ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 717 



preparation should be previously exposed to the light for a short time, 

 and in any case the treatment must be of short duration. If, after using 

 gold chloride, the resulting picture is found to be good, it is advisable 

 to expose the preparation to the light for a few days, as gold is reduced 

 much more slowly than silver. 



Staining Sections of Spinal Cord with Coerulein S.* — B. Rawitz 

 recommends Coerulein S (Hochst) for staining sections of spinal cord. 

 The following solution gives good results: — Cnerulei'n S 0*1 grm., 

 potassio-tartrate of antimony 1*0 grm., distilled water 100 ccm. The 

 potassio-tartrate is dissolved in lukewarm water, the pigment is then 

 added, and the mixture boiled in a sand-bath. When cold, the clear 

 dark-green fluid is decanted off and kept as stock. When required 

 for use, one part of the stock solution is mixed with ten to twenty times 

 its volume of distilled water. The time required is 21-48 hours, and 

 it maybe necessary to incubate at37°-10°. The sections are afterwards 

 washed in distilled water, dehydrated in 96 p.c. alcohol, and after clearing 

 in bergamot oil mounted in balsam. 



Simplified Method of Staining with Polychrome Methylen-Blue.f 

 B. Rawitz gets excellent results by means of the following simplified 

 procedure. The sections are placed for 24-48 hours in dilute poly- 

 chrome blue (1-50 Aq dest.)., and then after a short washing with water 

 are immersed for 24, 48-72 hours in 96 p.c. alcohol or until they 

 become quite light blue. They are then cleared up in dark-green 

 bergamot oil (the yellow is too acid) and mounted in xylol. 



Staining the Reticulum of Spinal Ganglion-cells. J — F. Kopsch 

 demonstrates the reticulum in ganglion-cells of the spinal cord in the 

 following manner. Not more than six ganglia are immersed in 2 ccm. 

 of 2 p.c. osmic acid solution for about eight days. The acid must be 

 renewed if there be any reduction. The reticulum begins to stain 

 about the fifth day, but does not attain its maximum till the eighth or 

 even later. Though this method is not successful with cells of the 

 central nervous system it gives good results with cells from other 

 regions, e.g. salivary gland. 



Zangrek, H. — Histologisch-Farbetechnische Erfahrungen im allgemeinen und 

 speziell iiber die Moglicbkeit einer morphologischer Darstellung der Zell- 

 Narkose (vitale Farbung). (A discussion on histological staining technique and 

 intra vitam staining.) 



Vierteljahrschrift Naturf. Ges. Zurioli, XVII. (1902) pp. 43-72. 



(5) Mounting - , including- Slides, Preservative FTuids, &c. 



Double Mounting for Whole Objects.§ — H. F. Perkins suggests 

 the following device for mounting objects to be studied from both sur- 

 faces. The object is mounted on a large cover-glass with a smaller 

 slip for cover. The larger slip is then laid on an ordinary slide and 

 one end fixed by means of gummed paper or sticking-plaster. This 



* Anat. Anzeig., xxi. (1902) pp. 551-5. t Tom. cit, p. 555. 



t S.B. Konigl. Preuss. Akad. Wiss. Berlin, xxxix. (1902) pp. 929-35 (1 fig.). 



§ Journ. App. Micr., v. (1902) p. 1926 (1 fig.). 



