1823.] Scientific Intetligence* *73 



and Thenard. The constituents of the mineral were dletefminecl to be 

 as follows : 



Water , I'OOO 



Fluoric acid i i . ;. * * * a,, 4 086 



Silica **.i^. ....32-666 



Peroxide of iron 2*333 



Magnesia ^'J-'OOO 



Potassa ;.< i .,*,.... . 2«108 



Loss . . , , i 4iii ,, 3*807 



100-000 

 (Silliman's American Journal, vol. v. p. 2.) 



XII. Comhustion of a Stream of Hydrogen Gas under Water. 



Mr. Thomas Skidmore, of New York, has discovered that if the 

 flame produced by the combustion of hydrogen gas, issuing in combi- 

 nation with oxygen from the compound blowpipe of Dr. Hare, be 

 plunged below the surface of water, it continues notwithstanding its 

 submersion in, and actual contact with, that fluid, to btirn, apparently 

 with the same splendour as it does in the common air. The only dis- 

 coverable difference is, that when the flame burns into water, it seems, 

 if the expression may be allowed, to conglobate its figure ; whereas in 

 the air, it assumes the shape of a long slender conical pencil. Care is 

 required that the flame be introduced slowly and gently into the water, 

 itl order to avoid the recession of the flame into the interior of the tube, 

 at its first entrance, which is apt to take place if suddenly immersed. 

 To obviate this evil more effectually, tubes of a fine capillary bore are 

 best adapted. 



When a piece of cork or pine wood was applied to the submersed 

 gaseous flame, it gave out a brilliant light, and this appearance conti- 

 nued till the recession took place, which, in some instances, might be 

 for a minute or two. Small pieces of copper wire, l-40th of an inch 

 diameter, became red-hot when exposed to the flame under water in 

 full day-light. The discoverer of this property of the flame of the 

 compound blowpipe suggests its application to the purpose of a sub- 

 marine instrument of nanal tKarfare, and thinks there are no difficulties 

 in the way of its being so employed that may not be easily overcome* 

 — (American Journal.) 



XIII. Fusion and Volatilization of Charcoal. 



The fusion and evaporation of charcoal has been effected in America 

 with the assistance of Dr. Hare's galvanic deflagrator. Prof Griscom, 

 of New York, describes the experiment in the following terms: " With 

 a deflagrator, of considerable size and in good order, these experi- 

 ments are, in fact, extremely easy ; and with well prepared charcoal 

 will never fail in a single instance. The surface of the fused charcoal 

 is brilliant, with a metallic and frequently iridescent lustre. Upon the 

 charcoal on the copper side, there is no appearance of fusion, but a 

 crater-shaped cavity extremely well defined, with the proper fibrous 

 and porous appearance of charcoal ; every thing indicating that the 

 charcoal is wasted from this pole, and transferred to the other. It 

 seems to pass in the state of vapour, to be accumulated or condensed 



