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Show H THE CHANGES IN MILK. B Contamination, In Nino Ones Out of Ten, Bj Cumoi from Without. B Ordinary milk niters in character after belay kept for some time, Buys BB American Dairyman. It usually loses B its sweetness and perfect fluidity', ami BB becomes aourod nntl curdled. The ra- BM pidity of these changes depends upon BJ certain circumstances, the chief of which, hoveer, appears to be- temper- B ature. Milk kept ut or a little below BB blood heat seems to change very quick- BB ly. That a favorable teinpcrnture BB nlonc cannot produce the changes re- BB f erred to may be proved by the follow- BB ing experiment, nays Biologist Hous- B ton, of Knglaml: "If milk be drawn dl- BB rect from the udtUr into the sterili7x?d BB vessel, extreme care being1 taken to BB prevent even the slightest contaminn- BB tion, and the mouth of the vessel B plugged with clean cotton wool.the milk BB may bo kept for days, yen, weeks BB without in the least turning sour, even BB during the warmest summer weather. BB If the plug be removed for a minute or BB so, and then replaced, the milk will BB gradually lose its sweetness, thus BB clearly show ing that unfiltered nir con- BB tn-ins something that, if permitted to BB teach the milk, hns the remarkable BB power of causing souring, and pcr- BB hups other changes, to take place in it. BB 2Covv, what is In the air that possesses H such potent influences upon the keep- BB ing properties of milk? Again an ex- BB porlment will best answer this qucs- BB tion. If a covered nnd sterilized dish BB containing a layer of nutritW gcla- BBj tlno be exposed to the nir, either jin- BB doors or in the open, for, say a iuinut, BB there-will fall upon tlie surface of the BB jelly minute pnrticles of dust, together BB with extremely minute spoies of molds, BBJ and htill more minute living particles BBJ of different kinds, collectively known BBJ us bacteria. liy covering the'diih and BBJ keeping it at a suitable temperature, BBJ there will appear within AH hours or H , lws-upon the elenr surface of the ieUy BH r j n-numlHjr of spiles, chcli (ti whlSUtrepM BB resents a colony of bnctorln that has BB rihen by rajiid inultipHcation irom r BB uinglo .germ thnt origlmillj settled oi. BB the jelly when the dish w a exposed to BB thu air. Immediately n. Ik is i awn BB from tho cow it is subject to this ! "in. BB of coatumiuaiiun. JJnctena of ',..- BB nt kinds nnd the spores of nu I ",0 ..- BB constantly falling upon it, and tlu BB fresldy drawn milk provides an c- eeptionnlly favorable medium f c r th- BB growth nnd development of Utese fuu- gal rganisms. Milk is, uufnituiiate- BBj ly, .1 ri .lily chicle for the lr:u.sin)rsioi BftV - ,"cn::s that, give rse to inoteor leiu BBY nous i;ini'nt in on8iin)i'r" of milk. K Vvpho.d, tuberculosis, diphtheria nnd BBf scarlet lever may be mentioned ns dan- BBf '.toiis diseases thnt are too frequently Bf ItJMSininntcd by milk. In mot eases BY the 'contamination comes from with- Bf out, but there are coses where- the milk BBf Is germ-Iaderi before it leaves tin? milk gland of" the animal. It is stated on BBf high authority that a large number of BBf milch cows suffer from tuberculosis BBf udder, and it is needless to say that Bf Much n stnte of affairs is a continuous KB riourcQ f danger to the public health." |