Absorption spectra and fluorescence of fats.
W. Sp r o e s s e r (Chem. Umschau, 1928, 3 5 , 325—327).—
Weak absorption maxima were found in the absorption spectra of cacao batter (between 270 and 280 u.(x) and some other vegetable butters in chloroform solution.
Suggestions arc made for the technical photometric
examination of the fluorescence of fats by comparison with a standard object, with the help of colour filters to limit the range of light transmission.
E. Le w k o w it s c ii.
Sham cola n u t s . D. V a n Os a n d 'Y . V a n d e r W a l
(Pharrn. Wcekblad, 1928, 65, 1266—1271).—Nuts from a consignment purchased as cola nuts, found to contain no caffeine, but 38% of fat, and differing in structure and physical properties greatly from the true product, were identified as seeds of Bassia Parkii (shea nuts).
S. I . Le v y.
Fat from the liver of the sperm whale. M. T s u j i-
m o t o and K . Ki m u r a (Chem. Umschan, 1928,35, 317—
318).—By ether extraction of sperm-whale liver, 6-3%
of a yellow-brown semi-solid fatty material was obtained, yielding on saponification 69 • 3% of fatty acids and 19 • 3%
of unsaponifiable m atter. The fatty acids formed a yellow-brown, semi-solid crystalline mass with m.p.
32—33-5°, <ZJ4° 0-8877, neutralisation value 194-1, iodine value 141-3, nf, 1-4610, ether-insoluble bromides 38-5% (blackened without melting a t 250°, bromine content 70-47%). The lead salt-ethcr separation yielded about 75-4% of liquid acids (neutralisation value 188-9, iodine value 175-5, n® 1 -4720), and about 24-6%
of solid acids (m.p. 52—53°, neutralisation value 209-5, iodine value 11-8). By the lithium salt^acetone method there were obtained 23-4% of the highly unsaturatcd acids with neutralisation value 170, iodine value 311, and nf, 1-4923. The unsaponifiable m atter was an orange-yellow, viscous, semi-solid material, iodine value 260, which gave colour reactions reminiscent of vitamin-A ; it contained 48% of cholesterol, and the authors further succeeded in isolating a new un- saturated hydrocarbon (cP]'5 0-8981, « V 1-5110, iodine value 379-5, mol. wt. 501) to which they assign the probable formula C35H60. E. L e w k o w it s c h .
Physical properties of pure triglycerides. R. B.
Joglekar and H. E. Wa t so n (J.S.C.L, 1928, 47, 365—
368 t).—The physical properties of the synthetic gly
cerides of capric, lauric, myristic, palmitic, and stearic acids have been ascertained ; the examination showed that the m.p. and refractive index afforded little criterion as to purity, but the densities, solidifying points, and especially the viscosities varied appreciably even when a fair degree of purity had been attained. Curves for the solidifying points of mixtures of tripalmitin and tristearin were p lotted; for mixtures w ith from 25 to 50%
of tristearin points were obtained characteristic of the two modifications (double m.p.) of this glyceride. The authors were unable to confirm Pascal’s values (B., 1914, 602) for the refractive indices of mixtures of tripalmitin and tristearm, but found a linear relation between wD and composition between 70° and 80°.
E. Le w k o w it s c h.
Swelling [absorption] phenomena of alum inium fatty acid [soaps] in various solvents. I.—III.
E. MfRKOWicz (Farben-Ztg., 1928, 34, 326—328, 414—
418, 503—505).—I. When dibasic aluminium palmitate, largely used as a flatting medium for paints, is stirred with certain organic media it gradually absorbs th solvent, swelling to form pastes or gels, the char of which depends on the solvent employed. The so1
B r itis h C h e m ic a l A b s t r a c t s —B .
102 Cl. X I I .—Fa t s ; Oi l s ; Wa x e s.
are classified under (1) aliphatic hydrocarbons (benzine, white spirit) yielding opaque soft pastes which are easily spread or painted o u t ; (2) aromatic and chlorinated hydrocarbons from which strongly swelling, jelly-like, translucent elastic gels are produced, and (3) crude turpentine etc., in which aluminium palmitate swells to a translucent non-elastic, ropy gel. On drying in air, the pastes with aliphatic solvents become more elastic, but do not flow, and ultimately dry to hard crusts, the process resembling generally the drying of a highly concentrated suspensoid. Benzene gels retain the solvent for very considerable periods ; with thick masses a skin is formed and finally a similar horny mass is produced.
Terpene gels are sharply distinguished in th a t the mass flows and retains its tenacious nature for several weeks (cf. aluminium linoleate); no skin-formation or shrinking was observable, although after long expo
sure the ductility is reduced. In the absence of air the viscosity of the aromatic and terpene gels, which is a maximum shortly after mixing, decreases gradually to a limiting value ; in the former case no further change occurs, but terpene gels become more homogeneous, and in greater dilutions may separate into gel and sol phases. The aliphatic pastes, however, are never stable, but always pass after a time into the gel condition, although remaining turbid. The fully dried crusts or gels may be made to swell again in the original or another solvent.
II. The reactions of aluminium palmitate with 25 different dispersion media are discussed in detail.
No swelling occurs in water, alcohol or acetone, dioxau or aniline (liquids of high dielectric constant), nor in viscous fluids such as linseed oil or paraffin oil. The other solvents, in which marked absorption occurs, are examples of the groups considered in part I. Inter
mediate types are represented by decalin and amyl acetate. Measurements were made of the changes of viscosity and time of setting depending on the concen
tration of the solvent; the decrease of viscosity with time is greatest with the chlorinated hydrocarbons and least marked in the ease of turpentine. W ith the aliphatic pastes the solidity, absorption, and trans
parency were found to vary with the b.p. of the solvent;
with terpene gels the form of the product depends on the age, origin, and purity of the solvent.
III. The difficulties encountered in the technical application of aluminium palmitate to m att varnishes etc. are discussed : care must be taken in the choice of solveut in order to avoid gelatinisation, and the fully- . saturated paste should be incorporated as soon as possible. A greater flatting effect is produced with lower-boiling solvents, of which greater absorption occurs. Amyl acetate is the most suitable dispersion medium for use with nitrocellulose lacquers, whilst for waterproofing textiles, for which a high concentration is required, benzene or carbon tetrachloride is recom
mended. If an impervious, continuous coating is desired, solutions in turpentine or decalin may be used.
E. Le w k o w it s c h.
D rying process of fatty oils. H. Wo l f f (Chem.
Umschau, 1928, 35, 313—317).—Following a discussion of various theories of the drying of oil films, the author - describes experiments on the influence of the base
employed (zinc, iron, glass) on the drying curves (increase in weight/time) of tung oil, linseed oil, and boiled oils.
I t is confirmed th a t an actual decrease in the weight of the drying film may occasionally be observed a t the beginning of the drying process. E. Le w k o w it s c h.
D eterm ination of unsaponifiable m atter in oils and fats. E. L . Sm it h (Analyst, 1928, 53, 632—
641).—A method for determination of unsaponifiable m atter in oils and fats, claimed to be accurate to within 1% of the amount present, consists in adding 40 c.c. of alcohol and 10 c.c. of 40% aqueous sodium hydroxide to 20 g. of oil, and boiling for 1 hr. under reflux. The solution is then transferred to a separating funnel with 150 c.c. of water, shaken with 300 c.c. of redistilled ether, the soap solution extracted twice more with 250 c.c. of ether, the combined extracts washed with 20 c.c. of water, and the bulk of the ether removed.
The soap solution is extracted three times more with 250 c.c. portions of ether, the extracts are washed, and the bulk is reduced in the same flask as the first extract. The extract is then rinsed with ether into a separating funnel, and 50—75 c.c. of ether in another funnel are used for extracting all the wash liquors from the first separator. The extract is washed twice w ith water, then with 2iV-sodium hydroxide in 10% alcohol, followed by two more water washings, and the whole repeated a t least once. Finally it is washed with 0-5iV-hydrochloric acid and then with water to wash out alcohol from the ether layer. The ethereal extracts are evaporated and the residue is weighed, mixed with 10 c.c. of neutralised alcohol, warmed, and titrated with 0-025iV-sodiuin hydroxide (1 c.c. = 7 mg. of fatty acid, as oleic acid). A shorter method involves only four extractions. The first three extracts are united, treated with 20 c.c. portions of wash liquors, using the fourth extract to re-extract the washings.
D. G. He w e r.
Determ ination of the hydrogen value of unsatur
ated com pounds. H. I. Wa t e r m a n, J. N. J. Pe r q o t n,
and H. A. Va n We s t e n (J.S.C.I., 1928,47,363—365 t).—
A new method for the determination of the hydrogen value of unsaturated compounds, especially suitable for substances having high vapour pressures, is described in detail. Hydrogenation is performed in the presence of a catalyst, and the volume of gas absorbed is measured
directly. E. Le w k o w it s c h.
H igh-vacuum grease. F. He in r ic hand F. Petzo ld
(Z. angew. Chem., 1928, 41, 692—693).—The value of nine varieties of grease for lubricating stopcocks of apparatus in which it is desired to maintain a high vacuum has been determined, and the results are repro
duced in a series of graphs showing on a logarithmic scale the increase of internal pressure with the time.
A . R . Po w e l l.
Action of air on nickel catalyst for oil hydro
genation. A. Bag (Masloboino-Zhir. Delo, 1928, No. 5, 6).—The loss of activity of a nickel catalyst cooled in carbon dioxide, when exposed to air for one month, is small. Ch e m ic a l Ab s t r a c t s.
Film characteristics of the esters of the co m ponent fatty acids of linseed oil. B. H . Th u r m a n x
and W. R. Cr a n d a l l (Ind. Eng. Chem., 1928, 20,
B r itis h C h e m ic a l A b s t r a c t s — B .
C l . X I I I .— P a i x t s ; P i g m e x t s ; V a r x i s i i e s ; R e s i n s . 103
1390—1392).—The behaviour of films of the ethyl esters of the fatty acids of both linseed oil and partially hydrogenated linseed oil—ethyl oleate and stearate—
singly and in admixture, has been examined. Nitro
cellulose lacquer was used as a fixative and the films, on muslin and tinned iron, were examined frequently over a period of 10 months. The esters of the less un
saturated fatty acids such as oleic acid are very stable in films, but the esters of the more unsaturated acids are not so stable. They rapidly become sticky, odorous, and dark-coloured, and it is therefore necessary to compare films of oleic derivatives or substances having a similar range of iodine value obtained by polymerisation or hydro
genation of linseed oil. E. H . Sh a k v l e s.
Com position of Chinese wood oil (tung oil).
A. St e g e r and J. v a n Loon (J.S.C.I., 1928, 47, 361—
3G3 t).—The authors summarise the literature on the constitution of tung oil, and give an account of the preliminary analysis of a typical wood oil, which they believe to consist principally of the glyceride of an isomeride of linolenic acid. Practically only fatty acids with an 18-carbon straight chain are present ; the saturated fatty acids appear to consist of a mixture of 75% of palmitic and 25% of stearic acids.
E . Le w k o w it s c h.
B audouin’s sesam e oil reaction. IL He l l e r
(Allg. Oel- Eett-Ztg., 1926, 25, 315—316 ; Chem. Zentr., 1928, ii, 301).—Baudouin’s test with hydrochloric acid, and the test with furfuraldehyde and hydrochloric acid, are not so trustworthy as is Soltsien’s test.
A. A. El d r id g e.
Determ ination of adsorptive power of bleaching earths used to decolorise oils. A. Wib e r g (Z.
angew. Chem., 1928,41, 1338—1342).—The bleaching effect on soya-bean and coconut oils of decolorising earths under varying conditions was studied by measuring the intensity of the colour remaining after treatment in a simple apparatus. I t is remarkable th a t the adsorp
tion of the colour increases with increased temperature of reaction (up to 98°). No advantage wTas gained by increasing the rate of stirring above 200 r.p.m. In order to obtain comparative results, it is essential that adsorp
tion equilibrium be reached (a condition attained in the tests recorded within 15 min. a t 98° and 200 r.p.m.).
E . Le w k o w it s c h.
Transform ations of fatty acids. St a d n ik o v and others. Fatty acids in petroleum . Ta n a k a and
Ku w a t a. M iscibility of castor oil w ith hydro
carbons. Ta b e rand St e v e n s. Oil testing. Fr ie d e- b a c h.—See II. Availability of nitrogen of oil cakes.
Ay y a r.—See XVI. Irish butter. Ar u p. Vitamin- D in butter and m argarine. Fl u r y.—See XIX.
Digestion of sew age grease. Ne a v eand Bu s w e l l.—
See X X III.
Pa t e n t s.
Apparatus for [solvent] extraction of oils, fats, etc. from substances containing the sam e. G. W.
Br a d s h a w and E. B. Ja c k so n (B.P. 298,675,15.7.27).—
A valve mechanism to be placed between the solvent extractor and the vessel used for solvent recovery from the meal is described. The inlet to the latter vessel stands up above the floor of the valve casing and
con-stitutes the seating of the valve, which consists of a horizontal sliding hollow casing, closed by a perforated plate through which the solution may be drained from the extractor. E. Le w k o w it s c h.
Lacquers etc. (B .P . 301,133).—See X III.
XIII.—PAINTS ; PIGMENTS ; VARNISHES ; RESINS.
Oil absorption in paint grinding. A. Eib n e k
(Farben-Ztg., 1928, 34, 725—729).—A summary of recent investigations on the oil absorption of pigments, special reference being made to the work of Wolff in this field. The modern hypothesis th a t equal volumes of pigments require approximately equal volumes of oil to produce the “ adhesion-cohesion equilibria ” con
stituting paste paints is discussed fully. The very wide variation in oil absorptions based on equal weights of pigments differing appreciably in sp. gr. has obscured the position in the past. Other factors receiving con
sideration are the relation between oil content of oil pastes and the amounts of oil necessary to convert such pastes into ready mixed paints, and the influence of structure and surface properties of various pigments on oil absorption. S. S. Wo o lf.
Distribution of pigm ent in paint film s. H. Wo l f e
(Farben-Ztg., 1928, 34, 669—670).—Dry films of white lead- and zinc oxide-oil paints were rubbed down under controlled conditions so th at the films were re
moved in ten equal layers. The pigment content of each of these was determined, and in the case of the white lead paint films the “ ether-soluble lead ” was also determined in each fraction. I t is established that a concentration of pigment occurs in the lowest layers, and in the case of white lead in the uppermost layers also. There is no parallelism between the extent of formation of “ lead soaps ” and the concentration of lead pigment in a particular layer. The reactions between white lead and linseed oil are speculatively
discussed. S. S. Wo o l f.
Decomposition of oil paints b y bacteria and fungi. W. Va u b e l (Farben-Ztg., 1928, 34, 505).—The observations of Haag (Arch. Hygiene, 1928, 100) and D’Ans (B., 1928, 935) on the action of fungi etc. on fatty acids, oils, and paints are discussed. E . Le w k o w it s c h.
T ypes of red lead. A. Ju n k (Farben-Ztg., 1928, 34,.
671—676).—A number of samples of red lead, both of the “ old type ” and of the modern “ disperse ” (or finely-divided, non-hardening) type, have been com
prehensively examined. Features of the modern type are low sp. gr., high content of “ true red lead ” (32%
being the minimum possible content of lead peroxide), average particle size of 2-5 ¡x with no particles greater than 4 a, relatively high bulking value, oil absorption to give paint consistency 25% (approx.) as against 15% for old-type red lead, and non-hardening on storage. The modern material settles out progressively, but can readily be brought back to normal consistency, whereas the older type reaches an equilibrium in its settling, due to thickening of the vehicle caused by interaction between the “ free ” litharge in the red lead with the oil and later with liberated glycerol, these reactions leading eventually to the formation of a hard,
B r itis h C h e m ic a l A b s t r a c t s — B .
104 C l. X IV .— In d i a- Ru b b e r ; Gu t t a- Pe r c h a.
Pa t e n t.
cement-like mass. The modern type in paint form gives thinner films and greater spreading power than the old type, but the film is discontinuous and has less pro
tective value than the latter. As an accelerated test, the prepared red lead paints were heated for 4 hrs.
at 80°, the results being in satisfactory agreement with
period tests. S. S. Wo o l f.
Determ ination of free m etallic lead in litharge and red lead. P. Fl u c h(Z. anal. Chem., 1928,75,371—
390).—The sample (5 g.) is dissolved in 2-5 c.c. of glacial acetic acid or in 30 c.c. of 80% acetic acid containing 0-5—0-6 g. of hydrazine sulphate. In the first case the insoluble residue consists of the free lead and any lead peroxide, and in the second of free lead and lead sulphate together with insoluble impurities. The residue is col
lected, washed with glacial acetic acid or ammonium acetate, then with hot water, and digested with nitric acid. The resulting nitrate solution is analysed for lead by any suitable method. For highly dispersed prepara
tions of litharge a saturated lead acetate solution may be used as the solvent for the lead oxide.
A. R. Po w e l l.
Value of lead pigm ents in iron protection.
A. Ei b n e r and W. La u f e n b e r g (Korrosion u. Metall- sohutz, 1928,4,107—110 ; Chem. Zentr., 1928, ii, 108—
109).—The imperviousness to water of a film of linseed oil increases with its content of lead soap and lead- glycerol compounds; hence, lead pigments selected for paints should be those which are able to form the largest quantities of lead soaps. The lead-linseed oil compounds could not be dissolved by treatment with benzene under pressure. The lead film aggregate is an irreversible colloid. The protective action of red lead is examined.
A. A. El d r id g e.
Sim ple accelerated exposure test for varnishes and lacquers. H. V. Ha n s e n (Ind. Eng. Chem., 1928,
2 0 , 1384—1385).—An apparatus is described for ex
posing small test panels to the action of ultra-violet light. The material during exposure can be subjected to wet and dry cycles, and the results obtained agree very satisfactorily with those given by outdoor ex
posure ; it is emphasised, however, th at great caution must be used in interpreting results until considerable experience has been gained on materials of well-known stability to outdoor exposure. E. H . Sh a r p l e s.
Constitution of gold resinate. F. Ch e m n it iu s and R. Ba r f u s s- Kn o c h e n d o p f e l (Chem.-Ztg., 1928, 5 2 ,
857—859).—Gold resinate (used in the ceramic industry) is prepared by precipitating a gold salt solution with
“ sulphur balsam ” (a compound of sulphur and tur- pontine oils). Previous work on the constitution of the
“ balsam ” and resinate is summarised, and details of the laboratory preparation and examination of these materials are given. The average values obtained on analysis of the precipitate w ere: Au 63 ■ 18%,
C 18-31%, II 2-35%, 0 (diff.) 6-15%, and S 10-01%.
S. S. Wo o l f.
Saffron crocus. Gr ik b e l and We i s s.—See IV.
W indow-glass substitute. Cr i s t.—See V III. Lin
seed oil film s. Th u r m a n nand Cr a n d a l l.—See X II.
Peru b alsam . Ts c h ir c h.—See XX.
Manufacture of lacquers, film s, artificial m asses, etc. J . Y. Jo iin s o n. From I. G. Fap.b e n i n d. A.-G.
(B.P. 301,133, 6.9.27 and 7.5.28).—The products com
prise urea-formaldehyde condensation products, nitro
cellulose, and vegetable or animal oils, e.g., linseed oil, castor oil, or cod-liver oil, which have been treated with oxidising gases a t a high tem perature to yield a viscous oil but not a jelly, and which may have been deodorised by hydrogenation. Resins, solvents, plasti
cising agents, etc. may also be added. L . A. Co l e s.
XIV.—INDIA-RUBBER ; GUTTA-PERCHA.
Im portance of tem perature and hum idity con
trol in rubber testing. I. S tress-stra in and tensile properties. Re p. Ph y s ic a l Te s t in g Co m m it t e e o f Div is io n o f Ru b b e r Ch e m is t r y o f t h e Am e r ic a n Ch e m ic a l So c ie t y (Ind. Eng. Chem., 1928, 2 0 , 1245—
1273).—By several thousand experiments it is shown th a t natural variations in temperature in a laboratory may affect the physical tests on vulcanised rubber as greatly as would an alteration of 25—10% in the time of vulcanisation, whereas humidity affects the results only to a minor degree. Variation in the absolute humidity of the atmosphere between mixing and vulcanisation, however, can affect the tensile strength and modulus of the products as greatly as does tem pera
ture variation after vulcanisation. Recommendations are therefore made th a t mixed stock prior to vulcanisa
tion, and vulcanised stock prior to testing, be con
ditioned for 24—28 hrs. at 27-8° a t 45% R.H., and th a t the testing room be a t 27 • 8°. If this tem perature cannot be maintained for conditioning prior to vulcanisation, the corresponding absolute humidity, viz., 0-012 g.
of water per litre, should still be used. The period between the removal of samples from the conditioning atmosphere and vulcanisation or testing should not exceed 2 hrs. The influence of variation in conditions before mixing is negligible as long as ordinary care is exercised in storing the rubber and compounding ingredients. Before complete standardisation of testing is possible it will be necessary also to specify limits for other variable factors. D . F . Twiss.
Strength test for rubber. Sc h u b e r t.—See V.
Pa t e n t s.
Treatm ent of rubber latex. L . Me l l e r s h-Ja c k s o n.
From Na u g a t u c k Ch e m. Co. (B.P. 282,011, 5.10.27).—
Alkali-preserved latex, concentrated and containing compounding ingredients if desired, is brought near to
Alkali-preserved latex, concentrated and containing compounding ingredients if desired, is brought near to