616 



MISCELLANEOUS FARM SUBJECTS 



Some of the elements of mineral matter are essential to the 

 body in carrying out many of its most important functions. Dur- 

 ing the activities of the body "waste products are produced, and if 

 these were allowed to remain in this form they would prove exceed- 

 ingly injurious. It is the function of some of the salts of calcium, 

 magnesium, potassium, and phosphorus to unite with these harmful 

 compounds and make them harmless. Thus they are gotten rid of. 

 The ability of the heart to beat, of the muscles to contract, of the 

 nerves to carry impressions are all dependent upon the presence of 

 some of the salts. The activity of the intestine depends upon them. 

 One fruitful source of constipation is a lack of knowledge of these 

 facts. 



Foods Rich in Salts. 



(Cornell Beading Course for Farmers' Wives, New Series II, No. 

 6 and 7.) 



Baking Powder. Although baking powder is not added to 

 food for nutrition, it must be considered under mineral foods. Bak- 

 ing powders are a mixture of sodium bicarbonate and some form of 

 acid salt, together with from one-fifth to one-half of their weight of 

 starch or flour. Baking powders may be classed under four kinds, 

 depending upon the acid salt used, viz : First, cream of tartar bak- 

 ing powders; second, alum baking powders; third, alum-phosphate 

 baking powders; and fourth, phosphate baking powders. So far as 

 their efficiency in bread-making is concerned, they are about of 

 equal value ; that is to say they all liberate about the same amount 

 of carbonic acid gas when fresh. It is the liberation of this carbonic 

 acid gas in the dough in the process of baking that causes the bread 

 to rise and to be porous. 



When baking powders are used in bread-making, a chemical 

 change takes place, caused by the water used in mixing the dough 

 and the heat in baking the bread resulting in the evolution of car- 

 bonic acid gas, and a fixed residue remains in the bread. This fixed 

 residue in the case of cream of tartar baking powder is potassium 

 sodium tartrate, usually called Rochelle salts. In the case of alum 

 baking powders or alum-phosphate baking powders, this residue, if 

 the reaction is complete, is sodium sulphate and alumina hydrate or 

 phosphate. In the case of phosphate baking powders, the residue is 

 calcium and sodium phosphates. 



