Coiitroverfy rtfyeBing 'PhfphQnis in Azotic Gas, ^ 



Count of this new dlfcovery i but to avoid being led into error by individual obfervations, 

 as is frequently the cafe with experiments, I joined Dr. Jaeger from Stuttgard, who was 

 juft then Vifiting me on a journey. We made a great number of experiments together, 

 which we endeavoured to diverfify in every poffible manner, in order to difcover all the 

 concurrent circumftances. In the ye/ia gel. Zeit 1794, No. 113, we publiilied a fliort 

 account of one of the chief occurrences ; but the full defcription of the refults from our in- 

 Veftig'atidnS Tortie time aftct was given in the following book, Uaer das Lfuchtcn ties 

 Phofphors tm aimofpherifchen Stickgas. Weimar 1795- To this work we have added ano- 

 ther trCatife on' GoEttling's theory by Dr. PfafF. 



The chief aim of this enquiry was to (hew by decifive experiments, ivhether phoffhovus 

 does really gix>e ligfjt in azotic gas, and whether it be totally decompofed by it ? Neitlier of thefe 

 two we could find by any procefs of operation. We made comparative experiments ovet 

 Vrater and over quickfdver, and clearly perceived that Mr. Goettling, having clofed hi^ 

 veflels merely by. water, Could not avoid a fource of error. VVc fpafed no exertions- t» 

 invefttgate as eia£tly as poITible the method of preparing azotic gas, and by that means 

 difcovered a variety of interefling circumftances. We always found that- the fumes of 

 phofphnreous add, rifing by a momentary combuftion of phofphorus in atinofpherical air, did 

 fo far envelope the remaining portion of oxygen, that tlic luminous appearance ftom the 

 onion of this with another part of the phofphorus could not be again produced until the 

 water had abforbed the acid fumes. We always found however that this light was of 

 iliort duration, accompanied by a very inconfiderablc diminution of the elaftic fluid, ariS 

 that it was altogether impoffible to caufe the phofphorus to emit any more light in the re* 

 maining air. On this account we had ev.ery reafon to confider this as pure azotic gas, 

 and to declare thofe experiments of Mr. Goettling incorreft, from which the combuftioa 

 of phofphorus was faid to take place in the pure ft azitic gas. 



To all this Mr. Goettling made no reply, except that he gave an anfwer in the Intelli- 

 genxbl. der allgem. Literat. Zeit. 1794, No. 117, to our firft very (liort notice, tending to 

 place the whole inveftigation in an unfavourable point of view. Of our tieatife, though 

 printe<i above two years ago, he has not yet taken any notice. 



Soon afterwards Mr. Girtanner took fome pains to explain the refult of Mr. Goettling's 

 .experiments, i<J/J. 1795, No. 23, by fuppofing the azotic gas employed had contained 

 fome water, which was decompofed by the phofphorus. He did not, however, take the 

 trouble to afcertain by experiments, whether phofphorus does really give light in azotic 

 gas thoroughly freed from oxygen. Mr. Goettling replied to this, by alledjing, that if 

 the water which exifts diflblved in the gafes were the caufe of this light, the phofphorus 

 ought alfo to emit light in oxygen gas, which according to his experiments did not take 

 place. Ibid. No. 27. He afterwards publlflied a more ample elucidation of the fhort an- 

 fwer here related in the Almatiach fuer Scheide Kuenjller,fjp^, aflerting that the luminous 

 appearance of phofphorus could not be obtained in an azotic gas, which had been pro- 

 cured by a long continued heating of the phofphorus in atmofpheric air, becaufe in that 

 cafe the phofphorus mixes with the azotic gas, and prevents it from maintaining the light. 

 He added, that the gas thus circumftanced is found to recover this property by adding a. 

 few drops of an acid. But he was by no means aware that his obfervation contained a 

 very important objedlion againft his own theory. For if, according to that theory, azotic 

 Vol. II. — April 1798. C gai 



