Rensselaer Union, Volume 7, Number 16, Rensselaer, Jasper County, 7 January 1875 — Some Facts About Milk. [ARTICLE]

Some Facts About Milk.

Milk consists of certain fatty or oily particles in solution of caseine and of sugar of milk. The fatty matters do not exist in a free condition, but are inclosed in little globules which rise to the surface on account of their being lighter than the liquid in which they float. The casing or covering of the fatty matters or the skins of the little globules are composed of caseine or curd. The globules are of different sizes in the milk of different animals. Some of them are round, but others are oval or egg-shaped. Milk contains, in addition, a certain portion of mineral matter, whieh consists of phosphate of magnesia, the chief constituent also of bones. In diseased milk there are certain other substances which may be said to be accidental and which cannot be identified by chemical testa, but only by the microscope. The whiteness of milk is due to the opaque globules which are suspended in it. A bluish tint indicates a small amount of cream. The whiter or the more opaque it is the more curd and butter it contains and the richer it is. The quality of milk is usually better from September to November than at other seasons of the year, but the quantity is usually less at that time. If cows are not well fed as the winter approaches the yield will not only be small, but the quality will be poor. In moist climates the yield of the cow will be more abundant, but the quality poor, that is, more thin and watery than in dry climates. The moisture in the food will have a very marked effect upon the quality. It is an error to suppose,' as many do, that the morning’s milk is richer than the evening’s. This depends very much on the character of the food which is consumed four or five hours previous to milking. If it is poorer at evening it will be found that the food consumed has been poorer in quality. The composition of cream varies as much or nearly as much as that of milk. The whole of the cream rises in twentyroiir hours’ time, when the milk is set at a temperature of sixty-two degrees. It is a mistake to suppose that more cream rises by letting milk stand thirty-six hours, as many do. The quantity will almost invariably be appreciably less and the quality poorer. The cream which rises first is the richest in quality, it being the largest globules that rise first to the surface. * A careful experiment was tried to ascertain the prbper time which milk should be allowed to stand to raise cream. Milk that was allowed to stand sixty hours produced only twenty-seven pounds of butter, while an equal quantity standing only thirty hours produced thirty pounds of butter. It was found also that one hundred measures of new milk yielded thirteen and a half - measures of cream after standing eighteen hours, and the same quantitv after twenty-four hours, but less than thirteen measures after standing forty-eight hours. The same experiment was care-, fully repeated, when one hundred measures after standing eighteen hours, yield-

ed thirteen measures of cream, and the same quantity after twenty-four hours, but it gave only twelve measures after standing forty-eight hours. It was proved that eighteen hours with milk standing in a temperature of sixty-two degrees is better than any longer time, and that all the cream that is worth getting will rise in that time. Milk that has been agitated or shaken up, as when sent by railway, throws up less cream than that which has been leas disturbed. A careful trial was made to settle this point and here is the result: One hundred measures of new milk, after standing twenty-four hours at sixty-two degrees, gave twelve measures or 12 per cent, of cream, while at the same time a like quantity of of the same milk, after having been gently shaken in a bottle, threw up only 8 per cent., a loss of onethird in the quantity of cream. This shows that the shaking the milk gets when transported by rail has the effect of breaking some of the cream or butter globules, the consequence of which is either that a portion of the fatty matter remains suspended in the milk, or, which is, perhaps, more probable, the cream which is thrown up becomes richer in fat. — Massachusetts Ploughman.