2(\ MANUAL OF HISTOLOGY. 



of silver, and, half an hour afterward, immerses it in water 

 acidulated with acetic acid ; after a day or two it is found to 

 have a glutinous appearance. The lamellae are then easily 

 stripped off, and in the middle portions, the corneal corpuscles 

 assume a purplish-brown color while their nuclei are uncol- 

 ored. The outlines of the lymphatic channels are also sharply 



Picro-hcematoxylin and eosine (triple-staining}. Wendt 

 has described a method of double-staining by picric acid and 

 liMMiiatoxylin. Only the very thinnest sections, however, give 

 satisfactory results. A strong solution of hsematoxylin is first 

 employed. In this the sections are allowed to remain about 

 twelve hours. After washing them in water, they are placed 

 in a saturated solution of picric acid and carefully watched. 

 They may be removed from time to time, examined with a low 

 power, and, when properly stained, put in alcohol and mount- 

 ed in Canada balsam with as little delay as possible. To ob- 

 tain triple-staining, eosine may be conveniently combined with 

 this picro-hfematoxylin method. To insure good results some 

 amount of practice is necessary. 



Double, triple, and quadruple staining. Dr. Gibbes re- 

 commends for double-staining, immersion first in picro-carmine 

 and then in logwood, or which is better, immersion first in a 

 spirituous solution of rosine or aniline violet, and then in an 

 aqueous solution of aniline blue or iodine green. ' In obtaining 

 more than two colors there is considerable difficulty. To ac- 

 complish it he -uses first the chloride of gold or picro-carmine 

 and then the spirituous and aqueous solutions of the ani- 

 lines. 



Staining with BismarJc brown. Make a watery solution of 

 gr. ij. j., heat and filter; soak in the solution about three 

 minutes ; set the color with acetic acid (glacial) 4 per cent, 

 for half a minute. After dehydrating with alcohol mount in 

 dammar varnish. Weigert prepares the Bismark brown as 

 follows : he makes a concentrated aqueous solution by boil- 

 ing in water, filtering from time to time. He also uses a weak 

 alcoholic solution, and combines with other colors. 



[To combine with eosine put the sections in a strong aqueous solution of 

 Bismark brown ; remove after about two minutes, set in weak acetic acid (four 

 per cent.), then place in a weak alcoholic or aqueous solution of eosine, and 

 then again in the acetic acid solution. T. E. S.] 



