LIME AND MILK. 



Bv R. Pape. 



A perfect cycle of the lime present in the soil may be observed 

 under primitive conditions on some isolated farm, which forms 

 a self-supporting and self contained universe in miniature. 



The lime is assimilated by the plants, passes into the animal 

 economy and after a longer or shorter journey returns to the 

 soil again. Now suppose the soil of such a farm contains suf- 

 ficient lime, then no shortage of lime will occur as long as every- 

 thing produced on the farm is consumed there, and all waste 

 products are returned to the soil. 



The hypothetical case, however, is a very exceptional one, 

 and on most of the farms part of the produce is exported beyond 

 the farm boundaries, and as a consequence part of the lime 

 originally present will be lost. 



The plants assimilate the available lime, i.e., the lime present 

 in such a condition that it may serve as a plant food. A soil 

 may, on analysis, contain considerable quantities of lime and 

 yet be " deficient " in lime from a farmer's point of view. Marble, 

 unbroken shells and bones are composed of lime but it takes 

 countless years before the forces at work in the soil layer have 

 changed these bodies into an assimilable state. 



The lime gathered in the plant passes into the body of the cow 

 and is partly used for bone formation, partly exuded again in the 

 udder into the milk. Milk contains on the average 075% of 

 mineral salts of which lime forms 23% or, 1,000 lbs. of milk con- 

 tain about I lb. ii| oz. of lime. For every 1,000 lbs. of milk 

 sent away from the farm a loss of i lb. 11 J oz. of lime is therefore 

 incurred. 



On farms where large quantities of milk are produced and where 

 the original soil was not specially rich in lime, this continuous 

 drain, insignificant as it may seem, makes itself seriously felt 

 in the exhaustion of the soil. In Europe the practical farmer 

 notices a change in vegetation ; when sorrel and mosses begin 

 to prevail he knows he must have recourse to a lime-containing 

 fertiliser. 



The exact role lime plays in the milk has not been elucidated 

 on all points, but we are able to trace the broad outlines. Nature 

 intended milk as the food for the young animal and the real 

 purpose of the lime is to help building up the animal body. Man 

 has intervened, deflecting milk from its original destination and 

 using it for artificial ends in dairying. 



The lime present in milk is partly combined with proteid, 

 partly dissolved as lime salt, partly suspended as insoluble salts, 

 and the proportion and quantities in which lime is present in 

 these three states is of the greatest importance to the dairy farmer. 



The basic lime salts serve as a protection against too rapid 

 souring of the milk. When the lactic acid bacteria disintegrate 

 milk sugar, forming lactic acid, the free acid combines with the 



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