Mineral Content of Southern Poultry Feeds 7 
are essential to cardiac relaxation, in fact the heart cannot functionate 
without the presence of sodium and calcium salts. The blood cannot 
coagulate, when drawn, without the presence of calcium salts. The 
essential alkalinity of the blood is due to the phosphate and bicarbonate 
of sodium. Iron is essential in the red blood corpuscle to give it its 
oxygen carrying power, 0.4 per cent of the hemaglobin being iron. 
The nature of the inner stimulus of the heart is intimately connected 
with certain organic salts of sodium, calcium, and potassium. These 
are probably in the form of chlorides. It has been shown that calcium 
promotes contraction, and that sodium and potassium bring about 
relaxation of the heart. The sodium carbonate of the blood probably 
assists in carrying the carbon di-oxide to the eliminative organs, the 
lungs. Bohr 6 disputes this point and maintains that the carbon di¬ 
oxide is carried in loose chemical union with the hemaglobin. 
Free acid formation in the stomach of fowls is probably formed by 
selective powers, possessed by the secretive cells, by an interaction of 
sodium chloride and sodium di-hydrogen phosphate of the blood. 
The digestive fluid secreted by the glands of Lieberkuhn is alkaline 
due to sodium carbonate. The pancreatic secretion contains much 
sodium, magnesium, potassium, and calcium in combination with chlo¬ 
ride, carbonate, and phosphate. Bile contains sulphur, phosphate and 
chloride of sodium, and salts of calcium, magnesium, iron, and potas¬ 
sium. The larger proportion of salt is sodium. 
The salts of the body perform important functions in connection 
with secretion and excretion. They direct the metabolism of the body, 
though how is little understood. They regulate the fluid flow from 
blood to tissues and vice versa. Irritability of muscle and nerve is 
due to salts. 
Young growing birds require more salts than adults. The activity 
of enzymes, whose function in building up and tearing down chemical 
compounds in the animal body, requires certain degrees of acidity 
and alkalinity is maintained in proper degree through the presence 
of mineral salts. Animals can live but a short time on feeds free from 
mineral salts 7 . Forster 8 fed pigeons on practically ash free feed. 
They died in a few days. He considered that the lack of mineral matter 
was the cause of death. Alkali bases furnished by the liver through 
its bile are necessary to fat digestion. 
Salts assist in the formation of secretions, repair and disintegration. 
The growth of the solid tissues depends on the inorganic material 
supplied by the blood. Water free from salts is destructive to pro- 
6 Ibid. 
7 Forster, J.^Zlscter. f. Biol. Vol. IX, p. 297. 
8 Ibid. 
