COMPOSITION OF BONE. 



271 



may be obtained, by long boiling under pressure, from previously-unaltered Bone ; 

 and the calcareous matter is then left almost pure. The Lime of bones is, for 

 the most part, in the state of Phosphate ( 76) ; but a certain proportion of 

 Carbonate is always present. The following are the results of some of the most 

 recent and careful analyses of Human Bone, by Marchand and Lehmann : those 

 of the former were made on the compact substance of the femur of a man aged 

 30 ; and those of the latter on the long bones of the arm and leg of a man of 

 40 years of age. 



Organic matter. 



Cartilage insoluble in hydrochloric acid 



Cartilage soluble in hydrochloric acid 



Vessels . . . . . ". , . 

 Inorganic matter. 



Phosphate of lime 



Fluoride of calcium 



Carbonate of lime 



Phosphate of magnes a 



Soda . 



Chloride of sodium 



Oxides of iron and manganese, and loss 



100.00 



100.00 



According to Dr. Stark, 1 the relative proportions of cartilaginous and earthy 

 matter, in the bones of different animals, in the bones of the same animals at 

 different ages, and in the different bones of the same body, never depart widely 

 from the preceding standard ; the amount of earthy matter being always found 

 to be just double that of the cartilaginous basis, when the bones have been care- 

 fully freed from oily matter, and completely dried, previously to the analysis. 

 The hardness of bone, he maintains, does not at all depend upon the presence of 

 an unusually large proportion of earthy matter ; nor does their increased flexi- 

 bility and transparency indicate a deficiency of the mineral ingredients : for the 

 transparent readily-cut bones of Fish contain the same amount of earthy matter, 

 in proportion to their gelatinous basis, as do the dense ivory-like leg-bones of the 

 Deer or Sheep. The same holds good of the bones even of the so-called Carti- 

 laginous Fish. The difference appears to depend upon the molecular arrangement 

 of the ultimate particles ; and especially, it seems likely, upon the relative amount 

 of water which the bones contain. 



. 262. Probably the most exact and comprehensive analyses yet made of Bone, 

 are those of Von Bibra f whose laborious investigations may be said to have 

 almost exhausted the subject. The following table shows the relative propor- 

 tions of the principal ingredients, in some of the principal bones of a woman 

 aged 25 years. 



Organic matter. 

 Cartilage 

 Fat . 



Inorganic matter. 



Phosphate of lime with ~| 

 a little fluoride of cal- >- 

 cium J 



Carbonate of lime 



Phosphate of magnesia 



Soluble salts 



Femur. 



29.54 

 1.82 



Occipital 

 bone. 



29.87 

 1.40 



Scapula. Rib. 



32.90 

 1.73 



33.06 

 2.37 



Os inno- Vertebra. Sternum, 

 minatum. 



38.26 43.44 46.57 

 1.77 2.31 2.00 



57.42 57.66 54.75 52.91 49.72 44.28 42.63 



8.92 

 1.70 

 0.60 



8.75 

 1.69 

 0.63 



8.58 

 1.53 

 0.51 



8.66 

 1.40 

 0.60 



8.08 

 1.57 

 0.60 



8.00 

 1.44 

 0.53 



7.19 

 1.11 

 0.50 



100.00 100.00 100.00 100.00 100.00 100.00 100.00 



1 "Edinb. Med. and Surg. Journal," April, 1845. 



2 "Chemische Untersuchungen iiber die Knochen und Ziihne des Menschen, und der 

 Wirbelthiere." 



