163 Scientific Intelligence. 



of their lamp narrow at the top, and thus increasing the capillasy ac- 

 tion of the wick, obtained a light which might be compared to that of 

 lamps of a constant level. Masson-Moinat, Milan and Osmond, in- 

 dependently of the use of capillary tubes, have modified their lamps 

 so as to keep them at a constant level, a condition essential to a lamp 

 with a double air current. The disposition of their lengthened re- 

 servoir renders the use of this apparatus easy, without loss of oil, 

 which is not unimportant to those who use them. Experience has 

 proved that in both of these lamps, the wick, though raised seven 

 millimetres, (one fourth of an inch,) above the beak, is carbonized 

 only two millimetres during the combustion of the oil. This eleva- 

 tion of the wick above the beak, has the further advantage of not be- 

 ing deteriorated, nor even blackened, whence it results that these 

 lamps have rarely any need of being cleaned. We propose to the 

 Academy, that it approve this apparatus, and testify to the inventors, 

 the interest which it takes in the perfection of these hydrostatic lamps 

 with a double current." — (Adopted.) — Idem. 



3. Watkins' dry Galvanic battery. — Prof. De Rive, in his ac- 

 count of this pile, (noticed in a former number,) states that the plates 

 must be at a very small distance from each other, (-^'^ or y'j inch,) 

 so as to be separated by a very thin stratum of air. Humidity favors 

 the action of the instrument, the results of which tend to confirm the 

 purely chemical theory of Voltaic electricity, for there is here no 

 point of contact of heterogeneous metals, and the developement of 

 electricity appears to be due uniformly to the oxidating action of the 

 air. The trough itself must serve as a conductor, for he has ascer- 

 tained that with a very dry wooden trough, the effect is much less, 

 and that when the plates are connected simply by glass rods with a 

 little cement, the efliect ceases. Hence, in common \oltaic batte- 

 ries, the liquid acts two distinct parts, viz. as an exciter, and as a 

 conductor. In this dry battery, the air is the exciter, and the trough 

 itself the conductor ; and the example proves that if the chemical 

 action be not equally intense upon the two surfaces of the metal, 

 there is no absolute necessity of coiitact between two heterogeneous 

 surfaces for the developement of electricity. — Idem. 



4. Eccentricity of Saturn's Ring. — Extract of a letter from 

 Prof. Schumacher to Prof. G. Maurice, one of the Editors of the 

 Bib. Univ. 



