274 THE ORGANIC BASIS OF BONE. [BOOK I. 



The following solutions may be employed for softening bones. 



(1) A mixture of one part of hydrochloric acid and five of water. 



(2) A mixture of nitric and chromic acids of the following com- 

 position : chromic acid 5 grms., nitric acid 10 cub. c., water 1000 c. c. l 



(3) A solution containing from 2 to 5 parts of chromic acid in 1000 

 parts of water (Ranvier). 



(4) A saturated aqueous solution of picric acid. 



In the case of solutions 3 and 4 it is important that the fragments of 

 bone to be softened shall be very small. 



Characters The organic basis of softened bone is insoluble in 



of the organic cold water, but is for the most part soluble on pro- 

 basis of bone, longed boiling in water. The solution contains gelatin, 

 which is identical in its reactions with that body as it is obtained 

 from white fibrous tissue. The structures which are undissolved by 

 boiling water are the perforating fibres, and apparently the decalcified 

 walls of the lacunae, canaliculi, and of the Haversian canals, which 

 appear to be formed of a substance resembling elastin. 



The organic basis of bone (which has by some writers been 

 termed ossein) then consists mainly of a body identical in chemical 

 reactions with collagen, mixed with a certain amount of elastin and 

 with the proteid matter of the bone cells. It is to be noticed that 

 the animal matter of cartilage before ossification does not consist of 

 normal collagen but of chondrogen (or, if we adopt Morochowitz's 

 theory, of a mixture of collagen and mucin). In the process of ossifi- 

 cation, which consists essentially in an intrusion of periostea! elements 

 into cartilage, which is pari passu removed by absorption, the animal 

 matter assumes all the characters of connective tissue proper. 



There appears to be always some fat in bone, but its relations to 

 the organic basis are not known. 



All organic matters are destroyed when bone is incinerated. The 

 following are the results of some analyses shewing the relative pro- 

 portion of organic and mineral matters in bone (Zalesky). 



Organic matters. Mineral matters. 



Bone of man (mean of 4 analyses) 34*56 65*44 



ox (mean of 6 analyses) 32*02 67*98 



guinea pig (mean of 2 analyses) 3470 65*30 



The Mineral Matters of Bone, 



The mineral matters of bone are deposited in the organic basis 

 in such a manner as to be invisible on microscopic examination. 

 They may for the most part be dissolved by employing the processes 

 already described as producing the decalcification of bone. They 

 may be obtained in a solid form by igniting or incinerating bone, 

 and they then retain the form of the original bones 

 bone). 



1 Kutherford, Outlines of Practical Histology, pp. 3 and 82. 



