442 RICHARD EVANS. 



washed over with spirit and acid, being snbseqnently immersed 

 for some time in 90 per cent, alcohol. They were afterwards 

 placed in a weak solution of bleu de Lyon dissolved in alcohol 

 of the same strength, and were left in it for from ten to fifteen 

 minutes. The sections were subsequently washed with 90 per 

 cent, alcohol in order to take away the excess of bleu de Lyon, 

 which sometimes tended to mask the carmine. The differen- 

 tiation went on slowly, and could be watched, therefore, under 

 the microscope. When this washing process was complete they 

 were washed with absolute alcohol and subsequently with pure 

 xylol, and finally mounted in Canada balsam dissolved in 

 xylol. 



{b) Carraalum and Bleu de Lyon. — Sections of material 

 preserved in Flemming's fluid and also in Hermann^s fluid 

 were stained for twenty-four hours in carmalum, and were 

 then treated in the same way as the sections stained in borax 

 carmine, omitting, however, the washing with acid, and to 

 some extent varying the time as well as using stronger solu- 

 tion of bleu de Lyon. 



(c) Hsematoxylin and Fuchsin S. — The sections were 

 first stained by Heidenhain's method in iron alum and hsema- 

 toxylin. After differentiation in the alum solution they were 

 washed in a current of water for twenty minutes, treated with 

 absolute alcohol, and stained for nearly a minute in a saturated 

 solution of fuchsin S in absolute alcohol, and then mounted in 

 the usual way. 



{d) Saf ranin and Gentian Violet. — The sections were 

 stained in safranin for twenty-four to thirty-six hours. They 

 were then washed with spirit very slightly acidulated, and 

 subsequently with absolute alcohol. Afterwards they were 

 stained with gentian violet for from three to five minutes, 

 when they were washed with absolute alcohol and placed in a 

 solution of potassium iodide and iodine dissolved in water 

 until they were quite black, the time required for this purpose 

 being usually four or five hours. They were then slowly 

 differentiated in absolute alcohol aud mounted in the usual 

 way. 



