AND PHYSIOLOGY. 



7 



solid parts, and in all the fluids except fat. They form the 

 chief and most important ingredients in animals and plants. 



12. Sulphur and Phosphorus, Magnesium, Sodium, Pot- 

 assium, Chlorine, Fluorine, Calcium, Silicon, Iron, Man- 

 ganese. — With scarcely an exception, these elements exist in 

 the body as compounds ; that is, two or more of them are 

 combined, as in water, in oxyds, and in various salts. Sul- 

 phur and phosphorus exist in albumen and fibrine, as well as 

 in the brain, about T 777th of its weight being phosphorus. 

 Bones are more than half made up of Phosphate of Lime, and 

 they contain a small per cent, of Phosphate of Magnesia. 

 Sodium, in the form of a chlorid (common salt), is found in 

 every solid and fluid of the body. Potassium occurs as a 

 chlorid in the muscles, and as an oxyd in salts. Chlorine 

 forms chlorohydric acid by combining with hydrogen in the 

 gastric juice. Fluorine exists in the bones in a minute quan- 

 tity, combined with calcium. Silicon is found in small quan- 

 tities m hair, wool, and feathers, as silica. Iron forms about 

 the 2000th part of the blood, and it exists also in the muscles, 

 hair, and milk. Manganese, in small quantities, has been 

 detected in bone, and perhaps in the hair. 



13. Copper, Lead, and Arsenic, — Copper, lead, and arsenic 

 have been detected in minute quantity in human flesh. But 

 it is not probable that they are normal constituents. 



14. Inferences. — From these facts we learn that our food 

 and drink should contain the fifteen ingredients above described. 

 Milk and eggs are the only articles that do contain them all ; 

 and hence, the importance of variety in diet. And the fact 

 that we are obliged to use ten mineral ingredients in our food, 

 shows the absurdity of a prevalent prejudice that no mineral 

 should ever be taken as a medicine. 



15. Immediate Principles, — As they exist in the body, the 



12. State in what organs Sulphur and Phosphorus are found. What is one of the prin- 

 cipal ingredients of bones ? Where is Chlorine found ? Fluorine? Silicon? In what 

 parts of the tody is Iron found? 13. What is to be said of Copper, Lead and Arsenic? 

 14. What should our food contain? Are mineral ingredients always poisonous ? 15. Pe« 

 fine Immediate Principles. 



