AND HOW TO USE IT. 41 



solution, dilute it with 6 times its volume of water, then immerse 

 the preparations from 5 to 20 minutes, wash them out and clarify 

 in oil of cloves, or glycerine. The peculiarity of this material 

 is that it never affects the nucleus, but only the cell-body. More 

 frequently, however, it is the intercellular substance that is coloured 

 blue. 



Sulphindigotate of Soda and Carmine.— Stain as usual in 

 carmine, wash in rectified or methylated spirit, remove the 

 sections from the spirit into 5 parts methylated spirit, and add to 

 it I part of pure hydrochloric acid for about 10 minutes. Wash in 

 strong rectified or methylated spirit, and allow the sections to 

 remain in it for an hour or two, so that all trace of the acid may 

 be removed. Transfer the sections into a large quantity (from 2 

 to 3 ounces) of the following for from 6 — 8 hours : — Add 2 or 3 

 drops of a saturated solution of sulphindigotate of soda to i 

 ounce of methylated spirit. This solution should be made as 

 required, from time to time. Mount in Canada balsam or 

 dammar (Cole, vol. i.). 



Ribesin and Eosin.— For the method of making the first 

 stain see the additional recipes in our next. A double stain 

 may be at once obtained by adding a little eosin to the above 

 ribesin solution, and filtering. (The filtrate should be 

 cherry red.) Wash the sections with absolute alcohol, charged 

 with a little eosin, and clear with clove oil also charged with 

 eosin. The blue of the ribesin remains fixed in the nuclei. In 

 many respects this is a better double stain than Renaut's 

 Haematoxylin eosin. 



Treble-Staining. — Gibbes recommends (i) picro-carmine, (2) 

 rosein, and (3) iodine green. Stain the sections well in number 

 I, and soak them in acidulated water. Immerse the sections for 

 2 — 3 minutes in a few drops of a solution of rosanilin hydrochlor- 

 ate diluted with spirit, then remove to methylated spirit, and wash 

 off the excess of the colouring matter. Place in a dilute solution of 

 iodine green. Coming from spirit the sections will float on the 

 top of the watery solution, and this in many cases, when the green 

 stain is not required very deep, is sufficient. If a deep stain is 

 required immerse them altogether, and let them remain a minute 



