On the Analyses of M. Klaprolh, 331 



Vanced ; for it is evident that, these flasks being filled with 

 atmospheric air, the latter could not be displaced by the azotic 

 gas, the specific gravity of which is less ; while the case ought 

 to have been different with carbonic acid gas, if any be con- 

 stantly disengaged from the skin, as Junne infers from his 

 experiments. 



Those which Jurine made, by placing his arm in a cover 

 of glass, are not more conclusive ; because, having been 

 made with a view to prove that carbonic acid gas escaped, 

 he did not employ the means proper for indicatmg the pre- 

 sence and quantity of azotic gas, of which he did not su- 

 spect the slightest disengagement. But why has not this 

 phenomenon, which I beheve to be general, been observed 

 by Dr. Priestley, Fontana, Juhne, 8cc. ? and why is it not 

 remarked in all individuals placed vmder the same circum- 

 stances ? ft is probable, as I have said at the commence- 

 ment of this memoir, according to M. Jurine, that the 

 ^^■ater acting by its gravity on the exhaling vessels of the 

 skin, which in different individuals are endowed with a dif- 

 ferent energv, opposes in the greater number the escape of 

 any gaseous substance. 



I shall here terminate this memoir, to which I might have 

 given more extent had I been inclined to treat of all the ques- 

 tions which naturally arise from the discovery of this phae- 

 nomenon ; but as I had no other object in view than to call 

 the attention of philosophers to this subject, and being satis- 

 fied with having laid the first stone of the edifice, I leave 

 to abler architects the glory of finishing the building. 



LXIII. Extract from the third Voltmie of the Analyses of 

 M. Klaproth. 



JL HIS celebrated chemist, so well known for the precision 

 pf his analyses, and by the valuable discoveries with which 

 he has enriched the province of chemistry, has published a 

 third volume of his Chemical Researches, dedicated to V'au- 

 quelin. Among the number of ingenious analyses it con- 

 tains, there an; some particularly interesting to geologues : 

 such as those ol' cryolite, sonorous porphyry, and basahes; 

 in which we are suprised to see soda form, and even incon- 

 siderable quantity, one of the constituent principles of rocks 

 and compact stones. That of the ombre earlli of Cyprus is, 

 we may say, the first with which we are ac(iuaiiiled, and the 

 pio.^t correct, 'i'he rest, some extracts from which we shall 



here 



