189*7] MICROSCOPICAL JOURNAL, 293 



as in the weaker grades. Clear in xylol and mount in 

 balsam. 



The use of aniline oil in the treatment of the sections 

 will be recognised as as having been recommended hy 

 Weigert for bacterial purposes. It likewise gives most 

 excellent results in ordinary histological work and is a 

 saving of time and material. 



MOUNTING. 



Many valuable specimens are ruined for the want of 

 suflBcieht precaution in the preparation of the balsam. In 

 its commercial state it contains many volatile principles 

 and traces of acids, which, in tlie course of time, act upon 

 the specimen and diminishes or entirely removes the color. 

 All this may be lessened, if the balsam be heated suffici- 

 ently to drive off' the volatile constituents, or more 

 thoroughly obviated if a little potassium carbonate or 

 mild alkali be added to neutralize the acid just before 

 the balsam is heated. When the balsam becomes hard 

 it can be broken into flakes and stored. When wanted 

 for use dissolve in xylol to the desired consistency and 

 filter through absorbent cotton. Specimens stained with 

 the Biondi-Ehrlich mixture (which fades so easily) have 

 at the end of a year shown no signs of losing their pris- 

 tine clearness. Trans. A. M. 8. 



EDITORIAL. 



Powders Identified by Pollen. — The Jour, of Pharnia- 

 colog-y contains an interesting- paper, by Mr. Chas. Pfister, 

 on the pollen of some officinal herbs, his inquiry havintj- 

 been undertaken with the view of determining- whether 

 the powdered drugs could be recognized by means of any 

 pollen which they may contain. Mr. Piister's conclusion 

 is that they can, and he submits fig-ures and descriptions 

 which corroborate his statement. Thus the pollen of 

 horehound is squarish oijlong, green and smooth ; that of 



