276 PHOTOMICROGRAPHY 



AQUARIUM CEMENT FOR TROUGHS 



Dry white lead 1 part 



Litharge 1 ,, 



Silversand 1 



Finely powdered resin J ,, 



Mix well and keep in a bottle. When required for use mix 

 with boiled oil and dryers till of the consistency of putty. 



Refractive Indices of Mounting Media, etc. /xD 



Water 1-334 



Glycerin 1-460 



Cedar oil 1-510 



Oil of Cloves 1-530 



Canada balsam 1-535 



Styrax 1-582 



Monobromo-napthalene 1-658 



Realgar /*E 2-549 



REFRACTIVE INDICES OF TYPICAL GLASSES, ETC. 



Fluor spar /xD 1-433 



Crown glass of various kinds from about 1-5 to 1-6 

 Flint 1-54 to 1-7, and 



even 1*9 



