154 THE MICROSCOPE. Oct. 



the frustule, so that this can be said to be multicellular. 

 Perhaps this is the case with other species when they 

 occur as sporangia, but I have not witnessed it as yet. 



Farrant's Medium. 



By THOS. J. BRAY. 



WARREN, OHIO. 



The mounting medium known as "Farrant's" is a very 

 viscid mixture of gum arabic, glycerine and camphor 

 water. It is an excellent, ready and suitable medium 

 for mounting vegetable sections, etc.. but is not as much 

 used as it ought to be by reason of the persistence with 

 which air bubbles are held in the compound. The question 

 is often asked, "How to remove the bubbles ? " My an- 

 swer is, "Don't let them get in." The reply to this is 

 invariably, -'Easier said than done." There is no trick 

 in it, provided certain rules are followed. I may not be 

 able to give your readers the best method of doing it, 

 but will give my way of operation, which, if followed 

 closely will avoid the troublesome air bells entirely. 



Prepare Cells. These may be Carter's culluloid, which 

 I use, or made of King's cement, gold size or other suit- 

 able material spun on the slide. They must be dry and 

 hard, see that the top surface of the cell is level and 

 smooth, then take a piece of clean wire and put it end 

 foremost into the bottle containing the medium and let 

 it remain there until ready for use; this wire is used as 

 a dropper. When ready lift out the wire and hold it 

 over the cell about a half an inch above it; a drop of 

 solid gum solution will soon form at the end and fall off 

 into the cell. Put the wire back into the bottle, take 

 the specimen and place it on the drop in the cell and al- 

 low it to fall to the bottom by its own weight if it will 

 do so, if not, then a very gentle pressure will help it. 

 Avoid stirring the mixture in the cell as that will cause 



