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INDUSTRIAL AND ENGINEERING CHEMISTRY
These measurements were made at different times over a period of 3 months. The values are considerably less than those obtained for pure nicotine at the same temperature, as a comparison of values in Tables I and I~ will show. Similar measurements made on a bentonite dust containing 2.99 per cent nicotine revealed a concentration of nicotine too low to determine, only the slightest trace of nicotine vapor being detected on passing air over the dust. The slight vapor concentrations exhibited by nicotine in nicotine-bentonite dusts are in accord with previous results showing the strong adsorption of nicotine by b e n t ~ n i t e . ~
Vol. 20, No, 7
Summary
I-The vapor concentrations of nicotine over the pure liquid increases from 1.76 mg. per 10 liters of air at 25” C. to 6.04 mg* at 400 c* 2-The vapor COncentration of nicotine Over a 2.97 Per cent nicotine-hydrated lime dust lies within the limits of 2.97 t o 3.42 mg. per 10 liters of air a t 35” C. 3-The vapor concentration of nicotine over a 2.94 per cent nicotine-bentonite dust was too small to measure, only slight amounts of nicotine being detected in the vapor phase.
Control of Chlorosis of the Pineapple and Other Plants’ Maxwell 0. Johnson CALIFORNIA PACKING CORPORATION, WAHIAWA,OAHU, T. H.
H E yellowing of pineapple plants on the manganese soils of Hawaii was first reported in 1909 by Kelley.2 In 1916 theauthor3found that this so-called “manganese poisoning” was a simple chlorosis due to deficiency of iron in the pineapple plant. Spraying of the plants about once a month with a 4 to 6 per cent solution of iron sulfate proved a very simple and practical means of control. The cost of the treatment, which is about 50 cents an acre per spraying, is negligible in comparison with the $400 or $500 it costs to bring an acre of pineapples into bearing. The great development of the Hawaiian pineapple industry since 1916 has largely been made possible by this spraying method. It has been known for many years that some plants become affected with chlorosis or bleaching when they are grown on soils containing very large amounts of calcium carbonate, and that applications of solutions of iron salts to the leaves will control this form of chlorosis. Gile and Ageton4 have probably made the latest and most thorough investigation of such highly calcareous soils. Gile5 found a chlorosis of pineapples on some Porto Rican soils containing excessive amounts of carbonate of lime. He also found that the plants were benefited when the leaves were brushed with solutions of iron salts, but that the treatment was impracticable for Porto Rican conditions.
T
Cause of Manganese Chlorosis
The chlorosis of pineapples in Hawaii differs from most chloroses on alkaline, excessively calcareous soils in that it occurs on acid soils containing no calcium carbonate, only a normal amount of lime, and in some cases extremely low amounts of lime. The author6 has found that there are probably a t least two influences affecting the availability of iron in the soil: (1) the relative acidity or alkalinity of the soil, and (2) the relative oxidizing or reducing agents in the soil. With soils whose p H is over about 4.5 (which includes most agricultural soils) ferric iron appears largely unavailable to plants sensitive to chlorosis and the chief Presented before the Division of Agri1 Received April 12, 1928. cultural and Food Chemistry a t the 75th Meeting of the American Chemical Society, St. Louis, Mo., April 16 to 19, 1928. 3 Hawaii Agr. Expt. Sta.. Bull. 93, 14 (1909); Bull. 26, p. 56; J. IND. ENG.CHEM.,1, 533 (1909). END.CHEM..9, Hawaii Agr. Expt. Sta., Bull. Si, 11 (1916): J. IND. 47 (1916). 4 Porto Rico Agr. Expt. Sta., Bull. 16, 44 (1914). 6 I b i d . , 11, 44 (1911). 6 Hawdi Agr. Expt. S a . , Bull. Sa, 25 (1924).
source of iron supply appears to be ferrous salts. The manganese dioxide present in the Hawaiian pineapple soils appears to keep the iron oxidized to the ferric form and unavailable, although these soils may run as high as 25 per cent iron as ferric oxide. Heavy applications of sulfur and as much as 3000 pounds per acre of iron sulfate in the soil a t planting have proved ineffective in preventing chlorosis, while about 10 pounds of iron sulfate an acre per month has been an almost perfect control. Control of Chlorosis by Iron Sulfide Dusts
Since 1919 an attempt has been made to improve upon the spraying method by developing a dust. The most practical material appeared to be the sulfides of iron. They are ordinarily insoluble in water but under exposure t o moist air are supposed to oxidize to soluble iron sulfates. This appeared t o be a very good idea, as enough material could be applied to supply iron t o the plant for a prolonged period without injuring the plant from a too concentrated solution. The action should be to generate a continuous supply of iron to the plant. Precipitated ferrous sulfide was tried, but proved too expensive. Iron pyrites appeared t o be a very cheap source of supply, but the ordinary pyrites did not oxidize rapidly enough t o be of value. I n 1923 Professor H. C. Peffer, of Purdue University, informed the author that certain samples of pyrites obtained from coal mines, and submitted to him, oxidized quite rapidly on exposure. These samples appeared to consist of marcasite, the same chemically as ordinary iron pyrites but crystallized in the rhombic instead of the isometric system. The change in crystalline structure appears to accelerate greatly the rate of oxidation under exposure to air. If a little of this powdered marcasite is placed in a filter paper in a funnel, a few leachings with water will remove all soluble iron salts. Overnight a new supply of soluble iron salts is produced by oxidation. This oxidation appears to continue slowly until all the marcasite has been decomposed. Experiments with Marcasite on Pineapple
A supply of marcasite was finally obtained from the Bethlehem Steel Company. This marcasite is picked out of the coal in mining and is known to the miners as “coal brasses” or “sulfur balls.” In earlier experiments attempts were made to furnish to the plant about a 6 months’ supply of iron in
July, 1928
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INDUSTRIAL AND ENGINEERING CHEMISTRY
725
one application, but the mechanical removal of the material have been practiced, however, as no reference has been found by expansion of the growing parts prevented successful con- in the literature on chlorosis. trol for so prolonged a period on young, rapidly developing Application of Marcasite on Sugar Cane plants. However, application of about 8 pounds per acre of Certain small areas of sugar cane on highly calcareous marcasite to the leaves every 2 months has proved a fairly effective means of control in experiments. I n order to dis- soils in Hawaii show chlorosis of the leaves. Spraying of tribute this small quantity of powdered marcasite, it was sugar cane is not very practicable. Application of marmixed with about one-third its weight of infusorial earth. casite to the leaves or in the leaf axils produced a very striking This mixture overcame most of the objections to the handling effect, a perceptible greening being noticeable in less than of marcasite alone. The powdered marcasite itself is some- a week. The treated plants resumed normal growth while what deliquescent and tends to cake on long standing, but the the adjoining untreated rows remained yellow and stunted. mixture can be handled fairly well in a dusting machine. It Alexander and Nichols, a t Ewa Plantation, Hawaii, found an is doubtful, however, if any treatment will replace the spray- extremely pronounced increase in growth curves of chlorotic sugar cane when marcasite was applied. The untreated ing method with pineapples. Recently it has been learned that the treatment for chlo- plants in some cases even died. rosis with iron sulfides as described above has been largely For many plants the marcasite treatment appears the most anticipated by German Patent KO.109,104, granted in 1900 practical method of chlorosis control. A possible fungicidal to Cyprien Chateau. This treatment does not appear to effect of marcasite dust is also worthy of investigation.
Coke Tumbler Tests’ A. R. Powell and D. W. Gould THEKOPPERSCOMPANY, CHICAGO, ILL.
ROM the standpoint of the production, distribution, and use of coke, s t r e n g t h and hardness are physical factors of prime importance. All coke is subjected to more or less handling between the ovens where it is manufactured and the blast furnace, cupola, watergas generator, or d o m e s t i c f u r n a c e , where it is used. This causes a degradation in size or the production of exc e s s i v e quantities of coke breeze, which are undesirable from the viewpoint of the user. Various tests have been d e s i g n e d to test coke for strength and hardness, which are the factors that largely determine the so-called handling qualities.
F
Tests for Strength and Hardness
A series of physical tests of coke have been made in a coke tumbler following a design suggested by W. A. Haven, and recently suggested for adoption by the American Society for Testing Materials. Duplicate tests in the coke tumbler give results which are concordant within 1.4 per cent for the stability factor (total per cent on 1 inch), and within 0.8 per cent for the hardness factor (total per cent on inch), the agreement being closer than duplicate results with the standard shatter test. Comparative results are given for twenty-six different cokes as to shatter test, tumbler test, and how these compare with actual plant yields of coke over 2 inches and coke over 1 inch. The stability factor, as determined by the tumbler test, correlates with plant yields of sized coke only as a general trend. The tumbler test does not imitate the type of handling coke receives in the plant as nearly as does the shatter test, but it is indicative of the ability of sized coke to withstand handling between the point of production and the point of use. The hardness factor, as determined by the tumbler test, has little practical significance. The effects due to certain variables, such as duration of test, possible sampling errors, and moisture content of coke, have been evaluated.
Tests for determining the crushing strength of coie have been devised, but the results are so irregular that they are practically worthless.2 Fortunately, coke resists crushing to such an extent that even poor grades will withstand the pressure imposed on it in blast
furnace^.^ Coke is much more liable to breakage by impact while being handled than to breakage by crushing. A standard test has been devised to measure this property-the shatter test.‘ f Presented before the Division of Gas and Fuel Chemistry at the 75th Meeting of the American Chemical Society, St. Louis, Mo., April 16 t o 19, 1928. * Proc. Am. Soc. Testing Materials, 16, Pt. 1, 359 (1915). U. S. Geol. Survey, Bull. 886. 4 Am, Soc. Testing Materials, Standards, 1927, Pt. 11. D 141-23.
*
As applied to coke, “hardness” is a term that means the ability to resist abrasion. The method used for testing the resistance of coke to abrasion is the tumbler test. This test also indicates the resistance to impact, a l t h o u g h f r o m a somewhat different standpoint than the shatter test. Some of the limitations of the tumbler test have been pointed out by Kinney and Perrott.5 The Shatter Test
This test is made on a 50pound sample of coke, which consists of pieces which will not in any p o s i t i o n p a s s through a 2-inch square mesh screen. This coke is dropped a distance of 6 feet four times in succession onto a rigidly m o u n t e d steel plate. The percentage of coke remaining on a 2-inch s q u a r e m e s h screen after this treatment is considered to be the significant figure of the test. Generally the coke used for this test is picked from run-ofoven coke or coke which has received a minimum amount of handling before the sample is taken. Such coke has shrinkage cracks which would normally cause breakage b e fore the final sizing a t the plant. Under such conditions, the desired indication of the ability of the finally sized coke to withstand impact is masked somewhat. Another objection to the shatter test is its relative inaccuracy. Kinney and Perrott6state than an accuracy of within 1to 3 per cent is poasible. It has been the present writers’ experience that J. IND. END.CxSM., 14, 926 (1922).
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