INORGANIC PRINCIPLES. 



491 



this with reference to the chloride of sodium. If a piece of muscle be placed in a strong 

 solution of common salt, as in salting meat, it becomes harder and loses a portion of its 

 water of composition ; but, if it be exposed to the action of pure water, it absorbs a cer- 

 tain quantity and becomes softer. The nutrient fluid of the muscles during life contains 

 water with just enough saline matter to preserve the normal consistence of the parts. 

 This action of saline matters is even more apparent in the case of the blood-corpuscles. 

 If pure water be added to the blood, these bodies swell up and are finally dissolved ; 

 while, if we add a strong solution of salt, they lose water and become shrunken and cor- 

 rugated. Their natural form and consistence can be restored, however, even after they 

 have been completely dried, by adding water containing about the proportion of salt 

 which exists in the blood-plasma. It seems clear, then, that water is a necessary ele- 

 ment of all tissues and is especially important to the proper constitution of organic m'tro- 

 genized substances ; that it enters into the constitution of these substances, not as pure 

 water, but always in connection with certain inorganic salts ; that its proportion is con- 

 fined within certain limits ; and that the quantity in which it exists, in organic nitrogen- 

 ized substances particularly, is regulated by the quantity of salts which enter, with it, 

 into the constitution of these substances. 



The quantities of water which can be driven off by a moderate temperature (212 

 Fahr.) from the different fluids and tissues of the body vary of course very consider- 

 ably, according to the consistence of the parts. The following is a list of the quantities 

 in the most important fluids and solids : 



Table of Quantities of Water. 



Parts per 1,000. 



In Enamel of the teeth 2 



" Epithelial desquamation 37 



" Teeth 100 



" Bones 130 



" Tendons (Burdach) 500 



12 ] " Articular cartilages 550 



" Skin (Weinholt) 575 



" Liver (Frommherz and Gugert) 618 



" Muscles of man (Bibra) ; 725 



" Ligaments (Chevreul) 768 



" Mean of blood of man (Becquerel and Rodier) 780 



" Milk of human female (Simon) 887 



" Chyle of man (Rees) 904 



" Biie 905 



" Urine 933 



" Human lymph (Tiedemann and Gmelin) 960 



" Human saliva (Mitscherlich) 983 



" Gastric juice 984 



" Perspiration 986 



" Tears 990 



" Pulmonary vapor 997 



Function of Water. After what has been stated respecting the condition in which 

 water exists in the body, there remains but little to say concerning its function. As a 

 constituent of organized tissues, it gives to cartilage its elasticity, to tendons their plia- 

 bility and toughness; it is necessary to the peculiar power of resistance of the bones; 

 and, as we have already seen, it is essential to the proper consistence of all parts of the 

 body. It has other important functions as a solvent. Soluble articles of food are intro- 

 duced in solution in water. The excrementitious matters, which are generally soluble in 

 water, are dissolved by it in the blood, are carried to the organs of excretion, and are dis- 

 charged in a watery solution from the body. 



