TAGTJCHI'S INDIAN INK. 235 



Aqueous Masses. 



480. Ranvier's Prussian Blue. Aqueous Mass (Traite, p. 120). 

 The soluble Prussian blue, 449, injected without any 



vehicle. It does not extravasate. 



481. Miiller's Berlin Blue (Arch.f. mik. Anat., 1865, p. 150). 

 Precipitate a concentrated solution of Berlin blue by means 

 of 90 per cent, alcohol. 



The precipitate is very finely divided ; the fluid is perfectly 

 neutral, and much easier to prepare than the formula of Beale. 



482. Mayer's Berlin Blue (Mirth, zool. Stat. Neapel, 1888, 

 p. 307). A solution of 10 c.c. of tincture of perchloride of 

 iron in 500 c.c. of water is added to a solution of 20 gr. of 

 yellow prussiate of potash in 500 c.c. of water, allowed to 

 stand for twelve hours, decanted, the deposit washed with 

 distilled water on a filter until the washings come through 

 dark blue (1 to 2 days), and the blue dissolved in about a 

 litre of water. 



483. Emery's Aqueous Carmine (Ibid., 1881, p. 21). To a 

 10 per cent, ammoniacal solution of carmine is added acetic 

 acid, with continual stirring, until the colour of the solution 

 changes to blood-red through incipient precipitation of the 

 carmine. The supernatant clear solution is poured off, and 

 injected cold without further preparation. The injected organs 

 are thrown at once into strong alcohol to fix the carmine. 

 For injection of Fishes. 



484. Letellier's Vanadate of Ammonia and Tannin (Journ. Roy. 

 Mic. Soc., 1889, p. 151). Vanadate of ammonia is soluble in 

 warm, and tannin in hot water. The two solutions are kept 

 apart until required for use, when they are mixed according 

 to the tint required. A black mass, very fine. The walls of 

 vessels are stained black by it. 



485. Taguchi's Indian Ink (Arch.f. mik. Anat., 1888, p. 565 ; 

 Zeit. f. wiss. Mik., 1888, p. 503). Chinese or (better) Japanese 

 ink well rubbed up on a hone until a fluid is obtained that does 

 not run when dropped on thin blotting-paper nor form a grey 

 ring round the drop. Inject until the preparation appears 

 quite black, and throw it into some hardening liquid (not 

 pure water). 



