236 SOLID PARTS OF ANIMALS. 



bones, published in 1806,* announced the existence of fluate of 

 lime in fresh bones ; but this discovery has not been verified by 

 other experimenters. Dr Wollaston tried in vain to extract 

 fluoric acid from recent bones ; and unless I have been misinform- 

 ed the same want of success attended the researches of Mr Brande 

 upon the same subject. In 1829, M. Denis published a compa- 

 rative analysis of human bones from subjects of very different 

 ages.f About the same time M. D'Arcet pointed out the quan- 

 tity of nourishment which bones contain, and the best method of 

 extracting itj The investigations of Muller in 1836, on the 

 structure and chemical properties of the animal matter in bones 

 and cartilages, have added considerably to our knowledge of a 

 set of bodies highly worthy of a more accurate and complete in- 

 vestigation than they have hitherto met with. 



1. If we leave a bone in dilute muriatic acid at the common 

 temperature of the atmosphere, the earthy salts are gradually 

 dissolved, and the acid may be removed by keeping the bone 

 for some time in water, which must be renewed till it comes off 

 from the solid residue of the bone quite tasteless. What remains 

 is now the cartilage. It has the size and shape of the original 

 bone ; but is soft, elastic, and translucent, and has a yellowish 

 white colour. When dried the cartilage diminishes somewhat in 

 bulk, though it retains its translucency. It is hard and brittle, 

 and assumes very much the appearance of horn. 



From the microscopic observations of Purkinje and Deutsch, || 

 it appears that when the cartilage from a long bone is examined 

 it consists of a congeries of long minute tubes filled with marrow. 

 These tubes, according to Muller, consist of very fine circular 

 plates, and the intervals between them are filled up by numerous 

 circular plates which encircle the tubes. These plates may be 

 separated from each other by macerating the cartilage for a long 

 time in water. Besides these marrow tubes the cartilage con- 

 tains numerous scattered oval-shaped particles, the length of 

 which varies from 0-0004 to 0-0006 inch, and their breadth from 

 0-00014 to 0-00025 - inch, according to the measurement of 

 Miescher. These particles usually lie so that their length is 



* Afhandlingar, i. 195. t J ur. de Physiologic, ix. 183. 



\ Jour, de Pharmacie, xv. 236. Poggendors Annalen, xxxviii. 295. 



II Muller, Poggendorfs Annalen, xxxviii. 296. 



