161 



invented by him, and spoke of some of the applications of the 

 gases thus prepared. 



Dr. Hare was under the impression that few chemists were aware 

 of the great advantage of the self-regulating reservoirs of gas, to 

 which he had resorted. He was enabled, by means of them, to keep 

 hydrogen, carbonic acid, nitric oxide, chlorine, chlorohydric acid, 

 sulphydric acid, and arseniuretted hydrogen, so as to use any of these 

 gases at pleasure. He had kept these reservoirs in operation for 

 months, without taking the constituent vessels apart. 



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. 



He had found it preferable to keep the sulphydric acid reservoir in 

 a flue, the gas being drawn, when wanted, through a globe of water, 

 by means of a leaden tube, at a convenient place. It would be de- 

 sirable that the reservoirs of chlorine and chlorohydric acid should 

 be similarly situated. 



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

 subject of determining longitudes from corresponding observa- 

 tions of meteors. 



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. Ac- 

 cordingly, 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 



