528 METHOD OF PRESERVING INSECTS. 



versate manu, versate diurna." The result has been astonishing 

 success, and a perfect conviction that there is no absolute and last- 

 ing safety for prepared specimens in zoology, from the depredations 

 of insects, except by poisoning every part of them with a solution of 

 corrosive sublimate in alcohol. I put a good large teaspoonful of 

 well-pounded corrosive sublimate into a wine-bottle full of alcohol. I 

 let it stand overnight, and the next morning draw it off into a clean 

 bottle. When I apply it to black substances, and perceive that it leaves 

 little white particles on them, I then make it weaker by adding 

 alcohol. A black feather, dipped into the solution, and then dried, 

 will be a very good test of the state of the solution. If it be too strong, 

 it will leave a whiteness upon the feather. 



A preparation of arsenic is frequently used ; but it is very danger- 

 ous, and sometimes attended with lamentable consequences. I 

 knew a naturalist, by name Howe, in Cayenne, in French Guiana, 

 who had lost sixteen of his teeth. He kept them in a box, and 

 showed them to me. On opening the lid " These fine teeth," said 

 he, "once belonged to my jaws: they all dropped out by my making 

 use of the savon arsenetique for preserving the skins of animals." I 

 take this opportunity of remarking that it is my firm conviction that 

 the arsenetical soap can never be used with any success, if you wish 

 to restore the true form and figure to a skin. 



I fear that your correspondent may make use of tight boxes and 

 aromatic atmospheres, and still, in the end, not be completely suc- 

 cessful in preserving his specimens from the depredation of insects. 

 The tight box and aromatic atmosphere will certainly do a great deal 

 for him ; but they are liable to fail, for this obvious reason, viz., that 

 they do not render, for ever, absolutely baneful and abhorrent to the 

 depredator, that which in itself is nutritious and grateful to him. In 

 an evil hour, through neglect in keeping up a poisoned atmosphere, 

 the specimens collected by your correspondent's industry, and 

 prepared by his art, and which ought to live, as it were, for the 

 admiration of future ages, may fall a prey to an intruding and almost 

 invisible enemy ; so that, unless he apply the solution of corrosive 

 sublimate in alcohol, he is never perfectly safe from a surprise. I 

 have tried a decoction of aloes, wormwood, and walnut leaves, think- 

 ing they would be of service, on account of their bitterness; the trial 



