PRESERVING INSECTS. 233 



consisting of a quart of the first solution and two ounces of 



arseniate of potash and a gallon of water. 

 M. H. Trois * gives the following formula for preserving 



caterpillars. 



Common salt, gr. 235 



Alum, gr. 55 



Corrosive sublimate, .... centigr. 18 

 Boiling water, . . . _ . . . litres 5 



When the liquid is cold add 50 grains of carbolic acid. 

 Let the liquid stand five or six days, and then filter. It is 

 claimed that by means of this fluid the colors of cater- 

 pillars can be preserved perfectly, even when exposed to a 

 strong light. 



The nests, cocoons, and chrysalides of insects may be 

 preserved from injury from other insects by being soaked 

 in the arseniated alcohol, or dipped into benzine, or a solu- 

 tion of carbolic acid or creosote. 



Dr. J. L. LeConte has published in the " American 

 Naturalist/' iii. p. 307, some new directions for the pres- 

 ervation of insects which will apply to beetles as well as other 

 insects. " Surgical art has given to us an instrument by 

 which a poisonous liquid can be rapidly and most effectively 

 applied to the entire surface of large numbers of specimens 

 as they stand in the cabinet boxes, without the trouble of 

 moving them. I refer to the ' atomizer/ 



" Opinions may vary as to the nature of the liquid poi- 

 son to be used, but after several trials I have found the 

 following formula to be quite satisfactory; it produces no 

 efflorescence, even on the most highly polished species, 

 while the odor is quite strong, and persistent enough to 

 destroy any larvae or eggs that may be already in the box : 

 saturated alcoholic solution of arsenious acid, eight fluid 

 ounces; strychnine, twelve grains; crystallized carbolic 

 acid, one drachm; mineral naphtha (or heavy benzine) and 



* A litre is 33.81 fluid ounces, or a little less than an English quart; 

 a gramme is 15.432 grains. 



