174 



Journal of Applied Microscopy. 



man corpuscles is easily made. The pu- 

 pils pass rapidly to the microscopes, re- 

 maining long enough to obtain informa- 

 tion sufficient to answer the follow- 

 ing questions found in the Laboratory 

 Manual. 



Microscopic Study of Human Corpus- 

 cles. 



1. What is the form of the corpuscles 

 in human blood? (Examine several 

 corpuscles before deciding.) 



2. In what respects do these corpuscles 

 differ from those found in frog's blood? 



Ten to fifteen minutes will be required 

 for this work. Before the close of the 

 hour the answers to the questions are re- 

 viewed, corrections being made in the 

 note-books by each pupil. 



Since but a small number can work at 

 the microscopes at one time, certain de- 

 finite work must be outlined for the rest 

 of the class that the teacher may give 

 his full attention to directing the mi- 

 croscopic work. Diagrams may be drawn 

 from the board in the note-book and la- 

 beled; charts may be copied; dictation 

 exercises or review outlines may be 

 taken down. 



An experience of several years has de- 

 monstrated that a large amount of suc- 

 cessful microscopic work can be accom- 

 plished in large classes, even in a short 

 recitation period, by careful planning on 

 the part of the teacher. 



James E. Peabody. 

 The High School for Boys and Girls, 



Third Ave and 157th St., New York 



City. 



Picro-Carmine and-Alum-Carmine 

 as Counter Stains. 



The following paper, presented before 

 the American Microscopical Society dur- 

 ing its recent meeting at Syracuse, with 

 slides illustrating the effectiveness and 

 superiority of the stains, is here published 

 at the request of the editor. 



The paper embodies the results of ex- 

 periments with picro-carmine and alum- 

 carmine* as counter stains, as developed 

 incidentally during the year in the his- 

 tologic laboratory at Cornell University. 



The excellence of picro-carmine was 

 first noticed last November, in staining 

 developing bone which had been decal- 

 cified. Picro-fuchsint was being regular- 

 ly used as a counter stain with hema- 



•For literature, see Lee's Vade Mecum, 

 and the most recent publication on the 

 subject by P. Mayer, Ueber Picro-carmine. 

 Zeitschrlft fer Wissenschaftlichen Micro- 

 skopie. Vol. XIV., pt. I., p. 18. 



tSee Freeborn, Trans. N. Y. Path. Soc, 

 1893, p. 73. Also, Studies from the Dept. of 

 Path, of the College of Physicians and Sur- 

 geons, Columbia University, N. Y. 1894-'95. 



toxylin. Merely for the experiment, 

 picro-carmine was used on one section 

 and left nearly two hours. Much to our 

 surprise and pleasure we found, instead 

 of our section being ruined, that 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 differentiation secured as illustrated in 

 the slides presented at the Microscopical 

 Society. 



The embryonal cartilage cells are bet- 

 ter 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 calcify- 

 ing cartilage that this superior differen- 

 tiation is noticed. The vertically ar- 

 ranged rows of cartilage cells have lost 

 their horizontal septa, but the vertical 

 septa are pronounced and project into 

 the primary marrow cavity as irregular 

 trabeculae of calcified cartilage. The 

 osteoblasts have enveloped these trabe- 

 culae with a covering of true bone and 

 at the same time the cartilaginous trabe- 

 culae within are being absorbed and true 

 bone substituted. 



This true bone, with the picro-carmine, 

 has taken a red which is brilliant in 

 comparison with the picro-fuchsin; and 

 the gradually diminishing and disap- 

 pearing cartilage which, with picro-fuch- 

 sin, has taken a stain not dintinguishable 

 from that of the cells of the true 

 bone is, with picro-carmine, beautifully 

 differentiated by a clear pronounced blue, 

 showing the alkalinity of the picro- 

 carmine. 



This tendency on the part of picro-car- 

 mine to bring out the hematoxylin as a 

 blue, while the acid picro-fuchsin fades 

 it, is very noticeable in the tonsil of dog 

 which was next submitted. In the mu- 

 cous cells near this gland the nuclei, re- 

 moved as far as possible from the lumen, 

 are brought out with unequalled clear- 

 ness. The structure of the blood vessels 

 is also brought out with great distinct- 

 ness, and the differentiation throughout 

 is very marked. 



Quite as striking a contrast between 

 picro-carmine and picro-fuchsin is no- 

 ticed in a section of the pyloric stomach 

 of a kitten. The stain with picro-car- 

 mine is not only more differential, but 

 the unstriped muscle of the stomach and 

 blood vessels is brought out much better 

 by the picro-carmine. 



During the summer picro-carmine was 

 tried with good results on the fallopian 

 tube of a mare. It has been used with 

 greatest success on tissues which pre- 

 sent a mucous surface, and while these 



