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T H E JOURNAL OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
The Rate of Evaporation of
Vol. 13, No. 4
Ethyl Chloride from Oils‘
By Charles Baskerville and Myron Hirsh2 COLLEGE
O F ’ T H E CITY O F
NEW YORK,N E W YORK,N. Y.
The determination of t h e rate of evaporation of ether from various oils3 gave the foundation of etheroil colonic, and later oral, anesthesia introduced by G ~ a t h m e y and , ~ since extensively used by a number of surgeons and specialists with gratifying success. I n particular cases analgesia is preferred t o anesthesia, in so far as t h e one may be caused t o prevail. Analgesia is evident previous t o anesthesia during induction and obtains as t h e patient comes out of t h e stage of full anesthesia, t h e period of analgesia varying in time and degree with t h e drug administered, rate of administration, body saturation, and rate of elimination. Analgesia is desirable in minor short, as well as prolonged, operations i n dentistry, when recourse need not be had t o anesthesia. Analgesia, without anesthesia, offers opportunity for comfortable dressing of serious wounds. Prolongation of post-anesthetic analgesia reduces t h e necessary time of anesthesia for the sewing of t h e incision; and t h e dressing may be done during t h a t period. Cocaine, stovaine, novocaine, and this general class of drugs are most useful for such purposes, being applied in various ways, but their use is always attended unhappily with a n element of uncertain idiosyncrasy. Ethyl chloride in quantity is about six times as strong (this term being used for lack of a better) as ethyl ether, and when judiciously administered produces prolonged pre- and post-anesthetic analgesia. Furthermore, its physiological action is less accompanied with t h e variegated hallucinations always evident in patients t o whom nitrous oxide is administered. A t t h e suggestion of Dr. J. T. Gwathmey, t h e senior author’s medical colleague in all his researches on anesthesia,%an investigation was undertaken on t h e rate of evaporation of ethyl chloride from oils and mixtures of ethyl chloride and ether from oils with the view of using t h e results as a basis for inducing analgesia, or prolonging it in conjunction with anesthesia, for the purposes indicated above. The mutual solubility of ethyl chloride and oils presented nothing novel, but t h e physical properties of t h e former (b. p. 12.5’ C.) indicated probable marked variations in rate of evaporation from t h a t of ethyl ether (b. p. 34.6’ C.). On account of t h e extremely rapid evaporation of ethyl chloride a t ordinary room temperatures, all mixtures were prepared cold, after containers and constituents had been chilled by melting ice. The rate of evaporation of ethyl ether from different 1 Presented before the Division of Medicinal Products Chemistry at the 60th Meeting of the American Chemical Society, Chicago, 111, September 6 to 10, 1920. * D u Pont Scholar, College of the City of New York. a Am. J. Surgery, January 1916; Proc. Am. Phil. Soc., August 1915. 4 International Medical Congress, London, 1913; “American Year Book of Anesthesia and Analgesia,” 1915. 6 Gwathmey and Karsner, J. Am. Med. Assoc., 70 (1918). 993; Brit. Med. J . . March 2, 1918; Ficklen, N . 0. Med. J.,January 1920; Lathrop, New Orleans Meeting, A. M. A., and others. 6 Gwathmey and Baskerville, “Anesthesia,” D. Appleton 81 Co.
oils1 having been shown t o be practically the same, or parallel, only one oil was used in these experiments, viz., neutral corn oil, which had been refined by t h e process of the senior author.2 The ethyl chloride used was “Kelene,” and t h e ether was 97 per cent ethyl ether and 3 per cent ethyl alcohol, purified by t h e senior author’s process.3 The procedure was essentially t h a t described in a previous paper.l However, t h e rate of evaporation of ether from oil having been shown t o have a direct ratio t o t h e surface exposed and related t o t h e distance from t h e surface of t h e liquids t o t h e top of t h e vessels, tubes of uniform size were used. It is recognized, of course, t h a t results obtained by such experiments do not disclose t h e conduct of such mixtures when in contact with t h e walls of the alimentary canal. The glass water thermostat was stirred by air and kept a t a constant temperature of 37’ C. ( *0.1’ C.) by heating coils of resistance wire, a calibrated thermometer reading t o hundredths being used. Large glass tubes, all of t h e same diameter and with walls of practically t h e same thickness, calibrated t o 1 cc. from 20 cc. t o 105 cc., were weighted with lead t o maintain their position in t h e ice bath and later when suspended in the thermostat t o within 8 cm. of t h e tops. During t h e first 5 min. after t h e tubes were placed in t h e thermostat, readings were taken every minute t o determine t h e maximum volume expansion up t o 37’ C. After t h a t , readings were made every 5 min. for 2 or 3 hrs. The mixtures by volume, measured a t t h e temperature of melting ice, are shown in the accompanying chart, which gives a graphic representation of t h e results obtained. The abscissae show the number of cc. of ethyl chloride evaporated from the oil mixture, and t h e ordinates t h e time of evaporation. The experiments offering results of value in connection with our particular object were verified by frequent repetition. The mixtures containing 25 per cent or more ethyl chloride by volume boiled vigorously during t h e time t h e temperature rose t o 37’ C. The use of such mixtures for internal administration was obviously out of question However, i t was determined t h a t the rate of evaporation of ethyl chloride from oil quickly acquires a definite and fairly fixed speed, which begins when t h e solution has acquired a volume composition of 13 t o 14 per cent of ethyl chloride. If an original mixture of 15 per cent be used, t h e uniform speed is established within 10 min. for surface exposures a b taining in t h e experiments. APPLICATION T O U S E I N ANESTHESIA
These facts may later prove t o be of moment in ethyl chloride-oil alimentary administration, for, as mentioned above, 5 cc. of ethyl chloride are equivalent 1 L O C . Cil. 2
J. Frank. I n s t , June 1916.
a Baskerville and Hamor, THISJOURRAL, 3 (1911), 302.
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
Apr., 1921
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Oil solutions containing 18 t o 22 per cent ethyl chloride lose one-fourth t o one-half of t h e volatile constituents upon standing for one week at room temperature in loosely stoppered bottles, which are occasionally opened for a few minutes. Hence, such ethyl chtorideoil mixtures must be tightly closed or kept in a refrigerator t o prevent changes in proportions. In fact, i t is advisable t o make u p such solutions immediately before use so t h a t t h e anesthetist may know t h e quant i t y of-anesthetic he is administering.
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E T H Y L C H L OR1D E E T H E R- 01L M I X T U R E S
As oil-ether (usually 2 5 : 7 5 ) has proved t o be such a valuable adjunct t o t h e comfort of t h e patient in operations and dressings, by either colonic or oral administration,' and as ethyl chloride exhibits such desirable analgesic effects, a mixture of oil, ether, and ethyl chloride was prepared a n d t h e comparative rate of evaporation determined. For reasons already indicated above, t h e mixture was made u p of oil, 30 per cent; ether, 6 5 per cent; and ethyl chloride, 5 per cent. The curve obtained is plotted on t h e chart. A s yet clinical d a t a are not available for drawing any conclusions. Further studies of mixtures have been inaugurated in this laboratory with a view of adapting them in special fields of surgery and treatment of t h e more elusive nervous and mental disturbances.
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/s
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dum CENTIMETERS€VAPORATED t o 30 cc. of ether as an inhalation anesthetic, although animal experimentation carried out by Drs. J. T. Gwathmey and G. B. Wallace in t h e Bellevue Laboratories, New York, with ethyl chloride-oil colonic administration, have not so far been encouraging; yet most satisfactory results have been obtained in dental surgery by Dr. M. Ecker i n cooperation with D;. Gwathmey. T h e technique is very simple. A vessel containing a n 18 per cent ethyl chloride mixture is interposed in t h e train of t h e nitrous oxide-oxygen mixture on its way t o t h e patient. Just enough ethyl chloride vapor is picked u p by passing over about 5 cm. of t h e ethyl chloride mixture t o induce analgesia for t h e extraction of teeth without t h e patient having experienced t h e excitement stage just prior t o surgical anesthesia, so noticeable i n the use of nitrous oxide. A s only a few hundred cases of humans have been so treated u p t o date, even though with t h e most gratifying success, i t is too soon t o draw conclusions. However, sufficient d a t a were accumulated t o warrant a study of t h e keeping qualities of such mixtures as might prove t o be most useful in dental surgery. T h e insertion of anesthol (ether, 47.1; ethyl chloride, 1 7 ; chloroform, 35.89 per cent) in t h e train has proved most successful in about 4000 cases.
Tests on Lubricating Oils The chemical engineering and the agricultural engineering departments of the A. and M. College of Texas have started an experiment to determine the properties of asphaltic base and paraffin base lubricating oils and the qualities that recommend them for use as lfibricating oils in internal combustion engines. Several oil manufacturers have contributed samples of their products for experimental material, specimen automobile and tractor motors of different makes and types have been obtained from manufacturers, and the various kinds of oil will be subjected to a practical test in these engines. Before and after the oils are used the chemical engineering department will make various tests to ascertain the physical and chemical qualities, and to determine the relation between the laboratory tests and the actual value of the oil. Manufacture of Research Chemicals a t the University of Wisconsin A summer course in the manufacture of organic chemicals is to be given a t the University of Wisconsin under the direction of Prof. Glenn S. Skinner. It is planned to utilize the laboratory facilities for the manufacture of such chemicals as are needed in the various departments, and the staff have been asked to hand in their orders for chemicals. Eight of the most promising advanced students will be admitted to the course. They will work from nine to ten hours a day, and will receive pay of about 40 cerits an hour. The course offers an opportunity for intensive training in practical organic chemistry and experience in large-scale manipulation.
Sugar Production in the Philippines, 1920 to 1921 The sugar crop in the Philippine Islands for the season 1920-21 as estimated by the Philippine Bureau of Agriculture is 552,027 metric tons, an increase of 128,500 tons or 30 per cent over the previous season. 1 LOC.
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