ON OILY HIDROGEN. 101 



This gas burnt with oxigen is wholly converted into car- The expanded 

 bonic acid, and is no longer dilatable however fmall the quan- ^ b J^^,jJ 

 tity of oxigen mixed with it may be. when burned 



The following are the conjectures which I form at prefent with 0X1 S en « 

 from thefe refults. 



I do not think that the refidue retains the lead trace of oxi- 

 gen after the inflammation, otherwife it would bum with rapi- 

 dity, which is far from being the cafe. 



Four inches of oxigen generally confume feven and a half Conjectures or 

 of pure hidrogen in my eudiometer, and as our refiduary gas ln erences * 

 contains only a very fmall quantity of carbonic acid, it follows, 

 that thefe four inches have confumed a quantity of hidrogen 

 which would have been at leaft equal to feven inches, had it 

 been in the ufual Hate of dilatation at which the preiTure of 

 the atmofphere keeps it. 



Four inches of oily hidrogen therefore contain, according 

 to this, feven inches of pure hidrogen condenfed into the bulk 

 of four. 



Again our refidue after the combuftion of four inches of 

 oily gas, is all at once changed into thirteen or fourteen inches 

 of carbonated hidrogen. We muft therefore conclude, that 

 the feven inches of hidrogen comprefled into the bulk of four, 

 held in folution a quantity of oil capable of being converted, 

 by a high temperature, into thirteen or fourteen inches of car- 

 bonated hidrogen. 



I fay a high temperature, becaufe in fact, that alone is ca- 

 pable of changing oil into carbonated hidrogen. 



Whence I conclude, that in the inflammation of four parts 

 of oily gas, by an equal quantity of oxigen, nothing is really 

 burnt but the hidrogen. 



VI. 



Letter from Fortis to J. G. Delametherie, on a Shower 

 of Mud which fell at Udina *. 



JL HAVE juft received at the fame time, the number of the 

 Journal de Phyfique, in which you notice the different opi- 

 nions refpecYmg flones fallen from above, of which almoft every 



* In the Journal de Phyfique, Germinal, An. XI. 



country 



