1895.] 21 



RELAXING INSECTS WITHOUT AQUEOUS VAPOUR* 

 BY H. GUAED KNAOOS, M D., F.L.S. 



For some time past I have been casting about for a fluid or vapour 

 (non-aqueous) which would render dried specimens of insects suffi- 

 ciently pliable to permit of their being reset, when badly displayed, 

 sprung, or not set at all, without the aid of those mildew and putri- 



faction causing agents the damp sand pan and laurel jar ; but 



hitherto all attempts on my part have proved failures. Recently, 

 however, through the kindness of my friend Mr. Clark, of Hackney, 

 who has imparted to me hia method, and given me permission to 

 publish it, the object of my search has been attained, and it is with 

 much pleasure that I am now enabled to place at the disposal of your 

 readers a simple but effective means of " relaxing " without the use 

 of watery vapour. 



The following is the modus operandi : — Take up the insect by the 

 pin in one hand and hold it upside down ; then with a camel's hair 

 brush dipped in " wood naphtha" (pyroxylic spirit) in the other hand 

 soak each side of the thorax, close to the insertions of the wings, till 

 the spirit extends, say, half way along the latter ; then put the insect 

 aside for three or four minutes, by which time it will probably be 

 supple enough to manipulate, but if not, repeat the process and wait 

 another one, two, three or four minutes, which will almost surely 

 suffice, unless the specimen be very large or old, for of course the 

 time taken to soften the tissues will depend greatly upon size, age 

 and condition ; but, as a general rule, not more than three or four 

 minutes will be required for the purpose. The operator should have 

 a saddle at hand, and, as soon as ever relaxation has commenced, should 

 start to get the wings into position, bracing them down firmly as the 

 work proceeds ; after an interval of twelve or twenty-four hours the 

 braces may be removed, and the specimens will show no inclination to 

 " spring," nor will any visible stain be left. The uninitiated may find 

 a little difficulty at first, but proficiency will come with practice. 



By this method insects may be reset in any position, and if the 

 antenna? be also soaked they may be arranged to the fancy of the 

 operator. 



It seems to me that entomologists ought to feel very grateful to 

 Mr. Clark for making this discovery known. 



London, N.W. : December 5th, 1894. 



* A writer in the October number of the " Entomologist " draws attention to the fact that 

 naphthaline will keep freshly caught insects relaxed for some days, even in a tropical climate ; but 

 this is a different thing from relaxing specimens after they have been dried ! If naphthaline 

 relaxed dried insects it would be a bad look out for those numerous entomologists who employ 

 it so freely in their cabinets for the purpose of protecting their collections against mites and 

 mould. -U. G. K. 



