1414 Journal of Applied Microscopy 



CYTOLOGY, EMBRYOLOGY, 



AND 



MICROSCOPICAL METHODS. 



Agnes M. Claypole, Cornell University. 



Separates of papers and books on animal biology should be sent for review to 



Agnes M. Claypole, 125 N. Marengo avenue, 



Pasadena, Cal. 



CURRENT LITERATURE. 



Rothig. P. "Ueber einen neuen Farbstoff Kresofuchsin is an amorphous powder 

 Namens Kresofuchsin." Arch. f. Mikrosk. of grey blue color, it is easily soluble 

 Anat. Bd. s6, igoo. . ^••11.1 i-i 



in acetic acid and aceton, less readily 



but quite soluble in alcohol, only very slightly so in water. It is insoluble in 

 benzol. The alcoholic solution appears blue, the aqueous red. The former 

 stains elastic tissue deep blue, mucous, cartilaginous and horny substances red- 

 dish ; while the latter does not stain elastic tissue at all, but mucous, cartilage, 

 keratin, as well as nuclei, are colored deep red. The author suggests that the 

 stain contains two components of which one has an affinity for chromatin, mucin, 

 chondrin, and keratin, while the other takes to elastin. To determine the stain- 

 ing of tissues by this new agent, the investigation was made on material fixed 

 24 hours in a weak alcoholic sublimate solution ( 9 parts of concentrated 

 aqueous sublimate solution to 1 part 05 per cent, alcohol), then washed with 

 alcohols of increasing strength through the iodized alcohol till free from subli- 

 mate, and finally embedded in xylol-paraffin. The sections were fastened to 

 slides by weak alcohol and placed successively in xylol, absolute alcohol,' and 

 then the stain. A simple alcoholic solution gives unsatisfactory results : the 

 addition of hydrochloric acid gives better differentiation. Results are still better if 

 a small quantity of picric acid is added as well as the hydrochloric acid. These 

 substances are combined as follows : 0.5 gram of kresofuchsin in 1UI> c.c. of 95 

 per cent, alcohol, and o c.c. hydrochloric acid. With 40 c.c. of this solution, in 

 which the particles of stain are not dissolved, are mixed 32 drops of a picric 

 acid solution, consisting of 1 part concentrated picric acid solu- 

 tion and 2 parts water. The sections remain 2 hours or longer in the stain ; 24 

 hours do no harm. Then into 95 per cent, alcohol, in which they must stay for 

 a long time. From that into absolute alcohol until the remaining color is 

 removed and the sections are dehydrated, thence into xylol and balsam. The 

 best counterstain is orange G, For a final nuclear stain carmin is used ; if 

 haematoxylin is used it is necessary to overstain with it owing to the picric acid 

 constituent of the kresofuchsin solution. After staining for an hour the sections 

 are washed with water, treated with alcohol of increasing concentration and 

 stained several hours with kresofuchsin. The violet color of the nuclei passes 

 into a dark brown to brown red. The author has also sought to stain unfixed 

 material with the new stain. He obtained the same results as in sublimate fixed 

 tissues. E. J. c. 



