ANALYSIS OF BONES. 



379 



cussion of the brain, and of other viscera, in Fi s- 162 - 



falls and blows. The demonstration, which 

 he gives of this, is simple and satisfactory. 

 If we suspend a series of six ivory balls by 

 threads; raise the ball at one extremity of 

 the series, and allow it to fall on the next to 

 it, the farthest ball in the series is impelled 

 to a distance which corresponds with the 

 momentum communicated by the first ball 

 to the second. But if we substitute, for the 

 middle ball of the series, a ball made of 

 the cellular structure of bone, almost the 

 whole of the momentum is lost in this 

 osseous structure; especially, if it be pre- 

 viously filled with tallow or well soaked in 

 water, so as to bring it to a closer approxi- 

 mation to the living condition. 



Bones consist of earthy salts, and animal 

 matter, intimately blended. The latter is 

 chiefly cartilage, gelatin, and the peculiar 

 fatty matter the marrow. On reducing 



bones to powder, and digesting them in water, Sections of a Bone, 



the fat rises and swims upon the surface ; 1,2. Longitudinal section of the ex- 

 and the gelatin is dissolved. According to 'Transverse section of the body. 

 the analysis of Berzelius, 102 parts of dry 



human bones consist of animal matter, 33'3; basic phosphate of lime, 

 51-04; carbonate of lime, 11-30; fluoride of calcium, 2; phosphate of 

 magnesia, 1/16; soda, chloride of sodium, and water, 1/2. It has been 

 much doubted, however, whether fluoride of calcium is contained in 

 recent bones ; whilst it is admitted to have been defected in fossil bones. 

 According to Dr. Daubeny, 1 it exists in the former, in about a quarter 

 of the proportion in which it is present in the latter; but the propor- 

 tions in different specimens of both kinds are variable. Dr. Daubeny 

 ascribes the failure of those who have not detected fluorine except in 

 fossil bones and teeth, to the tenacity with which it is retained by 

 animal matter ; and to its being carried off with the carbonic acid 

 evolved at the same time, too rapidly to act upon glass exposed to it. 

 He, therefore, before submitting the bones to the action of strong sul- 

 phuric acid, burns away all the animal matters; removes the carbonic 

 acid by dissolving them in chlorohydric acid; then throws down the 

 earthy phosphates by caustic ammonia, and dries them. 



MM. Fourcroy and Vauquelin found in bones oxides of iron and 

 manganese, silica, and albumen. Mr. Hatchett detected, also, a small 

 quantity of sulphate of lime. Schreger gives the following as the pro- 

 portions of the animal and earthy parts: 



Animal matter 

 Earthy matter 



95-68 



95-02 



Aged. 

 12-20 

 84-10 



96-30 



1 Philosophical Magazine, Aug., 1844, 



