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 C H E M I S T R Y
33 8
Vol.
11,
No. 4
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 had 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 the intensity of odors in varying concentrations in air. The odors of 2 4 different chemicals were examined with the 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 the 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 the development of chemistry has been the 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 far more troublesome than ground glass cocks or stoppers, and find only limited application. When such ground glass joints are broken it Often happens t h a t the 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 the broken ones. This means, of course, expense and delay in the work for which the apparatus is used. rn viewof the 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 the glass blower can make joints much more easily and accurately with these standard dies, and his income is.
Apr., 1919
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
not diminished by such standardization because broken apparatus must be replaced. When a needed article is not in the laboratory stock, i t would be easy, with such a set of dies in the chemical laboratory, t o replace a n y standard size ground glass stopper, stopcock, or other apparatus a t any time by having the mechanic use the suitable dies t o grind down a standard glass blank. The broken parts of a n odd size stopper might be returned t o the glass blower who would measure t h e length and larger diameter, for example, and would then be able t o make such a new stopper, from either standard or new blanks in a very short time. If either part of the ground glass joint or stopper were entirely destroyed, the other part could be measured and the length and larger diameter sent to the glass blower with instructions for placing holes a t the proper places. .
DJ
FIG.1
On account of the frequent inconvenience arising from broken glassware of odd sizes and because of the necessity for planning standard joints in the apparatus used. in connection with our investigations on conductivities, hydrogen electrode measurements, etc., we made arrangements several years ago with Mr. Otto Sterling, Bureau of Standards, t o make up standard sets of dies which enable us t o replace broken apparatus very quickly with the assurance t h a t the new joints will fit as well as the old ones. These dies can be made very conveniently from the standard Morse or Brown and Sharp tapers which can now be bought in the market a t a reasonable price. These tapers vary in diameter all the way from ‘/4 in. t o over 3 in. a n d one similar taper for giving diameters between l / 4 in. and ‘/sin., for example, can be easily made in a n y shop. The angle of the Morse taper corresponds in general t o a decrease in diameter of 0.625 in. per f t . a n d is nearly ideal for ground glass joints. Three of these tapers, however, which were made earlier by the Morse people before they began t o manufacture a complete set, had an angle corresponding t o about 0.600 in. per ft., and i t is therefore clear t h a t even the -Morse standard is not quite as perfect as it should be. This slight objection has no practical disadvantage, however, because two stoppers made by these two tapers one inch long and having the same middle diameter differ only 0.001 in. in diameter a t the ends. This difference is a “perfect match” in comparison with existing practice. Furthermore, the 8 tapers now available do not completely overlap, but the missing gaps are so short t h a t practically any diameter of ground glass joint desired can now be secured.
339
The following table shows the angle of the taper, the length, the large and small diameters, and other data: Diameter
of Plug at
TAPER
Small End In. . 0.252 0 ....... 0.369 1 ..... . . . 0.572 2 ...... . 3 ...... . 0.778 4 . . . . . .. . ,.. 1.020 1.475 5...... . . 6 . . . . . .. . . . . 2.116 7 ....... . ... 2.750
No.
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I
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.
.
TABLE I Diameter of Plug at Standard Taper Large End Plug Depth In. In. 0.356 2 0.625 0.475 21/8 0.600 0.700 29/18 0.602 3a/i8 0.938 0.602 1.231 4l/ia 0.623 1.748 58/16 0.630 2.494 71/~ 0.626 3.270 10 0.625
42t:
Taper per In. 0.05208 0.050 0.05016 0.05016 0,05191 0.0525 0.05216 0.05208
The Brown and Sharp tapers vary about in. per f t . although there are a few odd-size tapers with slightly different angles. The tapers do not exactly overlap but meet practically all needs. It is hoped t h a t in time every glass blower will adopt some fixed standard so t h a t it will not be necessary for each chemical laboratory t o have its own dies. The firm of Otto Hask & Sons, 545 North 5th St., Philadelphia, Pa., is now using Morse taper dies in making all of their apparatus and could doubtless be induced t o use them for anyone else. The following suggestions are offered t o show how we have our standard dies and ground glass joints made: The Morse taper A (Fig. I ) having the desired large and small diameters and lengths for the ground joint is employed for making the tool steel “collar” B, which is used for grinding the outside of the stopper. When the desired taper is not a t hand it is very easy to insert the blank “collar” in a lathe and turn o u t the interior a t the desired angle. A piece of tool steel rod is then put into the lathe and turned down a t the same angle so t h a t this steel “stopper,“ C, fits the collar as indicated in the figure. The grooves D in B and C hold t h e emery, etc., during grinding. Three sets of each die are made and labeled I , 2 , and 3. No. I is used with wet, coarse emery, carborundum, or other hard material for grinding down the glass forms so t h a t the ground surfaces are practically uniformly conical. There is, consequently, far greater wear on this first die than on Nos. 2 and 3. No. 2 is then employed with fine carborundum, emery, etc., t o make the two parts of the joint fit satisfactorily. No, is used with the finest rouge for making the glass stopper and the outer glass joint fit practically perfectly. If so desired, a final grinding of the glass joint itself with rouge and water or oil can be made. As N o . I becomes worn too badly i t is replaced by No. 2 ; No. 3 then becomes No. 2 , and a new set of dies is made t o replace No. 3 . These dies do not wear out rapidly under erosion of the carborundum and can be counted upon t o last several years. The dies can be kept in the laboratory and sent t o the glass blower when new joints are desired, or can be left with t h e glass blower. When covered with vaseline they do not rust. We have a large number of ground glass joints made in diameters varying from ’/8 in. up t o 2 in. and have found this method so satisfactory t h a t we advise its use b y others. THE NEWY O R E STATE C01,LEGE O F FORESTRY SYRACUSE UNIVERSITY SYRACUSE NEWYORK
