30 DEUTSCH AND MIESCHER 



unassisted eye, the slightest irritation with a probe will 

 cause them to bleed freely, and heat applied to a section of a 

 recent bone, will develop the fatty or oily matter even in the 

 compact portion. From the complexity of their organization, 

 and the frequency and importance of their diseases, bones demand 

 from the student, more earnest study, at least in regard to 

 their general anatomy than is usually given. 

 Deutsch,* under the direction of Purkinje, and Miescherf of 

 Berlin whose investigations were made prior to those of Gerdy, 

 have arrived at nearly similar conclusions in regard to the 

 structure of bone. In very thin transverse sections of long 

 bones, which had been macerated in dilute acid, they disco- 

 vered the circular orifices of the longitudinal canals in the com- 

 pact portions of the bone ; and in thin longitudinal sections 

 the canals were seen divided in the direction of their length. (See 

 Figs. 4 and 5.) The canals, according to these observers, com- 

 municate here and there with each other, and constitute the 

 longitudinal and transverse canals of Havers, and which are 

 described by Lewenhceck, as his third and fourth kinds of 



pores. 



Fig. 4.J 



These canals are rilled with yellowish medullary or adipose 

 matter, in which according to Miescher, are seen many minute 

 capillary vessels, when successfully injected after the method 

 of Krause. 



* De pentiori ossium stractura observations. Vratislavise, 1834. 



f De ossium genesi, structura et vita. Berolini, 1836. 



$ Fig. 4. Is a longitudinal section of a long bone, magnified one hundred 

 times, a. One of the longitudinal canals not fully exposed, b. b. Longitudinal 

 canals, c. c. These canals partially cut across, so as to exhibit the concentric 

 lamellae which surround each one. d. d. Transverse canals joining the others. 

 The straight lines near the margins of the cut, are the lamellae divided in the 

 direction of their length, which surround the canals. The spots seen are the 

 bony corpuscles, not sufficiently magnified to render them distinct. 



