ANALYSIS OP HUMAN BONES. 257 



announced, that we ha(i not found any in huin?^n bones ; in the bones of 

 and thought we might presume the cause of this difference ^^^^iri^peds 

 to be the excretion of phosphate of magnesia by the urinary 

 passages in man, while none occurs in the urine of ani- 

 mals. 



However, as we had made only a single experiment in 

 search of this substance, we did not assert positively* tha 

 absence of magnesian earth in these organs. 



On occasion of our last publication, in the month of Human bones 

 September, 1808, on the presence of iron and manganese in ^amined '^ 

 ex-^bones, we thought it necessary to resume with great 

 care the analysis of human bones, not only with respect to 

 magnesia, but also of the metals in question. 



. In treating these bones in the manner we have men- yjejded mag- 

 tioned with respect to those of the oxf, we found in them nesia, iron, 

 magnesia, iron, and manganese, in the same state as in the neseT*"**^ 

 latter. 



If we may be allowed to reckon on the proportions of the ^j^ jgsg ^f ^j,, 



substances we obtained from human bones, they appeared fi'st, and more 

 . . ^ • , . , 1 of the othsr 



to us to contam less magnesia, and more iron and manga- ^^^^ jj^^^^ 



nese, than the bones of herbivorous quadrupeds. The those of 

 small quantity of the first of these salts agrees with the con- ^"^^'■"P'** 

 tinual discharge of phosphate of magnesia in the human 

 urine. It is well known, that this is not the case with the 

 urine of herbivorous animals; on the other hand, the iron 

 and manganese, once entered into the course of the circu- 

 lation, and deposited in the various organs of the animal 

 economy, no longer finding an exit from the body, the 

 quantity of these two substances apparently must increase 

 with age, and from the known nature of food ; so that the 

 blood and bones of an old man ought to contain more iron 

 and ir.anganej^e than those of children, as well as of ani- 

 mals, who besides do not live so long as man. Thus the 

 proportions with respect to quantity confirmed by our ex* 

 periments are equally so by known physiological phenomena. 



Our last researches have shown us traces of alumine and They contain 

 silex likewise in human bones. The last exis^ in the pbos- ^^^j alurams 



• It appears however to be asserted positivelf enough in the pa^er re- 

 ierred to. See Journal, vol. VIII, p. S6. C. 

 f Soe Journal, as abo.ve quoted. <^, 



^<)«*XXX.— i)EC. 1811, S pb^te 



