1885.] 



MICROSCOPICAL JOURNAL. 



93 



fluid require treatment with hydro- 

 chloric acid to bring out the nu- 

 clei ; otherwise thev arc diftlisclv 

 stained. 



(We do not regard the last two com- 

 pounds as valuable additions to our 

 list.) 



37. Schneider. Ueber tlie Anflosung 

 der Eier und Spermatozoen in 

 den Geschlechtsorganen. Zool. 

 Anz. 1880. Jan. 12th and 

 May 24th. 

 Schneider boils 45 "d acetic acid 

 adds as much carmine as it 

 Stains with this 

 r dilutes it to 



and 



will dissolve. 

 lution direct 

 per cent. 



P. Mayer 



so- 

 one 



28 



der 



39. 



Ueber die in 



Zoologischen Station zu Nea- 



pel gebrauchlichen Methoden 



zur mikroskopischen Unter- 



suchung. Mitth. a. d. Zool. 



Stat. Neapel. ii, 1-27. 



Coarsely powdered cochineal is 



left covered by 70% alcohol for sevei-al 



days. The tincture is not a strong 



dj'e, but selective. 



Czokor. Die Cochenille-Carmin- 

 losung. Arch. Mikr. Anat., 

 xviii, p. 712. 

 • Cochineal 7 gi'ms., roasted alum 7 

 grms., rubbed together in a mortar. 

 Add 700 c. c. distilled water and boil 

 till reduced to 400 c. c. Cool, add a 

 trace of carbolic acid as presei'vative 

 and filter till clear. The liquid is 

 violet, will keep six months, when it 

 may require additional carbolic acid 

 and filtration. For tissues generally, 

 however hardened. Excellent for the 

 nuclei, which takes the color of hte- 

 matoxylon, while the other constitu- 

 ents are stained various shades of 

 cherry to dark red. (The best sub- 

 stitute for ammoniacal carmine, and 

 to be preferred, for staining nuclei. 

 It is better than the anilins, and may 

 be used for ordinary purposes in the 

 place of any other dye, especially 

 haematoxylon. It is parti c ularly 

 adapted for beginners, and for labora- 

 tory courses for instruction. For 

 large nei"ves it is to be recommended 



only for staining nuclei. Nerve cells 

 and their prolongations are not well 

 shown. In summer, unfortunatelv. 

 a precipitate often appears. I filter 

 just before using, usually. 



30. Hoyer. Beitrage zur histologi- 



schen l^'echnik. Biol. Cen- 

 tralbl. ii, p. 17. 



Hoyer thinks it very necessary to 

 have a dry preparation of ammonia- 

 cal carmine, that may be applied in 

 definite proportions and kept on hand 

 without deterioration. For such a 

 material he takes i grm. carmine and 

 1-2 c. c. strong ammonia and 6-8 c. c. 

 distilled water and warms till the ex- 

 cess of ammonia evajDorates. It will 

 be finished when large bubbles no 

 longer appear on boiling, and the 

 liquid becomes a clear red. Cool 

 and filter, the result will be a neutral 

 solution, which is treated with one or 

 two per cent, of chloral hydrate and 

 may be kept and applied like ordi- 

 nary ammoniacal carmine. On add- 

 ing 4 to 6 volumes of strong alcohol 

 a copious, bright-red precipitate falls, 

 which is to be filtered, washed and 

 dried. By mixing it with alcohol 

 and a little glycerin and chloral hy- 

 drate the alcohol will be changed to 

 a paste that is also very permanent. 

 Both preparations consist of perfectl}- 

 neutral ammoniacal carmine. They 

 are strong dyes and very convenient. 



(The above compounds made by 

 Hoyer himself work v^^ell, and some 

 of his preparations of the spinal mar- 

 row sent to Privy Councillor Heid- 

 enhain leave hardly anything to de- 

 sire. But such as are sold in the 

 market, though made by Hoyer's di- 

 rections, are far inferior to ordinary 

 ammoniacal carmine). 



31. Maschke. 1882. 



Has experimented much with car- 

 mine, and has made dry sodium car- 

 minate. I have used this, and find 

 that by a small addition of ammonia- 

 cal salt (as ammonium bicarbonate 

 2-5 drops in a watch-glass) it is of 

 great service. 



It is to be used exactly like ammo- 



