C. GENERAL PHYSICS. 147 



The principle upon which the action depends is that, in the 

 acid, lead is positive to copper; in the sulphide, it is negative. 

 -12 A, IX., 435. 



SYNTHESIS BY ELECTRICAL ACTION. 



Brodie, by the action of electricity, has recently performed 

 some highly interesting syntheses. By acting upon a mixt- 

 ure of carbonic oxide with hydrogen he obtained a consider- 

 able quantity of marsh gas; and, with carbonic acid and hy- 

 drogen, formic acid was among the products. He also in- 

 vestigated the effect of electricity upon pure, dry, carbonic 

 oxide gas. A contraction of about five cubic centimeters per 

 hour took place, carbonic acid was formed, and at the same 

 time a transparent reddish-brown solid deposit appeared upon 

 the walls of his tube. This deposit proved to consist of a 

 mixture of new oxides of carbon, apparently members of a 

 regular homologous series, like those of the hydrocarbons. 

 This discovery is exceedingly interesting in its bearings upon 

 theoretical chemistry, and probably affords us the first in- 

 stance in which a solid oxide of carbon has been obtained. 

 Ann. Chem. and Pharm., October 4, 1873, 270. 



ELECTRICAL DISTRIBUTION OF TIME BY ASTRONOMICAL 



OBSERVATORIES. 



The system of clocks controlled by electricity by the cen- 

 tral clock of an astronomical observatory, which was first es- 

 tablished in England by Jones some ten years ago, has already 

 made decided progress in this country. Not only has the 

 apparatus for this been ordered to be constructed for the city 

 of Cincinnati in connection with the observatory at that place, 

 but similar apparatus has been established in Pittsburgh and 

 Washington, and has been for some time in successful opera- 

 tion in those two cities. The clocks furnished these places 

 are manufactured by Hamblet, of Boston, and in the neigh- 

 borhood of this city four such clocks are in operation ; they 

 also exist in Washington, at the Capitol, the Treasury and 

 Navy Departments, and the Army.Signal-oftice, while at Pitts- 

 burgh a clock has been established to move the hands of sev- 

 enty different clock dials scattered all over the city. By 

 these arrangements every clock indicates exactly the same 

 time as do the others in the circuit. 12 A, IX., 193. 



