I-VD USTRIAL A N D ENGISEERING CHEMISTRY
iiugust, 1926
-.
Table IV H 100 90 80 70 60 55 50 45 40
Calculated time
d 1.222 1.247 1.278 1.318 1.370 1.403 1.433 1.494 1.555
D-d 1.32 1.293 1.262 1.222 1.170 1.137 1.107 1.046 0.986
(e),(for H
z
2.2 2.52 3.0 3.73 5.1 6.2 7.85 10.4 14.9
= 90) =
2 -
D-d 1.67 1.95 2.37 3.05 4.36 5.45 7.10 9.95 15.12
Calcd. time Areas
9
18.4 40 8 67 2 105 127 160 213 265
317 703 1160 1810 2190 2760 3670 4570
.
871
inn?
i
I The values of the inCALCULATED SETTLING CURVE tegrals are now divided bv the new value of B kaZ, giving the calculated values of the time H2 6o e. These have been plotted on Figure 5 and + compared with the ex- $40 periiiental curve. It FIG.5 will be seen that the agreement is very good, in spite of the fact that oo looo x)oo 3ooo 4ooo Moo noallowancewas made for initial turbulence. TIME IN SECONDS The curves and data given are representative of a large number of settling experiments and were not selected as particularly favorable. It is believed, therefore, that the use of the modified Stokes equation for sedimentation study is well justified.
The slope of the straight line in Figure 4 is equal t'o ka2, where a is the size of the particles in experiment A . In experiment B, k should be the same and a will be 0.000895 instead of 0.00174. The definite integrals are obtained in the same manner as before. Table IV gives the calculation of the points. Relative concentration 0.391 0.434 0.488 0.558 0.652 0.711 0.782 0.868 0.978
. .
2oHEi!433
18.4
Suitability of Monel Metal for Vanilla Flavoring Containers' By T. E. Hollingshead and T. J. Otterbacher ZION COLLEGE, ZION, ILL.
Experimental
NASM'C'CH as monel metal has proved to be a satisfactory material for containers for certain delicate photographic solutions, it was suggested that it might also prove suitable for vanilla flavors. An investigation was undertaken for the purpose of determining, first, the effect of contact with monel metal on various types of vanilla flavors, and second, the effect of flavors on the surface of the monel metal.
I
The odor and flavor of the flavors were tested every 2 weeks but no attempt was made to examine them for strength untiI the final tests were made a t the end of 3 months. Strips of monel metal, 1.5 X 7.5 cm. and approximately 20 gage in thickness, were placed in tightly stoppered 250-cc. Pyrex Erlenmeyer flasks containing 100 cc. of the flavor. This gave sufficient room to note the action at the air line. The sets were made up in triplicate. All sets were allowed to stand a t room temperature 18" to 25' C. (65" to 76" F.), One set was placed in the light, the second in the dark, and the third was reserved to test the residue for nickel and copper every 2 weeks. The strips were washed in water, alcohol, and ether, and dried in a desiccator over sulfuric acid before weighing.
Types of Vanilla Flavor Employed
Formula I is a standard vanilla extract prepared by diluting a commercial concentrate which was reported to be extracted from a good grade of Bourbon beans. Formulas I1 and I11 are the same standard extract fortified with vanillin and coumarin, and colored as indicated with certified aniline and burnt-sugar colors. Their coumarin content, although high, is according to the local demand for baked products. The higher lead number in I1 than in I11 is due to the precipitation of some lead by the aniline color used. Formula IV is the commercial concentrated Bourbon bean extract mentioned above. The vanillin and coumarin determinations were run by the ether extraction method and the normal lead number by the Winton and Lott method. Analyses of Vanilla Extracts Per cent Per cent I-Standard V a n i l l a Extvuct III-Fortified V a n i l l a Extract Vanillin 0.31 Colored with B u r n C S u g a v Coior Xormal lead number 0.49 Vanillin 0.58 Coumarin 0.23 Il-Fortified V a n i l l a Extract c o l Normal lead number 0.4 8 0 90 ored with Certtfied A n i l i n k Color ~ ~ Y ~ 8 . 0~ 0 Vsnillin n CIQ .-I... " . -" 0.23 IV-commercial Vanilla ConcenCoumarin h-ormal lead number 0.69 t7Qte, Bourbon B e a n s Glycerol 8.00 Vanillin 2.23 .4lcOhOl 8.00 Normal lead number 3.44 _ I
1
Received February 23, 1926.
Effect on Odor and Flavor
On comparing the odor and flavor of the samples of the flavors in contact with the monel metal with samples of the original flavor, no differences were observed until the sixth week. At that time the flavor was slightly weaker, although the odor seemed to be the same. At the end of the tenth week both odor and flavor were decidedly weaker than the original samples. The action in the light was the same as that in.the dark as far as could be discerned with the senses. No precipitate of any kind was formed and the color of all the flavors remained the same throughout the 12 weeks. Effect on the Surface of the Monel Metal l
The polished surface of the monel metal was not affected in any way by the various vanilla flavors until the end of the second week, when the strip in contact with IV was slightly dulled. By the end of the eighth week all the strips were dulled, and the strips in IV had a heavy, grayish brown tarnish. The flavor colored with burnt-sugar coloring did
INDUSTRIAL AND ENGINEERI,VG CHEMISTRY
872
not dull the strips quite so rapidly, nor to as great an extent, as did the other flavors. The standard extract, formula I, produced a greater dullness than did the fortified flavors. The corrosion was practically twice as great in the light as in the dark. Effect on W e i g h t of Monel M e t a l Strips At the end of 12 weeks the strips, each weighing approximately 5.5 grams, had lost weight as follows: In dark I n light
I Gram 0.0207 0.0288
I1 Gram 0.0005 0.0009
I11 Gram
0.0076 0.0141
IV
Gram 0.0375 0.0614
Qualitative tests for nickel and copper were found in the flavors after the tenth week in all cases except in formula 11. From the following results it can be seen that all the true flavoring properties of the flavors were affected. The vanillin and coumarin show a decrease in all cases. The normal lead number of the true bean extracts was higher after treatment than before. This is probably due to the resins forming compounds with nickel and copper, which precipitate more lead. I n the fortified extracts the normal lead number
Vol. 18, No. 8
fell considerably. This may not be of great significance, however, as the normal lead number of these fortified flavors is partially due to the artificial coloring matter. Effect on V a n i l l i n , Coumarin, and Normal Lead Number In dark I n light Per cent Per cent Formula I Vanillin 0.28 0.29 Normal lead number 0.67 0.79 Formula II Vanillin 0.49 0.47 Coumarin 0.16 0.21 Normal lead number 0.10 0.10 Formula III Vanillin 0.44 0.44 Coumarin 0.12 0.14 Normal lead number 0.28 0.16 Formula I V 1.47 2.08 Vanillin Normal lead number 6.31 4.27
Conclusion
Since vanillin, coumarin, and the resins of vanilla extracts react with and corrode monel metal, this alloy is not suitable for containers for the storage and transportation of the extract of vanilla beans or fortified mixtures thereof.
AMERICAN CONTEMPORARIES Charles Loring Jackson HARLES LORING JACKSON was born in Boston on April 4, 1847. After studying in private schools in Boston he entered Harvard College, from which he graduated in 1867. On graduation he was made a lecture assistant in chemistry. H e states t h a t his salary was supposed t o be free tuition, but that he received none. On his twenty-first birthday he became a n assistant with a regular salary. At t h a t time the Harvard chemistry department consisted of three members, the other two being J. P. Cooke and A. J. Hill. In 1870 he introduced a n elective course in elementary chemistry, which later developed into the famous Chemistry 1, which he taught for over forty years. I n 1873 he went abroad to learn chemistry, a feat which he had found impossible in Cambridge, since he had no teacher and had much teaching t o do himself. He studied at Heidelberg with Bunsen, specializing in gas analysis and the chemistry of the platinum metals. H e later worked with A. W. Hofmann in organic chemistry, although he did not a t t h a t time intend t o make organic chemistry his life work. One taste of the subject under this inspired teacher, however, showed him t h a t organic chemistry was t h e thing for him. As he expresses it, he learned under Hofmann “to use his mind,” which was a n interesting experience after his association with Bunsen, who rather discouraged t h a t type of activity. In 1874 he published his first paper, which dealt with organic selenium compounds. During his study with Hofmann, the latter was writing his Faraday lectures on Liebig and had Jackson correct his English. H e took full advantage of this chance for intimate association with the great teacher. Shortly after his return t o this country in 1875, he prepared
C
the first new organic compound made in the Harvard laboratory, p-bromobenzyl bromide. His work on substituted benzyl compounds gave a number of interesting results, including a synthesis of anthracene. During the following years he worked on curcumin, vanillin, benzene trisulfonic acid, and the method now in general use for making highly nitrated compounds-namely, preliminary sulfonation followed by nitration. I n the late eighties he discovered the r e a c t i o n of highly substituted aromatic halides with malonic ester in which a halogen is replaced by hydrogen. This was his most prolific source of scientific papers. Another subject on which he did considerable work was the o-quinones. H e missed the discovery of the parent substance, o-benzoquinone, by only a small margin. His chief amusements have been amateur theatricals and writing poetry and romantic fiction. Of late years he has taken up garden@ Marceau ing, and now makes this his chief occupation on his beautiful estate at Pride’s Crossing, near Beverly, Massachusetts. Last month his first volume of fiction was published by the Stratford Company of Boston, It bears the title of “The Gold Point and Other Strange Stories” and consists of a dozen fanciful tales whose themes are weird and imaginative enough for a Poe. The scores of chemists who have been fortunate enough t o spend graduate years working with Professor Jackson find it hard t o think of him merely as a chemist, or even as a teacher, because his beautifully friendly and helpful personality makes him stand out in their recollection more as a companion and guide in their chemical struggles than as a teacher or director.
FRANK
C. WRITMORE
