124 THE CONNECTIVE TISSUES, BY A. ROLLETT. 



When the view already mentioned, which led to the terms cor- 

 puscles and chalicophorous canaliculi being employed to indicate 

 the lacunae and canaliculi, had fallen into disrepute because it 

 had been shown by Lessing* that their dark appearance in dry- 

 bones on examination with transmitted light, and their white ap- 

 pearance with direct illumination, was to be ascribed to their 

 containing air, and observers were therefore inclined to regard 

 them as constituting a lacunar system, which in the living bones 

 was filled with fluid ; the researches of Yirchowf* again brought 

 into prominence the view that these structures were corpuscles 

 capable of being isolated. Virchow effected the isolation of 

 the bone corpuscles by macerating the lamellae in hydrochloric 

 acid ; but the same result can, according to Forster,J be obtained 

 by means of nitric acid. A still better mode of procedure is 

 to boil the bones deprived of lime with hydrochloric acid under 

 pressure. In this mode F. Hoppe isolated very beautifully 

 the bone corpuscles from the cutaneous plates of the sturgeon. 

 Virchow in the first instance believed that, in accordance with 

 his views on the nature of the connective tissues, he had in 

 these corpuscles isolated the proper cells of bone ; and their 

 isolability in such experiments was supposed to depend upon 

 the great resistance of an imaginary cell membrane to the 

 action of hydrochloric acid. We now know, however, that the 

 isolation of these structures can be effected, not only in dry 

 bones, as Virchow already knew, but also in bones which have 

 been long macerated or treated with strong alkalies,|| and there- 

 fore under conditions which would destroy all soft tissues; 

 hence we must admit, that in these experiments a peculiar 

 dense and resistant layer of the matrix of the bone itself is 



* Ueber ein plasmatisches Gefassystem in alien Geweben insbcsonders 

 in Knochen und Zdhnen, "On the presence of a Plasmattc Vascular 

 System in all forms of Tissue, but especially in the Bones and Teeth." 

 Hamburg, 1846. 



f Wiirzburger Verhandlungen, Band i., 1850, p. 193. 



| Archivfur Pathologische Anatomie, Band xviii., p. 70. 



Idem, Band v., pp. 179 and 181. 



|| E. Neumann, Beitrage zur Kenntniss des normalen Zahnbein 

 und Knochengewebes, " Essays on healthy Dental and Osseous Tissue." 

 Konigsberg, 1863, p. 42. 



