On Atmofpheric Air.' 4*7 



The author defcribes, alfo, two forts of crania found in the 

 moffes in the department of La Somme 3 and which have a 

 great refemblance to thofe of the urus, which are nearly one 

 fourth larger. i 



Cit. Cuvier concludes bis refearches as follows : I. It i« 

 not agreeable to truth to affert that the animals of the fouth 

 have formerly exifted in the jiorth, their fpeciesnot being 

 perfectly identic. 2. That there have exifted in all coun- 

 tries animals which do not exift at prefent, and that arc no 

 where to be found in any known part of the globe. He 

 therefore leaves it to gcologifts to make fuch changes or ad- 

 ditions, in regard to their fyflcms, as they may think necef* 

 fary to explain the fact* which he' has thus eftablifned. 



. 

 XVII. Ohfervations on the Confituent Parts of Atmofphenc 

 Air. By Count de MoROZZO. With the Remarks of 

 F. Van Humbolt: From the Journal de Phyfique, 

 Fruclidor, 6th Year. 



IN the memoir which I publifhed in 1784, on animal 

 refpiration in dephlogifticatcd or oxygen s;as, I offered fome 

 reflections refpe&ing the conftituent parts of atmofpheric 

 air, founded on experiments I had made. Lavoifier, in his 

 Elementary Treatife of Chemiftry, does not agree with my 

 experiments. That author fays, that the component parts 

 of atmofpheric air are 73 parts of mephitic or azotic gas, and 

 27 of oxygen gas, eminently refpirable. It will then be 

 fcen, .adds he, that when animal fubftances are diffolved in 

 the nitric acid, there is difengaged a great quantity of gas, 

 which extinguifhes a lighted candle, injures animals, and 

 which has a perfect rcl'emblance to that part of atmofpheric 

 air which is unfit for refpiration. If to 73 parts of this fluid 

 we add 27 of oxygen gas, obtained from, mercury reduced 

 to ihe ftate of an oxyde by calcination, there is formed a 

 Vol. I. Ee fluid 



