Intellige7ice and Miscellaneous Articles. 1 55 



second magnitude when they resemble fixed stars of the first magni- 

 tude ; and thus with the rest. Among 5302 meteors, the author 

 counted eight shooting globes and eighty shooting stars of the first 

 magnitude ; whence it follows that, if no obstacle prevented, an ob- 

 server Avould see one shooting globe a week, and one falling star of 

 the first magnitude each night of eleven hours. 



In general the falling stars have the same tint as the fixed stars. 

 Sometimes this colour passes into yellow, then into a bluish or < 

 greenish tint, in proportion as the meteor approaches the horizon. «? 



Among all these meteors there are some red ones, which travel 

 slowly, and have a globular form, like a billiard-ball coloured red. 

 The author thinks that these are of a particular character. Lastly, 

 he distinguishes others which are extinguished at their highest point 

 of brilliancy, as if they were plunged into water. 



With respect to the trains which some stars leave behind them, 

 these cannot be compared to smoke, but rather to a shower of sparks 

 like that of rockets. The train begins and ends always with the star 

 producing it, but it continues one or two seconds after the disappear- 

 ance of that star. Sometimes the star breaks up into fragments, 

 which form a continuation of the train, and which vanish almost as 

 soon. No star has ever caused any audible noise, whether remain- 

 ing simple, or producing a train, or separating into fragments. 



In general the course of shooting stars is rectilinear, or rather in 

 an arc of a large circle. The author has seen fifteen whose course 

 was curvilinear. 



At the conclusion of his investigation the author has given a ca- 

 talogue of the most remarkable shooting stars, with the indication of 

 the characters which they have presented. Before proceeding to the 

 theoretical part of the subject he announces some histoi'ical researches 

 relative to it. — Comptes Rendus, May 5th and June 2nd, 1845. 



ON THE SUPPOSED OCCURRENCE OF PHOSPHORIC ACID IN 

 ROCKS OF IGNEOUS ORIGIN. BY PROF. C. KERSTEN. 

 In the ' Philosophical Magazine,' vol. xxiv. p. 467, is an abstract 

 of a paper by Dr. Fownes, on the occurrence of phosphoric acid in 

 rocks of igneous origin. Dr. Fownes asserts that he found small 

 quantities of phosphoric acid in combination with alumina, &c. in all 

 these rocks, and supposes that it is probably to this presence of phos- 

 phoric acid that many soils which have originated by the decom- 

 position of those rocks owe their fertility. He found phosphoric 

 acid in a porcelain clay from Dartmoor, in the gray vesicular lava 

 from the Rhine, and in the white trachyte from the Drachenfels on 

 the Rhine, in tolerable quantity in the two latter rocks ; further, in 

 several basalts, in porphyritic lava inclosing crystals of hornblende 

 from Vesuvius, and in volcanic tufa from the same locality in consi- 

 derable quantity. As these observations of Dr. Fownes appeared of 

 some importance in a geognostical and agricultural point of view, 

 and, as far as I am aware, no phosphoric acid had hitherto been de- 

 tected in the above-mentioned rocks, I was induced to repeat Dr. 

 Fownes's experiments. 



