[199] 



Qn fmwQ tbe aniline 2)^C6. 



THE British Medical Journal for March lo, contains an article 

 by Mr. H. A. Reeves, F.R.C.S.E., on fixing the aniline 

 dyes in microscopical staining ; and though in the article 

 mention is only made of anatomical and pathological prepara- 

 tions, we think it likely that the method described will be found 

 capable of a much wider application. Mr. Reeves states, that for 

 the last eighteen months he has been systematically experimenting 

 with a vast number of chemicals, singly, and combined in various 

 proportions, with a view to finding a suitable mordant, and the 

 result has satisfied him that the dyes may be fixed by plac- 

 ing the stained sections first, for from three to five minutes in a 

 mixture of equal parts of a saturated aqueous solution of tannin, 

 to which a little carbolic acid has been added, and distilled water. 

 Then wash in water, and transfer for the same length of time to a 

 mixture of tartar emetic and water, a few drops of a saturated solu- 

 tion of tartar emetic being added to a watch-glass full of water. 

 The sections should then be again washed ; placed for five or ten 

 minutes in strong methylated spirit, drained of superfluous spirit, 

 and mounted in Canada Balsam or Dammar, after having been 

 passed through oil of cajuput, cloves, juniper, aniseed, or tur- 

 pentine. The tannin and antimony solutions should be filtered 

 into the watch-glass before using, as also the dyes. Preparations 

 hardened in Miiller's fluid or spirit answer best, but chromic acid 

 hardened specimens can be used, if, previously to staining, they be 

 soaked for twenty or thirty minutes in methylated spirit. 



Other agents will partially or completely fix some of the ani- 

 lines ; such as arsenious, acetic, hydrochloric, and carbolic acids, 

 hypophosite of soda, stannate of soda, and silicate of soda, to 

 which a little hydrochloric acid has been added, and these should 

 be tried in special cases. A saturated aqueous solution of acetate 

 of potash fixes roseine, saffranine, and soluble blue, and partly 

 fixes fuchsin. 



Mr. Reeves also draws attention to two or three new or little- 

 known dyes, which he thinks might be used with advantage in 

 microscopy. The new dyes are Phloxine and Erythrosine. They 



