V O L U M E 20, NO. 9, S E P T E M B E R 1 9 4 8 cates that when there is serious contamination extraction introduces a radical change in the results on the abrasion machine. A comparison of Table I with Table I1 s h o w that the percentage change produced by extraction in the abiasive index of the soling compounds is small compared to the change formed for the tread compounds. This may be attributed to the different compositions of the two types of compound. The fact that the horsepower invariably decreases on extraction is evidence that contamination of the sandpaper does not decrease, but rather increases, the friction between the sandpaper and rubber during the test. Nevertheless, although the friction increases, the wear decreases, presumably because the abrasive particles are covered with a coating that protects the rubber from the cutting action of the abrasive. The effect is that of a lubricating film of such high viscosity that fiiction is increased instead of being decreased. Sample 4,Table I, gives an example of the effect of horsepower Unextracted, with the sandpaper contaminated, the averagc horsepower during the test n*as 0.0187, and the wearing effect on the rubber only 0.28 cc. per hour. Extracted, the horseponer was reduced to 0.0163 but the wearing effect increased to 3.57 cc per hour. Obviously, the 0.0187 horsepower in the first euperiment was not all necessary in abrading the sample, as after extraction a much greater volume loss mas produced n i t h less horsepower; hence much of the horsepower in the first case was superfluous and associated with the contamination effect. I t is not known, of course, just 13 hat proportion of the horscponer of 0.0163 was used up solely in comminuting the extracted sample, but this figure can be looked upon as a maximum higher than which it would not be necessary to go in ordcr to comminute the sample. By proportion, if 0.0163 is the maximum for producing
847 an abrasion loss of 3.57 cc. per hour, then the horsepower required to produce a loss of 0.28 cc. per hour should not be greater than
0.03.57 163
X 0.28
=
0.1003 horsepower
Hence, in the abrasion test of the unextracted sample, 0.0187
- 0.0013
= 0.0174 horsepower
or 93YC of the total horsepower was superfluous, and associated with the contamination effect. This amounts to 186 gram-calories per minute, and because such heat would be generated at thr surface of the rubber, it would contribute considerably to the heating of the rubber surface before being dissipated. ACKNOWLEDGMENTS
The authors wish to express their indebtedness tc J. S. Tapp of the Polymer Corporation Limited, Sarnia, Canada, for valued comments and criticisms. They desire also to take this opportunity of thanking Clarence 11.Barker for his work in the preparation of the laboratory compounds for study. LITERATURE CITED
M., Eby, S.T..and Schrader, C. C., “A New Sandpaper Abrasion Tester,” A.S.T.M. BuZ1. 143 (December 1916). ‘ 2 ) Si&, P. A., and Holt, IT. I,., India Rubber W o r l d , 82, No. 5 , 6.7 11 Gavan, F.
(August 1930). ,SJ TYilliams, I r a , IND. ESG.CHEM.,19,674 (1927). RECEIVEDSeptember 23, 1947. Presented before the Division of Rubber CHEMICAL SOCIETY, New Chemistry at the 112th Meeting of the AMERICAPI York. S . Y.
An Application of Punch Cards Filing of Optical Properties of Crystals A. F. KIRI 5 are used to express the third decimal place. Optic Axial Angles. The optic axial angles, 2E and 2V, are coded in groups to allow for a range in values. The code uses the 7-4-2-1 field system. The first group (code 1) includes all anglee betLi-een 0 " and 20". The other groups are 10" intervals. Code 9 designates all angles greater than 90 ', Optical Character. Crystalline substances can be divided into three classes according to whether they are isotropic, uniaxial, or
/.
AMERICAN CYANAMID COMPANY
%
COMPOUND NAME
0 0.
I D
lHDEX
REFI).C,I"t
OX
. L :
Ammonium ThlocglYVrte
EMPIRICAL FORMULA
h&cNs
~
CRYSTAL SYSTEM CLASS
Monocllnio
AXIAL PLEMENTS
2.035:1:2.367
HAMIT
2 a a
-
1
v -
4
, n
STRUCTURAL FORMULA
0 0- 5 I
.. :d "0 4
L D .
rho *xo
0 a 62'58'
Tabular
C L E A V A G E ( ~and ~ O )(101)perfect REFRACTIVE INDICES
Figure 1. Typical Punch Card
4
:" 0 4
,
V O L U M E 20, NO. 9, S E P T E M B E R 1 9 4 8 biaxial. In this card system these three classes are designated collectively as optical character. These properties are clipped on the top margin of the card. The letter I refers to isotropic, U to uniaxial, and B to biaxial. Optic Sign. The optic sign is clipped as illustrated in Figure 1. Oblique Extinction. If any orientation of the crystal shows oblique extinction, this is noted by clipping the hole corresponding to 0 on the left top of the card. Extinction Angles. The extinction angles are measured from the trace of the elongation to the principal vibration direction most nearly parallel to this trace. The values of the angles are coded in groups of 5' from 0" to 45". When data are recorded from the literature, it is sometimes necessary to record the complement of the angle given in order to meet the above definition. .Although provision is not made in this system for recording the sign of elongation, this could be easily handled by designating two holes with a plus and minus sign as is done n-ith the optic sign.) Specific Gravity. The numerical value of the specific gravity is clipped directly. The card allows for the recording of gravities up 'to but, not including 4.1. Greater values are indicated by clipping only the outer holes marked >5 and < 5 and no others. Functional Groups. The presence of a specific functional group is coded. The groups considered are those determined by chemical tests or by spectroscopy. The presence of only one group can be indicated. The choice of the group to be coded is such that duplication of information as to the presence of X,X(halogens), .V, and P is avoided. Thus p-aminobenzoic acid would be coded by showing the carboxyl group and not the -NH, group, for the presence of nitrogen would be indicated under elements. Elements. The presence of the elements sulfur, halogens, nitrogen, and phosphorus detected by sodium fusion or other chemical tests is indicated directly by clipping the appropriate hole. Melting Point. The melting point is coded. The range is from 25 O to >300° in groups of 10 '. Atomic Number of Elements. The presence of a metallic element is indicated by recording its atomic number. Khen two or more metallic elements are present, the one most useful in the identification is noted. Thus, the presence of iron is recorded for .odium ferricyanide rather than sodium. Color. The colors of crystals are coded. The colors noted are red, orange, yellow, green, blue, violet, gray, and brown. Colorless is also noted. ARRANGEMENT OF CARDS
Because of the nature of the 7-4-2-1 system, it is possible to arrange the cards in increasing numerical order by a mechanical procedure described by Casey et al. (9). This procedure is of great use in the preparat,ion of tables of properties. The cards are kept in the order of increasing key refractive indexes. Tabs are placed in the file a t intervals of 0.05 for convenience in locating a group of cards. KECORD OF DATA
-1s is seen in Figure 1, provision is made on the face of the card
.;or recording complete data. Space is provided on the back for additional notes and draivings. These cards serve as a primary file of data. EXAMPLE OF U S E
During the examination of a commercial mixture of crystalline materials, a phase was observed which gave a biaxial negative in:erference figure and whose SYwas measured as 1.6% * 0.003. The group of cards, approximately 80, whose key indexes were between 1.65 and 1.70, iwre removed from the file and needles were inserted in the appropriate holes corresponding to the above properties. Three cards with these properties in common fell off :he needles. The A-z value was measured and found to be 1.691 * 0.003. The three cards were then examined and the card for
849 Table I.
Key Indexes for Various types of Crystals
Type of Crystal
Key Index
Isotropic Uniaxial Biaxial Crystals for which principal indexes are not identifiable Shou-ing parallel or symmetrical extinction Showing oblique extinction
jL
$' 7
N o and .VB N u if determinable XI for index of ray vibrating in a plane parallel t o elongation of crystal Ni for index of ray vibrating in plane corresponding t o niaximum extinction anglea
See diwussion of extinction angle.
ammonium thiocyanate n-as found to indicate this index value. The identification was confirmed by a quick check of the other propertit- listed (Figure 1). DISCUSSIOZi
* This punch card system has been in use for over a year and a half. 9 t present the data for over 600 compounds are on file and more are being filed daily. I t is planned to transfer all usable data from the literature and those determined in this laboratory to the card system. The system forms a primary file of optical and other physicochemical data and is unlimited in the number of compounds that can be recorded. A search of the file can be made by using any one or a combination of determinative properties. The nature of the punch card system is such that tables of data are easily prepared by routine manipulation of the cards. The certainty of an identification is increased by the knowledge that all data available to the analyst have been searched in a systematic manner. Without this system it is necessary to check all books, periodicals, and laboratory notes by inspection which always leaves the possibilit? that a set of data has been overlooked. This description is presented to show what can be done with punch cards in filing physicochemical data, especially optical properties. I t is hoped that it will result in the more efficient use of optical data and optical methods in the identification of crystalline siibstanres. 4CKNOWLEDGMEYTS
The author wishes to express his appreciation for the intereui shown and the encouragement given by T. G. Rochow, senior group leader of the RIicroscopy Group of the Stamford Research Laboratories, for the development of this filing system. He also wishes to acknowledge the suggestions of the members of the Stamford Microscopy Group, 9.S. Winchell, and the members of the Microscopy Group of the Calm Chemical Division of the hmerican Cyanamid Company. LITERATURE CITED
(1) Bailey, C. F., Casey, R. S.,and Cox, G. J., Sczence, 104, 181
(1946).
S.,Bailey, C. F., and Cox, G. J., J. Chem. Education 23, 495 (1946). Donnay, J. D. H., Ann. MinemZ., 23,91 (1938). Donnay, J. D. H., Ann. SOC. ~ 8 0 2 Belg., . 59, B250 (1936). Fairbanks, E. E., Econ. Geol., 41, 761 (1946). Larsen, E. S., and Berman, H., "Microscopic Determination oi the Nonopaque Minerals," U. S. Geological Sui rev Bulletin
( 2 ) Casey, R.
(3)
(4) (5)
(6)
2nd ed., 1934. (7) Winchell, 4 . N.,"Elements of Optical Mineralogy," 2nd ed. 2nd printing, Part 111, Determinative Tables, New York John-Wile>-& S o n s , 1939. ( 8 ) Winchell, -2.K.,"Microscopic Character of Artificial Inorganic Solid Substances or Artificial Minerals," New York, John Wiley & Sons, 1931. (91 Winchell, A . N., "Optical Properties of Organic Compounds.'' Madison, Wis., Vnirersity of Wisconsin Press, 1943. RhCEIx EO
February 1, 1918
.
