162 



PHOSPHORUS AND PHOSPHATES. 



White Haricots, 56 



White Garden Cabbage, . 810 



Do. dried at 212, . 83 



Oats, . . .117 



Rye, . . Ill 



Jerusalem Artichokes, . 539 



Carrots, . . 757 



Do. dried at 212, . . 95 



Horse Beans, . 44 



Peas, . i *-, . 67 



Thus 44 parts of horse beans, 67 of peas, or 83 of dried cabbage are 

 equal in nitrogen to 100 parts of wheat flour, 138 of maize, or 613 of 

 potatoes. But while Ihese afford the most nitrogen, they are deficient 

 in the elements (phosphate of lime and magnesia) which compose the 

 bones, and are therefore of much less value than others as articles of 

 food ; they satisfy the appetite, but add little to the strength. All 

 vegetable poisons contain nitrogen, and some nitrogenized articles of 

 food contain poisonous principles, as with the solanina of potatoes and 

 some others of that genus ; but these principles are always dissipated 

 or modified, as we have shown, by heat. 



Phosphorus is an essential constituent of animals and vegetables. 

 It is an ingredient in the bones and in the albumen and fibrine of tis- 

 sues, and in nervous matter. It has been thought that an unequal 

 proportion of this substance exists in the brains of sane and insane 

 persons and idiots ; but this has not been confirmed. In bones, it ex- 

 ists in combination with oxygen and lime, hence it must constitute an 

 element of animal food. It is an important part of the yolk of eggs, 

 and forms the skeleton of the embryotic animal; and also of milk, by 

 which the frame of young mamals is produced. In the flesh, blood 

 and bones of animals eaten as food, it is an essential element of nu- 

 trition. Fishes also abound with phosphoric matter, which is recog- 

 nized by the phosphoric odor of the breath of those who have eaten 

 much of them. In plants it exists in the form of earthy phosphates 

 in the ashes. It is yielded to them by the soil in the form of phos- 

 phoric acid ; and they yield it to animals and man, as a constituent of 

 the bones, the brain, &c. It being thus abundantly afforded in plants 

 and animals eaten as food, so much of it as is not required for the 

 ibove purposes is given out in urine, perspiration and excrement. 



Phosphate of magnesia and ammonia constitute a part of the seeds of 

 all the grasses consumed by animals and man. It is chiefly in the 

 outer husks. Horses consume much of it, and hence their coecum, 

 consisting of these substances, is often as large as a child's head, and 

 sometimes weighs 5 or 6 Ibs. Beer derives these principles from the 

 husks of barley ; and bread affords it by the bran of the grain. The 

 seeds of peas, beans, etc. contain little of the phosphates, though they 

 yield much nitrogen, and hence their insufficiency as food. An earthy 

 phosphate is abundantly afforded by unrefined sugar. The crust re- 

 maining after boiling raw sugar contains 92 per cent, of sub-phos- 

 phate of lime. The principal organic constituent of potatoes is also 



