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and sheeted than does the corresponding pulp obtained from the heartwood by an identical White Birch Spruce cooking procedure. No satisfactory explanation Wood specie6 Chip" aource SapHeartSapHeartSapHearthas been reached. I n some direct comparisons wood6 wood6 woodo woodo woodo wood0 the average fiber length of the sapwood pulp is Yield. yo 44.4 43.2 47.7 46.0 47.7 46.7 Screenings, yo 2.1 2.0 1.0 1.0 0.3 0.2 definitely greater than that of the heartwood Absence of shives Fair Fair Good Good Excellent Excellent product. This is not always the case, however. Ether-sol., '32 1.68 2.59 1.22 1.78 .... .... Pentosans, Yo .. .. 5.73 10.68 4.3 4.5 The fact that heartwood was once sapwood would Lienin. % .. .. 0.80 1.13 0.47 1.37 Prysiiai tests suggest that the difference in properties of the 125 112 156 155 111 52 Bursting strength two pulps may be largely accounted for by 183 143 190 116 Tear resistance 252 187 C1 requirement, % 5 6 5 6 5 6 chemical differences that take place as the 0 All chipa '/iinch long */# inch thick heartwood is formed and may indirectly inb Acid contained 5% iree €301, 1% bombined 80s (sodium base), 5% combined SOz based on wood: cooking curve, to 135' C . in 6 hours, held there 4 hours; 75 pounds maxifluence the hydrolytic effect on the cellulose t h a t mum pressure. occurs during a cook. c Acid oontained 5% free 50s. 17' combined 801 sodium base), 6% combined SO, based on wood: cooking curve, t o 1408 C . in 4 hours, h h d there 4 houra; 75 pounds maxiBoth softwoods and hardwoods yield regularly mum pressure. a sapwood pulp that bleaches more easily than does the corresponding heartwood pulp. Table VI11 shows some of the values obtained with spruce and with white birch. The yellow birch and the 5. When cooking the heterogeneous lot of mill-prepared wood chips, an increase in free sulfur dioxide from 5 to 8 per beech behave similarly. The bleachability of these several pulps parallels the respective lignin content and it, in turn, is cent renders the calcium-base acid almost as effective as a sodium-base liquor that is made up a t the lower free sulfur directly related to the lignin found in the original heartwood and sapwood (2, Table V). dioxide level. Table VI11 also shows that where values were established, 6. Improper penetration of the combined sulfur dioxide the heartwood pulps are richer in pentosans and in etheringredient of the cook liquor during the early stages of the soluble content. Wood analyses give no positive indication cook results not only in reduced yield and a high percentage that we should expect the pentosans to be in that order but of screenings, but also causes a marked sacrifice in physical show ample evidence that the ether-soluble content should tests and in cleanliness of screened pulp. be higher in the heartwood pulp. 7. Less complete penetration of the acid salt into the larger chips is responsible for the greater demand for chlorine or its equivalent when such pulps are converted into bleached Acknowledgment products. This is clearly demonstrated with all species of The author is indebted t o C. W. Thing, M. W. Hayes, and wood investigated. The results simulate those obtained D. H. McMurtrie for their help in supervising the experiwhen an attempt is made to cook wood chips with an initial mental cooks and the analyses. liquor that is deficient in the bisulfite salt. TABLEVIII.
COMPARISON OF SAPWOOD AND HEARTWOOD
Comparison of Sapwood and Heartwood Experimental cooks have shown repeatedly that pulp made from sapwood has a higher tear resistance when hydrated
Mildew-Resistant Treatments on Fabrics KE deterioration of cotton fabrics due to the growth of mildew causes enormous loss, both industrially and in the household. Sometimes mildew merely discolors the fabric or gives it a musty odor, but more often mildew actively attacks the cellulose and causes considerable loss in fabrio strength. Certainly any method which will prevent such growth will markedly increase the durability and utility of the fabric. Thus a mildew-resistant fabric would have increased value to the consumer.
T
1 Present address, Western Regional Research Laboratory, Bureau of Agricultural Chemistry and Engineering, U. 6. Department of Agriculture, Albany, Calif.
Literature Cited (1) Richter, IND.ENG.CHIM.,23, 266 (1931). (2) Ibid., 33,75 (1941).
MARGARET S. FURRY AND HELEN M. ROBINSON U. S. Bureau of Home Economics, Washington, D. C.
HARRY HUMFELD' U. S. Bureau of Plant Industry, Washington, D. C.
Chemical finishes can be applied to cotton fabrics that will give adequate protection against mildew development. However, for general utility these finishes must have other desired characteristics. They must be comparatively easy to apply; they must not decrease the strength of fabrics or cause excessive shrinkage; they should withstand weathering and repeated laundering; and they should be colorless, odorless, and nontoxic to human beings. At the Bureau of Home Economics, investigations were undertaken to obtain satisfactory treatments for making cotton resistant to mildew. This paper reports an exploratory survey of finishing treatments which were considered of possible value as mildew preventives. Included in the study
April, 1941
INDUSTRIAL AND ENGINEERING CHEMISTRY
were commercially advertised mildew-resisting agents and many other compounds for mildew prevention suggested in the literature, as well as certain chemical treatments originated in the laboratories of this bureau. All of these finishes were applied to unbleached cotton duck, and their effectiveness in resisting mildew growth was determined. A review of the literature shows that many investigators have studied the problem of mildew growth on cotton fabrics. A few (8, 17) have considered cleanliness of the fiber as a means of preventing mildew growth, and some (16, 16, 34, 36) have studied the problem from the standpoint of atmospheric conditions conducive t o growth of mildew organisms. Others have tried to reduce mildew deterioration in fabrics by treating them with mildew-preventing finishes. As a result of the latter investigations, many finishing treatments have been suggested. The source of these treatments is indicated in the tables. In most of the reports no exact method of testing the effectiveness of mildew prevention is indicated. Some investigators (7, 8, 26) merely judged deterioration by the appearance of the treated fabric after exposing i t in various ways t o the action of mildew; Rihre (30)used a dye material that differentiates between fibers attacked by fungi and those not attacked; others (13, 26) determined the toxicity of the chemical used in the treatments toward different fungi without the use of yarns or cloth; and a few investigators (3, 19, 96)determined deterioration by obtaining the loss in breaking strength of the treated fabrics after subjecting them to conditions favoring mildew growth.
Preparation of Fabric An 8-ounce unbleached cotton duck with two-ply warp and single fillin yarns was used in this investigation. It was degreased and desized before the special finish was a plied. For the degreasing procedure the material was extractextwice from 2 to 3 hours each in two changes of carbon tetrachloride. This was followed by a treatment with 0.05 per cent starch and protein-solubilizing enzyme preparation at 60' C. for 1 hour. Finally, the cloth was thoroughly rinsed (92). The fabric was cut into strips suitable for the raveled-strip breaking strength test ( 2 ) . In order to bring the fabric strips to the same moisture content before conditioning, they were dried in an electric oven at 35-40' C. for 18 hours. All samples were conditioned in a constant tem erature and humidity room maintained at 70" F. (21' C.) an965 er cent relative humidity for 24 hours, and then were weighezon an analytical balance to within 1.0 mg. The details of the treatments, some of which required immersing the fabric in more than one chemical solution, are given in the tables. Each strip of fabric was processed separately in 50 ml. of the finishing bath a t the required temperature. It was a itated frequently. Unless otherwise stipulated, the bath was &owed to cool gradually to room temperature during the time the sample was immersed. The strip was then quickly removed and placed between two sheets of blotting paper and a roller, 1 kg. in weight, was drawn over the blotting paper. The roller was pulled in such a manner that little or no downward pressure was exerted by the hand. When the treatment was applied in more than one bath, the sample on being rolled after the first bath was immediately immersed in the second bath. Then after the final bath (whether the first, second, or third) the sample was rolled between blotters and dried at room temperature for 48 hours, after which time it was rinsed twice for 5 minutes in two changes of distilled water at 25-30" C. The strip was removed from the second rinse, rolled between blotters, and dried at room temgerature. When dry it was placed in an oven maintained at 35-40 C. for 18 hours, and again conditioned in the humidity room and weighed. The percentage gain in weight due to the finishing treatment was calculated. In acetylating the fabric with acetic anhydride and glacial acetic acid (Table I), it was necessary to vary the usual procedure. Immediately a t the end of the required time for acetylation the samples were rinsed quickly and thoroughly in five changes of distilled water, rolled between blotters, rinsed five times more, rolled again, and then allowed to dry a t room temperature. For this treatment the fabric change in weight due to the treatments was not determined.
539
The deterioration of cotton fabrics due to the growth of mildew causes enormous loss, both industrially and in the household. Materials infected with mildew usually are discolored$ have a musty smell, and show a definite loss in strength. The Bureau of Home Economics studied 135 chemical treatments for the prevention of this deterioration. These include commercia1 products and chemicals suggested in the literature as good mildew-resisting agents as well as treatments originated by the authors. Bacteriological tests on treated cotton fabrics were made following the procedure described by Rogers, Wheeler, and Humfeld (32) in which the amount of microbiological deterioration of the fabric is measured by a determination of the loss in breaking strength. The chemicals used are classed in several divisions: chemicals which change the form of the cellulose itself; resins condensed in the fibers of the material and those applied to the surface of the cloth; quaternary ammonium compounds; common insecticides, such as rotenone and sodium silicofluoride applied in solution to the fabric; substituted phenols, both with and without water-resisting coatings; inorganic salts used alone and with soaps; common antiseptics such as chlorothymol, phenyl salicylate, and various borates; organic salts of heavy metals applied in emulsion form; and other organic compounds with possible antiseptic properties. Thirty-five of the treatments showed excellent protection against mildew growth, and at least ten of them are so simple that they can be applied in the home.
Test Procedure The mildew resistance of the treated strips of cotton duck was determined by measuring their change in breaking strength after inoculation and incubation with Chaetomium globosum, Kunze. The microbiological procedure followed was the same as that described by Rogers, Wheeler, and Humfeld (32),except that the inoculum was sprayed on each strip of fabric with an atomizer under sterile conditions instead of being transferred to the sample with a pipet. This ensured even inoculation over the entire strip, and the method was rapid for a large number of samples. In a few instances the steam sterilizing rocess affected the linishing treatment that had been applied. &herefore additional strips were inoculated without sterilization, but the same care and sterile technique were used in handling them. All samples were examined for sterility before inoculation and for amount of growth on the third, seventh, and fourteenth day of incubation. This test procedure was so severe on the fabric that inoculated strips of untreated material were completely deteriorated within the incubation period. Figure 1 shows the degrees of protection obtained by two different treatments as compared with the lack of rotection on an untreated strip. flt the end of the 14 days, the strips were removed from the bottles in which they were incubated and carefully rinsed in running water to remove the mildew growth. After drying in air they were again placed in the oven at 35-40' C. for 18 hours. The samples were conditioned for at least 12 hours in the humidity room, and breaking strength measurements were made on the strips, using the motor-driven Scott tester. Breaking strength tests were also made on similarly conditioned, sterilized, but uninoculated strips of untreated fabric. The percentage loss in breaking strength of the treated strips expressed in terms of the untreated material was calculated. It was realized that finishing treatments themselves might seriously affect the breaking strength of the fabric. In this preliminary study, however, only in the case of the acetylation process was this determined. For all the other treatments the
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FIGURE 1.
FABRIC STRIPS WITH Chaetomium INOCULATED globosum AND INCUBATED FOR 14 DAYS A , treated with aoap and cadmium chloride: B , treated with a double salt of chrominm fluoride and sodium antimony fluoride; C, untreated; D , untreated sample magnified IOX.
change in strength due t o the combined effect of treatment and mildew damage was obtained.
Discussion of Results Tables I t o V give results showing the effectiveness in preventing mildew growth of various finishing treatments applied to unbleached cotton duck. Each value is calculated from the average of three breaking strength determinations and is reported as the loss in breaking strength of the treated fabric after inoculation and incubation with Chaetomium globosum. The smaller this loss in breaking strength, the greater is the resistance of the fabric to becoming mildewed; that is, the greater is the protection furnished by the special finish. On some of the strips that were not sterilized there was a slight contamination; but whenever loss in strength resulted, it was evident from the character of growth that the loss was due t o Ch. globosum and not to the contaminating growth. For convenience the finishing treatments and the results are grouped in the tables according to the chief constituent used in the treatment. Fairly good protection again& mildew growth as tested by the method used in this study is furnished by the acetylation process using acetic anhydride, glacial acetic acid, and zinc chloride for 21 hours a t 20-25" C. (Table I). This process (12) transforms cotton into a cellulose acetate (the monoacetate) according to directions given by Rheiner. He claims (88, 89) that this low acetylated form is obtained by moderating the composition and temperature of the acetylating mixture and maintaining the reaction for 20 hours or longer. As shown in Table I by the first acetylation method, maximum protection against mildew without loss in fabric strength from acetylation is obtained in 21 hours a t 20-25' C. It is necessary to control the temperature carefully. However, this treatment causes the fabric to become slightly stiff, and shorter periods of acetylation are not sufficient t o give mildew protection to the fabric. If acetylated for longer than 21
hours the fabric loses much strength, owing t o the effect of the treatment but not to mildew growth. The fabric then becomes very brittle. I n method 2 the reaction is too rapid for low acetylation and the fabric is deteriorated. Recently, however, Thaysen (55), by different conditions and concentrations of this acetylating mixture, has been able to treat cotton without deterioration. Urea-formaldehyde resin with starch gives no protection against mildew, but this may be because the starch furnishes food for mildew growth. The combination of acetone and formalin probably forms a resin film over the surface of the fabric. According t o this preliminary study, it is a satisfactory mildew-preventive agent. However, it is difficult to apply this treatment evenly t o the fabric. A commercial product, an alkylated dimethyl benzyl ammonium phosphate, used alone and combined with methyl acrylate resin, gives excellent protection against mildew. The resin by itself is not satisfactory. The compound, pentachlorodioxytriphenylmethane sulfonic acid (4) is a commercially successful moth-repellent treatment for wool. The results of this study, however, show that it has no mildew-preventive action when applied to cotton. Although rotenone has good properties as an insecticide, i t gives practically no protection against mildew even when large quantities are used. It makes the fabric yellow and slightly stiff. All of the other finishing treatments included in Table I are colorless and do not change the appearance of the fabric appreciably. All are odorless. I n Table I1 are grouped the finishes formed from substituted phenols. The treatments of salicylanilide, applied alone and followed by methyl acrylate resin or by a wax and aluminum acetate emulsion, give excellent protection against mildew, provided the treated fabric is not steam-sterilized. But if the fabric is sterilized, salicylanilide is lost and these treatments are not effective. I n ordinary use, however, salicylanilide-processed fabrics need not be subjected t o steam. If an
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emulsion of salicylanilide is applied with the wax and aluminum acetate, it gives complete protection even after sterilization. This treatment stiffens the fabric slightly. Wax and aluminum acefate emulsion is B water-repelling agent, and although i t has no mildew-resisting action (Table IV), it apparently aids in holding the salicylanilide on the fabric. On standing, salicylanilide-treated fabrics turn faintly pink. This compound has been widely recommended as a m i 1d e w-pr e v e n t i ng agent by a number of investigators (IS, 21, %), and it has been used commercially for some time. T h e c o m p o u n d s ophenylphenol, 2-chloroo-phenylphenol a n d pentachlorophenol are good mildew-resisting agents. According t o the results in Table 11, the first two compounds give better protection than pentachlorophenol. The sodium salb, sodium o-phenyl phenolate, sodium 2,4,5- t r i c hIorophenolate, and sodium pentachlorophenolate, are so soluble in water that they tend to rinse out of the fabric. However, with a 2.0 per cent solution of sodium pentachlorophenolate a sufficient amount of the chemical is held in the fabric to give excellent protection. But because of the pungent and irritating odor of these salts, fabrics treated with them are difficult to handle. When borax, cadmium chloride, monobasic lead acetate, or aluminumpotassium sulfate is applied to a sodium-pentachlorophenolate-t reated fabric, t h e i n s o l u b l e pentachlorophenolate is formed and held in the fabric. These two-bath treatments give excellent protection, and the finishes are colorless. However, the treated
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incompatible with alkaline substances, including soaps and calcium carbonate. It changes to thymol which has such a low germicidal potency that it appears to give no protection against mildew. Morris (25) reported similar results for thymol, As shown by this study, a combination of thymol with phenyl salicylate is an effective mildew preventive when enough has been used. Furthermore, steam sterilization does not remove it from the fabric. Certain dyes and mordants (Table 111) have been considered for a long time as
of nets. It seems easier t o apply, gives more uniform results, and requires less catechu t o give Drotection than method 2 with Dotassium Zichrbmate. The quantity of cateccu needed for the latter, which Atkins (3) speaks of as Cunningham's method, is likely to make the fabric stiff. Martius yellow with tannin gives only about 75 per cent protection, and tannin alone furnishes even less. These two treatments make the strips yellow and gray, respectively. Finishing treatments of organometallic compounds and metallic salts of organic acids are grouped in Table IV. Investigators (3, $7) recommend the use .of various metallic naphthenates which are sold commercially as mildew preventives for textiles. These naphthenates are not definite chemical entities but comprise a series of cyclopentane carboxylic acids. Copper and zinc naphthenate (Table IV), applied either in water or in Stoddard solvent, give complete mildew-resisting protection when used in sufficiently large quantities. Copper naphthenate is green, zinc naphthenate is colorless; both have a pungent disagreeable odor and stiffen the fabric slightly. Another copper organic compound, copper propionyl acetonate, is used commercially as
April, 1941
INDUSTRIAL AND ENGINEERING CHEMISTRY
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a mildew-preventing agent. It gives excellent protection but colors the fabric gray-green. Phenyl mercury oleate and p-tolyl mercury salicylate are also used commercially and are satisfactory as mildewresisting agents. Mercury salts are usually poisonous, but data are not yet available regarding the toxicity of these two compounds. Two-bath processes of soap and inorganic salts (Table IV) form insoluble soaps in the fabric. The cadmium soap (Figure 1-A) and the copper soap give excellent protection against mildew growth, but the aluminum-potassium sulfate, chromium-potassium sulfate, and ferrous sulfate combinations give no protection at all. Copper soap on fabric is blue; Cadmium soap is colorless. These soap treatments have an advantage over many of the others in that they are easy to apply. Atkins (5) mentions the commercial use as mildew preventives of copper soaps of palmitic and lauric acids as well as oleic acid. Of the finishing treatments using inorganic salts (Table V), the only one which is entirely satisfactory for inhibiting mildew growth is cadmium chloride followed by borax. It gives excellent protection. Treatments of barium and zinc Salk followed by borax allow complete deterioration of the fabric. When applied a t 100’ C. the copper sulfate treatments give fairly good protection; but if applied a t 25-30’ C. they are unsatisfactory since not enough salt is held in the fabric. Jarrell and co-workers (19) reported similar results for copper sulfate. Strips treated with copper sulfate and sodium carbonate are brown before they are sterilized, but on sterilization they become yellow. Although chromium-potassium sulfate followed by hot sodium hydroxide is recommended as a mildew-resistant treatment (B), i t fails to give protection under the severe conditions of the test used. Treatments using chromium fluoride, a double salt of chromium fluoride and sodium antimony fluoride (Figure 1-B), and various silicates and silicofluorides mentioned by different investigators (10,IB,33) also allow breakdown in fabric strength. Perhaps this is due to the difficulty of getting enough salt into the fabric to give protection. The thiosulfates and sulfides, except for sodium sulfide followed by potassium dichromate, also give no protection.
Summary Many different finishing treatments have been applied to a degreased and desized unbleached cotton duck. The mildew resistance of the treated fabric has been measured by its loss in breaking strength after inoculation and incubation with the test organism Chaetomium globosum. According to this method the following treatments give satisfactory protection as indicated by little or no loss in fabric strength: Miscellaneous organic compounds: Acetylation using acetic anhydride, glacial acetic acid, and zinc chloride. Acetone with formalin. An alkylated dimethyl benzyl ammonium phosphate alone and followed by methyl acrylate resin. Substituted phenols: Salicylanilide applied alone and followed by methyl acrylate resin, not steam-sterilized; an emulsion of salicylanilide with wax and aluminum acetate emulsion. o-Phenylphenol; 2-chloro-o-phenylphenol;pentachlorophenol. Sodium pentachlorophenolate alone and followed by borax, cadmium chloride, monobasic lead acetate, or aluminumpotassium sulfate. Th mol with phenyl salicylate. ChLrothymol applied alone and followed by wax and aluminum acetate emulsion when not steam-sterilized. Dyes and mordants: Catechu. Organometallic compounds and metallic salts of organic acida: Copper propionyl acetonate.
Copper and zinc na hthenate. $-Tolyl mercury sal?cylrtte. henyl mercury oleate. Cadmium soap; copper soap. Inorganic salts: Cadmium chloride followed by borax. Copper sulfate and sodium hydroxide; copper sulfate and sodium carbonate; copper sulfate *followed by wax and aluminum acetate emulsion when not steam-sterilized. Sodium sulfide followed by potassium dichromate. I n addition, other organic compounds have been synthesized in this laboratory that have excellent mildew-resisting action when applied to cotton. These chemicals are being patented. Although the treatments listed give adequate protection against mildew, many of them have other properties which make them undesirable for this purpose. For instance, some are colored and some may be toxic or deteriorate fabrics and therefore are not suitable for all conditions of use or for all types of fabric. Some may not withstand weathering and laundering. Hence these treatments are being subjected to further tests. They will include determining the mildew resistance of treated fabrics after exposure to weathering for various periods of time, after storage, and after repeated laundering.
Acknowledgment Acknowledgment is made to Dorothea Klemme and Doris Hirschmann of the Bureau of Home Economics for assistance with the microbiological work.
Literature Cited (1) Anonymous, Rev. g6n. m t . plastiques, 14, 270 (1938). (2) Am. SOC. Testing Materials, Standards on Textile Materials (1939). (3) Atkins, J . Marine Biol. Assoc. United Kingdom, 20, 627-41 (1936). (4) Back, Proc. Entomol. SOC.Washington, 39, 269-81 (1937). (5) Barker, Textile Colorist,61, 233-5, 276 (1939). (6) Brown, U. 8. Patent 2,035,527 (1936). (7) Burgess, J. Teztile Inat., 19, T315-22 (1928). (8) Ibid., 25, T391-4M) (1934). 30, 622-6 (1938). (9) Carswell and Nason, IND. ENO.CHEM., (10) Carter, Ibid., 22,8 8 5 7 (1930). (11) Cross and Bevan, “Researches on Cellulose” (1922). (12) Cross and Briggs, Brit. Patent 5016 (1908). (13) Fargher. Galloway, and Probert, J. Textile Inst., 21, T245-60 (1930). (14) Furry and Viemont, U. S. Dept. Agr., Misc. Pub. 230 (1935). (15) Galloway, J . T e d l e Inat., 21, T277-86 (1930). (16) Ibid., 26, T123-9 (1935). (17) Garner, I d . Chemist, 8, 445-8 (1932). (18) Ivanovsky, SBifenaieder-Ztg., 65, 327-8 (1938). (19) Jarrell, Stuart, and Holman, Am. Dyestuf Reptr., 26, 495-500, 519-23 (1937). (20) Koenigsberger, Brit. Patent 496,543 (1938). (21) Lenher and Slowinske, Am. Dyestuf Reptr., 25, P326-31 (1936). (22) Lowe, Brit. Patent 454,468 (1936). (23) McCrea, Mywlogia, 26, 449-53 (1934). (24) Mahr, Marine News, 25, No. 11, 31-2, 73 (1939). (25) Morris, J . Textile Inat., 18, T99-127 (1927). (26) Neil1 and Travers, New Zealand J . Sci. Tech., 19, 646-51 (1938). (27) Prebluda, U. 8. Patent 2,135,111 (1939). (28) Rheiner, Zbid., 1,861,320 (1932). (29) Rheiner, Tiba, 11, 567-77 (1933). (30) RiBre, Re% gbn. m t . color., 43, 441-4 (1939). (31) Roeg, Am. J. Pharm., 110, 72-5 (1938). (32) Rogers, Wheeler, and Humfeld, U. 8. Dept. Am., Tech. Bull. 726 (1940). (33) Sprankle and Slabaugh, Tedile World, 87, 2015 (1937). (34) Stringfellow, Ana. Dyestuf Reptr., 28, P388-90 (1939). (35) . . Thavsen. Bunker. Butlin. and Williams. Ann. Avvlied Biol... 26., 756-81.(1939). . (36) Thom, Humfeld, and Holman, Am. Dyestuf Reptr., 23, 581-6 (1934). (37) Trevor, C h m . Industries, 45, 661 (1939). (38) Weed, U. S. Patent 2,014,676 (1935). (39) Zwicky, Kaspar, and Brunner, Ibid., 2,159,875 (1939).
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PRIUSIUNT~DD before the Division of Biological Chemistry at the 100th Meeting of the American Chemical Society, Detroit, Mich.
