THE MICROSCOPE. 135 



height, solidly made of black walnut. The lock and hooks which 

 secure it having been unfastened, the top lifts and the front falls, 

 exposing to view the series of closed trays capable of holding 500 

 slides. Each tray must be withdrawn from beneath those above it 

 in order to get at its contents, and they must be lifted again in 

 order to replace it. Otherwise it is as convenient as any other 

 form, while it has the great advantage that any one of its trays may 

 be used at any time as an independent box; still further, its cost 

 is about one-third of any comparable cabinet advertised by the 

 dealers. The binder's board trays have, when first made, a little 

 tendency to wrap, and had better be kept under pressure, but this is 

 only temporary. 



Such cabinets, to hold 500 slides, consisting of fifteen of the 

 larger and twenty of the smaller boxes, contained in a neat and 

 strong walnut box, with lock and handle, are manufactured by Mr. 

 Ivan Fox, optician, 1632 Chestnut street, Philadelphia, and sold at 

 fifteen dollars. — B. Alexander Randall, M. D., in Western Medical 

 Reporter. 



Mounting in Glycerine. — Dr. S. R. Holdsworth finds the 

 following plan to be efficacious in avoiding the difficulty found in 

 getting rid of the surplus glycerine when it has passed beyond the 

 cover-glass. He puts a very small drop of glycerine upon the ob- 

 ject, just sufficient that when the cover-glass is applied it will not 

 extend to the margin. A solution of Canada balsam in chloroform 

 or benzoline is then run in to fix the cover-glass, and not being 

 miscible with the glycerine, an air-space is formed between the two 

 fluids which has not been found to be detrimental. The slide can 

 be finished with a ring of balsam or other cement. — Am. Rep. Pos. 

 Mic. Soc. 



W. Pfitzner prepares dammar varnish as follows : Gum dam- 

 mar, benzine and turpentine, equal parts ; when solution has taken 

 place the clear liquid is poured off and allowed to evaporate to 

 proper consistency. 



