1885.] 



MICROSCOPICAL JOURNAL. 



93 



fluid require treatment with hydro- 

 chloric acid to bring out the nu- 

 clei ; otherwise they are diHlisely 

 stained. 



(We do not regajrd the last two com- 

 pounds as valuable additions to our 

 list.) 



27. Schneider. Ueber die Anflosung 



der Eier und Spermatozoen in 



den Geschlechtsorganen. Zool. 



Anz. 1880, Jan. 12th and 



May 24th. 

 Schneider boils 45 "ii acetic acid 

 and adds as much carmine as it 

 will dissolve. Stains with this so- 

 lution direct or dilutes it to one 

 per cent. 



28. P. Mayer. Ueber die in der 



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 70/0 alcohol for several 



days. The tincture is not a strong 



dye, but selective. 



29. Czokor. Die Cochenille-Carmin- 



losung. Arch. Mikr. Anat., 



xviii, p. 712. 

 Cochineal 7 grms., roasted alum 7 

 grms., rubbed together in a mortar. 

 Add 700 c. c. distilled water and boil 

 till reduced to 40x3 c. c. Cool, add a 

 trace of carbolic acid as preservative 

 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 hae- 

 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 particularly 

 adapted for beginners,, and for labora- 

 tory courses for instruction. For 

 large nerves it is to be recommended 



only for staining nuclei. Nerve cells 

 and their prolongations are not well 

 shown. In summer, unfortunately, 

 a precipitate often appears. I filter 

 just before using, usually. 



30. Hoyer. Beitrage zur histologi- 



schen Technik. 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 evaporates. 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 perfectly 

 neutral ammoniacal carmine. They 

 are strong dyes and very convenient. 



(The above compovmds made by 

 Hoyer himself work well, 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. 1S82. 



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- 



