January, 1924
INDUSTRIAL A N D ENGINEERING CHEiMISTRY
were dissolved in hot petroleum.ether and allowed to stand over night in the ice box. A white compound separated out and was filtered and washed with petroleum ether. The melting point was 114' C. This was evidently the tetrabromide of linolic acid. Ten grams of the unsaturated fatty acids were further examined by oxidation with a dilute solution of potassium permanganate by Hazura's method.8 The acids were converted into the potassium salt and an equal amount of potassium permanganate was added. The product of oxidation was digested with small amounts of ether to remove any unoxidized acids. It was then exhausted with large quantities of ether and the ethereal solution evaporated to small volume. A substance melting a t 127" to 128" C. separated. Upon
* Lewkowitsch, "Chemical Technology and Analysis OF
55
crystallizing from alcohol, glistening laminae separated, melting a t 130" C. ANALYSIS 0.1047 gram gave 0.2628 gram COa and 0.1093 gram HnO. H = 11.6. C1sHaaO4requires C = 68.4; H = 11.4
C = 68.5;
This is evidently dihydroxystearic acid, obtained on oxidation of oleic acid (melting point 136" C.). Using the iodine number of the unsaturated acid (105.4) and the theoretical values of oleic acid (90) and linolic acid (181.4), the percentages of acids in the unsaturated acid fraction were calpulated to be 83.3 per cent oleic and 16.8 per cent linolic. The composition of the oil is therefore approximately as follows:
Oils, Fats and
Waxes," Vol. I, 5th ed., p. 563,
. . . .. .. .. .. . . . . . . . . ........ g ~ ; ~ i ~ a ~] ; d Oleic acid, as glycerides.. . . Linolic acid, as glycerides.. . . .
Phytosterol (m. p . , 134' C , ) . . , ...
Per cent
80.0 16.0 4.0 Present
Influence of Water-Insoluble Matter w o n Polarization of Raw Cane Sugars' By G. H.Hardin N E W YORKS U G A R TRADELABORATORY, NEW YORK,N.
I
Y.
This table shows without N THE study of some of The water-insoluble matter content of a large number of raw cane explanation the relationthe more pressing probsugars is given. The average specific gravity of the water-insoluble ships of the various inlems pertaining to cane matter was found to be 1.87. The average percentage of watergredients tabulated. The sugar manufacture, cominsoluble matter of 96 degrees Cuban centrifugal sugar was found to majority of Cuban sugars paratively little attention be 0.159, the range extending from 0.017 to 0.423. The waterdo not contain sufficient has been paid to the presinsoluble matter consists of 87.5 per cent organic matter (cane fiber. ext,raneous substances to ence of extraneous subetc.) and 12.5 per cent mineral matter (earth. scale, lime salts, etc.). have an appreciable effect stances in raw sugars and The average error in polarization resulting from the presence of wateron the polarization, and it their effect on the polarizainsoluble matter is $0.021 sugar degree, the range extending from is only when percentages tion. While occurring in +0.001 to +0.057. I n the case of a sugar contaminated with of 0.2 and above are found relatively small amounts, 3.48 per cent sand, the error in polarization was found to be +0.35 that we may expect errors these substances should sugar degree. Owing to the high water-absorption capacity of cane of sufficient magnitude for neither be ignored nor confiber, a direct ratio is noted between moisture content of the sugars consideration. Much less sidered in any degree a and the insoluble constituents. interference is caused by negligible quality, but as a the inorganic matter, which factor of some importance in the fabrication and marketing of the raw commodity. has been reduced to almost a minimum in the improved Cuban raws contain varying amounts of bagacillo and foreign methods of manufacture. Consisting for the most part of matter, the latter consisting largely of minute particles of earth, lime particles, and iron rust and scale from the factory lime, scale, and earth. Since we are chiefly concerned with machinery, it constitutes a more or less stable factor in the the volumetric changes produced by these substances col- estimation of undissolved impurities, and apparently bears lectively, no attempt has been made to separate them further no well-defined relationship to other ingredients. Referring than dividing them into two general groups-viz., organic to the figures in the table, we find that 0.2 per cent of waterand inorganic matter. insoluble matter will cause an increase in volume of 0.028 Typical Cuban sugars, selected from samples received a t cc. for 26 grams of a sugar of 96 test. Bearing in mind that this laboratory, were used for examination and for ascertain- the divisions on the scale of the saccharimeter usually do not ing the effect of extraneous matter on polarization. The permit of a reading lower than 0.05 of a degree, the small settlings accumulated in the dissolved sugars were washed error might be assumed to be negligible; but taking the thoroughly with water by decantation, collected on filter premise that the small errors in sugar testing are largely addipaper, and dried. A weighed amount not exceeding 1 gram tive and that small differences are recorded in a general was taken for the determination of specific gravity. The average, no error of even 0.01 degree is too small to be igaverage specific gravity of the settlings from a number of nored. Not less significant from a commercial point of view different sugars was found to be 1.87. Results of the analyses is the fact that buyers and sellers of raw sugar employ averages of more than one hundred Cuban marks compiled by the t o the fourth decimal in settlement of their transactions. Roughly estimated, about 15 per cent of the Cuban raw laboratory when averaged gave 0.094 per cent of waterinsoluble matter, the percentages ranging from a minimum of sugars analyzed a t this laboratory contained on an average 0.017 to a maximum of 0.65 per cent. The figures of Table I of 0.25 per cent of water-insoluble matter, which, calculated arranged conveniently for quick comparisons will show the to volume in 26 grams, will give an increase in polarization proportion of inorganic to organic matter in the water-insolu- of 0.03 per cent. Furthermore, instances have been freble and the volume occupied by the latter in 26 grams of sugar. quently recorded of sugars running as high as 0.45 per cent in water-insoluble, but such sugars are not representative and 1 Presented before the Division of Sugar Chemistry at the 66th Meeting point to carelessness in manufacture. The effect on the polarof the American Chemical Society, Milwaukee, Wis.,September 10 to 14,1923.
INDUSTRIAL AND ENGl’NEERING CHEMILJTRY
66
ization of a large amount of water-insoluble matter is best illustrated by tke following example of a raw sugar contaminated with sand recently analyzed at the laboratory. Polarization Degrees
93.30
Volume Occupied by Sand in 26 Grams cc. 0.38
Sand Per cent 3.48
Increase in Polarization Degrees 0.35
It is evident that the observed reading of 93.30 is much too high, Computed on the basis of 3.48 per cent sand of specific gravity 2.38, it will be found t h a t the true polarization is 92.95. Practically the same result is obtained by Scheibler’s method of double diIution: 26 grams of the sugar dissolved in water, clarified with lead subacetate and made to 100 cc., polarized 93.30; 26 grams of the same sugar treated with the clarifying agent and made to 200 cc. polarized 46.55. Calculating, (46.55 X 4) - 93.30, we fmd the corrected polarization 92.90. The error in this case is obviously too high to be overlooked and emphasizes the importance of greater vigilance in manufacture and testing of raw sugars. In commercial practices the simple polariscopic test is all that is generally required, and in expediting this work the chemist is allowed little time and opportunity to make a close inspection of the sugars under observation. However, if considerable amounts of water-insoluble matter are noticeable and a true polarization is desired, one of the two methods just referred to should be used in making the proper correction for the saccharimeter reading. Errors of volume introduced by means of the precipitate of insoluble lead salts formed in the clarification of sugar solutions in the wet way are corrected for in a large measure by Horne’s method of “dry defecation.” This method, which consists in adding dry subacetate of lead to the measured volume of the sugar solution, does not, however, correct for the errors in polarization caused by the water-insoluble substances, since the volume of the solution in the 100-cc. flask before the addition of the clarifying agent is not 100. TABLE I
Volume
Orcunied ~.._ _ _ I
Av.
Av.
Total by Insol- Increase WaterOrganic Inorganic uble Mat- in polariInsoluble Bagacillo, Clay, Iron, ter in 26 zation of 96 Matter Etc. Lime Grams Test Sugar Moisture P e.. r cent Per cent Per cent Cc. Dearees Per cent . 0:ior 0.79 0.006 0.002 0.017 0.011 0.006 1.15 0.002 0.006 0.040 0,042 0.008 0.87 0.005 0.008 0,050 0.055 0.010 0.97 0.014 0.010 0.060 0.074 0.011 0.87 0.011 0.004 0.084 0.080 0.007 0.93 0.006 0.008 0.048 0.054 0.013 1.00 0.011 0.014 0.095 0.106 0.015 1.24 0.017 0.016 0.097 0.114 0.95 0.017 0.014 0.018 0.116 0.130 1.63 0.019 0.018 0.020 0.130 0.148 2.03 0.027 0.032 0.028 0.168 0.200 0.018 1.37 0.019 0.018 0.121 0.139 1.28 0.030 0 030 0,200 0.010 0.210 0.030 1.91 0.031 0.020 0.199 0.219 0.031 1.97 0.032 0.030 0.202 0.232 1.77 0.035 0.034 0.028 0.234 0.262 0.036 2.27 0.038 0.040 0.240 0.280 0.032 1.84 0.033 0.215 0.026 0.240 0.040 1.59 0.042 0.279 0.028 0.307 0.041 1.88 0.043 0.017 0.299 0.316 2.19 0.049 0.052 0.054 0.321 0.375 2.48 0.054 0.056 0 040 0.360 0.400 0.057 1.74 0.059 0.037 0.386 0.423 1.98 0.048 0,035 0.050 0.329 0.364 I
Av.
I
Av. Av. _- . of . 60 analyses 0.159
0.140
0,020
0.021
0.020
1.35
Because of its moisture-absorbing properties, the bagacillo of raw cane sugars increases the difficulty of manufacturing a sugar of high polarization and good keeping quality. The analyses of the numerous sugars in Table I point to a ratio between bagacillo and moisture content. Comparing the figures we find that as the water-insoluble matter increases there is similarly a general increase in percentage of moisture. The ratio of progression, while not uniform step by step, persists in no uncertain manner throughout a long series of
Vol. 16, No. 1
analyses. Averaging the percentages of the first group of five figures given in the moisture column, a result of 0.93 is obtained. The second group of the ascending series gives an average of 1.37, the third 1.84, and the fourth 1.98. Few of the large number of analyses that have been made can be tabulated here, but as an instance of the averages of twelve results the moisture content was found as follows: 0.90 per cent as compared with the bagacillo ranging from 0.01 to 0.1; 1.10 per cent for bagacillo between 0.1 and 0.2; 1.85 per cent for bagacillo between 0.2 and 0.3; 2 per cent for bagacillo between 0.3 and 0.4. It is clearly seen that there is a relation between moisture content and bagacillo and that the latter directly affects the keeping quality of sugars which, not being dried sufficiently, are exposed to many different fermentation processes with ultimate deterioration. ACKNOWLEDGMENT The author desires to express his thanks to C . A. Browne for many helpful suggestions in the preparation of this paper.
Apparatus for Making Momentary Electrical Contacts a t Regular Intervals’ By Harlan W.Johnson IOWA AGRICULTURAL EXPERIMENT STATION, AXES, IA.
ECENTLY it was desired in this laboratory that a series R of momentary electrical contacts a few minutes apart be made a t fairly regular intervals over an extended period of time. Apparatus for making such contacts could not be obtained, so the author devised a mechanism (page 57) that might be of interest to others confronted with a similar need. Its construction consumed not more than 2 hours and required only material and equipment found in most laboratories. The motive power operating it is a thin trickle of water. I t can be regulated to give contacts a t various intervals from 1 to 10 minutes and is positive in its action. The device has been used for nearly a year and has given the utmost satisfaction. The materials used were two 1-quart tin cans (those used happened to be square with round corners), a few feet of heavy wire, a piece of rod from a ring stand, some scraps of galvanized sheet iron, two small brass bolts with two burrs each, a small piece of fiber insulation, a short spring, a small piece of copper sheet, two small binding posts, and some solder. Two pieces of wire, A and A’, were soldered to the bottom of the cans and one, A”, a t the top, as shown in the illustration, to hold them rigidly 4 l / ~inches apart. To the top wire a t its center a small wire ring, B, was soldered. At the center of the bottom wires and underneath, a U-shaped piece of the sheet iron, C, was soldered to form a bearing around the ringstand rod D, which served as a support for the whole apparatus. Through the side near the top of each can a hole was punched for an overflow. In the side near the bottom a hole was punched and a needle valve, made of the small bolts and burrs as shown in the small insert in the drawing, was soldered on. This completed the main portion. To one end of the bearing rod D was soldered a piece of sheet iron, E , with which to screw the rod securely to the table. About the center was soldered a wire upright, F, 1 Received
June 30, 1923.
