THE CHEMISTRY OF FOOD. 55 



weight when dried with moderate heat. But it is in the 

 fluids of the body that water is found most abundantly. 

 It gives to them the power of holding a great variety of 

 substances in solution, and is the great highway by which 

 new supplies are conveyed to the point where they are 

 required, and by which old particles of matter, that have 

 served their uses, are brought to the outlets of the body to 

 te thus removed from the system. 



C. Man can remain a longer time without solid food 

 than without water.- He may be deprived of the former 

 for ten to twelve hours without great suffering, but depri- 

 vation of water for the same length of time will produce 

 both severe pain and great weakness. The food should contain 

 not less than two parts of water to one of solid nutriment. 

 Water constitutes the great bulk of all our drinks, and is 

 also a large constituent of the meats, vegetables, and fruits 

 which come upon the table. Fruits, especially, contain it 

 in great abundance, and, in their proper season, furnish 

 most agreeable and refreshing supplies of the needed fluid. 



7. Common Salt. Salt, or sodium chloride, as an 

 article of food, is obtained chiefly from the mineral king- 

 dom; although plants contain it in small quantities, and 

 it is also found in the tissues of nearly all animals used 

 as food. In the human body, it is an ingredient of all 

 the solids and fluids. The importance of salt to animal 

 life in general, is shown by the great appetite for it mani- 

 fested by domestic animals, and also by the habitual resort 

 of herds of wild beasts to the " salt-licks" or springs. In 

 those parts of the world where salt is obtained with diffi- 

 culty, man places a very high price upon it. 



8. Experiments upon domestic animals show that the 

 withdrawal of salt from their food, not only makes their 



6. Length of time man can do without food or water ? Give the comparison ? 

 Bulk of drinks ? Constituent, of meats?, etc. ? Fruits ? 



7. Salt, how obtained ? Where found? In the human body? Importance oi 

 ^alt ? What else can yon st ato of the value of salt ? 



8. Experiments upon animals? 



