238 SOLID PARTS OF ANIMALS. 



passed through the filter, the carbonate of lime will be thrown 

 down, and may be collected on a filter. The liquid still contains 

 magnesia, which was prevented from falling by the excess of am- 

 monia jised, or rather of sal-ammoniac formed, which, constitut- 

 ing with the magnesia a double salt, prevented it from falling 

 down when the carbonate of ammonia was added. 



Let the residual liquid be evaporated to dryness and the resi- 

 due exposed to a strong heat. The 'magnesia will remain near- 

 ly pure. But it is mixed with a little common salt. Water 

 dissolves the common salt and leaves the magnesia. In this 

 way may all the constituents of the earth of bones be separated 

 from each other. They consist of 



Subsesquiphosphate of lime, 



Carbonate of lime, 



Magnesia,* 



Common salt, 



Probably the common salt in the bone may have been partly in 

 the state of soda. 



Berzelius analyzed human and ox bones, having first deprived 

 them of all the fatty matter or marrow which they contained, 

 and also having freed them from their periosteum. The follow- 

 ing are the results which he obtained : 



Human. Ox. 



Cartilage soluble in water, 32-171 QQ on 

 Vessels, . MS/ 



Subsesquiphosphate of lime, 53*04 5 7 '35 



Carbonate of lime, . 11-30 3-85 



Phosphate of lime, . 1-16 2-05 



Soda with a very little common salt, 1*20 3-45 



100-00 100-00 



From the experiments of Dr Rees,f it appears that the pro- 

 portion of cartilage and earthy matter differs somewhat in dif- 

 ferent bones. The following are the proportions in different 

 human bones of an adult : 



* The magnesia is not in the state of phosphate, as Fourcroy and Vauquelin 

 supposed ; otherwise it would have been precipitated by the caustic ammonia. 

 It may have been in the state of carbonate. 



f Medico- Chirurgical Transactions, Vol. xxi. 



