288 Fragekasten. II. 2, 



Frag'ekasten. 



1. Auf die im Fragekasten Bd. II p. 144 gestellte Frage ist folgende 

 Antwort eingelaufen: 



„In regard to the Berichtigung by Dr. Flemming in tke last number of 

 the Zeitschrift für wiss. Mikroskopie concerning the hematoxylin Solution, 

 introduced by me into the pathological Institute at Heidelberg I would say 

 that the formulawas devised by Prof. J. Delafielu ofNew-York, the directions 

 for making the Solution as originally given and as used in this laboratory for 

 several years are as follows: 



To make 600 cc of the Solution, take 400 cc saturated aqueous Solution 

 of ammonia alum and add to this 4 grms of crystallized hematoxylin dissolved 

 in 25 cc strong alcohol. This at first produces a light violet or some- 

 times a dirty red color, but on exposure to the light in an unstoppered bettle 

 the color deepens and a Ught precipitate forms. After standing for three or 

 four days exposed to the air and light, the Solution is filtered and 100 cc 

 each of glycerin and methyl alcohol are added. The Solution is now allowed 

 to stand until the color is sufficiently dark and is then filtered and kept in a 

 tightly stoppered bottle. This Solution must be considerably diluted with water 

 before using. The amount of dilution depending, as usual, upon the specimen 

 and the end to be obtained". 



New- York April 18'h 1885. J. Mittchell Prudden. 



2. Mich interessirt es zu erfahren, wer hat zuerst Glycerin empfohlen 

 und wann? Frof. Dr. H. Frey. 



3. Der Unterzeichnete, mit einer neuen Auflage seines Buches: „Das 

 Mikroskop und tlie mikroskopische Technik" beschäftigt, bittet die Herren 

 Fachgenossen um Mittheilung neuer technischer Methoden und Präparate, die 

 Herren Optiker um Mittheilung ihrer neuesten Kataloge, sowie etwaiger Instru- 

 mente und Hilfsapparate. 



Zürich. Oberstrass. Prof. Dr. H. Frey. 



