248 ANNUAL OF SCIENTIFIC DISCOVERT. 



plants containing more hydrogen and less carbon than the plants 

 which produced coal-beds, and hence their fermentation produced the 

 petroleum." 



The Petroleum Trade of the United States for 1863. - - The export of 

 petroleum from the United States for the year 1863, is estimated at not 

 less than 28,000,000 gallons. As an illustration of the unexampled rapid- 

 ity with which the trade in this article has developed, we give the total 

 export of petroleum for the years 1861 and 1862. They were as fol- 

 lows : 1861, 1,112,476 gallons; 1862, 10,887,000 gallons; the quan- 

 tity exported in 1863 amounted to 252,000 tons' weight, and engaged 

 no less than 252 ships of 1,000 tons' burden each, to carry it. The 

 amount of money derived from its sale is estimated at $12,000,000. 



NOTES ON METEORITES. 



From numerous reports of eleven large meteors which passed over 

 England in the two years 1861-63, collected from the British Associa- 

 tion, the heights of appearance were found to vary from thirty to 196 

 miles above the earth, and of disappearance from fifteen to sixty-five 

 miles above the earth. Their velocities were from twenty-three to 

 sixty miles in a second. 



Referring to some recent experiments by Deville, of Paris, and 

 Pliicker of Bonn, in which, by great heat, oxygen has been dissocia- 

 ted from hydrogen in steam, and carbonic acid and other chemical 

 compounds had been decomposed, Herschel has conjectured that the 

 violent heat of a fire-ball is sufficient to destroy the chemical affinities 

 in the meteoric surface, and to cause the glowing sparks and phospho- 

 rescent streaks, which follow the flame, by the gradual recombustion, in 

 the rear, of the reduced metals and elements in the track of the me- 

 teor's flight. 



Meteoric Iron from Tucson, Arizona. A mass of meteoric iron 

 from Tucson has been presented to the city of San Francisco by Gen- 

 eral Carleton. In a recent letter, Prof. Whitney states that this iron 

 is four feet one inch long, and weighs 632 Ibs. It was found at or 

 near Tucson, Arizona, by Gen. Carleton's California column on their 

 march through that region, and has evidently been used for an anvil, 

 although it is not the one figured by Bartlett as having served that 

 purpose. 



A specimen of this meteorite analyzed by Prof. Bush, of Yale Col- 

 lege, gave the following result: Iron, 81.56; nickel, 9.17; cobalt, 

 0.44 ; copper, 0.08 ; phosphorus, 0.49 ; silica, 3.63 ; protoxide of iron 

 with a trace of alumina, 0.12 ; lime, 1.10 ; magnesia, 2.43 ; chlorine, 

 sulphur, chromium, minute traces. The composition of this meteorite 

 corresponds very closely with another meteoric iron from Tucson, dis- 

 covered by Mr. Bartlett, and described by Prof. J. Lawrence Smith, 

 in the Am. Journ. of Science, 2d ser., vol. xix. page 161. 



Molecular Structure of Meteorites. Mr. Sorby, the well-known 

 English geologist and microscopist, has recently turned his microscope 

 upon meteorites, or rather upon sections of these exotic minerals, with 

 a view to ascertain their origin by close examination of their micro- 

 scopical structure. The evidence thus far appears to be strong in fa- 

 vor of the conclusion that they are formed by the aggregation of small- 

 er fragments or minute particles, in which particular they are most 



