ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 731 



(4) Staining a,nd Injecting. 



New Staining Mixture.* — Dr. A. Pappenheim recommends the 

 following stain for bone-marrow, gonorrlioeal, and other suppurative 

 secretions, and spermatosomata hominis ; viz. a mixture of a saturated 

 aqueous solution of two basic pigments, containing 3-4 parts methyl- 

 green and 1-1 • 5 parts pyronin. 



Method for Preparing Neutral Picrocarmin. f — Herr J. W. van 

 Wyho prepares a neutral picrocarmin by the following simple and rapid 

 method. It is hest to start on an old strong carmin solution, composed 

 of 30 grm. carmin dissolved in a mixture of 2 parts of distilled water 

 and 1 part 10 p. c. ammonia. When two years old it is sufficiently ripe. 

 The mixture may, however, be rapidly ripened by boiling 10 grm. 

 carmin with 10 ccm. ammonia and 20 ccm. peroxide of hydrogen. 

 25 ccm. of the carmin solution are mixed, with 100 ccm. of 96 p.c. 

 alcohol and the solution filtered. The precipitate on the filter is 

 washed with 100 ccm. of 96 p.c. alcohol, and dried for 24 hours in a 

 thermostat at 40°-45° C. The ammonia-carmin obtained in this way 

 is completely soluble in aqueous solutions of ammonium picrate. This 

 salt may be purchased, or made as follows: — 9 grm. of picric acid are 

 dissolved in 100 ccm. 96 p.c. alcohol, and 15 ccm. ammonia added. 

 The solution is evaporated to dryness in a thermostat at 60°. 



The best proportion between ammonia-carmin aud ammonia picrate 

 is - 5 p.c. of the former to 1 p.c. solution of the latter. The solution 

 is invariably alkaline, but by boiling in a water-bath for a quarter of an 

 hour it is rendered neutral. The fluid lost is to be replaced by the 

 addition of distilled water. One per cent, chloral (Hoyer) may be 

 added as antiseptic. 



Method for Staining with Neutral Eosin-methylen-blue.J — M. E. 

 Laurent first describes how to prepare the neutral stain. One gramme 

 of potassium-eosin and 1 grm. of medicinal methylen-blue are dissolved 

 each in one litre of water. Then to 1000 ccm. of 1 per thousand eosin 

 solution, 882 ccm. of 1 per thousand methylen-blue are added, and the 

 mixture allowed to stand for 24 hours. The mixture is, however, now 

 purchasable. When required for use one part of the mixture and four 

 parts of water are boiled and then cooled down. While still warm the 

 object to be stained is immersed therein for from half an hour to six hours. 

 If any precipitate be found on cover-glass films it is brushed off, and the 

 preparation then treated with xylol before mounting in balsam. Sections 

 are washed in 96 p. c. and then differentiated in absolute alcohol. This 

 step takes from two minutes to some hours. Instead of alcohol, anilin 

 oil and xylol (3-1), or anilin oil and alcohol (1-3) may be used. 



Staining the Malaria Parasite.§— Dr. E. Ruge finds that the red- 

 methylen-blue staining (Romanowski-Ziemann) of the malaria parasite 



* Biol. Centralbl., xx. (1900) p. 373. See Centralbl. Bakt. u. Par., 1 Abt., 

 xxviii. (1900) p. 403. 



t Koniak. Akad. vau Wetenschappen te Amsterdam, Proc, Feb. 1900. See 

 Zeitschr. f. wiss. Mikr., xvii. (1900) pp. 200-1. 



% Centralbl. f. Allgem. Pathol, u. pathol. Anat., xi. (1900) pp. S6-d 7. 



§ Zeitscbr. f. Hygiene, xxxiii. part 2. See Centralbl. Bakt. u. Par., l t0 Abt., 

 xxviii. (1900) pp. 403-4. 



