OSSEOUS TISSUE. 333 



water) and frequently changed hydrochloric or nitric acid ; and thus 

 obtained, it perfectly retains the form of the bone of which it 

 constituted a part. In its moist state, 

 it is a tolerably elastic, yellowish, Flg * 221 * 



translucent substance; and in its che- 

 mical analogies it is found to coincide 

 perfectly with glutin, except that the 

 former has always a little sulphur 

 which is absent in the latter. Under 

 the microscope it shows a network of 

 obliquely decussating fibres, as seen 



TV rr-i mi i -L-I Thin layer peeled off a softened bone, 



in Fig. 221. The bone-cartilage is, as it app j rs u p nder a magnifying powe ; 

 therefore, actually osteine, as shown of 40 - The figure, which is intended to 



. 111-1 represent the reticular structure of the 



On page 99. It IS Converted by bOll- oste ine of a lamella, gives a better idea of 



mg Water intO three Or four times itS the b Je<*^hen held rather further off 

 than usual from the eye. 



volume of glutm. 



On the other hand, the osteine may be removed from the mineral 

 constituents by calcination, or by careful boiling in dilute alkalies. 

 In this case, also, the mineral constituents alone remaining, preserve 

 the original form of the bone. 



It is probable that the phosphate and carbonate of lime are united 

 together, before combining chemically with the osteine (Robin and 

 VerdeiT)] and possibly the fluoride of calcium and the phosphate 

 of magnesia are also previously combined with the two first men- 

 tioned salts. Still, the organic and mineral matters are by no 

 means always in the same proportion in the different bones of the 

 same person. The bones of the extremities contain more earthy 

 matter than those of the trunk ; and the humerus and femur more 

 than the other cylindrical bones. The ribs and the clavicles con- 

 tain on an average more osteine than the vertebrae; and the bones 

 of the pelvis approximate the latter. Of the different mineral mat- 

 ters, the phosphate of magnesia always rises and falls with the phos- 

 phate of lime ; while the ratio of the carbonate of lime to the phos- 

 phate varies, 1 though within certain not very wide limits at the same 

 age. Lehmarm found the proportion of the carbonate to the phos- 

 phate of lime in the bones of a new-born infant to be 1 : 3.8; in a 

 male adult, 1 : 5.9; and in a man 63 years old, 1 : 8.1. In disease, 

 however, the carbonate of lime often increases while the phosphate 

 diminishes; and hence it has been asserted, incorrectly, that the 



1 Von Bibra asserts that these two salts are always in nearly the same ratio. 



