164 ELEMENTS OF VEGETABLES. 



coming to the lungs. The hair contains iron ; the black colored more 

 the white. Iron has aTso"BeenlI?fecte(r in the gastric juice and 

 the chyle. It is found in eggs, milk, mustard, potatoes, peas, cabbage, 

 cucumbers, &c. 



Chlorine is an element of the blood and most of the secretions, as in 

 urine, saliva, tears, gastric juice and the foeces. It is combined with 

 sodium in the blood, and in the gastric juice with hydrogen. It being 

 constantly consumed in these states, it requires equally constant re- 

 newal. It is therefore taken into the body in the form of common salt, 

 (chloride of sodium.) It is found in the yolk of the egg and in the 

 mother's milk. It is an indispensable constituent of food, hence the 

 strong appetite for it evinced by animals. Persons are too often neg- 

 lectful of this fact, both with regard to themselves and the animals un- 

 der their care. It is of the greatest importance in the formation of 

 hydrochloric acid in the formation of the gastric juice. A disordered 

 condition of the functions of this secretion is no doubt often attributa- 

 ble to the want of an edequate supply of common salt. Its composi- 

 tion is water, gastric mucous, and hydrochloric acid. The mucous 

 membranes contain mucous, but none other. The juice may be made 

 artificially. 



Sodium is a metal (the base of soda), constituting a part of the 

 blood, tissues, and secretions of animals: also of feathers, hair, flesh, 

 bristles, &c. It is received into the system in the form of chloride, 

 &c., and exists in the form of sulphates and phosphates of soda. 



Calcium is a metal (the base of lime), and is a constituent of ani- 

 mals and vegetables, as well as of minerals, existing principally united 

 with phosphorus to form the bones. Subphosphate of lime is also a 

 component part of blood, milk, muscles, nerves, the liver, and in fact, 

 most of the animal solids. It is derived from the food from the three 

 kingdoms. It is found in the grains, onions, and most other vege- 

 tables. Rhubarb contains the oxalate, and grapes the tartrate ofcal- 



_^ ^cium. It is also derived from well and river water. The Chinese 



mix gypsum (sulphate of lime) with pulse, to form a jelly, which they 

 eat. A morbid appetite for lime is not unfrequent. It is said that 

 children not supplied with sufficient lime in their food, sometimes col- 

 lect and eat it. 



Magnesium. This metal forms a small part of the bones, nervous 

 matter, &c. of the body. It exists combined with oxygen and phosphoric 

 acid, and often with ammonia. It constitutes portions of vegetable 

 food, and is found in the cereal grains, potatoes, &c. 



Potassium is a constituent of animal and vegetable food. We have 

 spoken of this important vegetable product in a previous chapter. It 

 exists in plants combined with the acids, forming salts which are found 

 in their ashes. Liebig says that the production of milk without pot- 

 ash is impossible. It is found in potatoes, grapes, &c. 



