cheese, then putting two portions of the residue o£ exactly equal 

 weight and shape, say five grains, into separate half-ounce phials and 

 filling one with benzine, the other with ether. It will be found that 

 the ether has dissolved the mass in a quarter of an hour, while the 

 benzine has taken more than half an hour to do its work. My ex- 

 periment was tried with grease which had been extracted partly by 

 ether, partly by benzine, the two fluids were mixed and evaporated. 

 This I find was unfair to the ether, the action of which after henzine is 

 unsatisfactory — had I used grease extracted by ether for the ether 

 experiment, and by benzine for the benzine experiment, the result 

 would certainly have been still more favourable to the ether. There 

 is not time to go over it again now ; perhaps some of your readers 

 may think it worth while to do so. 



Ether is used in the same way as benzine, i. e., by subjecting the 

 greasy insects to repeated baths of it until the grease is thoroughly 

 eradicated, two soakings of from three to ten days each, according to 

 the size and state of the insects and bodies, are generally quite suffi- 

 cient, but it is also advisable to give a third shorter bath for the 

 purpose of rinsing off any surface grease w^hich may remain from 

 the previous baths. We can easil}'' ascertain whether the insects are 

 properly cleansed by observing whether the last bath is discoloured or 

 turbid, and by "feeling" the interiors of the abdomina with a thin wire. 

 When we have satisfied our minds upon this point, the more rapidly 

 we dry our specimens the fresher and brighter will be their appearance, 

 and for this purpose a warm temperature of not over 80° and fanning, 

 or a thorough draught will be of great assistance. Ether will not 

 affect the most delicate colours, even the sensitive green of lodis 

 vernaria, nor will it mat the cilia, on the contrary, if these are already 

 entangled with grease it wall liberate and restore them. 



When wings and thoraces are only superficially affected they are 

 soon cleaned by bedding them on to magnesia, saturating them with 

 ether, covering over quickly with more magnesia, and leaving till the 

 next day. After repeating this process three or four times, all trace 

 of grease will generally have disappeared. It is when the grease has 

 extended to the interior of the thorax and especially to the pin that 

 the great mischief is done, for the green salt of copper which is 

 formed so distends and distorts the thorax and displaces the wings, 

 that unless it be a rarity, it is not worth while to attempt a cure. Le 

 jeu ne vaut pas la chandelle. 



When the wings and thoraces have been freed from grease, and 

 after the powder has been shaken and blown off, and they have had a 



