92 



THE AMERICAN MONTHLY 



[May, 



carmine,' supposed to be less liable 

 to alteration. 



1 8. Lieberkuhn. Ueber die Einwir- 



kung^ des Alizarin auf die 



Gewebe des lebenden Korpers. 



Sitzungsb. d. Gesells. z. Be- 



forderung d. ges. Naturwiss. 



Marburg. 1874, No. 3, p. 33. 



Experiments to ascertain if living 



tissues would stain. Injections of 



ammoniacal carmine in the lymph 



sacks of the backs of frogs. (See 



previous articles.) 



19. Richardson. Mode of staining 



animal tissues of a permanent 



purple-grey color. Q_uart. 



Journ. Micr. Sci. 1874, p. 



281. 

 Carmine solution mixed with Dra- 

 per's dichroic ink strongly recom- 

 mended. The ingredients of the ink 

 are unknown. 



20. Pouchet et Legoft'. Sur la fixa- 



tion du carmin de cochenille 

 dans les ^l^ments anatomiques 

 vivants. Gaz. med. de Paris. 

 1876. No. 52. See No. 17, 

 above. 



21. Hoyer. Beitrage zur anatomi- 



schen und histologischen Tech- 

 nik. Archiv. mikr. A n a t . 

 xiii, p. 649. 

 Hoyer thinks the power of am- 

 moniacal carmine is increased by add- 

 ing alcohol. Beale's solution is pre- 

 ferred on that account, the glycerin 

 is rather an injury. The following 

 troublesome process gives a power- 

 ful dye. Warm some carmine in a 

 flask with alcohol to which a little 

 sulphuric acid has been added, till it 

 dissolves. Filter and dilute with 

 much water. Add to the filtrate 

 lead acetate so long as the rosy pre- 

 cipitate of lead sulphate forms. As 

 soon as the precipitate becomes vio- 

 let, filter and to the filtrate add lead 

 acetate 'till the vio'let precipitate no 

 longer forms. Collect this, wash, 

 dry, dissolve in a little strong alcohol, 

 and add alcohol acidulated with sul- 

 phuric acid drop by drop till the pre- 

 cipitate is colorless and the alcohol a 



deep red. This alcoholic solution is 

 a powerful dye. 



22. Obersteiner. Technische Notiz. 



Aixh. mikr. Anat. xv, p. 136. 

 Obersteiner dyes sections of large 

 nerves with ammoniacal carmine by 

 exposing them 2 to 5 minutes in watch- 

 glasses filled with the dye to hot steam. 

 He finds the sections stain quickly and 

 well, and he appears to use a rather 

 concentrated solution. (I have tried 

 his method, and can confirm his state- 

 ments, but do not recommend it, ex- 

 cept to save time.) 



23. P. Mayer. Die Verwendbarkeit 



der Cochenille in der mikro- 

 skopischen Technik. Z o o 1 . 

 Anz. 1878. No. 15, p. 345. 

 Mix powdered cochineal with 70% 

 alcohol, digest several days, filter. 

 The proportions are i gram, of coch- 

 ineal to 8-10 c. c. alcohol. Alcoholic 

 preparations free from acid are the 

 best for staining. 



(The following method of boiling 

 cochineal with alum is much better.) 



24. Grenadier. Einige Notizen zur 



Tinctionstechnik besonders zur 

 Kernfarbung. Arch. mikr. 

 Anat. xvi, p. 463. 

 A watery solution ofalumoralumed 

 ammonia (i to 5%) is boiled 10 to 20 

 minutes with ^ to 1% powdered car- 

 mine and filtered after cooling. The 

 purple solution dyes nuclei only very 

 quickly, and no excess of color results 

 from long soaking. 



25. Grenacher. 1. c 



One or two per cent, of borax in 

 water is boiled with ^ to f% of car- 

 mine. The cooled solution is treated, 

 drop by drop, with dilute acetic acid 

 till it assumes the color of the ordi- 

 nary ammoniacal carmine. After 

 standing 24 hours, filter. It stains 

 diffusely, but the color may be con- 

 fined to the nuclei by washing with 

 50-70/0 alcohol containing a few 

 drops of muriatic acid. 



26. Grenacher. L. c. 



In 50 c. c. of 60-80% alcohol, with 

 3-4 di'ops of hydrochloric acid, boil a 

 pinch of carmine for 10 minutes. Cool 

 and filter. Sections stained with this 



