Sept., 1918
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
AMERICANPRODUCTS SOLDIN URUGUAY ARTICLES 1914 Asphaltum Blacking, shoe paste, etc Celluloid and manufactures.. 286 Cement, hydraulic.. 3,632 Chemicals, drugs, dyes, etc.: Acids Alcohol. wood Baking powder 13,735 Bark extract f o r tanning.. Calcium carbide.. 21,413 4,338
..................................... ......................... .....................
............................. .................................. ........................... ................................ ..................... .............................. .......................... .......................... Medicines, patent or proprietary. . ............. Petroleum jelly, etc... ..... ............... Soda salts and preparations Sulfur (brimstone). ............................ Allother ..................................... Ex losives: &&ridges, loaded.. ........................... Dynamite.. ................................... All other.. ........................... Glass and glassware.. ................... Glucose. ............................... .............................. Soap stock, and other .......................... India rubber manufactures. ...................... I n k ............................................ ~
................................ .................................... ........................................ ........................ ........................... ..................................... ............................. .............................. .......................... ................................... ...............................
Leather, patent. Metal polish Naval stores: Rosin Tar, turpentine, pitch.. Turpentine, spirits., Oils: Animal.. Mineral: Gas and fuel... Illuminating.. Lubricating, etc... Gasoline Other light.. 1 Not stated separately in 1914.
I
.... .... ....
64,309 2,707
.... ....
56,610 40,067 10,946 2,612 10,948 17,796 11,240
....
62,561 2,233 6,105 62
I
106,295
1917 14,018 8.966 22 598 5,413 9.013 23,639 8,538 39,367 52,647 107,022 5,592 163,935 7,600 269 372 ~
~
..................................... .............................. ................................. ................................... .................................. ......................... ...................................... .................................
....
...................... ...................... ...................................... .....................................
....
5,731 81,271 42,965 19,201 1,462 188,096 9,914 15,432 3.853 157,100 50 19,366
....
467
15 824 809:056 48,651 291,828 20.675
AMERICANPRODUCTS SOLD IN URUGUAY (Concluded) ARTICLES 1914 1917 Vegetable : Corn $ 13,978 $ 62,416 Cottonseed. 334.381 147,425 Other fixed 6,806 Volatile. 388 3,011 Paints, pigments, etc.: D r y colors.. 11,225 14,954 Ready-mixed paints.. 18,750 32,612 Varnish 5,678 25,839 426 White lead.. 13,112 Allother ..................................... 103 35.316 Paper and manufactures: 18,505 87,722 Paraffin and paraffin wax... Perfumery, cosmetics, e t c . . 12,240 15,191 Soap : Toilet.. 6,021 12.418 Allother 8,783 9,163
50,209
....
24,527
707
4 976 ~
713,945 92,978 47,253 413.774
I n chemical lines Uruguay makes no important contribution t o the United States, as the following figures for the fiscal years 1914 and 1917 show: URUGUAYAN PRODUCTS SOLDIN THE UNITED STATES ARTICLES 1914 1917 Bismuth $ $ 4,067 Blood, dried 12,751 50,803 Bones, hoofs, and horns.. 75,304 110,401 Fertilizers.. 88,141 124,684 Flaxseed 24,032 Glycerin 8.520 Grease and oils 16,520 Hide cuttings, and other glue stock 23,748 83,851 53,015 Indiarubber Oleo stearin. 28,705 Tin ore 70,078
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.................................... ....................................... ....................................... .................................. ................ .................................... ................................... ........................................
.... ....
.... ....
.... .... ....
1
ORIGINAL PAPERS (‘JELLY VALUE” OF GELATIN AND GLUE By A. WAYNECLARKAND LOUIS DUBOIS Received April 23, 1918
The examination of samples of glues and gelatins in this laboratory during t h e past ten or twelve years has included a test which we have designated as “jelly value.” I n making this test we have not followed the common practice of t h e makers of these products b u t have endeavored t o improve upon i t by following a procedure which produces results t h a t can be expressed in absolute figures. The system apparently in common use among the makers seems t o be t o make u p a jelly of definite concentration and compare its physical strength with t h a t of a standard sample. The literature is exceedingly scant. Alexander1 in a n excellent paper has fully explained his methods and Fernbach2 also goes into the subject in considerable detail. It seems t o us, however, t h a t our methods result in a more scientific presentation of the jelly-forming characteristics of these materials in t h a t they can be expressed in per cent figures. Our practice has been t o make up a series of glue or gelatin solutions of various known concentrations, cool them until well set, and t h e n slowly warm them t o a predetermined temperature and a t t h a t point note which concentrations are solid and which are liquid. We are then able t o state t h a t a t a given temperature, the sample tested has a jelly value of, for instance, 6 per cent, meaning t h a t the 3 per cent, 4 per cent, and 5 per cent trials were fluid, whereas t h e 1 “The Grading and Use of Glues and Gelatin,” Jerome Alexander, J . SOC.Chem. Ind., 26 (1906). 2 “Glues and Gelatin,” Fernbach. D. Van Nostrand Co., 1907.
6 per cent, 7 per cent, and 8 per cent trials were solid. This procedure obviates the use of all “shot tests” or weighed devices for testing the physical strength of a given jelly. During the course of years in which these tests have regularly been made, we have used different temperatures for observing t h e setting of t h e water solution of the various percentages tried. T h e results have in many respects been quite unsatisfactory, until recently we have been able t o carry out a considerable number of experiments t o determine whether there might exist a trial temperature a t which such mixtures show the best results. Our efforts have been rewarded by the discovery t h a t there is in such mixtures a very plainly indicated temperature-range through which the “set” or (‘gel” of a definite concentration of solution is not changed. Our results, in general, as might be expected, are more satisfactory with gelatins t h a n with glues a n d they are probably not as definitely useful in judging the strength of glues as in judging the quality of gelatin.
h% x
As t o the character aind sources of t h e samples used in obtaining the curves shown herewith, i t will be necessary t o state as follows: The material designated “Gelatin” is a product
T 3 E JOURNAL OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
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1 BrownFhke Glue
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regularly used in manufacturing processes and, as far as we have been able t o ascertain, is of American manufacture. It is purchased from one of the most reputable of American manufacturers. The “Gelatin Edible, Knox’s,” the “Gelatin Edible, Cox’s,” and the “Gelatin Edible, Peter Cooper’s” were purchased in grocery stores for purposes of examination, as being reputable brands regularly on sale for household use. The so-called “White Glue” is simply a gelatin which might be called gelatin-glue, carrying a certain amount of white pigment. The ‘(Brown Flake Glue” is a,common commercial variety used chiefly for the manufacture of paper boxes a n d other similar purposes where strength is not especially required. The “Fish Glue” is a product about which we have complete information, as i t is made in one of our own departments for use in coating court plaster and corn plasters where we are desirous of using a thoroughly standardized product well boiled for purposes of destroying pathogenic bacteria, etc. I t is made from fish-sounds by thorough extraction with boiling water followed by protracted boiling in the steam kettle. This is then made into sheets and dried; in other words, i t is straight first-class fish glue. The method of procedure is to have on hand a sufficient number of ordinary 6-in. test tubes t o include the range of percentages t o be tried, each fitted with a cork and graduated for I O cc. Into each tube is put a weighed amount of the granulated glue or gelatin sample and t o these cool water is added up t o
0
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4
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6
8
10
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t h e I O cc. mark. A glass rod is now put into each tube and the contents stirred occasionally during several hours, after which t h e tubes are allowed t o stand in boiling water until the sample is completely dissolved. The rod is now removed and the tubes tightly corked so as t o avoid the formation of a skin on the surface of the solution when i t cools. These tubes are then cooled considerably below the temperature a t which the observation is t o be made. They are then stood in water, which is allowed very gradually t o come up t o the desired temperature. Observation of t h e crset” is now made b y tilting t h e tu‘be t o observe whether or not the jelly is solid. Naturally, this point is not absolutely accurate, b u t with tubes of uniform diameter the judgment of the “set” or “gel” is reasonably easy t o make. It will be observed t h a t this per cent is based on the weight of t h e solid and t h e volume of the liquid, as is usual under such conditions. As a result of this investigation, i t is evident t h a t for practically all of this work a temperature of I O O C.
Sept., ~ 9 1 8
T H E JOURNAL OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
is the most valuable for comparative purposes. For instance, on the sample represented b y t h e curve marked “Gelatin,” it will be observed t h a t the range of temperature between the points of liquefaction of the I per cent and the 2 per cent mixture is about one degree; also, t h a t between 4 per cent a n d 6 per cent concentration i t is about one degree, while between 2 per cent and 3 per cent t h e temperature range is about 18’. While in this particular instance the 10’ point is no more valuable t h a n t h e 16’ point for a standard jelly-value temperature, yet taking this curve in conjunction with the others illustrated herewith, i t will be seen t h a t 10’ C. is a good average working temperature-point for observation of the entire line of glues and gelatins. RESEARCH LABORATORY JOHNSON & JOHNSON NEW BRUNSWICK, N. J.
A NEW METHOD FOR THE QUANTITATIVE EVTIMATION OF VAPORS IN GASES A DIFFERENTIAL PRESSURE METHOD By HAROLD s. DAVISAND MARYDAVIDSONDAVIS Received March 27, 1918 INTRODUCTION
I n a former paper1 a new form of tensimeter was described for measuring t h e partial pressure, in a mixture of inert gases, from any liquid or from its solution in a nonvolatile substance. The ease with which these experiments could be carried o u t led us t o experiment with modified forms of this apparatus, having in view the development of a method for t h e estimation of small quantities of vapors in inert gas mixtures.2 THEORY O F METHOD
According t o t h e principle often referred t o as Dalton’s Law of Partial Pressuies, the vapor pressure from a liquid is independent of the kind of gas above it, provided the gas is inert. Deviations from this law are well known, b u t i t holds with surprising accuracy in t h e case of a mixture of benzene and air at atmospheric pressure, as has already been shown by one of US.^ Consider two closed flasks connected, as in Fig. I, by a manometer and filled with air a t atmospheric pressure. If now a small sealed bulb containing a volatile liquid be broken in each, the liquid will partially evaporate, and if the temperatures of the flasks remain the same, the same additional pressure will be developed in each, so t h a t the manometer connecting them will register no difference in pressure. Even if the temperatures of the flasks do vary, no difference in pressure will be recorded until there is a relative difference in temperature between them. S o w suppose t h a t one of the flasks had contained a certain quantity of the vapor of t h e volatile liquid corresponding t o a pressure less t h a n t h e saturation 1 “The Extraction of Aromatic Hydrocarbons from Gases by Means of Liquid Absorbents,” Harold S . Davis, University of Manitoba Publications, February, 1917. * Most of the work was done during the early part of the summer of 1917 and the results under the same heading as that of this paper were given to the Canadian Advisory Council and to the Imperial Munitions Board of Canada. United States Patent No. 1,272,922 on this method wasissued July 16, 1918.
7 09
pressure. When the small bulb of liquid was broken in this one, the liquid would not add all its vapor pressure t o the pressure already in the flask, for part of t h a t was already due t o its vapor. It would add only the amount of pressure necessary t o bring its pressure up t o saturation; and since the total saturation pressure was added t o the pure air in the other flask, the manometer connecting the two would register a pressure equal t o the pressure of vapor in the original gas. Two important points should be noted here: I-The partial pressure of any particular vapor in a sample of gas is independent of the temperature of the gas, provided t h a t the total pressure on the gas remains constant while the volume can change with the temperature, and provided the vapor remains always unsaturated and obeys the simple gas laws. 2-The difference in pressure developed between the two flasks, one of which contains air and vapor, and the other air free from vapor, will vary as the absolute temperature, provided the relative temperatures of the flasks remain the same; t h a t is, for practical purposes, t h e difference in t h e pressure is independent of variations of temperature. An apparatus constructed on this principle will, therefore, measure a definite quantity, v i z . , the pressure of the vapor in a gas a t any particular gas pressure. The differential pressure which develops between the two flasks is equal t o the original partial pressure of the vapor in the gas, when the total pressure on the gas is equal t o the atmospheric pressure a t the time of the experiment. This can be reduced t o standard conditions in the following way: Let P be the atmospheric pressure a t the time of the experiment. Let P o be normal atmospheric pressure = 76 cm. of mercury . Let X be the differential pressure developed between the flasks.
x p o is equal t o the partial pressure of the Then __
P
vapor in the gas when the total pressure of the gas is XPO P o . As was pointed out before, the value __ is
P
independent of the temperature provided every component of the gas remains unsaturated. I n a similar way the total of the partial pressures of two or more vapors may be reduced t o its value for a total standard pressure on t h e gas. However, though this partial pressure of a vapor is independent of the temperature, the actual weight of t h e vapor contained in unit volume of t h e gas depends on the temperature. For one vapor this may be calculated from the partial pressure on the assumption t h a t the vapor gives the same partial pressure as i t would if i t were a true gas a t t h a t temperature and molecular concentration. SOURCES O F ERROR
I-The permanent gases in one of the flasks may dissolve in the liquid t o a greater extent t h a n those in the other flask and thus lower the pressure on t h a t side.
