THE society's NOTE-BOOKS. 387 



that the heat on and near the Line had melted his balsam, and 

 had allowed the cover-glasses to fall to the bottom of the racks. 

 Even then, if the slides had lain flat, no harm might have 

 happened 



There is, I think, a practical inconvenience in ringing slides 

 that require to be examined with a high power, and that is, you 

 cannot slide your slide off the stage without screwing up the micro- 

 scope, and so losing your focus ; at least, this is so with a simple 

 stage like that of the Hartnack microscope. Of course, when one 

 comes to deal with deep cells, either for balsam or glycerine, 

 ringing and finishing become of first-rate importance. How 

 almost invariably the glycerine slides are spoiled, or at least 

 damaged, before they have completed the circuit of the P. M.S. 

 Farrant's medium, ringed with asphalte, stands much better than 

 glycerine. R. S. Pattrick. 



I own to being very much interested in the subject on 

 mounting and ringing slides. For years I have followed the idea 

 given me by an old friend, and use various colours for the different 

 groups of slides, viz. : — Green for vegetables ; blue for diatoms ; 

 purple for insects ; red for animals ; and white and black for 

 polariscope objects. 



I get a small tube of oil-colours, and squeeze a little into a 

 homoeopathic bottle ; then I pour a little benzole in and let it soak 

 for a day or two to take up the oil; then I pour away the oily 

 benzole and put in some fresh, and all is ready. Having ringed 

 on the zinc-white cement, I at once apply the colour of the ring, 

 as desired ; the benzole takes it over to the zinc-white, and the 

 slide is done. The advantage is that if you are showing slides to 

 people, you know from the colour of the ring the class of subject 

 you are showing, and when you want to put away your slides you 

 perceive at once where they are to go. I admit that there is no 

 further use in ringing slides, but why may not the outside look 

 pretty ? A. Clarke Smith. 



In my opinion, by far the neatest way to finish a balsam slide 

 is to put a ring of balsam on instead of zinc white. 



John E. Fawcett. 



