383 Proceedings of Scientific Societies. 



been found at various heights from the seed to the third joint : they would 

 seem to enter the pupa state about the beginning of June. 



This fly was not observed by Miss Morris to inhabit any other plant 

 than wheat. 



To prevent the ravages of this destroyer of the grain, it will be proper 

 to obtain fresh seed from localities in which the fly has not made its ap- 

 pearance. By this means the crop of the following year will be uninjured ; 

 but in order to avoid the introduction of straggling insects of the kind 

 from adjacent fields, it is requisite that a whole neighborhood should per- 

 severe in this precaution for two or more years in succession. This re- 

 sult was obtained, in part, in the course of trials made by Mr. Kirk, of 

 Bucks county. Pa., with some seed-wheat from the Mediterranean, in and 

 since the year 1837. His first crop was free from the fly, but it was grad- 

 ually introduced from adjacent fields; and in the present year the mis- 

 chief has been considerable. As Miss Morris states that the fly has never 

 made its appearance in Susquehanna and Bradford counties, seed-wheat, 

 free from the fly, might be obtained from these, and probably from other 

 localities. 



The committee recommend that the conclusion of Miss Morris " may 

 be subjected to the only efiicient test — repeated observations and effective 

 trials of the precaution she advises." 



The committee, consisting of Prof Rogers, Dr. Bache, and Mr. Booth, 

 on a communication, entitled, "on the perchlorate of ethule or perchloric 

 ether, by Clark Hare and Martin H. Boye," reported in favor of publica- 

 tion, which was ordered accordingly. 



Tn the above paper, the mode of obtaining the perchloric ether, by sub- 

 jecting a mixture of sulphovinate of baryta and perchlorate of baryta to 

 dislillation, is first described. The authors next detail the precautions to 

 be attended to in preparing and experimenting upon this highly explosive 

 compound. They afterwards describe the appearance and properties of 

 the substance which ranks in that class of organic salts, denominated 

 ethers. It is a colorless, transparent liquid, heavier than water, and sol- 

 uble in alcohol, from which it may be precipitated again, by the addition 

 of vvater. An alcoholic solution of the hydrate of potassa has the power 

 of decomposing it, forming perchlorate of potassa and alcohol. The most 

 characteristic property of the compound is its tendency to explode from 

 the slightest causes. 



Dr. Patterson called the attention of the society to the subject of the 

 evolution of electricity from steam, mentioned at the last meeting, and 

 stated that the experiments made lately in England had been successfiilly 

 repeated by Mr. Peale, Mr. Saxton, and himself, at the United States' 

 mint. 



Dr. Patterson said, that their first attempts were to collect electricity 

 from the steam as it issued from a gauge-cock, near the surface of the 



