Apr., 1918
T H E JOURNAL OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
months against nearly 5 0 per cent lost by commercial potassium cyanide. HOMESTAKE MINE
LEAD,SOUTH DAKOTA
A COMPARISON OF THE PROXIMATE AND MINERAL ANALYSIS OF DESICCATED SKIM MILK WITH NORMAL COWS’ MILK By EVERHART P. HARDINGA N D HUGORINGSTROM Received August 30, 1917
The purpose of this paper imate and mineral analysis with normal cows’ milk and whether foreign substances or during desiccation.
was t o compare the proxof desiccated skim milk t o determine, if possible, had been added before
METHOD O F DESICCATION
There are two general methods used in making desiccated milk. One is drying the milk on steamheated drums and the other is spraying the milk into a chamber through which a current of hot air is passing. -411 drum processes of drying the milk are really
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the moisture content which varies from 2 t o g per cent or even more. The fat content, of course, depends upon the extent t o which t h e fat is removed before t h e milk is desiccated. The amount present is very small, rarely exceeding z per cent. A number of proximate analyses have been made from time t o time, but the majority have been made within the last I O years. Of the eight analyses given in Table I, all except the first have been reported since 1905. EXPERIMENTAL PART
Four different samples of desiccated skimmed milk were purchased on the market or obtained from users of milk powders. Sample I was made by the International Milk Products Company, Detroit, Michigan; Sample I1 by the Minnesota Dry Milk Company, Anoka, Minnesota; Sample I11 b y the International Milk Company, Plymouth, Michigan; and Sample IV by the California Central Creameries, San Francisco, California.
TABLE I-PERCENTAGE COMPOSITIONOF SKIM MILK POWDERS Milchindust(e) Max Popp(b) Mansfield(c) Teichert(d) Fleming(e) Teichert(f) Goyk) Mohan(h) 8.96 8.54 2.53 7.40 2.81 8.3 4.54 Water. 4.17 1.56 2.10 1.7 0.57 1.31 1.81 1.25 Fat 1.65 Protein.. 35.56 35.01 30.59 32.71 38.16 33.8 32.50 33.51 Lactose.. 52.37 51.22 48.62 50.24 49.32 52.57 53.43 49.3 Ash 7.98 8.10 7.20 8.21 6.27 8.04 6.9 7.51 (b) Chem -Ztg. 33 (1909) 647. ( c ) X V I I I Jahresbericht der unter.-onstalt (a) Milchindust, 1889, 90; VNa., 4, 419; Chem. Zentr. 6 1 (1890) 72 des allgem. dster. Apotheker Vereins, 1906-6, 8; Z. Nahr. denussm. 13’ (1607), 285. (d) J a h . Milch. Un!er. Allgau zu Memmingen, 1909, 11; Z. Nahr. 4 (1912), 543. (f)Ailgauer M0natschr.f. Mzlchwirtsch. u. Vaeh., 1 (1913), 31; Z. Nahr. Genussm., 26 (1913), Genussm, 20 (1910), 476. (e) THISJOURNAL, 109. ( 9 ) Ibrd., 26 (1913), 445. (h) J. SOG.Chem. Ind., 34 (1915), 109.
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COMPOSITION OF S K I M MILK POWDERS AS GIVEN I N TABLE I COMPUTED ON MOISTURE-FREEBASIS Milchindust Max PODD Mansfield Teichert Fleming Teichert GOY Mohan 1.72 0.62 1.43 1.85 1.62 2.16 1.85 1.31 36.77 33.60 35.76 39.03 35.07 36.86 34.48 37.09 53.66 53.40 54.90 50.44 56.44 54.97 53.76 54.65 7.83 8.36 8.89 7.87 8.39 6.77 8.27 7.52
TABLE11-PERCENTAGE
__
..................... ............... ............... Ash .................... Fat Protein.. Lactose..
modifications of the Just-Hatmaker* process, in which t h e milk is spread in thin films on t o drums by a distributing pipe. I n the spraying process, the milk is pumped through a nozzle a n d delivered in a fine spray into a chamber through which a current of heated air is passing. The extent t o which the proteins are coagulated depends largely upon the method used in desiccating t h e milk. To increase the emulsifying power of t h e casein different substances may be used.
ODOR A N D coLoR-The color of t h e powders was yellowish white, except Sample 111, which had a brownish tinge and a n unpleasant odor. The other three samples had a milk-like odor. EMULSIFYING QuaLITY-The emulsifying power of the powders was tried with water a t room temperature and a t 40’ C. Approximately z g. of milk powder were stirred up with a little water t o a uniform paste. Water was then added slowly with vigorous stirring until about 2 0 cc. had been added, giving a n
TABLE 111-PERCENTAGE MINERALCOMPOSITION OF MILK ASH Marchand 1000 Parts of Milk Potassium oxide. ............................... 1.071 Sodiumoxide ................................... 0.636 Calcium oxide .................................. 1.864 Magnesium oxide ............................... 0.299 Ferric oxide.. . . . . . . . . . . . . . . . 0.127 Chlorine. ............... 0.751 Phosphoric anhydride.. . . . . . . . . . . . . . . . . . . 2.102 Sulfuric anhydride. ............................. 0.323 Carbon dioxide.. ............................... 0.27i Silica. 0.006
........... ...............
................. .................... ....................... Carbon and impurities.. ............................ ............................................. ...................................... ................
Loss. Total ash 7.456 Oxygen corresponding t o chlorine. 0.176 Corrected a s h . . 7.28 (a) Z. Biol., 10, 295. (b) Ber., Raden. 188S-6, 64.
................................. PROXIMATE
Bunge(a) 1000 Parts of Milk 1.766 1.110 1.599 0.210 0.0035 1.697 1.974
....
.... ....
.... ....
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8,360 0.383 7.977
ANALYSIS
The composition of the different desiccated skim milks is surprisingly uniform with the exception of J. A. Just, U. S. Patent 712,545, Nov. 4, 1912; J . SOC.Chem. Ind., 2 1 (1902), 1548; J. R. Hatmaker, English Patent 21,617, Oct. 4, 1902; J. SOC.Chcm. I n d . , 22 (1903), 1145.
Per cent in Ash 22.14 13.91 20. 05 2.63 0.04 21.27 24.75
...
.... .... .... .... ....
104.79 4.79 100.00
WHOLE MILK Schrodt Richmond Per cent Per cent Fleischmannib) in Ash in Ash 28.71 21.539 25.42 6.67 11.817 10.94 20.27 20.383 21.45 2.80 3.120 2.54 0.40 0.300 0.11 14.00 12.813 14.60 29.33 29.000 25.11 trace 4.11 2.378 0.97 0.533 ....
.....
AND
0.300 0,250 0.353 102.886 2.886 100.000
.... .... .. .. .. ..
103.28 3.28 100.00
... ... ... ... ... ... ...
Babcock Per cent Per 1000 in Ash Parts Mllk 1.75 25.02 0.70 10.01 20.01 1.40 0.17 2.42 0.01 0.13 1.00 14.28 1.70 24.29 0.27 3.84
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.... ....
....
100.00
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7.10
emulsion of approximately the same consistency and composition as normal skim milk. Samples I and I1 emulsified well with water a t room temperature, giving a milk-like emulsion, without any settling of protein in 4 hours. Sample I11 gave a very poor emulsion, yellowish brown in color. A flocculent
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
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TABLEIX-MINERAL CONSTITUENTS I N THE COMMERCIAL POWDERS COMPUTEDON THE MOISTURE-FREE POWDER,ASH AND NORMAL MILK BASIS Sample I Commercial Normal Milk SamDle Drv Powder Ash 9 % Solids Per Cent &¢ Per cent Parts per 1000 Potassium oxide.. . . . . . . . . 1.90 2.01 24.05 1,809 Sodium oxide.. 0.66 0.700 8.35 0.630 Calcium oxide. 1.86 1.97 23.57 1.773 Magnesium oxide.. ....... 0.251 0.266 3.18 0.239 Ferric oxide. 0.00273 0.0029 0.035 0.026 Sulfuric anhydride. 0.897 0.951 11.38 0.856 Phosphoric anhydride 2.58 2.73 32.69 2.467 Chlorine. 1.04 0.981 12.46 0.936 Sample I1 Potassium oxide.. . . . . . . . . 2.03 2.13 25.49 1.917 Sodium oxide.. 0.746 0.783 9.37 0.705 Calcium oxide. 1.75 1.84 21.99 1.656 Magnesium oxide.. 0.232 0.244 2.92 0.220 Ferric oxide. 0.0027 0.0029 0.035 0.0026 Sulfuric anhydride.. ...... 0.971 1.02 12.14 0.918 Phosphoric anhydride 2.51 2.63 31.44 2.367 Chlorine.. 1.14 1.20 14.28 1.080 Sample I11 TABLE IV-PROXIMATE ANALYSIS Potassium oxide.. 1.68 1.80 22.44 1.620 Sodium oxide.. 0.715 0.77 9.60 0.693 Sample I Sample I1 Sample I11 Sample IV Calcium oxide. 1.92 2.07 25.86 1,863 Per cent Per cent Per cent Per cent Magnesium oxide.. 0.228 0.246 3.07 0.221 Ash ..................... 7.45 7.49 7.89 7.98 Ferric oxide. 0.0025 0.0027 0.034 0.0024 1.42 1.82 1.01 0.85 Fat Sulfuric anhydride. 1.02 1.10 13.69 0,990 37.01 33.41 Protein 32.86 33.72 Phosphoric anhydride.. 2.45 2.63 32.78 2.367 5.60 4.71 7.09 6.60 Moisture.. Chlorine. 1.05 1.13 14.04 1.017 41.38 47.13 Lactose 48.49 47.67 1.43 1.69 Acidity. 1.58 1.57 Samole I V Potassium oxide.. 1.93 2.07 25.81 1,863 97.84 97.47 95.37 97.17 Sodium oxide.. 0.600 0.643 8.02 5.787 Hvdration of lactose. 2.43 2.38 2.07 2.37 Calcium oxide.. 1.75 1.87 23.32 1.683 Magnesium oxide. 0.230 0.247 3.08 0.222 TOTAL.. 100.27 99.85 97.44 99.54 Ferric oxide.. 0.0036 0.0039 0.0035 0.049 Sulfuric anhydride.. 0.909 0.974 0.876 12.15 TABLEV-AVERAGES OF THE PROXIMATE ANALYSISON MOISTURE-FREE Phosphoric anhydride. 2.57 2.75 2.475 34.25 BASIS 0.926 0.992 Chlorine. 0.893 12.37 Sample I Sample I1 Sample I11 Sample I V Per cent Per cent Per cent Per cent increase the protein still more or decrease the lactose 8.36 8.37 8.02 7.02 Ash 1.08 0.91 1.91 1.50 Fat still more. This ratio of protein t o lactose is abProtein(a) 34.81 35.38 39.83 35.77 normally high for herd milk. 46.76 53.00 52.52 Lactose 53.94 1.67 1.64 1.54 1.81 Acidity.
precipitate collected immediately on top of the emulsion, and a precipitate settled t o t h e bottom in a short time. After 4 hours the emulsion was stratified, t h e middle stratum having a serum-like, but turbid, appearance. Sample I V gave a fair emulsion from which some protein settled in 4 hours. With water a t 40° C., Samples I, I1 and IV gave good emulsions without any settling of protein in 4 hours. Sample I11 gave the same kind of a n emulsion as’ with water a t room temperature, except t h a t stratification proceeded more slowly. PROXIMATE ANALYSIS-The powders were analyzed for moisture, ash, f a t , protein, lactose and acid content and the acidity recorded as free lactic acid. The following results were obtained:
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100.28 99.82 97.23 (a) With one molecule of water of crystallization.
TABLE VI-PROXIMATE
Ash..
-
-
99.42
ANALYSISCOMPUTED ON MILK CONTAINING NINE PBR CENT “SOLIDS-NOT-FAT” Sample I Sample I1 Sample I11 Sample I V Per cent Per cent Per cent Per cent 0.72 0.72 0.75 0.75 0.179 1.097 0.082 0.135 3.58 3.22 3.18 3.13 4.20 4.78 4.73 4.85 0.15 0.14 0.16 0.16
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Fat.. ..............
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Protein., Lactose Acidity..
CONTENT COMPARED WITH THE PROTZIN AND LACTOSE A M & J N ~FOUND IN NORMALMILK Protein Lactose Ash Per cent Per cent Per cent 3.41 4.70 Richmond.. 0.73 3.55 4.88 Lea+. 0.71 3.80 4.50 Babcock 0.70 3.12 3.45 Sample1 0.75 3.18 4.73 Sample 11.. 0.75 4.20 3.58 Sample 111.. 0.72 3.22 4.78 Sample I V . . 0.72
TABLE VII-ASH,
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With the exception of Sample 111, the proximate analyses of the powders compared favorably with the analyses made by others on skim milk powders. I n Sample I11 t h e lactose is extremely low and the protein extremely high and these results were confirmed by repeated determinations. The use of some other number t h a n g for “total solids-not-fat” would either TABLE VITI-THE
MINERALCONSTITUENTS I N THE ASH Sample I Sample I1 Sample I11 Sample IV P e.~ r cent Per cent Per cent Per cent 25.81 25,49 22.44 Potassium oxide. .......... 24.05 8.02 9.60 9.37 8.35 Sodium oxide.. 23.32 21.99 25.86 23.57 Calcium oxide.. 3.08 2.92 3.07 3.18 Magnesium oxide. 0.049 0.034 0.035 0.03.5 Ferric qxide(a) 12.15 13.69 12.14 0.38 Sulfuric anhydride(b1. 34.25 32.78 31.44 32.69 Phosphoric anhydride(bj.. 12.37 14.04 14.28 12.46 Chlorine(c). - ., (a) T h e iron was determined volumetrically b y Lacks and Friedenthal’s modification of t h e otassium sulfocyanide method. (b) T h e sulfur a n d pEospiiorus were determined on the milk. powders. The organic matter was completely oxidized in a closed cartndge with sodium peroxide a n d the phosphorus determined by t h e titration method. The chlorine was d e t e r u u n e d b y the method[of Paul Poetschke, (c) THIS JOURNAL, a ( I ~ I O )210. ,
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The mineral constituents are found in Tables VI11 and I X . Tables I X a n d I11 give a comparison of t h e percentages of mineral constituents found in the milk powders and their ash and t h a t found in normal cows’ milk and its ash. I n reducing the percentages of the mineral constituents a s found in t h e milk powder t o corresponding percentages in normal cows’ milk, g per cent was assumed a s representing the total solids-not-fat in normal cows’ milk. CONCLUSION
The percentages of t h e mineral constituents in the four samples agree quite closely, but do not agree very well with those found b y other analyses. The potassium oxide and chloride agree well. The sulfuric anhydride is much higher t h a n t h a t found b y others; this is due t o t h e method used in its determination. The calcium oxide, magnesium oxide and phosphoric anhydride are all higher t h a n the values found by others. The higher phosphorus content may be due entirely t o the method used in its determination or also in part due t o the addition of some phosphate used as a n emulsifier. The calcium is also much higher and may have been added in some form as an emulsifier. The ferric oxide content is lower and this is probably due t o the method used in its determination. A low percentage of ferric oxide in milk has been found b y the “cupferon” method.’ This method was tried but did not give consistent results. The color, odor, emulsifying power, high protein, low lactose, high calcium and phosphorus content, and low total approximate analysis would indicate 12.Nahr.
Genussm., 28 (1912), 514.
Apr., 1918
T H E JOURNAL OF INDUSTRIAL A N D ENGINEERING CHEMISTRY
t h a t Sample I11 was not genuine desiccated skimmed milk powder. CHEMICAL LABORATORY UNIVERSITY OF MINNESOTA MINNEAPOWS, MINNESOTA
AN IMPROVED AUTOMATIC PIPETTE-WASHING DEVICE By AUBREYVAIL FULLER Received November 17, 1917
Since his publication of a n article in THIS J O U R K A L , Vol. 9 , p. 1046, entitled “A Convenient Automatic Device for Rapidly Washing Pipettes,” the author has designed a modified form of the apparatus referred to, which embodies several improvements. I n the accompanying illustration A is a cylindrical metal t a n k , provided with a siphon, B , and a n inlet pipe, C. D is a brass rod which carries a t its lower extremity a disk of rather heavy brass gauze, t o which is fastened three legs of such length t h a t when placed in the cylinder the gauze is supported a t a level slightly above the tops of the two lower orifices. There should be about in. clearance all around between disk and tank. The operation of t h e device is as follows: Water is admitted through the inlet C which is connected t o the supply t a p , a t such a rate t h a t the speed a t which t h e siphon empties the tank is somewhat greater t h a n the speed a t which the tank is filled. The pipettes t o be washed are then placed, tip up, in the tank, the lower ends resting on the gauze. As the tank is alternately filled and emptied the pipettes are rinsed. T o remove the pipettes they are raised t o within easy reach by means of the “lifter” D . With a n apparatus of the dimensions of t h a t pictured, the period of a complete cycle is approximately
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45 sec. Inasmuch as two cycles are required for the average pipette, only about one and one-half minutes are necessary for thorough rinsing. Its capacity in terms of 2 5 cc. transfer pipettes is 13, and in terms of I cc. measuring pipettes about 100, when loosely packed. The time economy 0 ‘ of such a device over hand washing is thus apparent. The points in superiority of this device over the one previously described are : (I) greater capacity, (2) smaller table space occu, pied, (3) lower first cost, I (4) cleansing of both outside and inside of pipette. I It might be mentioned t h a t an apparatus of this I type would find particular 9 I; A application in laboratories conducting serological work, I where large numbers of pipettes must be rinsed , before sterilization. Its ,I field of usefulness is, how1 ever, entirely general and I I, the details of its construcI tion admit of wide variaI I tions t o suit peculiar conI ditions.
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BIOCHEM. DIVISION BUREAU O F ANIMAL INDUSTRY u. s. DEPARTMENT O F AGRICULTURE WASHINGTON, D. c.
ADDRESSES METHODS OF GAS WARFARE’ By S. J. M . AULD, British Military Mission
All I can do in the short time available is to give you, if I can, a general idea of what gas warfare really means on the Western Front at the present time. Some of you may have gotten the idea that gas is just an incident, and that there is not as much attention being paid to it as there was two years ago. That idea is entirely wrong. Gas is used to a tremendous extent, and the amount that has been and is being hurled back and forth in shells and clouds is almost unbelievable. I will try to give you a general idea of what is occurring and make the lecture rather a popular than a technical description. I shall also, for obvious reasons, have to confine myself to describing what the Germans have been doing, and will say nothing about what we are doing. Possibly the best plan would be to state more or less chronologically what occurred. I happened to be present a t the first gas attack and saw the whole gas business from the beginning. The first attack was made in April 1915. A deserter had come into the Ypres salient a week before the attack was made, and had told us the whole story. They were preparing to poison us with gas, and had cylinders installed in their trenches. N o one believed him a t all, and no notice was taken of it,-
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Report of a lecture delivered before the Washington Academy of Sciences on January 17, 1918. Reprinted from the Journal of the Washinelon Academy of Sciences, 8 , No. 3 , February 4, 1918.
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Then came the first gas attack, and the whole course of the war changed. That first attack, of course, was made against men who were entirely unprepared-absolutely unprotected. You have read quite as much about the actual attack and the battle as I could tell you, but the accounts are still remarkably meager. The fellows who could have told most about it didn’t come back. The Germans have claimed that we had 6000 killed and as many taken prisoners. They left a battlefield such as had never been seen before in warfare, ancient or modern, and \ one that has no compeer in the whole war except on the Russian front. What the Germans expected to accomplish by it I am not sure. Presumably they intended to win the war, and they might conceivably have won it then and there if they had foreseen the tremendous effect of the attack. It is certain that they expected no immediate retaliation, as they had provided no protection for their own men. They made a clear and unobstructed gap in the lines, which was only closed by the Canadians, who rallied on the left and advanced, in part through the gas cloud itself. The method first used by the Germans, and retained ever since, is fairly simple, but requires great preparation beforehand. A hole is dug in the bottom of the trench close underneath the parapet, and a gas cylinder is buried in the hole. It is an ordinary cylinder, like that used for oxygen or hydrogen. I t is then covered first with a quilt of moss, containing potassium car-
