74 PRESERVING INSECTS. 



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 dangerous, 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 re- 

 store 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 successful 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 depre- 

 dator, 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 



