RANVIER'S NEUTRAL CARMINE. 105 



o be carefully avoided until staining is accomplished ; alcohol should not 

 even be used for wetting the section knife. 



Objects stained in strong solutions must be washed out in water, but 

 not too long, as the stain will wash out too much in time. The colour may 

 be "set," when required, by treatment with alcohol or a little acetic acid. 

 Objects stained in the dilute sections recommended will not require washing 

 out. Overstains may be reduced and made sharp by treatment with HC1 

 alcohol, as for borax-carmine. The stain is permanent in balsam, or iir 

 aqueous media containing a little (about 1 per cent.) of acetic or (better) 

 formic acid. 



164. KANVIEE'S "Neutral" Ammonia-Carmine (kindly communi- 

 cated by Dr. MALASSEZ, see Traite des Methodes techniques, &c., of Lee and 

 Henneguy, p. 82). Make a simple solution of carmine in water with a 

 slight excess of ammonia, and expose it to the air in a deep crystallising dish 

 until it is entirely dried up. It should be allowed to putrefy if possible. 

 Dissolve the dry deposit in pure water, and filter. 



165. Other Ammonia-Carmines. BEALE, How to Work, &c.,4th ed., 

 pp. 109, 304. BETZ, Arch. mik. Anat., ix, 1873, p. 112 ; GIEEKE, Zeit. f. 

 wiss. Mik., i, 1884, p. 76 (these two are methods for the preparation of 

 putrefied carmine, and are highly recommendable, but excessively lengthy). 

 HUXLEY and MAETIN, Pract. Elemen. Biol., p. 268. FEET, Le Microscope, 

 p. 167. HOYEE, Biol. Centralb., ii, 1882, p. 17. BOHN (not " BOHM "), 

 Arch. Anat. u. Phys. (Anat. Abth.), 1882, p. 4. HEIDENHAIN, Arch. f. mik, 

 Anat., vi, 1870, p. 402. 



166. Lithium-Carmine (ORTH, Berlin, klin. Wochenschr., 28, 1883, 

 p. 421). Two parts and a half of carmine are dissolved in ninety-seven 

 parts and a half of saturated solution of carbonate of lithium. 



The solution stains with equal readiness alcohol objects and chromic 

 objects. The stain is diffuse, but becomes restricted to nuclei on treatment 

 with hydrochloric acid (1 per cent, in 70 per cent, alcohol). The colour is 

 permanent both in balsam and glycerin. The only advantage of this solu- 

 tion is the readiness with which it stains tissues that refuse to stain in any 

 other medium. 



HAUG (Zeit.f. wiss. Mik., vii, 1, 1890, p. 47, and viii, 1, 1891, p. 52) has 

 three elaborate modifications that appear to me wild and uncalled for. 



j. Other Aqueous Carmines (Acid and Alkaline). 



167. Schweigger-Seidel's Acid Carmine (EANVIEE, Traite, p. 99). 

 Hamann's Acid Carmine (Intern. Mon. f. Anat. u. Hist., i, 5, 1884 j 

 Zeit. f. wiss. Mik., ii, 1885, p. 87). Neutral Borax- Carmine (Nizi T 

 FOBOW, Zeit.f. wiss. Mik., v, 3, 1888, p. 337). Neutral Borax-Carmine 

 (G-EENACHEE, Arch. f. mik. Anat., xvi, 1879, p. 466). HAUG'S modifications 

 of this, Zeit. f. wiss. Mik., vii, 2, 1890, p. 151, and viii, 1, 1891, p. 52. 

 "Woodward's Borax-Carmine (see Monthly Micr. Journ.,\\\, 1872, p. 38 ; 

 Am. Quart. Micr. Journ., i, 1879, p. 220 ; Journ. Roy. Mic. Soc., ii, p. 613) k 



