332 THE TISSUES. 



vided for. In man, however, the rods are so crowded that no la- 

 mellae exist between them ; but only the interstitial tissue with a 

 few lacunas (and their pores), as described in the preceding sen- 

 tence. (KolliJcer.) 



Chemical Composition of Osseous Tissue. 



* 



It is almost impossible to isolate the osseous tissue completely 

 from the vessels and nerves distributed to it ; and hence there is 

 some uncertainty in regard to its precise chemical composition. 



On removing the vessels and nerves from the compact bone- 

 structure, as far as possible, the following results are obtained by 

 the best chemical analysis of dried compact osseous tissue : 



Organic substance (osteine) . . . 33 ) 

 Mineral constituents . . . . 67 f 



Phosphate of Lime . . .57 

 Carbonate of Lime . . .8 

 Phosphate of Magnesia ... 1 

 Fluoride of Calcium ... 1 



Osseous tissue also contains the chloride of sodium, and some 

 alkaline sulphates and fat. The last, amounting to from one to 

 three per cent, in some bones, must belong, in all probability, to the 

 blood in the vessels, or to the marrow in the cavities of bone; while 

 Lehmann believes the chloride of sodium (.25 to .38 per cent.), also, 

 is derived probably from the vessels or the fluid in the lacunae and 

 pores; and the alkaline sulphates are a product of the incineration 

 of the bone. 



The amount of water in bone is about 13 per cent. (Robin and 

 VerdeiL) 1 The flat bones contain more water than the cylindrical; 

 probably because they are more vascular. Human bones contain 

 more water than those of any other mammal (Stark)] the bones of 

 birds still more ; and the bones of fishes most of all animals. Nasse 

 maintains that the hardness of bones is not affected by their pro- 

 portion of water; a proposition which seems untenable in respect 

 to diseased bones at least. 



The lone-cartilage, as Lehmann terms it, may be separated from 

 the mineral matters by the prolonged action of dilute (1 to 7 of 



1 Dr. Stark found only three to seven per cent. 



