] 52 Intelligence and Miscellaneous Articles. 



platinate of lime ; but according to my process for obtaining it, it is 

 a compound of chloride of platina and platinate of lime (Pt Ch* 



-f Ca Pt')- 



If this compound be heated in a platina crucible to bright red- 

 ness, it loses about 2.5 per cent., being water and a part of the 

 oxygen combined with the platina. It becomes a deep violet-coloured 

 powder, which becomes very hot when sprinkled with water, and 

 when treated with dilute nitric acid, &c , is decomposed into muriate 

 of lime, lime, and oxide of platina, of a deep violet colour. 



This oxide is, I believe, the protoxide of platina (Pt), the base of 

 the coppery oxalate already mentioned. This oxide does not dis- 

 solve in any oxyacid, but it combines by long digestion with oxalic 

 acid. When treated with formic acid it is reduced to spongy pla- 

 tina, and evolves carbonic acid tumultuously, and in such quantity 

 that its volume shows the quantity of oxygen contained in the prot- 

 oxide. Eight grains of this oxide dried at 212°, being reduced by 

 formic acid, gradually heated to ebullition, gave such a quantity of 

 carbonic acid as showed its composition to be 92204? metal, and 

 7*796 oxygen: according to Berzelius, the protoxide of platina con- 

 tains 7'6 per cent, of oxygen. This difference probably arises from 

 the circumstance of the oxide which I examined, and that once only, 

 containing a small quantity of peroxide, or that the protoxide of 

 Berzelius contained, as asserted by Liebig, some chlorine. — Ann. 

 de Chim. et de Phys. } torn. liii. p. 204. 



ON THE ROTARY MOTION OF CAMPHOR. BY M. CHARLES 

 MATTE UCCI. 



The phaenomena exhibited by camphor, when put upon water, 

 have been long known, and several philosophers have examined 

 them ; but if they are generally agreed as to the circumstances of 

 these curious phaenomena, this is not the case as to their cause. 

 Thus, it has been said they were owing to the development of elec- 

 tricity, or to the solution of camphor, and lastly, to the evaporation 

 of the camphor and water. It is easy to prove that it is not owing 

 to the solution of the camphor in the water, for there are several 

 substances which are much more soluble, but which do not turn 

 when placed on water. Nothing indicates the development of elec- 

 tricity, and in this case it is not conceivable how it could produce 

 the effect. The evaporation of water ought not to be considered in 

 the explanation of the phaenomena. It is therefore entirely to the 

 evaporation of the camphor and its solution in the strata of water 

 which surround it, that the cause of the motion must be attributed ; 

 and it is this opinion which I propose to develop and maintain. 



Potassium is a substance which, when thrown on water, resem- 

 bles camphor in the phaenomena it produces : in this case it is to the 

 disengagement of hydrogen and the vapour of water that the rapid 

 movement must be attributed. It is even possible to imitate this 

 rotation in a more simple manner ; for this, it is sufficient to throw 

 a small piece of red-hot charcoal upon water, or a very fine metallic 



