Intelligence and Miscellaneous Articles. 827 



milarly prepared, to produce the synthesis of ammonia, either when 

 substituted for the sponge, in the experiment above described, or 

 carried red hot from a fire and passed into a bell glass containing 

 the mixture over mercury. 



In fact a piece of charcoal soaked in a solution of chloride of pla- 

 tinum, (choroplatinic acid,) produced effects analogous to the pla- 

 tinated asbestus. 



To produce platinated asbestus, it was found sufficient to dip it 

 in liquid chloride of platinum, and then subject the mass to a red heat 

 in a common fire. 



ROTATORY MULTIPLIER. BY R. HARE, M.D. 



Dr. Hare has contrived a rotatory multiplier in the following way: 

 Just as the needle, in oscillating, reaches its appropriate position 

 in the meridian, by means of two pins proceeding from it perpendi- 

 cularly so as to enter two mercurial globules, it completes a circuit 

 through the coil ; one end of which terminates in one of the glo- 

 bules. The other end of the coil of the multiplier communicates 

 with one pole of a galvanic pair, of which the other pole communi- 

 cates with the other globule. The needle is thus subjected to an 

 impulse which causes it to revolve until it receives another impulse 

 by the same process repeated. Each revolution therefore causes 

 an impulse which is productive of a succeeding revolution so long as 

 the galvanic reaction is sustained. 



The construction was subsequently improved by employing two 

 coils of copper wire of equal length, separated by paper and varnish, 

 one being wound over the other. They were so arranged that the 

 needle receives two impulses in each revolution, one as above de- 

 scribed, the other when its north pole points to the south. Again, 

 two needles associated so as to form a cross are made to complete 

 a circuit every fourth of a revolution, and thus to receive four im- 

 pulses in one revolution. 



METEOROLOGICAL OBSERVATIONS FOR JULY 1837. 



Chiswick. — July 1. Cloudy : fine: clear and cold at night. 2, 3. Very 



dry. 4— 12. Very fine. 13. Overcast. 14. Cloudy and fine, heavy 

 showers. 15. Showery. 16. Very fine. 17, 18. Cloudy and fine. 



19. Very fine. 20. Fine. 21 — 26. Very fine. 27, 28. Very hot and 

 sultry. 29. Heavy rain : excessively boisterous in the afternoon. 



30. Cloudy: showery. 31. Very fine: showery. 



Boston. — July 1. Cloudy. 2, 3. Fine. 4—7. Cloudy. 8. Fine. 



9. Cloudy. 10, 11. Fine. 12. Cloudy. 13. Cloudy: rain with thunder 

 and lightning p.m. 14. Cloudy: rain early a.m. 15. Cloudy: rain early 

 a.m.: rain p.m. with thunder and lightning. 16, 17. Fine : rain p.m. 



18. Cloudy: rain p.m. 19. Fine. 20. Cloudy : rain a.m. and p.m. 



21 -25. Cloudy. 26. Fine : rain a.m. 27. Cloudy. 28. Rain. 



29. Rain and stormy. 30. Cloudy and stormy. 81. Fine: rain with 



thunder and lightning p.m. 



