236 



J. W. GROVES ON SECTIONS OF ANIMAL TISSUES. 



the structures, as well as in some cases of affording a wider surface 

 upon which to rest the razor. 



For cutting sections by hand the best embedding materials are : — 



1. Olive oil and white wax in equal parts ; or, 



2. Cacao butter. 



While in machines with hollow cylinders, or for use without any 

 machine, either of those or of elder pith or carrot may be employed. 



In cutting sections, by whatever process may be preferred, care 

 should be taken : — 



1st. That the razor is in perfect condition, and that its surface be 

 kept thoroughly moist with water if the freezing method be adopted, 

 or with spirit, when any other mode of hardening is used. 



2nd. That each section as it is cut be floated into water or 

 spirit, instead of allowing several sections to accumulate on the 

 razor, as they thereby get torn, or otherwise injured. 



The next subject we have to consider is that of stains, and how 

 to use them. 



The following is a table in which the most useful stains are classi- 

 fied according to their qualities, or method of use : — 



A. General stains. 



< 



B Selective 

 stains, "i 



( Carmine with excess of Ammonia. 



Eosin (Dreschfeld). 



Molybdate of Ammonia. (This requires the 

 ^ action of light.) 





. be 60 



Carmine (Beale's). 



Borax Carmine (Golding Bird). 



Logwood (Golding Bird). 

 <( Logwood Acid Soln. (Schafer). 



Indigo Carmine ^Tiersch . 



Anilin Blue (Heidenhain). 

 t Picric Acid. 

 ( Gold Chloride. 



Silver Nitrate. 



Osmic Acid. 



'S..6S 2 *o ! 



P3 .a = ^ Chloride of Palladium 



( Molybdate of Ammonia and Carmine. 



o 

 R 



< 



Picro Carmine (Schafer). 

 Chloride of Palladium and Carmine. 

 Carmine and Indigo Carmine. 

 Logwood and Anilin Blue. 

 Gold Chloride and Logwood. 

 Silver Nitrate and Logwood. 

 Silver Nitrate and Gold Chloride. 



