AND HOW TO USE IT. 37 



are more required than in that of double-staining. The student 

 must not be discouraged by many failures, as from each there is 

 some new fact to be learned and noted, and in the application of 

 these to future experiments some brilliant results are sure to be 

 obtained. Let us give a hint before going further. Always note 

 the stain, strength of it, the time required for the operation, etc., 

 in a note-book, to be kept specially for that purpose, as it will be 

 found to be of great value. The following are some of the best 

 combinations : — 



I. — Picro-Carmine and Logwood. 



2. — Picro-Carmine and Safranine. 



3. — Picro-Carmine and Iodine Green. 



4. — Eosin and Aniline Blue. 



5. — Eosin and Logwood, 



6. — Eosin and Aniline Green, etc. 



7. — Aniline Rose and Aniline Green. 



8. — Bismarck Brown and Aniline Green. 



9. — Borax Carmine and Indigo Carmine. 

 10. — Methyl Green and Induline. 

 II. — Gold Chloride and AniUnes. 



1.— Picro-Carmine and Logwood. 



To Stain Sections of the Scalp, Skin, or Tongue. — Stain the 

 sections first in picro-carmine (10 drops to a watch-glass full of 

 distilled water), let the sections remain in this for from 20 to 30 

 minutes, then wash in water, place in distilled water acidulated 

 with I or 2 drops of acetic or picric acid. Leave for about one 

 hour ; then remove and place in dilute logwood stain (5 to 7 

 drops in a watch-glass of distilled water) ; do not let them stain too 

 deeply. When coloured as required, wash to remove the excess of 

 logwood, and mount in the ordinary way. This is very good 

 when used with fresh tissues, as mucous membranes ; it brings out 

 connective tissue corpuscles in the mesentery of a newt, and 

 shows non-striped muscular tissue very well. It is also useful in 

 bringing out delicate tissue in the tubuli seminiferi of the testis, 

 and showing the developing spermatozoa there. Developing 

 bone shows very well. 



