THE LAC^HRYMAL GLAND 223 



Formalin 40 per cent, 1 i)ar( . . . 



K,Cr,0;3per eent A<i. s,,!., 3 parts ""^ P^''^' 



Sat. sol. of HgCU in 95 jier cent alcohol one part 



Distilled water two parts 



Fixative was made at time of using. Small pieces of tissue were 

 placed in it for about three hours to insure proper fixation. 



(c) Formalin bichromate sublimate method — Fixed for twenty- 

 four hours in the following solution: neutral formalin 10 cc. and 

 Zenker's solution without the acetic acid 90 cc. 



(d) 70 per cent alcohol. 



Tissues fixed in (a), (b), (c), and (d) were stained in muchae- 

 matein, mucicarmin, iron haematoxylin counterstained with 

 mucicarmin, Bensley's Cll) neutral gentian, Bensley's ('11) 

 safranin-acid violet, and copper chrome haematoxylin used 

 singly or with mucicarmin (see Stains). 



(e) Acetic osmic bichromate method (Bensle}^ '11, p. 308). 

 V. Staining methods. 



1. Muchaematein (Bensley '03) — haematein Igram, aluminum 

 chloride 0.5 gram, 70 per cent alcohol 100 cc. Haematein and 

 chloride rubbed together, dissolved in alcohol and allowed to 

 stand for a week to insure ripeness. (If alcohol is made by 

 diluting absolute alcohol with tap water stain can be used im- 

 mediately.) Sections were flooded with stain, placed on stage 

 under microscope and watched until deep color, then rapidly 

 washed in 95 per cent alcohol, dehydrated, cleared and mounted 

 in xylol balsam. The granules in the intercalary duct stained 

 definitely and intensely blue. 



2. Mucicarmin — 1 gram of carmin and 0.5 gram aluminum 

 chloride ground in porcelain evaporating dish after which small 

 amount of w^ater was added; heated over a Bunsen burner, 

 grinding process continued during heating, till mass became very 

 dark red (almost black) then dissolved in absolute alcohol and 

 filtered. Stain must be used while fresh. Technique same as 

 V, 1. 



3. Iron haematoxylin. 



4. Iron haematoxylin counterstained with mucicarmin. 



5. Copper chrome haematoxylin (Bensley '11, p. 310). 



