20 The Microscope. 



drying medium per se. Resins might be treated with chromate 

 of lead in the same manner. Whether this suggestion is prac- 

 tical, I will leave for others to decide who have more experience 

 and skill in chemistry than I. 



What can be done with sulphur and phosphorus ? Can we 

 dissolve sulphur in oil and make a transparent medium of it ? 



There are phosphorus, 2.224; carbonate of lead, 1.866; oil of 

 anise seed, 1.111 ; bi-sulphate of carbon, 1.678 ; all pretty high; 

 what can be done with them ? There may be other substances 

 higher and better than those mentioned. How many will act in 

 this important matter ? 



LEAVES FROM A MICROSCOPICAL NOTE-BOOK. 



GRAYBEARD. 

 I. 



MORE than a half-century ago I had a compound micro- 

 scope made by Benjamin Pike, Sr., of New York, placed 

 in my hands, and from that time to date it has been a constant 

 microscopical evolution with me — a survival of the fittest. 



If there is any one grand mystery involved in the manipu- 

 lation of the instrumeut my experience would assert that it is 

 to be found in the handling of the mirror. Like many others, I 

 have had my full share of attacks from the accessory fever^ 

 each new purchase, in the main, being laid aside to study more 

 thoroughly the effects obtained alone by the mirror — the master 

 agent of manipulative skill. 



My stand-by for work is George Wale's little stand with its 

 accurately ground plane and concave mirrors, " Grey beard's, dia- 

 phragm lamp " (see Elmira meeting of A. S. M.), and an occa- 

 sional bull's eye brought into play over such tests as Amphipleiira 

 pellucida. As to objectives, my preference is for wider angles of 

 aperture, dry adjustable ones from tg up to ^. One-sixth and 

 higher, homogeneous immersion of the highest grade of work- 

 manship, aye, more, of art inspiration in its corrections, and ad- 

 justable in every instance. 



" When I get old what effect will the use of the microscope 

 have upon my sight?" I can only answer this by saying that 

 in my case I can sit for from four to six hours over the tube, 

 night after night and not fatigue my eyes ; but let me advise 

 those younger than the writer to avoid any verging to a dazzling. 



