180 Experiments to determine the [Sept. 



Article IV. 



'Experiments to determine the Constituents of Azote. 

 By John Miers, Esq. 



(To Dr. Thomson.) 

 SIR, 



The consideration of the nature of azote has been, from the very 

 first period of its discovery, a subject of continual controversy ; and 

 to the present moment chemists are yet divided in their opinions as 

 to its teal nature. The earlier experiments of Priestley, of the 

 German and the Dutch chemists, those of Girtanner, with the 

 refutations of them by Berthollet and Lagrange, the more recent 

 ones of Allen and Pepys on respiration, and the delicate researches 

 of Sir Humphry Davy, have all tended to the alternate proval and 

 disproval of the compound nature of azote. 



Goettling, Crell, and Wigleb asserted, that on passing water in 

 a state of vapour through ignited tubes, they found it converted 

 into azote ; they hence concluded azote to be compounded of water 

 and caloric. Van Troostwyck, Dieman, Van Hausch, Van Mons, 

 &c. denied the truth of this asserted conversion of water into 

 azote, accounting for the appearance of the latter by supposing that 

 atmospheric air must have passed through the interstices of the 

 earthen tubes. Girtanner repeated these experiments of the 

 German chemists, and confirmed their assertion of the formation 

 of azote from water ; but accounted for its appearance by supposing 

 the water to be deoxidated, a portion of its oxygen having been 

 attracted by the argillaceous earth of the tube. He hence con- 

 cluded azote to be a compound of hydrogen and oxygen, in which 

 the latter existed in a less proportion than in water, or in other 

 words, that " azote is water deprived of part of its oxygen." The 

 air of certainty with which these experiments were published 

 roused the attention of Berthollet, who, in concert with Lagrange, 

 repeated them with every precaution recommended by Girtanner; 

 but, after the most strict research, they could not find the least 

 appearance of azote. As this assertion of the Germans thus re- 

 ceived the most positive contradiction by two chemists so justly 

 famed for their accuracy of investigation, it naturally resulted that 

 the indecisive opinions of chemists was determined in favour of the 

 simple nature of azote. Recurring, however, to the experiments 

 of Girtanner, it is possible that atmospheric air may have intro- 

 duced itself through the pores of the earthen tubes, as supposed by 

 Berthollet and Lugrange : but it is also possible, from the experi- 

 ments which I have now to detail, that it was really formed in the 

 process, and not derived from without. Be this as it may, the 

 subsequent silence of Gil tanner, the known rhapsodical style of hie 



