FIXING AND PRESERVATIVE MEDIUMS 37 



more rapidly, which, when delicate butterflies are plunged 

 therein, is of some importance. It is an effectual remedy for 

 " mites " infesting dried insects. ' 



12.— Ether and Bichloride of Mercury (M.B.) 

 Pure sulphuric ether i pint 



Bichloride of mercury . . . .10 grains 



13. — Alcohol and Chromic Acid (Lo Bianco, p. 443) 



Alcohol (70 per cent.) \ ^^^^j ^^^^^ 



Chromic acid (i per cent.) ) 



This is used by Lo Bianco to kill an octopod, Sccsurgiis 

 {Octopus) tetracirrhus, which, after twenty minutes, should be 

 passed into alcohol alone of 70 per cent. 



14. — Alcohol and Hydrochloric Acid (Lo Bianco, p. 443) 



Alcohol (50 per cent.) . . .100 parts 



Hydrochloric acid (concentrated) . -Si, 



Fecundated and transparent eggs of fishes may be pre- 

 served by leaving them for some minutes in the above mixture, 

 and passing them afterwards into alcohol. 



15- — Alcohol and Iodine (Lo Bianco, p. 443) 

 Alcohol (35 per cent, or 70 per cent.) . .100 parts 



Alcoholic tincture of iodine . . 2 or 5 parts 



Such Radiolaria as species of the genus Spharozoum and 

 Collozoum are fixed in the 35 per cent, solution by being left 

 from fifteen minutes to about an hour, care being taken to agitate 

 the liquid, otherwise, in resting too long at the bottom of the 

 vessel, the animals become flattened. Afterwards they should 

 be transferred to alcohol of 3 5 per cent, for two hours, next to 

 alcohol of s o per cent, and, twelve hours afterwards, into alcohol 

 of 70 per cent., which must be renewed after twenty-four hours. 



Rectified Naphtha for Snakes and Frogs. — This has been 

 used in the Leicester Museum for preserving small mammals 



