POTASH: SODA: LIME. 27 



the body. A minute quantity of fluorine in combination 

 with calcium has been found in the bones, teeth and 

 urine. 



Potassium and sodium are constituents of the blood and 

 all the fluids, in various quantities and proportions. They 

 exist in the form of chlorides, sulphates, and phosphates, 

 and probably, also, in combination with albumen, or certain 

 organic acids. Liebig, in his work on the Chemistry of 

 Food, has shown that the juice expressed from muscular 

 flesh always contains a much larger proportion of potash- 

 salts than of soda-salts ; while in the blood and other 

 fluids, except the milk, the latter salts always preponderate 

 over the former ; so that, for example, for every i oo parts 

 of soda-salts in? the blood of the chicken, ox, and horse, 

 there are only 40*8, 5-9, and 9-5 parts of potash- salts ; but 

 for every TOO parts of soda- salts in their muscles, there 

 are 381, 279, and 285 parts of potash-salts. 



The salts of calcium are by far the most abundant of the 

 earthy salts found in the human body. They exist in the 

 lymph, chyle, and blood in combination with phosphoric 

 acid, the phosphate of -lime being probably held in solu- 

 tion by the presence of phosphate of soda. Perhaps no 

 tissue is wholly void of phosphate of lime ; but its especial 

 seats are the bones and teeth, in which, together with 

 carbonate of lime and fluoride of calcium, it is deposited 

 in minute granules, in a peculiar compound, named 

 bone-earth, containing 51-55 parts of lime, and 48-45 of 

 phosphoric acid. Phosphate of lime, probably the tribasic 

 phosphate, is also found in the saliva, milk, bile, and most 

 other secretions, and superphosphate in the urine, and, 

 according to Blondlot, in the gastric fluid. 



Magnesium appears to be always associated with calcium, 

 but its proportion is much smaller, except in the juice 

 expressed from muscles, in the ashes of which magnesia 

 preponderates over lime. 



The especial place of iron is in the cruorin, the colouring- 



