STRUCTURE OF OSSEOUS TISSUE. 117 



various thickness is left surrounding them, or the spaces may 

 be of relatively small size, in which case the surrounding sub- 

 stance is split by parallel, straight, or annular lines, into a series 

 of ribbon-like laminae, to which the corpuscles are attached 

 with tolerable regularity in successive rows. 



The dark markings caused by the corpuscles appear equally 

 delicately white and lustrous, if the section is examined by 

 direct instead of transmitted light. 



The bone corpuscles and canaliculi were first described by 

 Purkinje and Deutsch.* J. Miillerf- first pointed out the 

 connection existing between the two, and at the same time 

 expressed his opinion that the entire system of these corpuscles 

 and canaliculi was filled with lime, on which account they 

 were for some time described as corpuscula and canaliculi 

 chalicophori. 



The matrix of bone which, as follows from what has been 

 stated above, frequently exhibits a well - marked lamellar 

 structure, is brittle and friable, and confers upon it its peculiar 

 consistence. If a portion of bone be treated with diluted acids, 

 which expel the carbonic acid from its combination with lime, 

 and render the latter as well as the phosphate of lime soluble, 

 the bone becomes soft, whilst it preserves its original form. 

 The softened remains of the matrix represent its organic basis, 

 the so-called bone cartilage or ossein; and this, on being boiled 

 with water, is converted into gelatine, though more slowly than 

 collagen is obtained from connective tissue. J 



Bones thus softened in acids are well adapted for the prepara- 

 tion of fine sections for the microscope, and present the same 

 appearances as those already described, except that the bone 

 corpuscles now appear by transmitted light more transparent 

 than the matrix. 



If lime-containing bones are boiled for a long time, the 

 organic material is in great part or completely removed, and 

 the earthy matters of the bone remain behind, still preserving 

 their original form. Chemical examination shows that these 



* De Tenitiori Ossium Structura, 1834. 



t Miiller's Archiv, 1836, p. 6. 



t Kiihne, Physiologische Chemie, 1866, p. 391. 



