Intelligence and Miscellaneous Articles. 317 



he referred at last to the cases of Siliceous calculi, and stated that 

 some new matter had been added to the subject lately, on this point, 

 by Dr. Yelloly ; but as we understand Dr. Yelloly's paper will come 

 before the Royal Society, we shall probably have occasion to notice 

 it more minutely hereafter. 



March 19. — The evening was,'occupied by Mr. Ritchie, who gave 

 an account of the methods proposed for measuring the intensities 

 of natural and artificial light. He referred to the methods of Bou- 

 guer, Leslie, Rumford, and others; and amongst the rest to that upon 

 which his own photometer is founded. This and the other instruments 

 are known to the public. Mr. Ritchie's appears to be a very accu- 

 rate and convenient instrument in numerous cases. By means of it 

 the light of an Argand oil lamp and a gas lamp were compared ; also 

 the light of the Argand lamp and wax candles. The light of phos- 

 phorus burning in oxygen gas was compared to the light of the 

 candle and lamp ; and also a comparison made of the light of a 

 wax-candle with that of the ball of lime ignited by the oxyhydrogen 

 flame, as in Lieut. Drummond's application. Mr. Ritchie proposes 

 to ascertain these numbers very accurately, and give the results 

 to the public. 



XLIV. Litelligence and Miscellaneous Articles. 



CORRECTION IN MR. PHII-LIPs's PAPER. 



IN order to complete the quotation from Dr. Thomson, the fol- 

 lowing is to be inserted after line 32, p. 131, of the Phil. Mag. 

 and Aimals, for February last : — 



" The salt contains, besides, 5 atoms of water. ... = 5*625 



2 atoms of hydrogen = 0*250 



3 atoms of oxygen . . =3-000 



8-875 

 Making a total of 8-875, which added to 34 make 42875, the 

 atomic weight of the solid salt. But 2 atoms of hydrogen, and 

 3 atoms of oxygen, cannot unite together so as to constitute water." 



ACTION OF METALS ON WATER AND CARBONIC ACID, &C. 



M. Despretz has stated to the French Academy, that nickel, cobalt, 

 zinc, and tin, pos.sess, like iron, the property of decomposing water at 

 a red heat, and that their oxides are reduced by hydrogen at the same 

 temperature} he has also observed that carbonic acid is converted by 

 zinc and tin into oxide of carbon, and that this gas completely reduces 

 the oxides of these metals. Thus a fact, which was considered as ano- 

 malous, extends to several metals and binary compounds. — Le Globe. 



GLACIAL ACETIC ACID. 

 M. Despretz also states that crystallizable acetic acid may be pro- 

 cured by heating a mixture of an atom of acetate of lead, well dried, 

 with one of concentrated sulphuric acid j and lie further mentions, 

 that in a good forge, at a high temperature, a mixture of sulphur and 

 oxide of zinc yielded a sulphuret, which experienced mineralogists 

 mistook for blende or native Rulpluirct. — Ibid. 



MKT£0«0- 



