T H E J O L - R S A L OF I N D C S T R I A L AA’D E S G I S E E R I S G C H E d f I S T R Y .
498
samples. The data obtained is recorded in the tables given below.* All attempts t o get samples of wood oil of known source and purity were without avail. The difficulty was due t o the primitive condition in the collection of the oil and its shipment t o the coast from the country districts of China.1 We received a sample from Mr. Bacon (also purchased on the open market) which is supposed t o be a standard, b u t its source has not been indicated. The results tabulated below, therefore, represent the refractive indices of courtmylercial wood oils shipped t o us for use in the manufacture of varnish. The shipments cover a period of approximately eight months, during 1911-1912. Some of them have proved unsatisfactory in the processes of manufacture, and there is some indication that a relation exists between the refractive index and the “working quality” of the oil. That question can be settled only by a f a r more extended research. Gross adulteration is certainly indicated very clearly and rapidly by the use of the refractometer, and whether foreign oils, present in small quantities may be detected, will depend very largely on the results of future cooperative investigation. TABLEI . Index of refraction Mark. at 25’ C. A.3.20.12.. . . . . . . . . . . . . . . . . . . . . . . . 1.5148 A No. 1 A . . . . . . . 1.5118 1.5130 A K o . 3 4 ........................ 1.5164 A No. 4 4 . . . . . . . . . . . . . . . . . . . . . . . . 1.5153 A No. 9A (R.Y.S. 3534) . . . . . . . . . . 1.5154
......................
1.5168 Mr. Bacon . . . . . . . . . . . . . 1.5186
c&\c
.........................
1.5121
.....................
1.5116
....................... C /s;‘.,C.. A N o . 19 .......................... R . M . S. 3 5 0 5 . . . . W. K . C. \I7.0
....................
.
1.5167 1.5163 1.5099 1.5110
The results in Tables I1 and I11 require little comment; they show clearly t h a t the admixture of small amounts of other drying oils lowers the refractive index. TABLE11. Sample. Index of refraction at 25’ C. wood oil (mark) A . 3 . 2 0 . 1 2 . .. . . . . . 1.5147 wood oil, 5 per cent. soya bean oil 1.5122 wood oil, 5 per cent. linseed oil. . . . 1.5128 wood oil, 10 ge soya bean o i l . . linseed oil.. . . .
100 per 95 per 95 per 90 per 100 per 100 per
cent. cent. cent. cent. cent. cent.
100 per
TABLE111. Sample. Index of refraction at 25 C. cent. u.ood oil (Bacon’s sample). . . . . . . . . 1 ,5186 cent. wood oil. 5 per cent. soya bean oil 1.5163 cent. wood oil, 5 per cent. tallow o i l . , , , , 1.5161 cent. tallow o i l . . ...................... 1.4833
95 per 95 per 100 per
All indices of refraction were taken without the use of water circulation. All refractometric readings were made in the Advanced Physics Laboratory of Columbia University.
* The explanation of these high refractive indices will probably be found in the examination of the chief constituent of the oil, namely, the remarkable glyceride of oleomargaric acid, which is present in none of the other common drying oils. 1 Private communication.
July,
1912
I n conclusion, I beg t o thank Mr. Bloch, chemist for the Standard Varnish Works, for his material aid, Dr. C. C. Trowbridge, of the Department of Physics of Columbia University, for his kind advice and.Dr. Parker C. McIlhiney for his just criticism and his help. LABOR.4TORIES
OF T H E STANDARD VARNISH W O R K S .
ELM PARK,N. Y.
THE REFRACTIVE INDEX OF BEESWAX.’ B Y L FELDSTEIN. Received Jan. 5, 1912.
Lewkowitsch, in “Chemical Technology and Analysis of Oils, Fats, and Waxes,” recommends refractometric examination as a preliminary test in the examination of beeswax, giving as the limits between which pure beeswax should fall, 42 .9‘-45.6 O ; butyro-refractometer scale, calculated t o 40’ C. These figures were obtained from the work of Werderl and Berg,j who made the determinations at temperatures ranging between 70’ and 84’ C. and then calculated them t o 40’ C. Seither Werder nor Berg in their original articles give the figures actually observed nor explain how their calculations were made, but it is assumed t h a t they added to the observed figures the correction 0 . 5 5 O butyro for each degree centigrade between the observed figures and 40’ C., the correction value 0 . 5 5 O being generally used for all fats and oils when calculated to 40’ C. I n this laboratory a n AbbeZeiss direct-reading refractometer is used, and for beeswax a correction of 0.00037 per degree centigrade was found necessary. This figure was obtained by taking the refractive index a t 6 j O , j j O , and 8 j O C. and dividing the difference in the reading by the difference in degrees centigrade. This correction of 0.00037 per degree centigrade was found t o be practically constant between these temperature limits not only for all pure beeswax examined, b u t also for those which, upon further examination, showed adulteration. As beeswax is a solid a t 40’ C. and the refractive index is always read on the melted wax a t some temperature above 63’ C., i t seems desirable t o eliminate the use of the calculation to 40’ C. and t o set limits for the refractive index of pure beeswax a t some temperature above the melting point. For this purpose a number of samples of known purity and origin, obtained from the Bureau of Entomology, Cnited States Department of Agriculture, and some others purchased on the open market were examined. All of these have been analyzed by the drug laboratory of the Bureau of Chemistry. The readings were made a t 6 5 ” , j s o , and 8 j o C., and the results are given in the following tables. Table I consists of the figures obtained on the samples of pure beeswax secured from the Bureau of Entomology. Table I1 shows the results on those samples obtained in the open market, many of them adulterated samples. I n the column headed “Remarks” are placed conclusions as to the nature of the sample based on the chemical analysis: 1 Contribution from the Contracts Laboratory, Bureau of Chemistry Washington, D. C. 2 Chem. Ztg’., 22, 59 (1898). Ibid.. 27, 752 (1903).
July, 1912
T N E JOL-R.Y.4L
OF I-1-DCSTRIAL A S D E S G I S E E R I N G CHEJIISTRI'.
TABLE REFRACTIVE INDEX READISCSAT DIFFEREST TEUPERATURES o s BEESWAXSAMPLES OF K N O W N PURIT~-. Refractive index. Contract laboratory NO. A t 65' C . 12616.. . . . . . . . . 1.4458 12617. . . . . . . . . . 1.4458 12618., . . . . . . . . 1.4456 12619.. . . . . . . . . 1.4454 12620., . . . . . . . . 1.4449 12621.. . . . . . . . . 1.4453 12622.. . . . . . . . 1 ,4460 12623.. . . . . . . . . 1.4441 12624.. . . . . . . . . 1.4449 12625., . . . . . . . 1 ,4448 12626.. . . . . . . . . 1.4448 12627., . . . . . . . 1.4458 12628.. . . . . . . . 1.4456 12629.. . . . . . . 1 . 4 4 8 8 12656 ,,. 1,4440 12657 . , . 1.1443 12658. . . . . . . . . . 1 ,4460 12659.. . . . . . . . . 1.4449 12660. . . . . . . . . . 1.4444 12661.. . . . . . . . . 1.4450 12662.. . . . . . . . . 1.4458 12663,. . . . . . . . . 1.4444 12664. . . . . . . . . 1.4436 12665 . . . . . . . . . . 1.4434 12666.. . . . . . . . . 1.4435 12667 . . . . . . . . . . 1 4 4 4 i 12801.. . . . . . . . . 1.4470 TABLE II.-REFRACTIVE ON
.A t
750
c
1.4424 1 ,4425 1.4420 1.4418 1.4414 1.4416 1 ,4426 1.4403 1.4412 1.4410 1.4414 1.4424 1.4420 1.4451 1.4402 1.4406 1.4424 1.4413 1.4405 1.4413 1.4422 1.4405 1.4398 1.4398 1 ,4400 1.4410 1 ,4433
A t 8 5 0 c. 1.4390 1.4391 1.4380 1.4378 1,4380 1.4377 1.4388 1.4365 1.43T5 1.4374 1.4374 1.4387 1.4384 1.4415 1.4363 1.4367 1.4388 1.4377 1.4368 1.4378 1.4384 1.4368 1.4361 1.4361 1.4362 1.4375 1.4395
Locality. Kot given
Mexico S o r t h Carolina Wisconsin Cuba Habana Haiti Southern S t k e s Africa S e w York San Doming0 Yot given TVisconsin Illinois Texas Iow-a Utah 1ou.a California Hilo
S o t given Minnesota
READINGS A T DIFFERESTTEMPERATURES COMMERCIAL SAMPLES.
499
One sample (No. 12636), showing a high refractive index of I . 4540, proved on chemical examination t o have resin in it. I t was not possible to obtain a clear reading of this wax a t 6 j 0 C. Those samples which have a very low refractive index proved to be grossly adulterated with either paraffin or stearic acid, or both. A temperature of 7 j " C. was selected because a t this point all beeswaxes are liquid, a clear, sharp line can be obtained in the refractometer, and it is comparatively easy to make the reading. I t is seen t h a t the determination of the refractive index of beeswaxes is of great help in detecting gross adulteration and will generally reveal small adulterations, samples containing only a small amount of foreign material generally giving figures outside the limits mentioned, namely, I . 4398-1.4451 a t 7 j O C. The results obtained show also t h a t it is both unnecessary and unwise t o calculate the refractive index t o the butyro scale a t 40' C., for the following reasons: ( I ) I t is unreasonable to report the refractive index of a wax at a temperature a t which it is a n opaque solid, when the actual reading is made on the melted wax. ( 2 ) The calculation consumes time. (3) A clear reading can be obtained a t 7 j C. and the figures obtained can be reported unchanged.
INDEX
Refractive index.
THE CHEMISTRY
OF ANAESTHETICS, IV:
CHLOROFORM.
B y CHARLES BASKERVILLE A N D V7.4.HAHOR.
Contract laboratory S o .
At 65' C.
12630.. . . . . . . 12631.. . . . . . . 126321. . . . . . . 12633.. . . . . . 12634'. . . . . . . 126351. , . , , , , 12636.. , , . , , , 12637l.. . . . . . 12638l 12639. 12640 . . . . . . . . 126411.. . . . . 126421. , , , . , 12643 . . . . . . . 12644. , , . . , , , 12645., , , . , , , 12646 . . . . . . . . 12647. . . . . . . . 126481.. . . . . 12649'. , . , , , , 12650'. . , . , , , 1265 1. . . . . . . . 126521. . , . , , , 12653. , . . , . , . 12654l.. , , , . 12655. , . , . , , .
1 4463 1.4459 1 ,4379 1,4456 1,4380 1.4379
.
At 7 5 ' C.
1.4425 1.4425 1,4340 1,4421 1.4344 1.4342 , . , , 1 ,4540 1,4375 1,4338 1,4350 1.4313 1 4448 1.4410 1.4454 1.4416 1.4421 1.4384 1,4363 1,4323 1 4447 1.4410 1 ,4437 1 , 4 4 0 0 1.4440 1,4402 1.4445 1,4410 1.4438 1.4401 1.4421 1 4384 1.4335 1.4300 1.4342 1.4304 1 ,4439 1 ,4402 1.4345 1.4305 1 , 4 4 4 5 1.4408 1.4355 1.4318 1 , 4 4 4 1 1,4406
At 85' C.
1.4389 1.4387 1.4302 1.4387 1.4307 1.4302 1.4505 1.4301 1,4275 1.4372 1.4380 1.4346 1 ,4284 1.4372 1.4364 1.4368 1.4372 1.4362 1.4348 1.4260 1.4268 1.4365 1.4269 1.4372 1.4280 1.4369
Grossly adulterated samples.
(Continued front JuPte S o . ) VIII. The Examination of Anaesthetic Chloroform.
Pure w a s "
Paraffin present Pure wax Paraffin present Stearic acid and paraffin present Resin present Paraffin present Pure w a s "
Paraffin present Pure wax " "
Paraffin present Stearic acid and paraffin present Paraffin present
Pure wax Paraffin present Pure wax
Upon examining the tables i t will be found t h a t the refractive index at 7 j C. for pure beeswax falls between I . 4398-1.44 51. Table I1 shows t h a t the refractive indices of all those samples bought in the open market, which on chemical analysis appeared to be pure, fell within the limits for pure beeswax ( I . 4398-1,4451), while of the adulterated samples only one fell within these limits. This sample mas So. 126 j 1 , which has a refractive index of I ,4402,a figure very close t o the lowest value obtained for pure beeswax. I n this instance it is quite possible that the beeswax had a high refractive index and was adulterated with a small amount of paraffin 1
Received December 13, 1911.
Remarks.
4. T H E D E T E C T I O N O F WATER IS CHLOROFORSI.
Since pure chloroform is not hygroscopic in the ordinary sense, and r o o cc. dissolve but 0.152 cc. of water a t z z 0 , 1 such chloroform is not likely t o contain appreciable amounts of water. I n the case of anaesthetic chloroform, 0.0~5-0.0 j per cent. by volume of water is introduced by the alcohol; it may be said, therefore, t h a t the maximum amount of water likely to be present in anaesthetic chloroform is approximately 0.2 per cent. by volume, although the usual amount is about 0.05 per cent., according t o our experience. Tests for the presence of water in anaesthetic chloroform are generally not specified. Since, however, the presence of water facilitates oxidation, it is a t least desirable t h a t the amount present is not excessive; and occasions may arise which require anhydrous chloroform. The authors are able to present tests, by the application of which both of these conditions may be met. -4.Tests Based upon the Evolution of Gus. (a) T h e Test with Calcium Carbide.--Vitali2 found t h a t calcium carbide serves for the detection of water in chloroform; and we have learned t h a t it is both a convenient and generally suitable reagent for the presence 'of water, even in minute amounts, in chloroform of all grades. I t is the test which we recommend for establishing the anhydrous nature of a chloroform desired in a water-free condition. Herz, Ber., 31, 2670. Boil. chim. f a r m . , 37, 257; JOCRSAL,3. 311. 1
2
cf.
Baskerville
and Hamor, THIS
