SOLID PARTS OF ANIMALS. 



Carbonate of soda, . 35-068 



Sulphate of soda, . 24-241 



Common salt, . '8-231 



Phosphate of soda, . 0-925 



Sulphate of potash, 1 -200 



Carbonate of lime, 18-372 



Phosphate of lime, 4*056 



Phosphate of magnesia, 6-908 

 Peroxide of iron and loss, 0'999 



100-000 



The animal portion was soluble by long boiling in water, and 

 was converted into gelatin. It has been already stated in a for- 

 mer chapter of this volume, that Miiller has shown that gelatin, 

 from the permanent cartilages, differs in its properties from collin, 

 or the gelatin from the skin and serous membranes ; being pre- 

 cipitated from its solution in water by alum, sulphate of alumina, 

 acetate of lead, and persulphate of iron, which have no action on 

 the aqueous solution of collin. On that account he has distin- 

 guished it by the name of chondrin. The properties of chondrin, 

 so far as they have been investigated, have been given in a pre- 

 ceding chapter of this volume. 



The cartilages of the ribs, those that unite them to the ster- 

 num and to each other, give chondrin. Miiller found that the 

 cartilages obtained from bones by removing the bone earth, by 

 means of an acid, yielded collin ; yet the same cartilages before 

 ossification has taken place yield chondrin. From this it seems 

 to follow that a change takes place in the nature of the cartilage 

 during the process of ossification. 



It is probable that the cartilages of cartilaginous fish would 

 yield chondrin, though I do not know that the experiment has 

 been tried. 



The cartilages which cover the extremities of bones destined 

 to move on each other, cannot be converted into collin or chon- 

 drin by boiling in water. When deprived of the membrane that 

 covers them, they are much brittler than the cartilages of the 

 ribs. So far as I know, no chemical analysis of such cartilages 

 has been hitherto attempted. Mr Hatchett conceives them to 

 have the properties of coagulated albumen. But this conjecture 

 would require to be verified by actual experiment before it could 

 be admitted as true. 



