580 METHODS AND FORMULAS MS 33.1 



33.1 del Rio-Hortega 1917b 21344, 16:367 



preparation: To 100 MS 33.1 del Rio-Hortega 1917a add 1 pyridine. 



33.1 del Rio-Hortega 1919 3231, 9:68 



preparation: To 50 ml. sat. aq. sol. {circ. 1.5%) lithium carbonate add 12 10% silver 

 nitrate. Allow ppt. to settle and wash by decantation. Add just enough ammonia to 

 dissolve ppt. Dilute to 100. 



33.1 del Rio-Hortega 1921 3232, 21:14 



preparation: To 50 5% sodium carbonate add 12 10% silver nitrate. Leave ppt. settle 

 and wash by decantation. Add just enough ammonia to dissolve ppt. Dilute to 100. 



33.1 del Rio-Hortega 1923 21344, 21 :95 



preparation: To 50 5% sodium carbonate add 12.5 10% silver nitrate. Add just 

 enough ammonia to dissolve ppt. Dilute to 100 ml. 



33.1 del Rio-Hortega 1927 3232, 27:199 



preparation: To 80 5% sodium carbonate add 20 10% silver nitrate. Add just enough 

 ammonia to dissolve ppt. 



33.1 del Rio-Hortega 1932 test. 1933 Cajal and de Castro 



Cajal and de Castro 1933, 263 

 preparation: To 100 MS 33.1 del Rio-Hortega 1917 add 1 pyridine. 



33.1 Robb-Smith 1937 11431,45:312 



preparation: To 28.5 10% silver nitrate add 0.6 10% sodium hydroxide. Add just 

 enough ammonia to redissolve precipitate and dilute to 100. 



33.1 Rogers 1931 763, 49:81 



preparation: To 48 20% silver nitrate add just enough ammonia to redissolve the ppt. 



first formed. Then add 0.5 ammonia and 48 water, 

 note: Debauche 1939 (20540b, 14:121) differs only in using twice as much 10% silver 

 nitrate. 



33.1 Romanes 1946 11025,80:205 



preparation: To 2 5% silver nitrate add just enough ammonia to redissolve the ppt. 

 first formed. Dilute to 100. To this add 33 1% gelatin, 2.5 0.5% tannic acid, and 1 

 pyridine. 



33.1 Steiner 1937 11284, 23:293 



preparation of stock solutions: I. Dissolve 1 silver nitrate in 20 water. Add am- 

 monia until ppt. first formed is not quite dissolved. Dilute to 100. II. Dissolve 0.2 

 silver nitrate in 100 boiling water. Add 0.165 sodium potassium tartrate and boil 

 till ppt. turns grey. Filter hot. III. 25% gum arable. 

 WORKING solution: stock I 40, stock II 60, stock III 4 



33.1 Wallert 1936 4285a, 12 :254 



preparation: To 100 10% silver nitrate add 1.5 40% sodium hydroxide. Add just 

 enough ammonia to dissolve ppt. 



33.1 Weber 1944 4285a, 21 :45 



formula: To 25 10% silver nitrate add not quite enough ammonia to redissolve ppt. 

 first formed. Dilute to 100. 



33.1 Weil and Davenport 1933 21458, 14:95 



preparation: To 40 ammonia add just enough 10%, silver nitrate (about 60) to produce 

 a permanent opalescence. 



33.1 Wolff 1905 766, 26:135 



preparation: To 100 10% silver nitrate add 40% sodium hydroxide until no further 

 ppt. is produced. Then add just enough ammonia to dissolve ppt. 



33.1 Zettnov 1891 23684,11:689 



preparation: To 100 0.4% silver nitrate add triethanolamine until ppt. first formed is 



just redissolved. 

 note: Craigie 1928 (3566, 9:55) is identical. 



