Intelligence and Miscellaneous Articles. ^Q1 



sensible change in its physical properties, nor does it exhibit any phae- 

 nomenon which may be considered as the result of any elementary 

 action. 



If, however, it be exposed to the influence of solar light on a glass 

 vessel, provided with a tube, the concentrated solution of oxalate of 

 iron soon presents a very interesting phasnomenon : in a short time, 

 the solution receiving the solar rays develops an infinite number of 

 bubbles of gas, which rise in the liquor with increasing rapidity, and 

 give the solution the appearance of a syrup undergoing strong fer- 

 mentation. This ebullition always becomes stronger, and almost tu- 

 multuous, when an unpolished gliiss tube is immersed in it, with a 

 small piece of wood ; the liquid itself is afterwards thrown into ascend- 

 ing and descending-currents, becomes gradually yellowish, turbid, and 

 eventually precipitates protoxalate of iron in the form of small brilliant 

 crystals, of a lemon yellow colour, gas continuing to evolve. 



These opposing phaenomena, the disengagement of gas, and the 

 precipitation of crystals, continue until the whole of the oxalate of 

 iron is converted into protoxalate *; the liquor then becomes totally 

 colourless, and all internal movement ceases. The gas disengaged is 

 carbonic acid. 



The preceding phaenomena are analogous to those of vegetation, 

 in which, by the action of light, carbonic acid is converted into solid 

 matter and oxygen. 



A solution of muriate of platinum is decomposed by the oxalic acid 

 and the oxalates, by exposure to solar light, with almost as much 

 energy, and almost as active a disengagement of gas, as the solution of 

 peroxalate of iron j there is no precipitation of protoxalate of pla- 

 tinum, but some metallic platinum is deposited. 



Muriate of gold is reduced by oxalic acid when heated, as first 

 shown by Van Mons and Pelletier; but the reduction effected by 

 light covers the interior surface of the vessel with a uniform brilliant 

 gilding, which is of a fine sea-green colour by incident light. Oxalate 

 of silver does not suffer any change under water by heat, but by solar 

 heat it is partially decomposed into metallic silver and carbonic acid. 



Muriate of iridium dissolved in water acts in the same manner. 

 If the red brown solution of this salt be mixed with oxalic acid, and 

 the mixture be heated to ebullition, the colour of the liquor is not 

 changed, nor is any carbonic acid disengaged ; but if the coloured 

 mixture be exposed to the sun, total decolouration promptly occurs. 

 Carbonic acid is disengaged, and in a little time the disengagement 

 of gas continuing, metallic iridium of a gray colour is precipitated.— 

 Journal de Pharmacie, Mars 1 832. 



PIIEPARATION OF THE IODIDES OF BARIUM AND STRONTIUM. 

 M. Henry, fils, recommends the annexed method of preparing the 

 above-mentioned compounds, which he observes is similar to the nie- 



• Protoxalate of iron has been found native in crystals imbedded in 



moor-coal, near Bilin in Bohemia, and has been called Humbnldtiiw by 



M. De Rivcro : hence the allusion to the salt by that name in the heading 



of the notice above. Sec Mohs's Mineralogy by Haidinger,vol. iii. p. 110. 



3 2 thod 



