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LV. Oti a simple Method of exhibiting the Comlmstion of the 

 Diamond. By Mr. W. HERArATH. 



To the Editors of the Philosophical Magazine and Annals. 

 Gentlemen, 



I AM not aware that any simple method of exhibiting the 

 combustion of the diamond has been published ; 1 there- 

 fore send you a description of an apparatus by which it may 

 readily be effected in oxygen gas. 



Provide a wide-mouthed gas receiver for the oxygen, with 

 a ground upper surface so as to be closed by a glass plate ; fit 

 it with a cork, in which make two holes to pass tubes through ; 

 one to convey hydrogen gas from a bladder, the other to al- 

 low a passage to the carbonic acid. — Perhaps the hasty sketch 

 which accompanies this will explain better what I mean. 



A is the bladder of hydrogen gas capable of transmitting 

 a stream upon the diamqnd by means of a bent jet at the end 



of the glass tube. The diamond is supported by a fine pla- 

 tinum wire passed over it as a running noose, the ends be- 

 ing left an inch long to twist round the flattened end of a stout 

 platinum wire, B, stuck in the cork. By holding the diamond 

 thus it may readily be detached after the experiment, and the 

 fine wire will not conduct away so much caloric as to prevent 

 the combustion from continuing. C, a recurved tube with a 

 stopcock attached, to permit the transmission of the carbonic 

 acid gas into lime-water. 



Bring the diamond up to a fine white heat by directing a 

 stream of the ignited gas upon it (pressing the bladder under 

 the arm); plunge it while at this heat into the oxygen gas, taking 

 care to turn off the hydrogen when in the act of introducing it. 

 Combustion will begin, and continue as long as a fragment re- 

 mains. I think it the most splendid experiment in chemistry, 

 as no flame, smoke or scintillation occurs, while the diamond 

 clows like a little suii. 

 ^ The 



