^554r ^'^ ''^"^- GAstous oxrpfe of azote. 



of its operation can be accurately aCcerlained. For (he vefTets 

 which coiitey and impel* the Irue lap, or fluid from which 

 the new wood appears to begeneiated, pafs immediately from 

 the leaf-ftaik towards the root ; and though the motion of this 

 fluid may be' impeded by gravitation, and it be even again 

 returned into the leaf, no portion of it, unlefsil had been es:- 

 travafaled, could have defcended to the part from which the 

 bark was taken off in tlie experiment I have defcribed. I am 

 not fenfible that in the different papers which I have had the 

 I honour to addrefs to you, I have drawn any other inference 



which the fadts, on rt-petilion of the experiments, do not ap- 

 pear capable of fupporting, 



I am, 8cc. 



THO'. ANDREW KNIGHT. 



.Eltont May 12, 180.). 



■ XV. 



Expcrmcnts na the Gaftous Oxide of Azote, by a Society of /Itfia- 

 teurs at Touloufe. Fublijhed by M. P. Dispan, Profejfor of 

 Cherniftry in the College of that City.* 



Difagreemeni of ■'*■ HE motive for the following experiments was the very 



former experi- different, and even contradidory refults, which have been 



©xide of azote, pu^'iflied of fornjer effefts. The experiments were tried 



upon more than a dozen perfons, and in feme cafes repealed 



two or three times; the fenfatlons which each experienced 



were written down at the moment, by the reporter, from 



whofe memorandums the fubfequent obfervalions are drawn. 



Preparation of The nitrate of ammonia ufed for the experiment was indif- 



the nitrate of tincilv crvftallized, but was quite neutral. Its tafte was very 

 ammonia. -'-'., ,,. , , , , , , r , , , ,- 



pungent, wrlh a llight odour. It had been formed by the ia- 



turating very pure nitric acid with ammoniacal gas obtained by 



difiilling fal ammoniac with the common potafh of commerce. 



Procefs for ob- About one he6^ogramme (1545 grains) of this fait was put 



taining the ga_- j^j^ a fmall retort, and placed on a fand-balh, where the fait 

 feous oxide ol 



azDte. 



*PhiI. Tranf. of )804. 



f Annales d'^ Chimie, Vol. LVI. p. 243. 



melted 



