Vol. 18, No. 1
INDUSTRIAL A N D ENGINEERING CHEMISTRY
72
alcohol 3, water 5, and n-butyl alcohol 67 cc. The results of the analysis are indicated ,on the graph. The binary mixture of n-butyl alcohol and water boiling at approximately 93' C. contains 37 per cent water, and this figure is used in calcuiating the amount of water given off at that temperature. Figure 4 shows the result of a distillation of a mixture containing 30 CC. acetone, no ethyl alcohol, 5 cc. water, and 65 cc. n-butyl alcohol. If, although the curve shows no break, it were assumed that ethyl alcohol were present in this mixture, and the amount were calculated in the same manner as for the previous case, the ethyl alcohol would be estimated as 0.3 cc. If this correction is applied to the other curve, it brings the ethyl alcohol down to 3.2 per cent, which is very close to the true value. It will be seen that amounts of ethyl alcohol as low as 3 or 4 per cent can be determined with a fair degree of accuracy, and concentrations as small as 1 per cent can be detected with considerable certainty in a single distillation. Application to Organic Isomers For an instance of the application of this type column to the separation of organic isomers, we are indebted to Dr. M. L. Cline, working with Professor Reid of Johns Hopkins University. At his request one of the writers designed a column for the separation of 0- and pethylnitrobenzenes. The column was 12.5 mm. bore and was packed with glass rings for a length of 150 cm. The column was jacketed and was heated with the vapors from a flask of boiling xylene, the condensed xylene being returned to the flask. The distillation of the isomers was carried out under reduced pressure, so controlled as to bring the boiling point of the lower-boiling isomer a few degrees below the jacket temperature. The ortho compound distilled over at constant temperature and finally distillation ceased. The pressure was then lowered in steps and the distillation continued until the temperature remained constant while 30 cc. of the less volatile isomer distilled o?er. The original sample weighed 760 grams. The pure ortho compound distilled off weighed 384 grams (50 per cent). The intermediate mixed product weighed 60 grams (8 per cent), leaving in the flask 317 grams (42 per cent) of the pure para compound. By way of comparison, it may be noted that to separate these same isomers Beilstein and Kuhlberg4 fractionated twenty times while Schultz and Flackslanders fractionated eighty times in %degree cuts to get two fractions 220-30" C. and 245-50' C. with a small middle portion. They fractionated one hundred more times to obtain constant boiling fractions 223-4' C. and 241-2' C. The saving of time effected by the use of an efficient column can readily be appreciated, A number of these columns have been in use in the laboratories of this company for over a year and have proved themselves practicable and efficient in the distillation of a variety of materials. 4 1
Ann., 156, 206 (1870). J . firakt. Chern., [2]66, 162 (1902).
Future Policy of British Dyestuffs Corporation Lord Ashfield, the chairman of the British Dyestuffs Corporation, has stated that under the management of the present board of directors the corporation will not be permitted t o become a mere distributing agency for dyestuffs, and that no matter what arrangements are made they will not be inimical t o t h e interests of their customers, the color users, but will be made for the purpose of securing the widest measure of freedom for them in the conduct of their business and for the purchase of their colors at the world's prices. The corporation will continue t o be a large manufacturing company, whose aim will be t o meet, so far as its resources will permit and upon an ever-widening scale, the needs of English color users. A large staff of skilled chemists will be employed.
Effect of Sulfur upon Nitrogen Content of Legumes' By J. R. Neller STATEAGRICULTURAL EXPERIM~NT STATION, PULLMAN,WASH.
OTWITHSTANDING the rapid advances in methods for the chemical fixation of elemental nitrogen, it is still recognized that the natural or bacterial processes of fixation continue to supply by far the greater amount of fixed nitrogen needed for plants and animals. As a consequence the discovery that sulfur, or a sulfate salt such as gypsum, will in some cases increase the nitrogen content of legumes is worthy of considerable attention. Early in the history of the United States it was found that under certain conditions, gypsum would cause a marked increase in the growth of clover. More recently it was found that elemental sulfur functioned in a manner similar to gypsum. Experiments have shown that sulfur undergoes s comparatively rapid oxidation after mixing with a warm, moist, arable soil. This oxidation goes completely to the trioxide stage. Moreover, it is known that the oxidation is caused by microorganisms, as very little takes place in a sterilized soil. The bacteria which thus have the ability to convert sulfur into sulfuric acid have recently been studied and described by Lipman2 and his associates. Table I shows the percentage of sulfur recovered as watersoluble sulfate sulfur from two types of eastern Washington soils after periods ranging from 15 to 105 days. It may be noted that the rate of oxidation gradually decreased, probably owing to the initial oxidation of the more available portion of the flowers of sulfur used. The sulfur was added a t the rate of 1 part to 2000 parts of soil, or approximately 1000 pounds per acre. A large amount of the sulfuric acid produced by the bacterial oxidation is neutralized by basic compounds in the soil, but as shown in a previous papera the pH of the soil solution may also be decreased.
N
Table I-Progressive
Palouse silt loam Ritzville silt loam
Oxidation of Sulfur Added t o Eastern Washington Soils -PBR CENT oXIDIzSD-------. 15 30 45 75 105 days days days days days 72.1 85.5 33.7 53.9 63.9 29.8 43.1 51.4 66.3 82.9
The nitrogen contents of yields of alfalfa given in Table I1 were obtained under plant-house conditions with a Ritzville loam brought in from the semiarid east central part of Washington. These results are indicative of field crops that may be obtained under irrigated conditions in that region. As shown in this table, sulfur and gypsum gave similar results, the yield increases ranging from 49.3 to 81.1 per cent. Table 11-Yield and Nitrogen and Sulfur Contents of First Cuttlng Alfalfa on Sulfured and Unsulfured Ritzville and Palouse
Loam
SULPUR AND GYPSUMAPPLICATIONS LBS.PBR ACRE 1000 159 500 200 cas04 Check Sulfur Sulfur Cas04 61.7 47.5 53.4 Yield, grams 31.8 57.6 2.38 2.37 2.18 Nitrogen, per cent 1.65 2.27 Sulfur, per cent 0.120 0.237 0.321 Yield increase, per cent 81.1 94.0 49.3 68.0 Nitroaen increase, per cent 37.6 44.2 43.6 32.7 Sulfur increase, per cent 97.5 175.8
The point of particular interest in this table is that in every case the use of sulfur caused an increase in the nitrogen I Presented under the title "Sulfur and the Utilization of the Other Chemical Elements by Legumes," as a part of the Symposium on Chemistry and Plant Life before the joint sessions ,of the Divisions of Agricultural and Food Chemistry and Biological Chemistry at the 70th Meeting of the American Chemical Society, Los Angeles, Calif., August 3 to 8, 1925. I Soil Scicncd, 12, 475 (1921). a J . Am. SOC.Agron., 17, 26 (1925).
INDUSTRIAL AND ENGINEERING CHEMISTRY
January, 1926
content of alfalfa, the increases varying from 32.7 to 44.2 per cent. Since this increase in nitrogen occurred in crops which were much increased in yield, it is apparent that sulfur caused a very marked increase in nitrogen fixation. Similar results for alfalfa and clover were obtained in other experiments. The data of one of the clover experiments (Table 111)show that, whereas the nitrogen content was not more than from 10 to 23 per cent greater than the checks, the use of sulfur actually caused over three times as much nitrogen to be fixed than was present in the checks. Table 111-Yield a n d Nitrogen Content of First Cutting Clover on Sulfured a n d Unsulfured Ritzville L o a m s SULFUR A N D G y p s u m APPLICATIONS LBS. PER ACRE Yield, grams Nitrogen, per cent Yield increase, per cent Nitrogen increase, per cent
159
Check
Sulfur
20.4 20.7
98.3 2.54
500
200
1000
Sulfur 82.7
Cas04
Cas04
381.8
305.4
83.6 2.28
309.8
22.7
27.0
10.1
86.0 2.35 321.5 13.5
2.63
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The sulfur content of the plant is often considerably increased, as shown in Table 11. There is less effect upon the intake of the other plant food elements. There is some evidence that the iron content, although not increased in amount, may be changed in its state of combination. Sulfur and gypsum are selective in their actions in that they may affect legume crops, as shown above, but are not known to influence the nonlegumes. Moreover, the principal effect upon legumes appears to be that of increasing their nitrogen-fixing capacity. An understanding of how and why sulfur and sulfates cause legumes to fix more nitrogen is far from complete. It is known, of course, that legumes are able to utilize atmospheric nitrogen by virtue of the bacteria that grow in nodules on their roots. It would thus seem that sulfur has an indirect effect upon legumes through its direct action or effect upon the nitrogen-fixing organisms.
Rate of Combination of Sulfur with Rubber in Hard Rubber’ By W. E. Glancy, D. D. Wright, and K. H. Oon HOODRUBBERCo., WATERTOWN, MASS.
T THE Pittsburgh meeting of the AMERICAN CHEMICALhave now determined approximately the amount of sulfur SOCIETY a paper2 was presented giving the results of necessary to make a compound hard and the effect of several a n investigation of the influence of certain compound- of the more common organic accelerators upon the coeffiing ingredients in hard rubber, more especially of their in- cient of vulcanization and the tensile strength. fluence upon the physical properties of hard rubber. At Experimental that time a suggestion was made that it would be desirable to correlate the changes in composition and the changes in Five mixings were made, as shown in Table I. These physical properties which take place during the vulcanization mixings were made on a small laboratory mill and the usual of hard rubber. The information presented here is compiled precautions with regard to mastication, heat on the rolls, etc., with this end in view. were taken to insure uniformity of treatment. The mixed During the past ten years or more, investigation into the stocks, after aging for 24 hours or more, were vulcanized in mechanism of vulcanization has been largely centered about a mold in a hydraulic press, the temperature of the press bethe function of organic accelerators in hastening vulcaniza- ing maintained a t 170” C. The test specimens were molded to tion. The characteristic curing curves, the most desirable form, so as to eliminate cutting, and the time of cure varied temperatures of vulcanization, and the action of inorganic from 10 minutes in some cases to a maximum of 120 minutes. activators for various organic accelerators have been studied Table I and theories evolved to explain the facts. It is not the in1 2 3 4 5 Number of mix tention to discuss here a theory of vulcanization, but to point First aualitv kiln-dried 70 70 70 smoked sheet 70 70 out that in formulating any comprehensive theory the hard Sulfur 30 30 30 30 30 1.4 Diph;nylguanidine rubber field ought not to be neglected, especially since the one 1.4 Ethylidene aniline accepted compound of rubber and sulfur exists in this field. Hexamethylenetetramine 1.4 Tetramethyl thiuramdiWeber3 points out that the end product of vulcanization 0.7 sulfide is polyprene disulfide, CloHl&. Other investigators have The test specimens were of the size and shape which it is confirmed this statement. Hubner4 examined a sample of ebonite, which, however, showed less than 4 per cent combined customary to use for testing hard rubber-that is, 15.24 cm. sulfur, and reported that he had found only the monosulfide (6 inches) long, with a restricted section in the center 1.27 of rubber. Spence and Young5 have also shown that the rate cm. (0.5 inch) wide. It is that recommended by the Hard of combination of sulfur with rubber is constant for a given Rubber Division of the War Service Committee. The specitemperature until 32 per cent of sulfur (estimated on the mix) mens mere broken on a horizontal Scott testing machine, is combined with the rubber. The writers’ previous work, the jaws of which were separated a t the rate of 0.5 cm. per on the changes in tensile strength as the vulcanization pro- minute, and the temperature was maintained a t 21’ C. during ceeds, shows that the tensile strength increases slowly during the testing. Previous to the testing the specimens were imthe first part of the vulcanization, then very rapidly, and mersed in water at 21 O C. for one hour. The results reported finally a t a much slower rate continues to a maximum. They are the averages of at least three tests, and experimental error has been reduced as far as possible by additional check tests 1 Presented before the Division of Rubber Chemistry a t the 69th when it seemed desirable. Meeting of the American Chemical Society, Baltimore, Md., April 6 to 10, 1925. The fragments from the tensile tests were ground to about 3 THISJOURNAL, 16, 359 (1925). 20 mesh and were used for the determination of coefficient 8 “The Chemistry of India Rubber,” p. D1. of vulcanization. The method employed is that adopted by Gumni-Zfg., $4, 627 (1910). SOCIETY, the Rubber Division of the AMERICAN CHEMICAL * Kolloid-Z.. 13, 265 (1913).
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