INDUSTRIAL AND ENGINEERING CHEMISTRY
July, 1928
were dried on a porous plate and were recrystallized from hot alcohol. A constant melting point of 185" C. was finally obtained. The crystals had the same degree of sweetness as cane sugar, and did not reduce Fehling's solution. Analysis gave the following results: = $65.4 FOWND Per cen CHsO C €I
15.67 43.22 7.40
CALCD. FOR PINITE Per cent 15.9 43.27 7.27
Acetylation with acetic anhydride and anhydrous sodium
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acetate and subsequent hydrolysis showed the presence of five hydroxyl groups. I n addition to pinite the writers have isolated a new from the cold-water extract of the heartcyclose, C~H~607, wood of redwood. The two are found together, although when one is found in considerable quantity the other is always present in a smaller amount. The new compound is extremely sweet, has a melting point of 234" C., and sublimes with little or no decomposition. The writers advance the tentative formula CJ3s(OH)6CH20CH3, methoxy mytilit, and suggest the name "sequoiite." A report on the experimental work in confirmation of this formula will appear a t an early date.
Volatility of Nicotine',' W. R. Harlan and R. M . Hixon DEPARTMENT OF CHEMISTRY, I O W ASTATECOLLEGE, AMES,IA.
0 quantitative data are available upon vapor concentrations obtained either from pure nicotine or from dusts impregnated with nicotine. I n the course of investigations involving the volatility of nicotine from dusts using various materials as a carrier, the vapor concentration over the pure liquid was desired in order to find the limiting value for nicotine vapor over any dust carrier. Accordingly, the concentration of nicotine in the vapor phase has been determined a t 25", 30°,35", and 40" C. by the air-bubbling method, this range including temperatures usually met in fumigation. The vapor concentrations of nicotine over a 2.97 per cent nicotine-hydrated lime dust and a 2.99 per cent nicotine-bentonite dust a t 35" C. are also reported. The apparatus used was free from rubber connections, it having been shown in a previous paper3 that rubber adsorbed nicotine to a considerable extent.
N
Concentrations of Nicotine over the Liquid
Measured quantities of dry air were saturated with nicotine vapor by bubbling the air through pure nicotine contained in a Mohr-Geissler potash bulb and an 8-inch (20-cm.) test tube tightly packed with glass wool containing nicotine in the bottom. It was necessary to pass the air saturated with nicotine through the test tube packed with glass wool in order to eliminate the spray which passed over from the MohrGeissler bulb. The nicotine vapor was adsorbed by washing the gases in a series of bubblers containing 2 N sulfuric acid. Analysis was made by precipitating the solution with silicotungstic acid, igniting, and weighing the residue according to the A. 0. A. C. methods. The quantities of air passed through the nicotine were measured with a calibrated flowmeter. The air was passed through a t rates varying from 5 to 10 liters per hour, constant results being obtained showing that equilibrium had been attained. Temperature control was maintained to * 0.5" C. by an air thermostat. From the weight of nicotine obtained and the volume of air passed over, the concentrations of nicotine vapor were calculated in milligrams per 10 liters of air and also in parts of nicotine per million of air, assuming the ideal gas law for 1 Received April 30, 1928. These studies were made possible through a fellowship maintained by the Tobacco By-products and Chemical Corporation a t Iowa State College. * Harlan and Hixon, Iowa State College, J . Sci., in press.
nicotine vapor. The barometric pressure was 740 mm. These data are reported in Table I. T a b l e I-Vapor C o n c e n t r a t i o n s of N i c o t i n e AIR PASSED NICOTINE T E M P E R A T U ROVER E NICOTINE OBTAINED CONCENTRATION Liters Gram M g . / l O 1. air P. 9 . m. c. 1.84 28.525 60 0.01106 1.76 27.3 0,01056 25 60 2.73 43.00.01635 60 30 2.66 41,90.01596 30 60 4.17 0.01250 35 30 66.84.11 0.01232 35 30 65.95.74 40 94.3 0.01723 30 6.04 40 99.2 0.01812 30
The vapor pressure may be approximately calculated from the data in Table I, but for practical purposes the concentration as given in the table is more convenient for this type of work. Concentrations of Nicotine in Vapor Phase over Hydrated Lime and Bentonite Dusts The apparatus consisted of a humidity control, mixing bottle, and flowmeters, to regulate the volume of air, being essentially the apparatus described by Hixon and Drake.4 The dusts were made with hydrated lime and bentonite as carriers. These materials were sieved, that portion being used which passed a 100-mesh and was retained by a 200mesh sieve. The size of particles of a carrier undoubtedly influences the rate of attainment of equilibrium of the vapor phase, but should not influence the value of this equilibrium. Pure nicotine was used for preparation of the dusts, analyses showing 2.97 per cent nicotine in the hydrated lime dust and 2.99 per cent nicotine in the bentonite dust. Measured quantities of air were passed over a sufficient quantity (20 to 30 grams) of the dust in the mixing machine to give equilibrium conditions. The rates a t which air was passed over the dust varied from 5 to 10 liters per hour. KO consistent variation in results was obtained a t the different rates, indicating that the vapor phase was in equilibrium with the nicotine in the dust. The data on the nicotine-lime dust are given in Table 11. C o n c e n t r a t i o n s 2.97 Per C e n t of Nicotine-Hydrated Lime Dust at 35O C. NICOTINE CONCENTRATION OVER DWST OBTAINED Mg./lO 1. air P. P. m . LifWS Gram 3.28 52.5 60 0.01971 3.13 50.1 0,00940 30 3.42 54.8 0,00892 0.01025 30 2.97 47.6 30
Table 11-Vapor h.0.
1 2 3 4
*
4
AIR PASSED
Iowa State College, J . Sci., 1, 373 (1927).
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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
