1899] MICROSCOPICAL JOURNAL. 367 



Picro-Carmine and Alum-Carmine as Counter Stains. 



B. D. MYERS. 



The excellence of picro-carmine was first noticed in 

 staining developing bone which had been decalcified. 

 Picro-fuchsin was being regularly used as a counter stain 

 with hematoxylin. Merely for the experiment picro-car- 

 mine was used on one section and left nearly two hours. 

 Much to our surprise and pleasure we found that,instead 

 of our section being ruined, we had secured an excellent 

 differentiation. This was not the first attempt with picro- 

 carmine, but always before, the time had been short, from 

 two to fifteen minutes. The advantage of the stain over 

 picro-fuchsin is noticeable in the superiority of differenti- 

 ation secured. 



The embryonal cartilage cells are better marked by the 

 hematoxylin and picro-carmine, for the alkaline picro- 

 carmine does not fade the hematoxylin as does the acid 

 picro-fuchsin. It is particularly in the zone of calcifying 

 cartilage that this superior differentiation is noticed. The 

 vertically arranged rows of cartilage cells have lost their 

 horizontal septa,but the vertical septa are pronounced and 

 project into the primary marrow cavity as irregular tra- 

 becule of calcified cartilage. The osteoblasts have envel- 

 oped these trabecule with a covering of true bone and at 

 the same time the cartilaginous trabecule within are be- 

 ing absorbed and true bone substituted. 



This true bone, with the picro-carmine, has taken a red 

 which is brilliant in comparison with picro-fuchsin ; and 

 the gradually diminishing and disappearing cartilage 

 which, with picro-fuchsin, has taken a stain not distin- 

 guishable from that of the cells of the true bone is, with 

 picro-carmine, beautifully differentiated by a clear pro- 

 nounced blue, showing the alkalinity of the picro-carmine. 

 This tendency on the part of picro-carmine to bring out 

 the hematoxylin as a blue, while the acid picro-fuchsin 



