THE OSSEOUS SYSTEM. 387 



structure of the compact substance and of the lamellar systems 

 of the Haversian canals, which, in this case also, sometimes 

 appear isolated, as in macerated bone. For the microscopic 

 examination of the inorganic constituents of bone, sections are 

 subjected to heat on platinum foil, but they must be very thin, 

 as they afterwards become more opaque, and, on account of 

 their fragility, except in minute fragments, do not admit of 

 being ground thinner (Bruns) ; or sections may be boiled in 

 caustic potass. In either case, the lacunae arc seen distinct, 

 and empty, with the beginnings of the canaliculi, in a finely 

 granular matrix. The natural condition of the lacunae is 

 readily seen in perfectly recent bone, in thin sections or 

 lamellae ; as, for instance, in many parts of the bones of the 

 face. In recent bone, also, the vessels may be studied, naturally 

 injected, and with the microscope, being thus, far fitter for the 

 purpose than when injections, which often fail, have been 

 practised, and for the closer examination of which, more- 

 over, the bones must afterwards be macerated in hydrochloric 

 acid, and preserved in oil of turpentine. The nerves of the 

 bones may be seen by the naked eye, on the nutritious arteries 

 of the larger cylindrical bones, and readily, by the microscope, 

 on the smaller vessels ; those of the periosteum must be studied 

 after the membrane has been rendered transparent by caustic 

 soda or acetic acid. The costal and articular cartilages are the 

 most suitable for the study of cartilage, the membranes of the 

 cartilage-cells being evident, sometimes without any addition, 

 sometimes after that of acetic acid or soda, which render 

 the matrix transparent. The development of bone may be 

 investigated in a cylindrical bone, and in the parietal bone ; 

 the formation of the lacunae, in specie, in rachitic bones, and 

 in the osseous surfaces of the symphyses and synchondroses.] 



Literature. — Besides the works cited in §§ 22 and 25, are 

 to be noticed, F. Bidder, 'Zur Histogenese der Knochen,' 

 ('On the Histogenesis of Bone'), in Mutter's 'Arch./ 1819, 

 p. 292 ; E. v. Bibra, 'Chemische Untcrsuchungen lib. die 

 Knochen und Zahne des Menschen und der YVirbelthiere/ 

 (' Chemical Researches on the Bones and Teeth of Man and 

 the Vertebrata') ; Schweinfurt, 1 844 ; Yotsch, ' Die Heilung 

 der Knochenbriiche per primam intentionem,' ('Union of 

 Fractures, &c.') ; Heidelberg, 1817; Kolliker, ' Ueber 



