1022 General Notes. [December, 



the insects exposed to a dense atmosphere of this gas were imme- 

 diately killed. It was, therefore, used simply as a diluent of the 

 ordinary air. The Colorado beetles lived in an atmosphere over- 

 poweringly odorous of chlorine for one hour, and partially re- 

 vived upon their release. 



Nitrous Oxide I laugJung gas) —The Colorado beetle gave in this 

 gas no signs of exhilaration, lived two hours, and died upon re- 

 moval ; probably from exhaustion. 



Young of the common grasshopper (Caloptenus femur-rubrum) 

 were confined two hours in this gas and were but little affected. 

 Moths (Noctua) died in an hour and a-half. 



Illuminating Gas.— l\\z gases used were variable mixtures of 

 hydrogen, marsh gas, carbonic oxide, and hydrocarbons, a notori- 

 ously dangerous and irrespirable compound. 



Colorado beetles were instantly prostrated, folding up their legs 

 underneath them, and gave in twenty minutes scarcely discernible 

 indications of life. After an hour thev were taken out and par- 

 tially revived ; some entirely recovered. The paralysis of the legs 

 was the noticeable feature, especially that of the front pairs. 



Croton bugs (tetobia gennanica) behaved similarly in the illu- 

 minating gases, and on being removed after half an hour's con- 

 finement recovered almost completely. 



Voung of grasshopper (Caloptenus femur-rubrum) evinced signs 

 of life one hour after their introduction, and one individual taken 

 out at that time appeared completely lifeless, yet recovered and 

 was sufficiently strong to force its way out from under a beaker 

 glass. Others left in one day were killed. 



A cicada {Cicada fruinosa) died m ten minutes. Flies impris- 

 oned m these gases, though thev instantly fell to the bottom of 

 the jars in an almost lifeless state, recovered after five minutes 

 immersion on being removed. A longer imprisonment dis- 

 patched them. & V 



It seems quite feasible that insect cases made air-tight could be 

 charged from time to time with ordinary illuminating gas, and 

 their contents thus protected against 1 he inroads and devastations 

 of Anthreni and Dermestes. Other objects could, of course, be 

 ■so treated. The cases should be thoroughly tight, and the gas a 

 pure and well-cleaned product. I have kept admirably some spe- 

 cimens in this way, but have noted several aberrant phenomena 

 when specimens were moist. Some fragments of mummy skins, 

 which I had in gas were in excellent condition after a long trial; 

 they had been taken from a decomposing subject. On moisten- 

 ing them a rich growth of Fungi started out over them, which 

 flourished in the atmosphere of gas for a short time, but after re- 

 peated charges sickened and died. 



I am convinced that in place of ordinary illuminating gas the 

 vapors of Prussic acid diluted with air or pure carbonic oxide, in- 

 jected into tight insect boxes, will prove most efficacious for the 

 protection pf their contents.— L. P. Gratacap. 



