ITS CHEMICAL CONSTITUENTS. 19 



conditions, as has been already shown in the first volume. The 

 differences which the different bones of one and the same indivi- 

 dual exhibit are especially interesting. Von Bibra has especially 

 elucidated this point by the most conclusive results. With regard 

 to the proportions between the organic and inorganic matters, 

 Rees has, next to Bibra, most distinctly shown that the bones of 

 the extremities are in general richer in earths than those of the 

 body ; of the former the humerus and femur contain somewhat 

 more than the other cylindrical bones ; the cranial bones contain 

 about the same quantity of earths as the cylindrical ones, while 

 the metatarsal and metacarpal bones have a closer affinity in this 

 respect to the bones of the trunk. The ribs and the clavicles con- 

 tain on an average rather more organic substance than the vertebrae; 

 those of the pelvis approximate very closely in this respect with 

 the last-named bones. The carbonate of lime appears to be entirely 

 dependent upon the quantity of the phosphate of lime in the 

 different healthy bones of the same individual ; at all events, Bibra 

 found that in the most diverse bones of the same animal, the car- 

 bonate and phosphate of lime always stood in nearly the same 

 ratio. Moreover, it would appear from the observations at present 

 in our possession, that the quantity of magnesia in the different 

 bones rises and falls with that of the phosphate of lime. The 

 short bones always contain, according to von Bibra, more fat than 

 the cylindrical bones, even where the former have been as com- 

 pletely as possible freed from spongy substance. The quantity of 

 water contained in the bones has been made the subject of special 

 investigation by Stark*: it cannot generally be determined with much 

 accuracy, but Stark' s observations show that the flat bones contain 

 more water than the cylindrical (probably from the former being 

 the more vascular). 



Although the female skeleton is on an average far lighter than 

 that of man, the comparative analyses of the same bones of both 

 sexes show very trifling, and, as it would appear, altogether un- 

 essential differences. If we may be allowed to assume (with 

 physicians) the existence of a certain predisposition, we would say 

 that it would appear from the various recorded analyses of morbid 

 bones, that the female bones more readily undergo a loss of earthy 

 constituents than male bones, or to speak more correctly, that 

 processes which contribute to the absorption of bone-earth are 

 more frequently developed in the female than in the male 

 organism. 



* Edin. Med. and Surg. Journ. Vol. 163, pp. 30&-325. 



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