o use for determining the value of agricultural limes a n d limestones. SUMMARY
I-The value of agricultural limes was determined by means of the acid-soluble calcium and magnesium, by means of COz determination with boiling hydrochloric acid, and b y digesting in standard acid and titrating the excess acid. 11-Pot cultures on two very acid soils were conducted using calcite, wollastonite, raw rock phosphate, gypsum, dolomite, magnesite, enstatite, and serpentine as correctors of soil acidity. 111-‘Wheat and clover were grown in each soil and the crop increases reported. JV-Soil acidity was determined after cropping b y means of the Hopkins potassium nitrate method and the C. 13. Jones calcium acetate method. V-Crop increases due t o various treatments were obtained in t h e following order, the highest being placed first: Calcite, dolomite, magnesite, wollastonite, rock phosphate, serpentine, enstatite, and gY Psum. 1 McIntire and Willis, THISJOURNAL, 6 (1914), 1005, Ames and Schollenberger, Ohio Expt. Sta., Bull. 306 (1916), 385; Cowles, Met. 6’ ~ C h e m .Eng., 17 (1917), 664. p Dana, “Manual of Geology,” 234. * Clarke, U. S. Geol. Surv., Bull. 616, 378 and 603.
THE DETERMINATION-OF THE HEXABROMIDE AND IODINE NUMBERS OF SALMON OIL AS A MEANS OF IDENTIFYING THE SPECIES OF CANNED SALMON By H. S. BAILEYAND J. M. JOHNSON Received June 21, 1918
A t the suggestion of Mr. H. M. Loomis, formerly of the Bureau of Chemistry, an examination of salmon oils for their chemical and physical characteristics was made in 191j by L. B. Burnett in this laboratory. His preliminary experiments seemed t o indicate t h a t the iodine numbers and hexabromide values would furnish a method of distinguishing between the various salmon species. We have this year made a further study of oils expressed from canned salmon and believe t h a t the results we have obtained justify the assumption t h a t the oil from different species of salmon have characteristic iodine numbers and hexabromide values. I n order t o get a good working method for determining the so-callad hexabromide value of a n oil, we carried out a series of experiments using the different procedures suggested by previous investigators. METHODS OF A N A L Y S I S
The precipitation of insoluble hexabromides from the ether solution of oils and fatty acids was first accomplished in a qualitative way b y K. Hazura.1 A quantitative methodwforthe determination of the hexabromide value was afterwards worked out by Hehner and MitchelL2 This method depends upon the low solubility of the hexabromides in a solution of ether and glacial acetic acid. I n their method, the precipitate of hexabromides was brought upon a filter paper, washed with ether, dried and weighed. Procter and Bennett3 found difficulty with Hehner and Mitchell’s method especially with thz filtration of the precipitate. They changed the solvent and used carbon tetrachloride instead of ether, finally precipitating with alcohol. However, they did not succeed in getting good results when brominating the glycerides and recommended working with the fatty acids. L. M. Tolman4 modified Hehner and Mitchell’s method, using a centrifugz for separating and washing 1
Monatsh., 7 (1886), 637; 9 (1887), 148.
8
J . Sac. Chem. Ind., 26 (1906), 798. THISJOURNAL, 1 (1909), 340.
* The Analyst, 23 (1898), 310. 4
