February, 1933
INDUSTRIAL AND
ENGINEEHIXG CHEMISTRY
carbonate and the absence of ammonia and carbon dioxide in the case of the laboratory solubility experiments doubtless account for the difference. I n the plant the magnesium is present as chloride and sulfate, and is probably precipitated hst as a basic partially ammoniated carbonate, which changes over to the normal salt shown by the analysis. The formation of such a triple salt frcrm solutions of' magnesium chloride, sodium carbonate, and sodium chloride was claimed by de Schulten, but little information is available concerning 1 Mellor, J. W., "Comprehensive Treatise o n Inorganic and Theoretical Chemistry," Vol. 111, p. 367, Longmans, 1924.
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its properties or exact method of formation. The loss of alkali due to the co-precipitation of sodium carbonate and sodium chloride amounts to about 4 and 2 tons, respectively, per hundred tons of soda ash produced. The purity of the final product is, however, very satisfactory, analyzing 99.04 per cent sodium carbonate. Experiments are now in progress with the object of finding a n economical method of removing the magnesium from the brine before it enters the ammoniation system. RECEIVED .4upup.t 27, 1932.
Photochemical 0.xidation of Cottonseed Oil GEORGER. GREENBANKAND GEORGEE. HOLM Bureau of Dairy Industry, 1 :. S. Department of *\griculture, Washington, D. C.
A
T h e relalire accelerating effect of light of filters ( 3 ) p r e p a r e d by filling Petri d i s h e s with solutions of t h a t heat and light acdifferen[ of the visiblf specfrun upon the dyes or inorganic salts and sealcelerate the autoxidation aatoxidation of cottonseed oil is studied. The ing the space between the bases of fats and oils. However, there greatest accplerafi%' effect is nofed in the range and covers w i t h s e a l i n g wax. seem to be no available data on Thesefilterswerepermanentand of fhe oranae band; the blue range is fhe least t h e relative effects of various easily prepared. I n making the bands of the spectrum upon the effeciipe. comparisons, i t mas necessary p r o m o t i o n of these oxidative that the transmitted energy for c h a n g e s , notwithstanding the general impression that light transmitted by amher glass of each range of wave bands used should be equal. To accomplish this, a thermopile (described by Coblentz, I ) was placed various shades is the least effective in this respect. Because of the general practice of packing fat-containing in the position to be occupied by the fat container and the products in glass containers of various colors. a better knowl- light source adjusted in each case to give equal deflections edge of the relative accelerating effect of different spectral of a galvanometer. Table I1 gives the oxygen absorption per 100 grams of bands of light upon fat oxidation is of consideraLle practical fat when light from different sections of the spectrum was interest. studied. These results confirm the qualitative observations O X Y G E N ABSORPTIOX CAT.4LYZED BY L I G H ~ and indicate that the orange band of the spectrum is decidedly more powerful as an accelerator of fat oxidation T h a t oxygen absorption by a fat is strongly accelerated than are the red, green, or blue bands. There also seems by light of the visible spectrum is indicated by tlie results of to be an indication in these results that yellow-orange light the following experiment. is more powerful in this respect than is orange-red light. One hundred prams of cottonseed oil were placed in a dosed tube with a small side tube t o R hich I\ as attached t graduated TABLE I. RELLTIVE C.4TlLYTIC EFFECT O F LIGHT O F J-ARTING gas buret containing oxygen The tube containing the fat was ISTEXSITY so arranged that it could be shaken continuouslv, thus producing LIGHT 01 ABSORBED BY PHOTOthorough mixing of the fat and ovvgen To askertain the effect INTEKSITT TIME 100 0 . Of OIL ACCELERATION of light of the visible spectrum, the beam of light from a proHours cc. X check jection lantern carrying a 500-matt hIa7dn lamp I\as directed None 8 0.2 1.0 upon the tube. A filtw prepared from a solution of 17 grams Diffuse 8 1.1 5.5 IntenPe 13.1 8 65.5 of copper sulfate in a liter of Yater R as used to sei een out the infra-red rays, and this filter was cooled xith a currmt of air. TABLE11. ABSORPTIOSOF OSTGES BY COTTONSEED OIL \VHESThe absorption of oxygen by the fat, when kept in the dark PLACED IS LIGHTOF VARIOCS BANDSOF VISIBLE SPECTRUM and when subjected to the diffuse light of a room and to the LIGHT TIME ABSORPTIOS OF TRlKSMITTED B.4sD OF EXPT. 0 2 PER 100 CC. strong artificial light described, waq determined. The 2. FIours cc . results are given in Table I. 4450-4950 Upper blue 8 2.60 UTHORS generally agree
OXYGEN
ABSORPTION iiCCELERATED BY LIGHTF R O \ l PARTS OF SPECTRUM
T'SRIOL-S
Qualitative observations had been made from time to time which indicated that the light of the red m d of the spectrum was the most active as a fat-oxidation accelerator. T o ascertain the most effective wave bands as well as to determine their relative effects, the oxygen absorption by samples of cottonseed oil in different lights consisiing of wave bands covering a range of approximately 500 -4.each mas measured. The desired spectral band was obtained by the use of
5100-5660 5540-5940 6100-6650 6500-7250
Green 1-elloa Orange Red
S 8
8 8
1.65 5.00 9.20 1.10
RATE OF REDUCTION OF METHYLENE BLUE IN FATSBT DIFFERENT BASDSOF LIGHT The effect of various bands of visible light as accelerators was studied further by means of the methylene blue reduction method published by the authors ( d ) , wherein the time of reduction of a n alcoholic methylene blue-fat solution is determined. The time of reduction is a measure of the resistance of a fat to oxidation.
1 3 I) 1, S ' I li 1 A I.
168
a h 1) li N
(;
Glasses of various colurs were cut to fit one side uf a Lovibond tintometer cell, and the cell was filled with an alcoholic fat-dye solution. The cell was then
