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Show 1 1 HOW TO SAMPLE AND TO TESTJJLK BY JOHN A. CnOCKETr, Dairy Foreman Agricult Ural Collfgo of Utah Every year many samples of milk and cream and other dairy products nro sent to the Stnte Agricultural college dairy department for analysis of fat content. In almost every Instance the sample when received Is ln tho worst possible condition for making a positive posi-tive determination. A short time ago a sample of milk was sent to the college dairy by a largo creamery In the southern part ot the Btate. No preservative had been added to keep the milk sweet, and as a consequence conse-quence the sample was In a sour, lop-pered lop-pered and fermented condition. Upon removing the cork most of the contents were thrown violently from tho bottle thus rendering nn accurate test Impossible. Impos-sible. Other samples arrive in n partially par-tially churned condition, while others come with tho cream leathery and tough; nnd still others with the butter fnt in a melted condition. The first step toward an accurate anoljsla Is a true nnd a representative samplo fiom which the test Is to be made. How can the same be secured? The butter tat of milk Is not In solution solu-tion ns sugar or salt Is dissolved In water but Is held ln suspension. The fat being l'ghtcr than the other solids of the milk thc tendency Is for thc globules to rise quickly to the top It Is owing to tho force of gravity acting with different Intensities upon the fat and the other collds of thc milk that a separation by the gravity plan takes place In tho cream separator the force of gravity Is displaced by tho centrifugal centri-fugal forco generated In the bowl If milk be allowed to stand for but a few minutes the upper layer will bo very much IlICHnn IN TAT than the lower one; and If tested without with-out thorough mixing, the test Is liable to be too high or too low depending upon up-on whether the sample Is taken from the top or bottom. Only a amall amount (17 5 c c ) Is required for the test, and thus tho necessity of having thc fat evenly distributed through the whole mass before the amount required Is token. to-ken. This can be done best by first shaking the bottle or other vessel with a gentle rotary motion till all tho cream Is washed from the sides, then pour from one vessel to nnother several times The amount necessary for the Habcock test should then be taken as quickly as possible. If the sample Is to be sent away for analysis be sure that tho original from which the sample Is taken Is thoroughly thorough-ly mixed by tho process given nbove. Into a bottle holding not less than four ounces place a small quantity (about what will lay on the point of a small penknife) ot corrosive sublimate, potassium potas-sium bichromate, or a part of a corrosive corro-sive sublimate tablet This will destroy nil germ life and the milk will keep for a long time. Comp'etcly fill tho bottle as soon as tho process of mixing Is finished; fin-ished; as this will prevent the milk from churning during transportation. If Bamples are sent by farmers to asccr-tlon asccr-tlon whether or not the crcamcrj" la giving giv-ing them a correct test, tho sample sent should be n part of the same as the crenmery operator has or the results aro VW apt to be different. SAMPLING MILK. In most cre.amerlcs the method followed fol-lowed ln Barreling the milk ot Its patrons pa-trons Is verf liable to result In dissatisfaction. dissatis-faction. A small amount Is taken rnt as a sample to be tested but once or at the most twice dui.ng the month and the amount ot fat figured from this test. The fat Is the most variable constituent of milk Experience has taught the writer that jou cannot depend upon the results obtained from the one-day sample, sam-ple, unless, perhaps from a large herd. It Incurs too much labor to test the milk every lime It Is sent to the factory, so the common method In use to obviate this is the ' Composite Test." This consists con-sists of taking a small sample of mllU every time milk la delivered nnd then test tho sample every two woelts or not longer thnn one month. The two tcsti can be averaged and tho total fat fig-uied fig-uied the same ns If only one test wero taken, or separate calculations can bo made for each period. If thc milk In the composlto Jar stands too long tho cream Is liable to get moldy, tough nnd leathery,' thus rendering n complete Incorporation of the fat globules Impossible Im-possible Somo preservative will havo to be used to destroy the lactic acid germs An aliquot snmplo should bo taken, I. e , a proportionate pnmple of ench lot of milk. This can best be accomplished by using whnt Is known ns tho ' milk thief or the ' Scovilie milk sampler," tho latter lat-ter is used nt the college nnd la In every way satlsfactorj. If for Instance "A" brings 100 pounds ot milk ono day and the next 200 pounds, then only half ns much should be taken for n sample the first day as Is taken the second. THE TEST. Mnny objections nro offered against the llabcock test ns a means of determining deter-mining the butter fat of milk nnd its products In most cases the ones who do the most kicking nre the ones who 'inderstand least nbout the method The claim Is made by thc opponents of the Babcock test that no two operators can get the same result from the same sample of milk or cream This appears to me to be speculation and has no foundation whatever. It tho milk Is the same ln both cases and the operation is completed by competent men tho results will be thc snme Creamery patrons havo told tho writer that they could make more butter by keeping the milk at home even by tho shallow pan method meth-od of skimming than they could by sending to tho creamery. This may be true nnd it may not. The creamery operator has everything in his hands, and If he desires to be dishonest there Is hardly any means to detect him If tho shaving of the test Is small. Dissatisfaction Dis-satisfaction among creamery patrons may bo due to carelessness of the operator oper-ator of the test or It may be due to Improper Im-proper care of the milk by the farmer. After testing thousands of samples by thc Dabcock method thc writer has full faith ln Its results. A correct reading, however, depends upon certain things, some of which nrc, a representative sample, clean glassware, thc graduation of which Is correct, sulphuric acid of the proper strength, the speed of tho machine, the length of time forco Is up-piled up-piled and method of adding the hot water. Carelessness In any ot theso details de-tails will result ln a poor reading. If not nn entirely Inaccurate one. It la safe to say that In nlncty-flve cases out of a hundred tho fault of Inaccurate determinations de-terminations Is not with the llabcock test, but with the method used ln sampling sam-pling and operating It. COMPAItATIVE HEADINGS. In Bulletin 52 of the Wisconsin experiment experi-ment station Is given a comparison of the readings obtained from skim milk by the llabcock method and Gravimetric Gravi-metric nnnljsls. Although the determinations deter-minations from thc Dabcock method nre slightly lower the results aro practically practi-cally the same Many operators of tho test forget tho fact that the reading of the fat column In the ,.. , the bottle shouhl bMM,, line to the lower one T " " from 2 to .4 of 1 per c.r mlil ln this way. v ""I can Every dairyman i,,. to "fty cow. shUuieTJ" 'ran-llabcock 'ran-llabcock tester. H it? " oo. these machines and a iu,"" M e Ing of tho weight ot miiVr ,""rj i the Individual cow, ,"1 bllnY few yrars be nble to X Ul unprofltnble cows nnd in f?,t i, up his herd Only tho 15" r produce milk nt n pron, .?' I for breeding The JiA houl-l bt point out to you th?rohk li the dairyman should low ?.. TO posing of her. Two ul.Um sary to determine the aSS u t fat that a cow I, ?$ . of fat and tho weight of l,f,t" forget tho latter and thM 1 former. A Holsteln cow th,? 3 per cent milk may b. 1 ,lT" cow than a Jersey that rl ! l The per cent of fat in SI l.rr half, the other half Uln. iv? " tho milk. t,n " Vlj: THE TESTER. Now that thc hand set,,. , ment Is being agitated and?" era aro purchasing msAhi.. ! greater need than' eveffe lh to own and operate hli i ,Ter" will enable l.lm to !".' nnd thereby cheek up ,nye,.'Jim occur. The efficiency "f ,c" th,t and tho work It will aoVn 1"U condltlona can bo "SruinM "i? ""'ount of butter fat utt InV' milk. Operating the n,w,th qulrea a little careful p'Ji " tentlon to the details ot the S2 "1 son with ordinary IntemitV- A be nble to get correct iS ,k operating the aame a halffi" The "Winter course" o ,."! ' tural college of Utah b i .i" IMS Persons Interested 7"u,a any of Its branches should If ! take the work at this InSiL11? the winter term. Practlca li. "' scientific work la glvtaft ! irrigation, stock Judging. cl'?,n ngement of stock. dalryli LW nnd In fact everHhlnZtft should know;. Tho sclentlnc takea more pleasure out of S?,.,J one who knows nothing buttK cal part, tho two gohandtah,.V and be convinced ,Bl c |