I N D U S T R I A L A N D ENGIiVEERI,VG CHEMISTRY
576
The most striking feature of this series is the effect of sulfides, which cause a loss of fluorine. This appears to occur during the oxidization of the sulfur and would probably ocmr in any method in which a fusion is used. When sulfur is added in the form of a sulfate the loss is very much less and is probably from a different cause. No entirely satisfactory method was found to eliminate this trouble. The least loss appears to occur when just enough sodium peroxide is added to the flux to oxidize the sulfide. Phosphorus pentoxide when present is precipitated in the
Vol. 18, S o . 6
acetic solution by the lead acetate. This will dissolve in the nitric acid added to dissolve the lead chlorofluoride, and it might reasonably be expected not to interfere with the determination. The fact that it does so to some extent is probably due to the fact that when lead phosphate precipitates in presence of chlorine it carries with it some lead chloride (the same as the mineral pyromorphite), which causes results to be somewhat too high. Apparently the presence of lead and zinc has little effect on the result.
Chemistry of Wood' VIII-Further
Studies of Sapwood and Heartwood By G. J. Ritter and L. C. Fleck
U. S. FOREST PRODUCTS LABORATORY, MADISON,Wrs.
HE present paper represents a continuation of a pre-
T
vious study of the chemistry of sapwood and heartwood2 to determine whether any additional generalizations can be made in grouping hardwoods and softwoods on the basis of chemical differences between sapwood and heartwood. The methods of analysis are identical with those used in former experiments of this ~ e r i e s . ~The determinations were made in duplicate, and the average of each pair of determinations is shown in the accompanying table. Discussion of Results The results confirm the conclusions stated in the sixth paper2 of this series, to the effect that softwoods form a single group having high relative amounts of extractives in the heartwood. Also, with only one exception, the softwoods 1 Presented before the Division of Cellulose Chemistry a t the 66th Meeting of the American Chemical Society, Milwaukee, Wis., September $0 t o 14, 1923. Received January 28, 1926. f THIS JOURNAL, 16, 1055 (1923). 8 I b i d , 14, 1050 (1922).
here reported exhibit another characteristic in common with those reported in paper VI, in that the high extractives in the heartwood are accompanied by low percentages of lignin and cellulose. I n the exceptional case of white spruce the lignin and cellulose content is approximately the same in sapwood and heartwood. The hardwoods, also in accord with the findings of the earlier paper12 are distributed between two groups having high relative amounts of extractives in the sapwood and heartwood, respectively. The acetic acid obtained by acid hydrolysis is uniformly higher in the sapwood than in the heartwood of both hardwoods and softwoods. By the results here reported more species have been fitted into the scheme of classification advanced in the sixth paper of the series; Whether additional groups of softwoods exist is a question that can be answered only after a larger number of species have been analyzed. Combining results for the hardwoods listed in the sixth and the present paper, it is seen that Group A (with high extractives in the sapwood)
Analyses of Sapwood a n d Heartwood of S o m e American Woods (Results in percentage of oven-dry (105' C.) samples) ---SOLUBILITY IN-MoisCold Hot 1% Acetic Meth- Pento- Methyl Cellu- LigSample ture Ash water water Ether NaOH acid oxy1 Jan pentosan lose nin
SPECIES :Hemlock: 219 6.39 0.37 1 . 1 6 2 . 2 8 0.34 10.93 1 . 8 3 Sapwood 220 6.90 0.51 4.12 5.36 0.70 15.01 1 . 7 3 Heartwood -Redwood : 231 6 . 6 9 0.27 4 28 6.50 1 . 9 5 15.54 0 . 9 9 Sapwood 232 7 . 5 3 0.14 10.53 14.39 2.07 25.85 0 . 4 8 Heartwood -White spruce: 500 6.59 0 . 2 8 1.54 1 . 9 9 . . . . 10.83 1.74 Sapwood 501 5.37 0.26 2 38 3 . 3 1 . . . . 11.83 1.64 Heartwood .Red alder: 201 5 . 0 2 0.32 4.28 5.35 1 . 0 3 20.16 3 . 5 3 Sapwood 202 6.82 0 . 4 5 3 . 9 7 5.21 1.39 20.01 3.50 Heartwood 203 5.77 0.24 3.49 4 . 7 5 0 . 9 0 20.28 3 . 6 9 Sapwood 204 3.70 0 . 2 3 3.31 4.67 0.77 21.61 3 . 4 0 Heartwood Red mulberry: 223 5.82 1 . 0 3 9 . 1 2 12.56 1 . 7 5 29.08 4.07 Sapwood 224 5.S2 0 . 4 8 7.08 10.20 1 . 7 1 27.58 3.63 Heartwood Sugar maple: 225 5.80 0 . 3 1 3.05 4 . 1 5 0 . 5 8 19.21 3.79 Sapwood 226 5.71 0 . 6 6 2.19 3 . 1 5 - 0.58 19.18 2.23 Heartwood .Catalpa: 227 3.95 0 . 5 3 6.55 9.37 0 . 9 3 28.11 4.59 Sapwood Heartwood 228 3.90 0.34 6.46 9.24 0 . 7 1 28.56 4.37 Red oak: 229 4 . 1 4 0.14 3.57 6 . 1 3 1 . 2 4 22.04 5.08 Sapwood Heartwood 230 3.78 0.18 5.74 8.29 1 . 2 3 24.10 3.67 Locust: Sapwood 221 5.08 0 . 5 5 3 . 0 8 3.91 0.74 17.64 3.16 222 6.55 0.14 8 . 2 9 11.04 1 . 7 0 25.72 2.86 Heartwood -Sucalyptus: 215 4.98 0.41 2 . 0 1 3.10 0 . 3 8 15.72 3.14 Sapwood Heartwood 216 7.07 0 . 1 8 8.07 10.43 1.09 23.85 2.25 217 4.64 0.42 2 . 2 2 3.33 0 . 4 5 17.54 2.61 Sapwood Heartwood 218 6.58 0.26 6.69 10.23 0.72 25.12 1 . 8 4 a Combined pentosans and methyl pentosans reported a s pentosans.
-
c IN'CELLULOSEPento- Methyl Alsan pentosan pha Beta Gamma
3.59 2.76
54.76 52.83
31.82 30.30
5.32 4.37
2.04 45.39 4 . 3 1 48.17
33.85 22.66
20.76 29.17
5.28 10.04 2.80 5 . 1 1 8.86 2.08
46.35 41.54
33.98 31.82
6.62 6.54
1.07 52.20 35.05 1.46 56.18 31.02
12.75 12.80
4.11 4.37
59.30 59.45
26.71 26.93
8.5qCL 9.47"
... ...
...
...
... ...
56.36 25.97 57.41 26.68 57.28 26.64 57.75 26.94
20.98 0.72 20.80 0.82 19.30 1 . 1 3 20.23 1.79
42.02 49.19 40.93 38.67
35.53 29.82 37.44 38.50
22.45 20.99 21.65 22.83 8.69 16.51
4.95 5.36
8.79 9.06
12.84a 13.63a
5 . 2 9 20 81 1.13 5.33 21.03 1.20 5 . 2 7 20.76 1 . 4 7 5 . 2 6 20.51 1.91 4 . 2 4 21.16 4.47 20.28
1.86 47.80 1.68 48.56
22.76 24.00
22.81 1.21 76.51 23.03 2.04 57.72
15.80 25.77
5 , 7 8 20.50 5.88 20.42
2.06 1.56
56.29 56.47
25.37 27.37
20.18 20.57
3.49 22.69 12.62 20.55
55.79 55.99
21.06 20.90
4.83 4.38
22.75" 22.54O
1 . 4 8 63.82 1 . 3 8 66.83
22.83' 22.81j5
72.25 71.41
18.35 9.40 17.86 1 0 . 7 3
6.05 5.98
21.88 20.95
1.87 53.98 1.69 53.58
24.47 23.12
22.46 22.68
1 . 6 9 70.18 2.00 72.13
13.22 12.10
16.60 15.77
4.20 4.54
21.64 20.77
1.99 60.31 23.22 1.70 52.04 23.11
21.70 24.78
0.00 65.96 0.00 44.97
24.46 38.93
9.58 16.60
43.77 41.77 59.08 26.97 36.39 45.68 47.21 36.84
14.46 13.95 17.93 15.95
6 . 4 5 20.47 5.82 18.81 6 . 4 3 21.31 6.06 19.86
1.13 1.10 1.33 1.33
55.29 26.60 51.08 27.53 56.67 28.21 52.31 30.00
19.16 0.82 18.88 1 . 3 1 18.51 1 . 3 3 19.08 1.22
June. 1926
I S D C S T R I A L ,450 EXGINEERISG CHEMISTRY
includes white ash, pignut hickory, red ‘alder, red mulberry, sugar maple, and catalpa; Group B (with high extractives in the heartwood) includes yellow poplar, yellow birch, white oak, red oak, locust, and eucalyptus. Conclusions
1-In softwoods the water, ether, and alkali extracts are higher in the heartwood than in the sapwood, and the cellulose and lignin are correspondingly lower in the heartwood
577
(except in white spruce, in which cellulose-lignin content is approximately the same in the two bands of growth). 2-On the basis of water, ether, and alkali extractives, hardwoods are divided into two groups: (a) those with high extractives in the sapwood, and ( b ) those with high extractives in the heartwood. The former have low cellulose in the sapwood, the latter low cellulose in the heartwood. 3-Acetic acid by hydrolysis is higher in the sapwood than in the heartwood of all the woods.
Industry Finds a New Tool-X-Rays By D. H. Killeffer, Associate Editor
The discoz‘ery of the X - r a y has opened the door to vast stores of industrially important facts. Already’it i s reziolutzonizing the metallurgical industry and as our knowledge of X - r a y technic iucreases new wonders are being recealed in other jields. NDUSTRP usually looks, to its own hurt, with disdainful indifference upon the newest advances of what it considers “high brow” pure science until its operations are revolutionized by the application of some newly discovered principle or method. Each year, each month, almost each day, sees some advance of pure science put into the overalls of industry. The scientific oddity of yesterday becomes the foundation of tomorrow’s practice. Science and scientists repeatedly prove the truth of that and industry teems with illuminating illustrations. Yet it is one thing to prove and t o illustrate, and quite another to realize in practice a point of view so obviously axiomatic. So it has been with X-rays. How distant seem the experiments of Roentgen leading to the discovery of a new kind of radiation, which for want of a better name he called X-rays, from the hardening of steel, the sealing of an envelope, the multitudes of catalytic reactions, and the vastly important problems of corrosion. Yet in the scientific toy of a very few years ago-few of us fail to recall with what awe and wonder we first beheld the bones in our own hands in the fluoroscopic screen of a side showhas been found the key to vast stores of industrially important facts about diverse kinds of matter. Already our theories of the haraening of steel and the ductility of metals have undergone a complete revolution and our preconceived ideas of colloids, crystalloids, and amorphous matter are being materially modified as the result of the use of this new tool. Only a beginning has been made and no one’s imagination is yet equal to the task of foreseeing the possible end. Already industry has taken profitable cognizance of this apparently purely theoretical advance and has made it its own.
I
s
Properties of X-Rays
X-rays were discovered by their ability to penetrate matter opaque t o visible light. They could be made to affect a photographic plate through the human body and to reveal in bold outline its parts of different opacity to them. Bones, fractures, and foreign materials of any kind within the human body could be discerned as if the surrounding tissues were rendered invisible. One might even imagine that the tellers of fairy tales foresaw such a thing when they conferred upon their characters the ability to render themselves invisible. This phenomenon of selective absorption of X-rays has become of the greatest practical importance, particularly in the field of metallurgy where minute flaws in castings may have serious effects on their usefulness. Rays of greater and greater penetrative poner have finally made it quite an ordi-
nary thing for an investigator to outline accurately voids one or two millimeters in dimensions in blocks of steel a decimeter thick without altering the steel in the least. Tt is thus possible to detect minute flaws in the interior of castings whose value would have to be destroyed to render any other method of test applicable. Study of Castings
Industry moves forward as fast as it is supplied with the minutiae of its operation and no faster. For instance, the widening use of very high pressure superheated steam for power and of high-temperature and high-pressure cracking processes in refining petroleum has brought into prominence defects in cast-steel valves and pipe fittings not hitherto important. The casting of pipe fittings from steel has been considered a comparatively simple thing for the reason that strains in use have seldom been sufficiently great to give them a real test. However, under the severity of the newer types of service even very slight flaws soon showed themselves and often led to disastrous results. To correct this, careful studies of all parts of such castings by X-ray methods were made and casting practice improved to correct the defects found. The result has been a vast improvement in the quality and service of the finished fittings. Such methods had previously been applied with great success to the casting of cannon, their carriages, and other gross objects cast of steel. Study of Atomic and Molecular Structure
This kind of thing has proved very valuable to industry, but when compared with the possibilities in the study of so vast a field as atomic and molecular structure its importance is greatly overshadowed. In 1912, Von Laue in Germany and Bragg in England began the publication of a series of papers dealing with the ability of X-rays to be deflected, reflected or, perhaps better, refracted when passed through crystal substances. Basing their experiments on the analogy to the diffraction spectra produced by passing visible light through fine gratings, these investigators passed X-ray beams through crystals in various orientations and found that the deflected beams showed distinct maxima and minima as the crystal was rotated and that the angles of deflection were quite definitely properties of the internal structure of the crystal. Other investigators mere attracted to the field thus opened, and fact has been piled upon fact until in the hands of a skilled worker this technic will now reveal far more about the infinitesimal structure of inatter than was ever conceived
