90 THE CLASS OF INSECTS. 



Tip. Gl3'ccrinc is excellent for preserving the colors of cater- 

 pillars, though the internal parts decay somewhat, and the 

 specimen is apt to fiiU to i)ieces on being roughly handled. 



Laboulbene recommends for the preservation of insects in a 

 fresh state plunging them in a preservative fluid consisting of 

 alcohol with an excess of arsenious acid in fragments, or the 

 common white arsenic of commerce. A i)int and a half of al- 

 cohol will take about fourteen grains (troy) of arsenic. The 

 living insect, put into this preparation, absorbs about jr?oo of its 

 own Aveight. When soaked in this liquor and dried, it will be 

 safe from the ravages of Moths, Anthrenus, or Dermedes. Tliis 

 liquid will not change the colors of blue, green, or red beetles 

 if dried after soaking from twelve to twenty-four hours. He- 

 miptera and Orthoptera can be treated in the same way. 



A stay of a month in this arseniated alcohol mineralizes the 

 insect, so that it appears very hard, and, after drying, becomes 

 glazed Avith a white deposit Avhich can, however, be Avashed off" 

 with alcohol. In this state the specimens become too hard for 

 dissection and study, but Avill do for caljinet specimens designed 

 for permanent exliibiti(Mi. 



Another preparation recommended hy LaboulbL-ne is alcohol 

 containing a A'ariable quantity of corrosiA'c sublimate, but the 

 latter has to be Aveighed, as the alcohol evaporates easity, the 

 liquor becoming stronger as it gets older. The strongest solu- 

 tion is one part of corrosive sublimate to one hundred of alco- 

 hol ; the Aveakest and best is one-tenth of a part of corrosive 

 sublimate to one hundred parts of alcohol. Insects need not re- 

 main in this solution more tlian two hours before drying. Both 

 of these preparations are very poisonous and should be handled 

 with care. The last-named solution preserves specimens from 

 mould, Avhicli Avill attack pinned insects during damp summers. 



A A'cry strong l)rine Avill preserve insects until abetter liquor 

 can be procured. Professor A. E. Verrill recommends two sim- 

 ple and cheap solutions for preserving, among other specimens, 

 the larvie of insects "Avith their natural color and form remark- 

 ably perfect." The first consists of two and a half pounds of 

 common salt and four ounces of nitre dissolved in a gallon of 

 water, and filtered, Spi'cimens should be prepared Cor perma- 

 nent preservation in this solution by being l)re^■iously immersed 



