METHOD OF ANALYSING IT. 35 



crucible over Berzelius's lamp is a much less rapid method of pro- 

 ceeding ; in either case it is advisable that the bone-ash should be 

 moistened with carbonate of ammonia and again heated before it 

 is weighed. There is almost always a more or less considerable 

 quantity of caustic lime formed during incineration. When the 

 above precaution is neglected, the ash is often found to yield less 

 carbonic acid than the fresh bone, a result which may, however, 

 depend upon other circumstances. 



With regard to the individual determinations of the phosphoric 

 acid, magnesia, fluorine, and traces of sulphuric acid, we presume 

 that our readers are acquainted with the different methods em- 

 ployed in analytical chemistry ; we would, however, especially 

 recommend the mode of procedure devised by W. Heintz.* 



We have only very unsatisfactory data for the determination 

 of the quantitative relations existing between the bony skeleton 

 and the whole weight of the animal organism in different classes 

 of animals, and during different diseases ; and in many cases we 

 have no data of any kind. 



At the age of 21 years, the weight of the skeleton is to that of 

 the whole body in the ratio of 10*5 : 100 in man, and in that of 

 8*5 : 100 in woman (the weight of the body being about 125 or 

 130 Ibs.) 



The special consideration of the parts which stand in a close 

 relation to the bones, such as the periosteum, the marrow, and the 

 cartilaginous investments, does not fall within the limits of our 

 inquiry, since they are organic parts composed of several simple 

 tissues, and cannot, consequently, be made the subject of a rational 

 chemical investigation. 



Although numerous histological observations have been made 

 on the development of the bones from cartilage, the subject 

 has been very imperfectly considered in a chemical point of view. 

 In reference to the development of individual bones, we scarcely 

 know more at the present day than what was known long since, 

 independently altogether of chemical investigations ; namely, that 

 the bone, as long as it continues in a state of cartilage, contains a 

 substance yielding chondrin, which becomes converted into a body 

 yielding glutin during the progress of ossification, when the earths 

 are simultaneously deposited in the bone in large quantities. 

 Boussingault made some interesting experiments on pigs in con- 

 nection with the absorption of mineral substances during the 

 development of the skeleton. It would appear from these obser- 

 * Monatsber. dcr Akad. der Wiss. z. Berlin. 1849, S. 50-53. 



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