ON THE STRUCTURE OF HYALINE CARTILAGE. 5 



arvangementj in the substance of cartilage as a settled 

 question. 



This is not intended to discourage other investigators, who 

 may probably have more frequent success, but to suggest the 

 advisability of the attention of histologists being directed to 

 the study of the conditions of success of a process Avhich 

 produces so important results. 



One of the most successful series of preparations was ob- 

 tained from the head of a frog's femur, Avhich was operated 

 on after the animal had been left dead twenty hours at the 

 temjDerature of a room in London in the end of May. A 

 number of vertical incisions were made through the cartilage 

 before the head of the bone was'put into the solution ; but as 

 this was amongst the last experiments that were made, it is 

 at present uncertain whether the time that had elapsed after 

 death and the incisions had anything to do with the 

 success. 



The results obtained by subjecting cartilage to the action 

 of nitrate of silver are now to be described. 



The author believes them to be mostly, if not entirely, 

 new. The success Avhich has been obtained is due not so 

 much to any special merit in the methods employed as to 

 the number of preparations that were made. The light that 

 was thrown on the structure of cartilage by potash prepara- 

 tions stimulated him to a more persistent application of silver 

 than he Avould probably have otherwise undertaken. The 

 appearances seen will first be described, and an attempt will 

 afterwards be made to explain them in conjunction with 

 those obtained by other methods. 



One of the commonest effects of the action of nitrate of 

 silver on cartilage is a uniform dark-brow^n staining of the 

 ground-substance. A section so acted on shows a framework 

 of dark substance enclosing in its meshes circular or oval 

 colourless spaces. This appearance is figured by Ranvierin 

 the part that has appeared of his ' Traite technique d'Histo- 

 logie,' p. 283, and need not, therefore, be repeated here. To 

 the best of my knowledge that is the only effect produced by 

 nitrate of silver that has hitherto been noticed. 



The cells on the surface of articular cartilage may be 

 demonstrated in the following manner : — The sections are 

 made from the newdy disarticulated head of the frog's femur, 

 one surface of each section consisting of the free surface of 

 the cartilage, and are placed instantly] in a half-per-cent. 

 solution of nitrate of silver. 



As soon as all the available surface has been so removed, 

 the sections are transferred from the silver solution to a half* 



