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Grbnsidb, V.S Professor of Veterinary Saienoe. H. H. Dean, B.S.A. Profe8«)r of Dairy Husbandry. E. Lawbenob Hont, B. A. Assistant Resident and Mathematical Master. Captain Waltrb Clarke Instructor in DriU and Gymnasticn. 0. A. Zavitz, B.S.A Assistant Superintendent of Experiments. Geohoe Habooubt, B.S.A. Assistant Chemist. A.M0OAU.UII. B,,^ ADVISOBY BOABD. "^ ®^'"' Deputy Minister of Agriculture, Toronto. J0HNI.H0B80N Mosborough, County of Wellington. John McMillan, M.P. Oonstonce, County of Huron. Edwabd Jeffs Bond Head, County of Simooe. J. S. tsMiTH Ailsa Craig, County of Middlesex, G. B. BoTOE Norham, County of Northumberland. D.A.DOWLIN3 ... Appleton, County of Oarleton. Wm. Donaldson Woodstock, County of Oxford. Chairman of Board .... Jqhn I. HoBSON. aeerttary of Board : . . • » . A. Blue. BULLETIN LXl. Guelph, President, rintendent. Chemistry, id Geology, ry Ssience. lusbandry. 3al Master, rymnasticd. periments. it Ohemiat. ..Bursar. , Toronto. Vellington. of Huron, of Simooe. Middlesex, imberland, f Oarleton. of Oxford. DETERMINATION OF FAT IN MILK. Badoook's Ckntiiifuoal Method. Methods have been suggested from time to time for the rapid determination of fat in milk, useful, not simply in the chemical laboratory, but also in the creamery, the cheese-factory and thedaiiy. Some of these have been modified and improved, most of them rejected as impracticable. Any method suitable to the demands of analysts and dairymen must meet at least four requirements, yiz : 1. It must be rapid in its work and in giving results. 2. It must be comparatively easy o! manipulation. 3. It must not be very expensive. 4. It must be accurate under varying conditions. After a thorough test in which the results have been verified by thorough gravimetric analysis, we have concluded that the method devised by Dr. S. M. Babcock, chemist of the Wisconsin Experiment Station, most nearly fulfils the above four requirements. His method was given to the public in Wisconsin bulletin No. 24, 1890, entitled •« A new method for the estimation of fat in milk, especially adapted to creameries and cheese-factories." Method of analysis. Small glass bottles are provided in which the milk is to be tested. These are seven inches high, carry- ing a graduated neck four inches long and one-quarter inch internal diameter. As the accuracy depends primarily upon the correct graduation of these bottles, they should be purchased only from a reliable firm that guarantee their correctness. Equal volumes (17.5 cubic centimetres) of milk and stroug commercial sulphuric acid or oil of vitriol are mixed in these test bottles. The effect is that the casein is dissolved and a rim of yellowish oil begins to form on the dark purpje colored solution. The test bottles are then placed in a whirling machine and while kept warm by hot water or steam the centrifugal motion forces the heavy acid to the bottom and the light oil to the top. Warm water is added and the melted oil slowly _: :-i.^ i.1,^ w,nr.u t-kA omnnnt voad hv fhn oradiiAtiona oivinir the percentage of butter fat in the milk. Machines may be obtained that will carry from four to sixty bottles at one time. -«-«d b, . .„.„ ^aZ^^ ."^ • * - '"be, th. «ia added ™"°^ "•"» water added toTh' Wt?.°^ """"■■•'«"»' «'• "Mule. reading, uken. botUea e^lS^ !' .'*'"° '•""<«» '»' on. '■«.« required depend, ^f 00"™. «T,t " "'"^- ■"» •■»»»■" of o.. wUriing ,i„ a„ for .i«;: ^J ^'^ »"""«' «' .nai,.e. n,.d. ; Pn«c.p.|j^ oon,„n>ed in ««.,„„„! -n ' ^ ""' **« «°>o i. b« warn, water. After u,inr.* """' '"'' ""'' «"' ^ "dding "■« tbe whole ope^tion for t"n IT"'"' ''" ~'°» «™ »« «-- ^k-« . hint fron. tH. p«otL :to,"'"'r'»'" •"" « W. Expenment Station, wohavo found .f! '" "' *« ^o™"-' "etlj^ b- rtortened th, tLe " „"^' 'W «« "-o following 2Sc»b,eoentin,et«.„f „i,k„"° "«""^^ «■«» "ghtened the l.bo,'? cnti^etre, of a .ol„a„n otZTZtT T'' '''" •'™"' » «»•• c (e?.^ parte); then the boltlei, Medtt. r""™ -"""""^ «« «■« ™lph«rio •team, whirled for one BinutT a":?':.!,.'"""'"' "^ >■<" "«<»• or bn-g the fat into the CT>du.t!^' , ^ ™™ ""o' or aoid to »ven..enth. of whioh ^ttfcror' "" r""'' " o-"^- 2- E«. 0. M.»„„,„,„;°™' P«'-"««ooff.t in the ^ilk.' «.d pre^nt no great diffloulty The^° '"' °"'''"' "" 9°"««i™ple « 't "Pidly oha„ wood and burlol' . """"."^ '"°'"«' """'"Sy! W «u.t be done c.refull/.n7o„t ''..''"'' *"««"• ^he „„^' knack or dexterity in work wU W '"'°°"^' ^ '""o -"tu^ ">e te.ti„g, b„e I ^„ ^^ no «^:^^ '^"' '" *'» "-Ting on " pnoo by ca«f„lty fo„„„i thel^I r "^T" °' ordinary inWU » O'ery d,ter„,inati„„. * ° "»'™<".on, d,o„ld not have ,„X, S- Cost or Eipuk,, ti. « •ments before instructions e »cid added iried for five I'led for one e amount of 'yaes made ; the time is i in adding me we find If an hour. Vermont ' following 'he labor : ut 3 cubic "iatic acid sulphuric water or '«• acid to ce taken, the milk. e simple, arefuljy, e samp- natural gon of intelli- auccess i cost, ations. at, the 3 costs antity c aeld its for every hundred tests). The first cost of the complete outfit may be gathered from the following three sets of catalogue prices • JoTi:VL';^lt?'A,^oTl:^?^^^^^ At.in.o„. W... for which 4 bottle test mMhine. 10 " "• •• 16 " " «• 20 " " '• SO " " •• $14 00 aooo 2200 26 00 2900 3 bottle test machine •an ni\ 8 •' •• i< V20 00 12 '• «• M 25 00 24 82 00 60 00 Machines made by D. H. Roe & Co., 64 Nortli Clinton St., Chicago, III 4 bottle teat machine 8 " " •• 12 «* •• •• 24 90 60 •I 18 00 10 00 14 00 20 00 40 00 60 00 I understand that some other United States dealers are handling machines, but we have not seen their prices. Our Canadian dairy supply companies should be in a position either to manufacture or to handle for this province some of these machines. 4. Accuracy OF Rbbults. The first experimer rade by us was to test the agreement of the bottles with one anotli.r. They read as follows on a sample of milk : Seven bottles gave «»t«„.- ^ t. Three botUes ^ve. .....::.:; . . . i i i ! .' .' i .' ; ; ; ; H ^ "«?.*• '»*• A gravimetric analysis made in duplicate by the asbestos method gav3 UB for the same milk 2.65 and 2.68 per cent. fat. We have since tested the bottles and also those of the Beimling machine as follows : o I »» AU bottles/S-'. °: & G. machine ... 8.36 per cent fat. \ Beimling machine 8.31 " •• * An advantage of this method is that sour milk can be handled ^mte easily. We tested a sample of milk fresh and then again after two days standing. ^ "«wr Fresh milk by machine gave s « n«. ^„* * ,. Same mUk verv Bonr »«.^ 25 P?F <»??*• '»t. For the analysis of skim milk and b^*t«rmiIk, bottles can be obtained that give more delicate readings. We made four com- pariwns on different days with diffitrAn* ^t\v u . (•) R«pid omilrihml .- m RTpinafr'"''^'-- •■■■'■■••■••• Ih "^ "«"• 's^ w|".;r^Srr^;°^^i---- ■■•••• i :; :: ;; o»,„«u,.(Ad«.'.p.p„^eu;iii:;:; |:S ;; ;; ;: ini^otion in cUi«^ „" fa Cnlto„' .".f ? '^^'"'^ """k toiy. Any one d«i™.T» , . ' '" *"'' "" » »"' '•'»»• able in their work wiU ^^ T ^^^'"^ ^ ^ f'^o^io- food in-pecto,^ by enterp'wn, ^rX iT ' f ""' *-''' In conclusion I append, as showing the use to wh.Vl. f i. «w» be put, the averai« n# « l, ^*^° *^® machine ,. ^ ' "** average of one week's analvseii of m.'ii, t ordinary cows fed for experimental purposT ""^ "* Cow. Average for one week of MorninR milk. Evening milk. 3.26 ».96 2.76 . 4.00 8.18 4.88 8.42 4.46 2.76 4.18 2.ttS urn this rapid fat lotions are ry. It ia ories, milk leriea and )r amount ur labora. oethod of M praotio- nd dairy Seers and } and in sed is to factories, he work, machine 'rem six