150 



SCIENCE. 



[N. S. Vol. XVIII. No. 448. 



in tlie investigation of the relation of these 

 elements to animal production. 



Many analyses show that the percentage 

 composition of plants grown on diilerent soils 

 varies quite noticeably. From Wolff's tables 

 of analyses, for example, the calcium oxide in 

 maize varies from 0.6 to 3.8 per cent., and in 

 meadow hay from 6.0 to 40.1 per cent, of the 

 ash. Wunder found {Landw. Vers. Stat. 4 

 (1862), p. 264) that turnips grown in a clay 

 soil rich in lime contained 9.28 per cent, of 

 lime in the ash, while those grown in a sandy 

 soil poor in lime contained only 5.47 per cent. 

 Emmerling and Wagner report (Centhl. Agr. 

 Chem., 8 (18Y5), p. 333) that hay from a 

 peaty meadow contained only 6.50 per cent, 

 of lime in the ash, while that from a good 

 marsh soil contained 9.83 per cent, of lime. 



It is a well-known fact that the greatest de- 

 velopment in live stock has been attained in 

 limestone regions. Opinions differ as to the 

 reason for this, but it would appear that at 

 least the chemical composition of the soil in- 

 fluences the size and the strength of the bone 

 of animals feeding upon the herbage grown 

 thereon. A number of experiments go to 

 prove that the strength and composition of 

 the bones of our domestic animals may be 

 modified by feeding. Notably, Henry found 

 (Wisconsin Station Bui. 25) that the bones 

 of pigs fed on corn with bone meal or hard- 

 wood ashes in addition were double in strength 

 of those of pigs getting corn alone, while the 

 per cent, of ash in the bones of the former 

 was 50 per cent, greater. The feeding of 

 mineral matters to quick-maturing animals 

 like pigs is now generally practised, and it 

 can probably be wisely followed with animals 

 of large size and of longer maturity in those 

 regions where there is a deficiency of lime in 

 the soil and a relatively small percentage in 

 the plants. 



In our former work we found that there 

 was a relation between the amounts of avail- 

 able lime and magnesia in the soil for the 

 most favorable growth of plants. Loew states 

 with reference to plants (Bui. 1, Bureau of 

 Plant Industry, p. 16) that lime is necessary 

 for the formation of certain calcium com- 



pounds of nucleo-proteids required in the or- 

 ganized structure of nuclei and chlorophyl 

 bodies, while magnesia serves for the assimila- 

 tion of phosphoric acid, since magnesium 

 phosphate gives up its phosphoric acid more 

 readily than other phosphates of plant juices. 

 In case of an excess of lime the assimilation 

 of phosphoric acid will be retarded, because it 

 will combine with the lime and thereby di- 

 minish the formation of magnesium phos- 

 phate. On the other hand, the presence of 

 an excess of soluble magnesia will tend to the 

 transformation of the calcium nucleo-proteids 

 •oi the organized structures into magnesium 

 compounds, thereby causing a disturbance 

 that may prove fatal. 



In the animal structure lime is very neces- 

 sary in the formation of bone, and its presence 

 in the blood and tissues of the body indicates 

 the need of it in other organs. Boehm states 

 {Ber. Alcad. d. Wissensch., Wien, 1875) : " In 

 order to form the cell wall from starch and 

 sugar lime is just as important as for the 

 formation of the bone. The lime forms the 

 skeleton of the cell wall." Again, lime salts 

 have great effect upon the action of the heart, 

 as repeated results have demonstrated. Lime 

 also plays an important part in the division 

 of cells. Herbst states (Arch. f. Entwich- 

 lungsmechanik. Vol. V., p. 667) that the most 

 important salt for the development of the sea 

 urchin's egg is calcium phosphate, and in its 

 absence the completion of segmentation is 

 impossible. 



In this, the blue grass region of Kentucky, 

 the soil has been formed largely by the dis- 

 integration of a limestone very rich in phos- 

 phates. It is a region long noted for the 

 beauty and quality of its live stock, especially 

 the thoroughbred horse, an animal uniting 

 the greatest speed with endurance. The 

 studies here reported have been undertaken 

 with the view of finding whether in even this 

 favored section the quality of our animals 

 may not be improved by the further addition 

 of certain mineral elements to the food. So far 

 experiments have been carried on with pigs to 

 which varying amounts of lime and magnesia 

 have been given in the feed, noting the rate 



