18 [January, 



demand much rubbing of the specimen if it is to become pjenuinely 

 clean, as they do not possess sufficient detergent power. INIoreover, 

 it is necessary to relax the specimens in order to handle them safely, 

 and this often causes a delay of several days, which, irritating in 

 itself, may make it impossible to properly examine insects which cannot 

 be removed from the collections to which they belong. 



A careful examination of insects cleaned by such methods too 

 often shows that while they appear superficially clean, there are under 

 the head, in the joints of the armour and round the legs, neglected 

 deposits of dirt which are always harder to remove than they were at 

 the time of the original cleaning. 



And there is certain to be such a deposit on the precise spot 

 which it is desired to examine. 



Necessity, that chiefest of stimuli, has led me to devise a method 

 for cleaning such begrimed specimens, which in my hands, and those 

 of my friend Mr. Champion, has proved more convenient and effectual 

 than any of the above, on which Entomologists mostly rely. It con- 

 sists simply in the judicious use of caustic potash. 



The materials required are two wide-mouthed stoppered bottles, 

 one containing methylated spirit, the other a strong solution of po- 

 tassium hydrate in distilled or soft water ; the exact strength is 

 immaterial, about two drachms to the ounce of water may be conve- 

 niently used. Also a suitable vessel for washing the specimens, such 

 as a small white " developing dish " containing distilled water or water 

 free from lime, a supply of brushes (preferably sable), sheet cork and 

 blotting paper. Care must be taken not to dip the brushes into the 

 potash solution or they will be rapidly destroyed, and not to allow 

 drops of it to fall on the experimenter or his surroundings. 



The beetles to be cleaned need not, indeed should not, unless very 

 rigid and brittle, be relaxed before cleaning. 



Take off the labels, and holding the point of the pin, dip the 

 insect into the spirit. This is to enable the potash to attack the 

 surface, and is chiefly necessary when the specimen is very mouldy. 

 Eemove it from the spirit to the potash solution, immersing it from 5 

 to 30 seconds ; the time depends on the dirtiness of the specimen and 

 on the amount of rigidity which its limbs possess. A little practice 

 will show how long will be required. 



Drain off the superfluous potash on the side of the bottle, and 

 pin the insect on a piece of cork for three or four minutes while 

 others are proceeded with. Then hold it under water in the dish and 



