TAGUCHI'S INDIAN INK. 277 



The soluble Prussian blue, 476, injected without any 

 vehicle. It does not extravasate. 



508. Miiller's Berlin Blue (Arch. f. mile. 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. 



509. Mayer's Berlin Blue (Mitth. 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 (one to two days), and the blue dissolved in about 

 a litre of water. 



510. 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. 



511. 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. 



512. 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). 



