373 Miscellanies. 



phuric acid had been introduced, and the evolution of gas was no 

 longer sufficiently active, heat might be applied until nearly all the 

 chlorohydric acid should come over. 



The residual diluted sulphuric acid was, with the addition of nitrate 

 of soda or potassa, or nitric acid, as serviceable for galvanic purpo- 

 ses, as if it had not been thus used. 



Dr. Hare furiher communicated a method of preparing hydrochlo- 

 ric acid and chlorine in the self-regulating reservoir invented by him, 

 and spoke of some of the applications of the gases thus prepared. 



By means of the reservoir of chlorohydric acid he had been en- 

 couraged to make an effort which proved successful ; to form artificial 

 camphor by the impregnation of oil of turpentine with that gas. 



Subjecting an ingot of tin to a current from his reservoir of chlo- 

 rine, it was rapidly converted into the bichloride, or fuming liquor of 

 Libavius. To his surprise the ingot was fused by the heat generated. 

 In the last mentioned reservoir the materials were manganese, in 

 lumps, and concentrated chlorohydric acid, diluted sulphuric acid 

 being also introduced ; as the reaction of this last mentioned acid with 

 the manganese was more active than that of the chlorohydric acid. 

 In fact, sulphuric acid, diluted with its weight of water and common 

 salt, might be used without chlorohydric acid. In the reservoir for 

 chlorohydric acid, the materials were sal ammoniac and sulphuric acid, 

 to which some water was added, but not so much as to prevent the 

 chlorohydric acid from assuming the gaseous state. 



Mr. Sears C. Walker made an oral communication on the subject 

 of determining longitudes from corresponding observations of me- 

 teors. 



It had been recently remarked by Prof. Schumacher, Astr. Nachr. 

 No. 283, that, so far as his information extended, no trial had been 

 made of the observation of meteors for determining longitude ; 

 though the subject had been proposed long since by Prof. Benzenberg. 

 Accordingly, on the 11th of August, 1839, observations, chiefly of the 

 instant of vanishing of meteors, were made at the observatories of 

 Altona, Bremen, Konigsberg, Breslaw, &c., with such success as to 

 lead Dr. Oibers to the conclusion announced in a succeeding No. (284) 

 that observations of this kind are adequate for the complete determi- 

 nation of longitudes of places. By means of twelve coincidences on 

 the same night, Prof. Boguslawski found the Breslaw Observatory to 

 be 28m. 22.073. east of Altona, differing less than a second from that 

 which had been previously adopted. 



As the subject of priority in this inquiry might be considered im- 

 portant, Mr. Walker deemed it his duty to communicate the substance 

 of a letter from Prof. Alexander, of Princeton College, New Jersey, 



