3 



of materials used for human food is shown by the following- 

 figures: 



100 lbs. dry material Contain lbs. lime. 



Beef 0.029 



Wheat 0.065 



Potato. 0.100 



Egg- albumen 0.130 



Peas 0.137 



Human milk • 0.243 



Yolk of egg 0.380 



Cows' milk 1.510 



In fodder plants and materials the variation is quite as wide. 

 There are three factors which influence this variation which 

 should be considered in this connection: 



I. Different species of plants growing under the same con- 

 ditions have the power of taking up from the soil, and incorpo- 

 rating in the plant tissues different amounts of inorganic sub- 

 stances. As an example of this, sorghum and alfalfa growing 

 side by side were found on analysis to contain: 



Sorghum Alfalfa 



Potash 0.41 0.84 



Lime 0.05 0.45 



Phosphoric Acid 0.15 0.30 



II. Plants of the same species grown upon different soils 

 may contain different amounts of ash ingredients. If an ash 

 ingredient is present in the soil in a soluble form, in large ex- 

 cess over the needs of the plant, the plant tissues will contain 

 an excess of this ingredient. A marked example of this was 

 noted in comparing sisal fiber from Sisal Plantation with that 

 from the Experiment Station. The total ash in each was 

 approximately the same. In the case of the fiber from 

 Sisal Plantation where the soil is disintegrated coral, 40% of 

 the ash was lime, while in that from the Experiment Station, 

 where the soil contains less than l7c lime the amount was but 77c. 



III. Different parts of the same plant contain different 

 amounts of ash ingredients. In other words the mineral matter 

 taken from the soil becomes localized in the plant. Seeds are 

 rich in phosphorus, leaves and straw in potash, old mature 

 cells richer in lime than growing parts. 



Amount of Lime necessary . — It has been found that to main- 

 tain full grown oxen the fodder should contain 0.10 lb. of lime 



