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T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
The optical rotation of true scammony resin obtained from the root is reported by P. Guigues t o vary from -18’ 30‘ t o - 2 3 O 3 0 ’ and t h e upper limit of natural scammony resin as -2.5’. Resins having a rotation of - 2 3 ’ t o - 2 5 O are considered t o be derived from Ipomoea orizabensis. The resin of Resina drastica is less soluble in ether and in chloroform t h a n is true scammony resin or the Mexican scammony resin. It is more slowly soluble in alkalies than is true scammony resin, as also is t h a t of the Mexican scammony. All three gave markedly cloudy solutions in ammonia and in potassium hydroxide solution, but the insoluble portions were so fine t h a t the solution passed through an analytical filter without clearing and without collecting an appreciable residue on the filter. Acidulating t h e alkaline solutions did not precipitate the resin in any case. The alcoholic solution of Resina drastica reduced Fehling’s solution both before and after heating with weak sulfuric acid. It is thus uncertain whether t h e resin has a glucosidal character or not. The supply was limited and a separation plan could not be carried out. I n general character, this resembles both true and Mexican scammony resins. It is slightly more acid and is more strongly levorotatory. Its color alone would distinguish it, and treatment with decolorizing
I
B y V. C. ALLISONAND S. H. KATZ
The Bureau of Mines recently made an investigation of the use of stenches as a warning in mines. Odors are p u t t o various other industrial uses; principal among these are t h e testing of boilers for leaks with either air or water under pressure and t h e testing of plumbing or pipe lines. Ether, oil of peppermint, and oil of wintergreen are used mostly for these purposes. It has also been suggested t h a t some strongly odoriferous gas or vapor, free of sulfur, be mixed with water gas t o indicate its presence in case of leaks or other accidental escape into the air of a room. During the work described in this paper a considerable number of chemicals were examined t o determine their applicability t o t h e mining needs and conditions. I t was desired t o use stenches, t h a t is, unpleasant rather t h a n pleasant odors; and those most powerful at low concentrations were t o be preferred. Of the chemicals examined those most useful were adopted for mine warnings. However, those which were less satisfactory for mine use may find other applications. For t h a t reason the results are given in this paper. Published by permission of the Director, Bureau of Mines. Read at the 56th Meeting of the American Chemical Society, September 10 t o 13, 1918. 1
2
11,
NO. 4
charcoal does not take out t h e color appreciably. When freshly precipitated it has an agreeable tea-like odor which disappears on drying. Probably a small amount of volatile oil is present in t h e drug. The powdered resin resembles scammony resin in odor. The special distinguishing features of the three resins are ( I ) the brownish color of true scammony resin, and the very deep green color which it gives with iron salts, ( 2 ) the light color of Mexican scammony resin, producing a colorless alcoholic solution, and giving almost no color with iron salts, and (3) the deep lemon-yellow color of the Resina drastica. The iron test distinguishes quite sharply between true and Mexican scammony when a ferrous salt is used. If 0.5 g. of the resin be dissolved in I O mils of alcohol and 0.5 mil of a I O per cent aqueous solution of ferrous sulfate added, t h e Mexican scammony resin shows only a very faint green while the others become dark green and on standing deposit a dark mass, leaving an olive-green supernatant liquid. Subsequent efforts t o obtain another sample of the Resina drastica for botanical study have failed, though samples of drugs having a different character were sent. It seems probable t h a t several botanical species, closely allied, are seeking a market as scammony or scammony substitutes. LABORATORYOF PARKE, DAVIS& C O M P A N Y DETROIT,
MICHIGAN
LABORATORY AND PLANT AN INVESTIGATION OF STENCHES AND ODORS FOR INDUSTRIAL PURPQSES1~2
Vol.
I
APPARATUS A N D PROCEDURE
The apparatus used, t h e “odorometer,” is shown in Fig. I . A number of Venturi type flow meters were so arranged t h a t a measured volume of air could be passed at a uniform rate through or over the chemical, and this air then mixed with another measured volume of pure air also flowing at a uniform rate. The concentration of the chemical was measured by determining its loss in weight after a measured volume of air had passed through or over it. From this loss in weight and t h e total volume of air with which the chemical was mixed, t h e concentration in milligrams per liter of air and in parts of vapor per -million parts of air were determined, The mixture of air and chemical passed through a rubber tube with a glass funnel a t the open end. The funnel was placed over the nose when smelling t o prevent contamination of t h e issuing mixture by room air. The apparatus was placed in a good hood and t h e room was well ventilated t o protect t h e operator from t h e effect of continually smelling the chemical, which might reduce his sensitivity t o t h e odor. An arbitrary scale for odors of five degrees was adopted. The degrees are designated: I-Detectable 2-Faint 3-Quite Noticeable +Strong 5-Very Strong
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
33 7
Tibe ex fendr up flue of hood
FIG.I-THE ODOROMETER
Only one inhalation of t h e current of air and chemical was used t o determine t h e intensity of t h e stench or odor. The concentration a t which t h e odor of a chemical can be determined in the above manner may be greater t h a n t h a t a t which t h e odor can be detected in still air over a period of, for instance, I O seconds or more. The method used, however, is more closely related t o actual working conditions in most operations. The position of a n y strength of odor on t h e scale depends upon t h e sensibility a n d judgment of t h e
operator, b u t with one person conducting a test from start t o finish, i t has been found quite satisfactory. RESULTS
Twenty-four stenches were examined. The results are given in Table I. T h e curves, odor vs. concentration in parts per million, are given in Fig. 2. It is worthy of note t h a t t h e cumulative effects of increasing concentrations vary widely with different substances. Those materials which have a soporific effect are seen t o have least odor for a given concentration, probably due t o t h e anesthetizing effect upon t h e olfac-
CONCENTRATION,PAR" PER MILLION
FIG.2-cCURVSS
SHOWING CONCENTRATION VS. I N T E N S I T Y O F O D O R OP V A R I O U S CHBLIICALS
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
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TABLE I-RESULTS OF MEASUREMENT OF THE INTENSITY OF VARIOUSSTENCHES VOLUMES OF THE CHEMICAL AS A PERFECT MILLIGRAMS O F CHEMICAL PER MILLIGRAMS OF CHEMICAL PER GAS,PER MILLIONVOLGMES OF AIR CU. FT.OF AIR LITER OF AIR -INTENSITY OF ODOR-INTENSITY O F ODOR7 , INTENSITY OF ODOR-. Quite Quite Qujte DetectNoticeVery DetectNoticeVery DetectNottceVery CHEMICAL able Faint able Strong Strong able Faint able Strong Strong able Faint able Strona Strona 7 10 Amyl acetate.. . . . . . . . . . 13 90 246 1.1 2 14 1.5 38 0 06 0.478 1.326 615 1236 1753 19.4 Ethyl acetate.. ......... 190 339 34.6 63 191 126 2:2J 6.733 4.457 123 439 Amyl alcohol.. . . . . . . . . . 63 83 8 . 5 13 601 6.4 45 61 0.442 2.167 1.581 Butyric acid.. 2.4 6 18 161 0.3 91 9 0.6 2 16 0.066 0.580 0.329 962 7 29 125 332 Valeric acid.. 0.8 39 3 . 4 15 114 0.523 4.036 1.394 1923 3352 4927 19982 5825 Ethyl ether 165.1 287.7 423 500 1715 14.944 17.667 60.600 6 12 Butyl mercaptan.. 56 18 38 1 .o 2 3 0.5 5 0.055 0.120 0.177 3.5 5 16 7 11 Isobutyl mercaptan. .... 0.2 2 0.5 0.7 1 0.025 0.041 0.060 73 Ethyl mercaptan.. ...... 18 35 198 1.3 141 2.5 5 10 14 0.186 0.357 0.501 9 2 7 Propyl mercaptan.. ..... 14 17 0.6 0.2 0.8 1.2 0.028 1.6 0.043 0.054 Amyl thioether. 0.2 1 1.6 1.7 2.2 0.2 0.04 0.3 0.0115 0.012 0.5 0.4 0.015 Ethyl thioether.. 3 12 29 61 74 0.3 1.2 8 3 6 0.107 0.223 0.271 6 ’ Allyl isothiocyanate.. 2 3 8 50 6 0.3 0.2 0.7 0.9 0.024 0.030 0.201 5 13 Methyl isothiocyanate.. . 23 36 48 0.4 r. 1 2 4 0.067 0.108 0.144 Amyl isovalerate.. ...... 12 6 10 1.7 3 1 0.5 2 2.3 0.4 0.039 0.072 0.082 1461 1588 Carbon tetrachloride. , . 718 4964 609 1 128 886 1087 260 283 10.024 31.333 38.444 Chloroform. 674 1389 2600 5887 9528 192 360 93 816 1321 46.666 12.733 28.833 Iodoform, .............. 1.l(a) . . O.S(a) ... Artificial musk.. .. 0.001(a) ... ... Nitrobenzene. .......... 4 29 36 44 114 296 5 6 16 42 0: 222 0:563 1 i93 Phenvl isocvanide . . . . . . . 10 25 0.5 1 3 0.4 3 0.06 0.1 1 0.013 0.105 0.042 4 Pyridine. . . . . . . . . . . . . . . 10 45 93 700 1764 0.9 9 162 64 0.301 5.710 2.265 Methyl salicylate. 23 29 16.1 2.8 244(a) 4 5 0.179 1.526(a) . . . Oil of peppermint.. 0.68 3 0.9 0.109 0.332 9.9 01348 (a)Maximum concentration obtainable.
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TABLE11-PHYSICAL Boiling Point CHEMICAL Amyl acetate..
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c.
Freezing Point O
148
c.
-75 (thick) -83.8
....
Butyric acid., . . . . . . . . . 162.3 -7.9 Valeric acid.. . . . . . . . . . 186.4 -58.5 Ethyl ether 35 -112.6 Phenyl isoc . . . . . 165 .... ... Allyl isothiocyanate., . 151 Methyl isothiocyandte.. 119 34 Amyl isovalerate. ...... 190 Butyl mercaptan.. ..... 97 ... Isobutyl mercaptan. . . . 88 ... Ethyl meicaptan 37 -144.4 Propyl mercapta 67 Methyl salicylate. . . . . . 222.2 -8.3 Amyl thioether.. 95-98 ... Ethyl thioether.. .. 92 -99 5 Carbon tettachloride. 76.74 -19.5 Chloroform 62 -63.2 Iodoform.. Decomposes 119 Artificial m nsk 5.71 Oil of peppermint Pyridine. 115 . 2 -42
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PHYSIOLOGICAL PROPERTIES OF CHEMICALS USED AS STENCHES
Character of Odor Banana oil Fruity, pleasant Alcoholic Very disagreeable Very disagreeable Pungent Very disagreeable Mustard oil disagreeable Mustard oil: disagreeable Very disagreeable Very disagreeable Very disagreeable Very disagreeable Very disagreeable Oil of wintergreen, pleasant Very disagreeable Very disagreeable Sweet, unpleasant Sweet, agreeable Unpleasant Pleasant Almonds, pleasant Pleasant Very disagreeable
tory nerves. Table 11 gives the physical and physiological properties of t h e chemicals. SUMMARY
The Bureau of Mines h a d need of a suitable stench for use as a warning in mines. For this purpose an apparatus, or “odorometer,” was developed f o r measuring t h e intensity of odors in varying concentrations in air. The odors of 2 4 different chemicals were examined with t h e apparatus, since other industrial applications may be made of these results, they are given in this paper. ACKNOWLEDGMENT
Acknowledgment is made of t h e valuable assistance given by Mr. A. C. Fieldner, chemist in charge of t h e gas mask research of t h e Bureau of Mines, in devising laboratory apparatus, and in selection and securing of suitable chemicals. GAS LABORATORY
BUREAU OF MINES EXPERIMENT
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STATION
PITTSBURGH, PENNSYLVANIA
THE USE OF STANDARD DIES IN MAKING GROUND GLASS JOINTS By S. F. ACREE Received December 21, 1918
It is perhaps not too much t o say t h a t one of t h e most important mechanical aids in t h e development of chemistry has been t h e use of ground joints for glass
Physiological Properties of Vapor REMARUS Harmless Pleasant t o most people; disagreeable to some Harmless .............................. Harmless .............. Harmless .................... Harmless .................... Soporific Unknown 1,achrymatory and toxic Lachrymatory and toxic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Harmless Harmless Unknown Probably harmless .................... Harmless Unknown Harmless ........... Unknown Unknown Probably harmless Harmless .................... Soporific Harmless Harmless Unpleasant in higher’ Concentrations Toxic Harmless Toxic
or metal stoppers, stopcocks, and other similar means of enclosing gases, liquids, and solids. While mercury seals and similar devices are often used for holding liquids and gases in confined spaces, these are ill general f a r more troublesome t h a n ground glass cocks or stoppers, and find only limited application. When such ground glass joints are broken it Often happens t h a t t h e entire apparatus is lessened in value because such joints are not easily accessible for reThe glass apparatus must grinding or then be sent t o a glass blower who makes new ground glass joints which are inserted in place of t h e broken ones. This means, of course, expense and delay in t h e work for which the apparatus is used. rn viewof t h e importance of such ground glass joints in routine and research worlr in chemistry, physics, and othersciences, and in t h e industrial and daily life, i t seems strange - t h a t chemists and manufacturers of glass apparatus have ndt established a uniform set of dies having a standard angle. An agreement could be reached on standard sizes of stopcocks, stoppers, etc., for regular apparatus such as 100, zoo, 500, and 1000 cc. flasks and bottles, for various sizes of one-way, two-way and three-way stopcocks and other similar apparatus, which could be furnished as stock articles or made on short notice. We have found t h a t t h e glass blower can make joints much more easily and accurately with these standard dies, and his income is.
