Sept.. 1914
T H E J O U R N A L O F I,?iDUSTRIAL d N D E Y G I , V E E R I S G C H E M I S T R Y
t h a t peanuts contain 37.48 t o 41.63 per cent of oil. Beattie, in Farmers’ Bulletin No. 376, United States Department of Agriculture, says t h a t t h e oil m a y r u n as high as 50 per cent in some peanuts. These results are evidently on t h e peanuts before roasting; after roasting t h e oil would be higher, due t o a corresponding loss in water. Our results on the manufactured peanut b u t t e r d o not show a n y more oil t h a n m a y occur in the roasted peanut. The U. S. standards for peanut, olive and cottonseed oils as given b y Leach are as follows: Refractive index at 25’ C. P e a n u t . . . . . . . . . . 1.4690 t o 1.4707 Olive.. . . . . . . . . . 1.4660 t o 1.4680 Cottonseed.. . . . . 1.4iO0 t o 1.4725
Iodine value (Hiibl) 57 t o 100 19 t o ‘)O 104 t o 110
The iodine value falls well within t h e limits of those given for pure peanut oil. T h e greatest variations are in the refractive index. Considering t h e fact t h a t t h e oils obtained from t h e roasted peanuts give results comparable with t h e manufactured product, one could hardly sa.y t h a t oil h a d been added. T h a t added oil can be detected is seen in t h e lowering of t h e refractive index b y t h e use of olive oil. K A N S A SSTATE AGRICGLTURAL COLLEGE
,
MANHATTAN
THE INFLUENCE OF SULFUR ON SOIL ACIDITY By H.
CLAY L I N T
R.eceived June 2 , 1914
T h e control of parasitic fungi which art: capable of persisting in t h e soil has occupied t h e attention of m a n y scientists and agriculturalists within recent years. T o t h e above t y p e of fungi belongs t h e one causing t h e ordinary scab of t h e potato. Even before this specific organism ( O o s p o r a scabies) h a d been isolated b y Thaxter much work h a d been d0n.e toward devising methods of control. Halstead’ in t h e annual report of t h e New Jersey Experiment Station for 189j reports favbrable results in controlling the potato scab as a result of t h e application of flowers of sulfur t o t h e soil. This work was not continued b y Dr. Halstead, b u t within t h e last year t h e problem has been t a k e n up again. It m a y be well a t this time t o s t a t e some of t h e facts t h a t have been noted on phase of t h e sulfur question relating t o its effect on soil acidity. Researches b y 11. A. Demolon* have shown t h a t on soils of different origin, containing 3 per (cent a n d 2.8 per cent, respectively, of calcium carbonate, there is a great increase in t h e a m o u n t of sulfates due t o t h e addition of sulfur t o t h e soil. He added I per cent of flowers of sulfur t o these soils and incubated t h e m a t z o o C. for forty (days. An analysis of t h e viater extract .gave these relative amounts of sulfates per hundred grams of soil as indicated b y t h e weights of BaSO, given below. Gms. B a s 0 4 XVith sulfur Soil A , . . . . . . . . . . . . . . . . . .0 970 Soil H . . . . . . . . . . . . . . . . . . 0 , 6 1 2
Gms. B a s 0 4 XVithout sulfur 0.062 0.047
Experiments b y the same investigator demonstrated t h a t the oxidation of sulfur was accomplished b y bac1
2
S . J . Exp. Station R e $ , 1895, p . 270. Comfit. r e n d . , 166 (1913). 7 2 5 .
747
teria in the soil. Brioux a n d Guerbet’ have gone f u r t h e r a n d not only proven the, bacterial nature of t h e action, b u t have furnished d a t a on t h e influence of various substances-calcium carbonate, saccharose, peptone, etc., when added t o the soil in which t h e sulfur was introduced. I n our recent work under field conditions where as much a s 600 pounds of sulfur was applied per acre i t was noticed t h a t a large amount of t h e sulfur was still present in t h e soil a t digging time, apparently in an unchanged condition. In order t o ascertain facts on t h e rate of oxidation of t h e sulfur in t h e soil a series of tumblers containing I O O gram portions of soil were arranged, one-half containing sulfur, t h e other half without i t . Thirty-three mg. of sulfur, equivalent t o 1000 pounds of sulfur per acre foot (3,000,000 pounds), were added. The soils were made up t o t w e n t y per cent moisture content and covered with Petri dishes. B y t h e addition of sterile water once a week t h e moisture content was practically cons t a n t throughout the experiment. One tumbler containing sulfur mixed with the soil and one not containing sulfur were removed each week and tested for acidity. I n this work t h e Jones2 calcium acetate method of determining soil acidity was used. Preliminary tests comparing t h e Jones method with t h e Yeitch method on a number of soils showed a close correlation, a n d as comparative results only were desired, this method was thought sufficiently accurate. I n t h e following table are included the results of t h e analysis of this first series:
-
Lime requirement in pounds C a 0 per 1 000 000 oounds of soil
Time of incubation Weeks 1
-.
I
n’ithout sulfur
I
A
XVith sulfur 2393
2 3
4 5 6
7
a
9 10 11
4110
From t h e foregoing table i t would appear t h a t the sulfur h a d practically all been oxidized within t h e first eight or nine weeks. There is very little change in t h e acidity after t h e seventh week. Assuming t h a t t h e Jones method has given the correct lime requirements i t is interesting t o note how closely t h e above lime requirements check u p with t h e theoretical. .4n average of t h e lime requirements of the two soils from t h e seventh t o t h e eleventh weeks inclusive gives 2431 pounds for t h e check a n d 4177 pounds for t h e sulfured soils. Obviously t h e difference of I 744 pounds of lime is due t o t h e oxidation of sulfur. By means of t h e following proportion 32 : j 6 : : 1000 : x we find t h a t the C a O equivalent t o the 1000 pounds sulfur per acre would be 1 7 j o . Apparently t h e reason t h a t no further increase in acidity takes place after t h e eighth week is due t o the fact t h a t all of the sulfur has been oxidized. The fact t h a t sulfur causes this increase in acidity 1
Comfit. r e n d . , 156 (1913), 14i6.
Reported a t the 30th Annual Convention A . 0. A . C., Washington, D. C . , r\-ovember, 1913. .’
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
748
under field conditions is shown b y t h e following table i n which are t h e analyses of soils from four old p o t a t o rows t o which sulfdr was applied last year. Samples were t a k e n approximately one year after t h e application. T h e rows were 1400 f e e t long a n d borings 0-3 inches were made about every t w e n t y feet. T h e sulfured rows r a n consecutively b u t 1 2 rows were skipped before samples on t h e check row were t a k e n . T h e sulfured rows were t w o feet eight inches a p a r t . Rate of sulfur application Lime requirement in Lbs. per acre lbs. CaO per acre 1 ...................... 600 3187 300 2590 2 ...................... 3 ...................... 600 3025 4 ...................... 300 2247 5 . . .................... None (check) 883
Row
Rows I a n d z received ammonium sulfate i n t h e fertilizer last year, while rows 3 a n d 4 received sodium nitrate, a fact which would account for a difference i n t h e acidity. Laboratory experiments with a heavy clay loam soil a n d a sandy loam soil show a much more rapid oxidation of sulfur with t h e l a t t e r soil. Soils made u p t o water content ( 2 0 per cent) once each week a n d allowed t o dry did not give as rapid oxidation as those kept covered so a s t o maintain optimum moisture content. T h e influence of texture,, moisture a n d bacterial content will serve as a basis upon which further work o n t h e influence of sulfur o n soil reaction will be carried out. NEW JERSEY AGRICULTURAL EXPERIMENT STATION NEW BRUNSWICK
THE FERRIC ALUM ESTIMATION OF CASEINEI By H. V. ARNY AND H. H. SCHAEFER Received May 20. 1914
At t h e j 3 r d ( 1 9 0j ) meeting of t h e American P h a r m a ceutical Association, one of us, with T. M. P r a t t , presented a paper on a rapid estimation of caseine i n milk based o n precipitation of t h e casein with a n excess of a solution of ferric alum of known t i t e r , estimation of t h e unused iron i n t h e filtrate a n d t h e n calculating t h e a m o u n t of iron used b y t h e caseine i n t h e a c t of precipitation. This paper was published i n t h e Proceedings of t h e American Pharmaceutical Association, 53 ( 1 9 0j ) , 2 7 5 , a n d i n t h e American Journal of Pharmacy, 78 (1906), 1 2 1 , b u t a s our attention has been called t o t h e fact t h a t these t w o publications are not always conveniently accessible t o t h e general chemical worker a n d as t h e paper was frankly a preliminary one, i t seemed advisable t o report further work on t h e topic a n d t h a t i n a strictly chemical journal. I n t h e previous paper was presented t h e method of manipulation a n d figures showing influence of t e m p e r a t u r e , of presence of f a t ( b u t t e r ) , of presence of sugar a n d , lastly, a few parallel experiments comparing t h e ferric alum figures with t h e Kjeldahl figures of t h e same sample of milk. These l a t t e r figures, t h e a t t e m p t t o express t h e value of I cc. of ferric alum solution i n t e r m s of nitrogen a n d of caseine, were n o t sufficiently exact nor were t h e number of assays performed sufficient for 1 Presented a t the 48th Meeting of the American Chemical Society, Rochester, September 8-12, 1913.
Vol. 6, N o . 9
a positive s t a t e m e n t of t h e ferric alum factor. While t h e process i n t h e empiric commercial milk testing work for which i t was devised proved entirely satisfactory, proof of i t s scientific accuracy was yet t o be shown; a n d this has been t h e aim of our experiments during t h e past winter. Since t h e publication of our prior paper, VanSlyke & Bosworthl have published a titration method based o n use of tenth-normal alkali. This plan has n o t proved as satisfactory in our hands as t h e ferric alum method b u t t h e fact has n o bearing on our investigation, since there is room for more t h a n one simple estimation of caseine. T H E F E R R I C ALUM E S T I M A T I O K
Since t h e publication of our previous paper, several modifications of t h e process a s originally published have suggested themselves a n d have been tried o u t . I n all t h e work we have used as t h e s t a n d a r d iron solution, a ferric a l u m containing 4 8 . 2 2 2 4 g. F e ( N H 4 ) (SO4)2.12H2O t o t h e liter, standardizing this solution b y t h e usual method of volumetric ferric estimat i o n ; adding potassium iodide a n d hydrochloric acid a n d titrating t h e liberated iodine with tenth-normal sodium thiosulfate. One cc. of our s t a n d a r d solution, therefore, liberates 12.692 mg. iodine which i n t u r n requires I cc. tenth-normal sodium thiosulfate for decolorization. I n our previous work, in a n a t t e m p t t o dispense with t h e use of t h e rather costly potassium iodide, we have repeatedly tried estimation of t h e iron solution b y titration with tenth-normal alkalis, noting e n d of reaction b y use of phenolphthalein a s indicator. I n this case t h e ferric alum solution ( 4 8 . 2 2 2 4 g. t o 1000 cc.) was standardized b y titration against tenth-normal sodium hydroxide, I cc. of ferric alum solution taking 3 cc. tenth-normal aIkali for complete neutralization. This, we found a n easier procedure t h a n would seem a t first glance, as a f t e r a little experience, i t is not difficult t o note t h e red t i n t of t h e alkaline phenolphthalein combination i n t h e supernatant liquid a b o u t t h e ferric hydroxide precipitate. T h e figures of such a line of assays i n which t h e excess of ferric alum was estimated with N / I O alkali are given below. COMPARISON
OF
THIOSULFATE
ASSAYS
U-ITH
XORMAL
ALKALI ASSAYS
I n this a n d all other experiments described i n this paper, t h e ferric alum solution employed was one containing 48.2224 g. FeNH4(S04)212H20 t o t h e liter a n d I cc. of this solution represented I cc. N sodium thiosulfate solution or 3 cc. N sodium hydroxide solution a n d in t h e rest of this paper this solution will be called t h e s t a n d a r d ferric solution. Five cc. of milk were mixed with j cc. of t h i s s t a n d a r d ferric alum solution, t h e mixture filtered, t h e precipitate washed free from water-soluble iron a n d a m o u n t of iron i n t h e filtrate a n d washings were estimated either with tenth-normal thiosulfate or with tenth-normal alkali. T h e results of such parallel assays from same samples of milk are here tabulated. ( a ) Five cc. milk with j cc. ferric alum a n d t h e 1
THISJ O U R N A L , 1 (1909), i 6 8 .
