1920.] 



75 



at Garforth contains more than per cent, of free lime ; 

 most of them contain considerably less. If there is a deficiency 

 of lime in the soil, it is only natural to expect a deficiency ol 

 lime in the crop growing on that soil. For bone formation, 

 the ratio of lime (CaO) to phosphoric acid (P 2 5 ) should be 

 approximately 1:1. In green foods like grass, hay, turnip- 

 lops, etc., lime is in excess ; in the cereals and concentrated 

 foods phosphoric acid is in excess. The ratio of lime to phos- 

 phoric acid in normal meadow hay is approximately 2^:1; 

 in normal seeds' hay the ratio is approximately : 1. Thir- 

 teen different samples of hay produced on the farm at Garforth 

 have been analysed, and the average resulting ratio of lime to 

 phosphoric acid in the samples has been, not 3:1, but 

 1 12 : 1. Since hay and grass are practically the only foods 

 fed to cows where the lime present is in excess of the phos- 

 phoric acid, and since the ratio, phosphoric acid to lime, is :— 



in linseed cake . . . . . . 4:1 



in cotton cake . . . . . . 10:1 



in coconut cake . . . . . . 3:1 



in palm nut cake . . . . . . 4 : 1 



in ground oats . . . . . . 7:1 



it is to the hay and grass that the cow must look to make up 

 the deficiency of lime in the other foods. In a normal milk 

 the lime and phosphoric acid are usually present in appr si- 

 mately the same proportions as are required for bone format >n, 

 and the ratio of lime to phosphoric acid approximates to 1 : 1, 

 and rarely falls below 1 : 1*25. 



Some two or three hundred samples of milk produced on the 

 farm at Garforth have been analysed, and all have shown a 

 considerable deficit in lime, the average ratio of the samples 

 analysed being not 1:1, but 1 : 1*54* and in some cases being 

 nearly 1:2. This poorness in lime of the milk produced in 

 our industrial areas is a matter of considerable importance. 



Economic Effects of Smoke Pollution. 



The economic effects of smoke pollution with its deposits of 

 tar and acid upon the grass land in the smoke areas are enormous. 

 The leguminous plants and finer grasses disappear and the 

 herbage usually consists of bent, Yorkshire fog, woodrush, 

 sorrel, yarrow and moor grasses, while the feeding value of 

 the coarse grasses and weeds which survive is considerably 

 reduced. 



This deleterious ef ect on vegetation is also reflected in the 

 diminished stock-carrying capacity of the land ; and land 



